Sample records for zn complexes including

  1. Periodic trends within a series of five-coordinate thiolate-ligated [MII(SMe2N4(tren))]+ (M = Mn, Fe, Co, Ni, Cu, Zn) complexes, including a rare example of a stable CuII-thiolate.

    Brines, Lisa M; Shearer, Jason; Fender, Jessica K; Schweitzer, Dirk; Shoner, Steven C; Barnhart, David; Kaminsky, Werner; Lovell, Scott; Kovacs, Julie A


    A series of five-coordinate thiolate-ligated complexes [M(II)(tren)N4S(Me2)]+ (M = Mn, Fe, Co, Ni, Cu, Zn; tren = tris(2-aminoethyl)amine) are reported, and their structural, electronic, and magnetic properties are compared. Isolation of dimeric [Ni(II)(SN4(tren)-RS(dang))]2 ("dang"= dangling, uncoordinated thiolate supported by H bonds), using the less bulky [(tren)N4S](1-) ligand, pointed to the need for gem-dimethyls adjacent to the sulfur to sterically prevent dimerization. All of the gem-dimethyl derivatized complexes are monomeric and, with the exception of [Ni(II)(S(Me2)N4(tren)]+, are isostructural and adopt a tetragonally distorted trigonal bipyramidal geometry favored by ligand constraints. The nickel complex uniquely adopts an approximately ideal square pyramidal geometry and resembles the active site of Ni-superoxide dismutase (Ni-SOD). Even in coordinating solvents such as MeCN, only five-coordinate structures are observed. The MII-S thiolate bonds systematically decrease in length across the series (Mn-S > Fe-S > Co-S > Ni-S approximately Cu-S tren)]+, represents a rare example of a stable CuII-thiolate, and models the perturbed "green" copper site of nitrite reductase. In contrast to the intensely colored, low-spin Fe(III)-thiolates, the M(II)-thiolates described herein are colorless to moderately colored and high-spin (in cases where more than one spin-state is possible), reflecting the poorer energy match between the metal d- and sulfur orbitals upon reduction of the metal ion. As the d-orbitals drop in energy proceeding across the across the series M(2+) (M= Mn, Fe, Co, Ni, Cu), the sulfur-to-metal charge-transfer transition moves into the visible region, and the redox potentials cathodically shift. The reduced M(+1) oxidation state is only accessible with copper, and the more oxidized M(+4) oxidation state is only accessible for manganese.

  2. Improved performance of organic light-emitting diodes using a Zn complex

    Jang, Yoon-Ki; Kim, Dong-Eun; Kwon, Oh-Kwan; Kwon, Young-Soo [Dong-A University, Busan (Korea, Republic of); Kim, Won-Sam; Lee, Burm-Jong [Inje University, Gimhae (Korea, Republic of)


    We have synthesized new electroluminescence materials, including [2-(2-hydroxyphenyl) benzoxazole] (Zn(HPB){sub 2}) and [(1,10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q. The photoluminescence (PL) spectra of Zn(HPB){sub 2} and Zn(phen)q were observed to be blue and yellowish green, respectively. The ionization potential (IP) and the electron affinity (EA) of each Zn complex were measured using cyclic voltammetry (CV). Zn(HPB){sub 2} was used as an emitting material while Zn(phen)q and Alq{sub 3} were used as electron transport materials. We investigated the electron transport properties of Zn(phen)q compared with Alq{sub 3}. The fundamental structures of the organic lightemitting diodes (OLEDs) were ITO/NPB/Zn(HPB){sub 2}/Zn(phen)q and Alq{sub 3}/LiF/Al. As a result, the electron transport properties of Zn(phen)q were better than those of Alq{sub 3}. Therefore, Zn(phen)q should be useful as an electron transport material to enhance the performance of OLEDs.

  3. Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(II) Complex Including the Reduced Derivative of Nitronyl Nitroxide,[Zn(Him2Py)(N3)2]2

    王利亚; 张晨曦; 廖代正; 姜宗慧; 阎世平


    The title compound [Zn(Him2Py)(N3)2]2 (Zn2C26H38N18O2, Mr = 765.48) has been prepared and structurally characterized by X-ray diffraction methods. It crystallizes in monoclinic, space group P21/n with a = 10.989(3), b = 11.519(3), c = 13.812(4) A, β = 101.700(5)°,V = 1711.9(9) A3, Z = 2, Dc = 1.485 g/cm3,μ(MoKα) = 1.456 mm~1, F(000) = 792, the final R =0.0401 and wR = 0.0861 for 2054 observed reflections with I>2σ(I). The imino nitroxide 2-(3 ′-methyl-2′-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-lH-imidazolyl-l-oxyl (im2Py) was reduced to obtain 2-(3′-methyl -2′-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-lH-imidazole-1-ydroxy (Him2Py)coordinating to the zinc (Ⅱ) ion, around which the coordination geometry is a square-based pyramid with a terminal nitrogen atom located at the apical position. The four basal sites are occupied by two μ1,1 nitrogen atoms from two different bridging azide ions and two nitrogen atoms from Him2Py.The units of [Zn(Him2Py)(N3)2]2 were connected as two dimension planes by intermolecular hydrogen bonds.

  4. Sb complexes and Zn interstitials in Sb-implanted ZnO epitaxial films

    Liu Yao-Ping; Ying Min-Ju; Mei Zeng-Xia; Li Jun-Qianng; Du Xiao-Long; A.Yu.Kuznetsovc


    In the present work, post-annealing is adopted to investigate the formation and the correlation of Sb complexes and Zn interstitials in Sb-ion implanted ZnO films, by using Raman scattering technique and electrical characterizations.The damage of Zn sublattice, produced by ion bombardment process is discerned from the unrecovered E2 (L) peak in annealed high Sb+ dose implanted samples. It is suggested that the Zn sublattice may be strongly affected by the introduction of Sb dopant because of the formation of SbZn-2VZn complex acceptor. The appearance of a new peak at 510 cm-1 in the annealed high dose Sb+ implanted samples is speculated to result from (Zn interstitials-O interstitials)Zni-Oi complex, which is in a good accordance with the electrical measurement. The p-type ZnO is difficult to obtain from the Sb+ implantation, however, which can be realized by in-situ Sb doping with proper growth conditions instead.

  5. Chemical-Biological Properties of Zinc Sensors TSQ and Zinquin: Formation of Sensor-Zn-Protein Adducts versus Zn(Sensor)2 Complexes.

    Nowakowski, Andrew B; Meeusen, Jeffrey W; Menden, Heather; Tomasiewicz, Henry; Petering, David H


    Fluorescent zinc sensors are the most commonly used tool to study the intracellular mobile zinc status within cellular systems. Previously, we have shown that the quinoline-based sensors Zinquin and 6-methoxy-8-p-toluenesulfonamido-quinoline (TSQ) predominantly form ternary adducts with members of the Zn-proteome. Here, the chemistries of these sensors are further characterized, including how Zn(sensor)2 complexes may react in an intracellular environment. We demonstrate that these sensors are typically used in higher concentrations than needed to obtain maximum signal. Exposing cells to either Zn(Zinquin)2 or Zn(TSQ)2 resulted in efficient cellular uptake and the formation of sensor-Zn-protein adducts as evidenced by both a fluorescence spectral shift toward that of ternary adducts and the localization of the fluorescence signal within the proteome after gel filtration of cellular lysates. Likewise, reacting Zn(sensor)2 with the Zn-proteome from LLC-PK1 cells resulted in the formation of sensor-Zn-protein ternary adducts that could be inhibited by first saturating the Zn- proteome with excess sensor. Further, a native SDS-PAGE analysis of the Zn-proteome reacted with either the sensor or the Zn(sensor)2 complex revealed that both reactions result in the formation of a similar set of sensor-Zn-protein fluorescent products. The results of this experiment also demonstrated that TSQ and Zinquin react with different members of the Zn-proteome. Reactions with the model apo-Zn-protein bovine serum albumin showed that both Zn(TSQ)2 and Zn(Zinquin)2 reacted to form ternary adducts with its apo-Zn-binding site. Moreover, incubating Zn(sensor)2 complexes with non-zinc binding proteins failed to elicit a spectral shift in the fluorescence spectrum, supporting the premise that blue-shifted emission spectra are due to sensor-Zn-protein ternary adducts. It was concluded that Zn(sensors)2 species do not play a significant role in the overall reaction between these sensors and

  6. Synthesis, characterization and phosphotriesterase mimetic activity of some Zn(II) and Cu(II) complexes

    Mamata Singh; Ray J Butcher; Jerry P Jasinski; James A Golen; Govindasamy Mugesh


    We report here the synthesis and characterization of a few phenolate-based ligands bearing tertamino substituent and their Zn(II) and Cu(II) metal complexes. Three mono/binuclear Zn(II) and Cu(II) complexes [Zn(L1)(H2O)].CH3OH.H2O (1) (H2 L1 = 6,6′-(((2-dimethylamino)ethylazanediyl)bis(methylene))bis(2, 4-dimethylphenol), [Zn2(L2)2] (2) (H2L2 = 2,2′-(((2-dimethylamino)ethyl)azanediyl)bis(methylene)bis(4-methylphenol) and [Cu2(L3)2.CH2 Cl2] (3) (H2L3 = (6,6′-(((2-(diethylamino)ethyl)azanediyl)bis(methylene)) bis(methylene))bis(2,4-dimethylphenol) were synthesized by using three symmetrical tetradendate ligands containing N2O2 donor sites. These complexes are characterized by a variety of techniques including; elemental analysis, mass spectrometry, 1H, 13C NMR spectroscopic and single crystal X-ray analysis. The new complexes have been tested for the phosphotriesterase (PTE) activity with the help of 31P NMR spectroscopy. The 31P NMR studies show that mononuclear complex [Zn(L1)(H2O)].CH3OH.H2O (1) can hydrolyse the phosphotriester i.e., p-nitrophenyl diphenylphosphate (PNPDPP), more efficiently than the binuclear complexes [Zn2(L2)2] (2) and [Cu2(L3)2.CH2Cl2] (3). The mononuclear Zn(II) complex (1) having one coordinated water molecule exhibits significant PTE activity which may be due to the generation of a Zn(II)-bound hydroxide ion during the hydrolysis reactions in CHES buffer at pH 9.0.

  7. Pressure-Photoluminescence Study of the Zn Vacancy and Donor Zn-Vacancy Complexes in ZnSe

    Iota, V.; Weinstein, B. A.


    We report photoluminescence (PL) results to 65kbar (at 8K) on n-type electron irradiated ZnSe containing high densities of isolated Zn vacancies (V_Zn) and donor-V_Zn complexes (A-centers).^1 Isotropic pressure is applied using a diamond-anvil cell with He medium, and laser excitations above and below the ZnSe bandgap (2.82eV) are employed. The 1 atm. spectra exhibit excitonic lines, shallow donor-acceptor pair (DAP) peaks, and two broad bands due to DAP transitions between shallow donors and deep acceptor states at A-centers (2.07eV) or V_Zn (1.72eV). At all pressures, these broad bands are prominent only for sub-gap excitation, which results in: i) A-center PL at energies above the laser line, and ii) strong enhancement of the first LO-replica in the shallow DAP series compared to 3.41eV UV excitation. This suggests that sub-gap excitation produces long-lived metastable acceptor states. The broad PL bands shift to higher energy with pressure faster than the ZnSe direct gap, indicating that compression causes the A-center and V_Zn deep acceptor levels to approach the hole continuum. This behavior is similar to that found by our group for P and As deep acceptor levels in ZnSe, supporting the view that deep substitutional defects often resemble the limiting case of a vacancy. ^1D. Y. Jeon, H. P. Gislason, G. D. Watkins Phys. Rev. B 48, 7872 (1993); we thank G. D. Watkins for providing the samples. vih>(figures)

  8. Defect complexes formed with Ag atoms in CDTE, ZnTe, and ZnSe

    Wolf, H; Ostheimer, V; Hamann, J; Lany, S; Wichert, T


    Using the radioactive acceptor $^{111}\\!$Ag for perturbed $\\gamma$-$\\gamma$-angular correlation (PAC) spectroscopy for the first time, defect complexes formed with Ag are investigated in the II-VI semiconductors CdTe, ZnTe and ZnSe. The donors In, Br and the Te-vacancy were found to passivate Ag acceptors in CdTe via pair formation, which was also observed in In-doped ZnTe. In undoped or Sb-doped CdTe and in undoped ZnSe, the PAC experiments indicate the compensation of Ag acceptors by the formation of double broken bond centres, which are characterised by an electric field gradient with an asymmetry parameter close to h = 1. Additionally, a very large electric field gradient was observed in CdTe, which is possibly connected with residual impurities.

  9. Zn-OH2 and Zn-OH complexes with hydroborate-derived tripod ligands: a comprehensive study.

    Ibrahim, Mohamed M; Olmo, Cristina Pérez; Tekeste, Teame; Seebacher, Jan; He, Guosen; Maldonado Calvo, José A; Böhmerle, Karin; Steinfeld, Gunther; Brombacher, Horst; Vahrenkamp, Heinrich


    The complete array of those hydrotris(pyrazolyl/thioimidazolyl)borate ligands that were developed and used in the author's laboratories, with N3, N2S, NS2, and S3 donor sets, was scanned for their ability to form Zn-OH2 and Zn-OH complexes. The coordination motifs found were Zn-OH2, Zn-OH, Zn-OH-Zn, and Zn-O2H3-Zn. Of these, the well-established Zn-OH motif was complemented with novel species bearing N3, NS2, and S3 tripods. The Zn-OH2 motif was observed only with pyrazolylborate ligands and only in unusual situations with coordination numbers higher than 4 for zinc. The new Zn-OH-Zn motif was realized for three different pyrazolylborates, for one NS2 tripod, and for two S3 tripods. Finally, it was verified that the Zn-O2H3-Zn motif again occurs only with pyrazolylborate ligands. The new complexes were identified by a total of 11 structure determinations.

  10. Selective Zn2+ sensing using a modified bipyridine complex

    Akula, Mahesh; El-Khoury, Patrick Z.; Nag, Amit; Bhattacharya, Anupam


    A novel fluorescent Zn2+ sensor, 4-(pyridin-2-yl)-3H-pyrrolo[2, 3-c]quinoline (PPQ), has been designed, synthesized and characterized by various spectroscopic and analytical techniques. PPQ exhibits superior detection of Zn2+ in the presence of various cations tested, including Cd2+ and Hg2+, via wavelength shifted fluorescence intensity enhancement. The emission wavelength at 500 nm, ensures probable noninterference from cellular components while performing biological applications.

  11. Synthesis, spectral and third-order nonlinear optical properties of terpyridine Zn(II) complexes based on carbazole derivative with polyether group

    Kong, Ming; Liu, Yanqiu; Wang, Hui; Luo, Junshan; Li, Dandan; Zhang, Shengyi; Li, Shengli; Wu, Jieying; Tian, Yupeng


    Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on carbazole derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.

  12. Stability on the 109Cd, 65Zn Complex with Humus Acids

    HUA Luo; CHEN Shi-bao; BAI Ling-yu; WEI Dong-pu


    The radioactive isotope tracer and ion exchange balanced method was used to study the stability of 109Cd, 65 Zn complexes with humus acids. In the 109Cd and 65 Zn single existing system with humic acids,the stability constants of the humic-109 Cd (65 Zn) complex compound was higher than the fulvic-109 Cd (65 Zn)complex compound. The stability constant of the humic (fulvic) -65Zn was higher than that of the humic (fulvic)-109Cd. In the 109Cd and 65 Zn coexisting system, the stability constant and the co-ordination number of the humic (fulvic)-65Zn complex obviously increased, but the stability constant and the co-ordination number of the humic (fulvic)-109Cd complex obviously decreased as compared with its respectively single existing system.The result showed that the humus matter with higher molecular weight could more effectively reduce plant availability of heavy metals than that with lower molecular weight in polluted soil by heavy metals. The humus matter could more effectively reduce plant availability of Zn than that of Cd. Application of humus-acid increased the harm of Cd and decreased the harm of Zn to plants in Cd-Zn coexisting system.

  13. Solvent induced cooperativity of Zn(II) complexes cleaving a phosphate diester RNA analog in methanol.

    Mohamed, Mark F; Sánchez-Lombardo, Irma; Neverov, Alexei A; Brown, R Stan


    The kinetics of cyclization of 2-hydroxypropyl p-nitrophenyl phosphate (1) promoted by two mononuclear Zn(II) catalytic complexes of bis(2-pyridylmethyl)benzylamine (4) and bis(2-methyl 6-pyridylmethyl)benzylamine (5) in methanol were studied under (s)(s)pH-controlled conditions (where (s)(s)pH refers to [H(+)] activity in methanol). Potentiometric titrations of the ligands in the absence and presence of Zn(2+) and a non-reactive model for 1 (2-hydroxylpropyl isopropyl phosphate (HPIPP, 6)) indicate that the phosphate is bound tightly to the 4:Zn(II) and 5:Zn(II) complexes as L:Zn(II):6(-), and that each of these undergoes an additional ionization to produce L:Zn(II):6(-):((-)OCH(3)) or a bound deprotonated form of the phosphate, L:Zn(II):6(2-). Kinetic studies as a function of [L:Zn(II)] indicate that the rate is linear in [L:Zn(II)] at concentrations well above those required for complete binding of the substrate. Plots of the second order rate constants (defined as the gradient of the rate constant vs. [complex] plot) vs. (s)(s)pH in methanol are bell-shaped with rate maxima of 23 dm mol(-1) s(-1) and 146 dm mol(-1) s(-1) for 4:Zn(II) and 5:Zn(II), respectively, at their (s)(s)pH maxima of 10.5 and 10. A mechanism is proposed that involves binding of one molecule of complex to the phosphate to yield a poorly reactive 1 : 1 complex, which associates with a second molecule of complex to produce a transient cooperative 2 : 1 complex within which the cyclization of 1 is rapid. The observations support an effect of the reduced polarity solvent that encourages the cooperative association of phosphate and two independent mononuclear complexes to give a reactive entity.

  14. Variation of the coordination environment and its effect on the white light emission properties in a Mn-doped ZnO-ZnS complex structure.

    Cheng, Yan; Chen, Rui; Feng, Haifeng; Hao, Weichang; Xu, Huaizhe; Wang, Yu; Li, Jiong


    Mn-doped ZnO-ZnS complex nanocrystals were fabricated through coating of dodecanethiol on Mn-doped ZnO nanocrystals. The relationship between the component of white light emission and the coordination environments of Mn-dopants were experimentally investigated. It was shown that Mn ions mainly formed Mn(3+)O6 octahedra in as prepared Mn-doped ZnO, while the Mn(3+) ions on the surface of ZnO transferred into Mn(2+) ions at the interface between ZnO and ZnS after dodecanethiol coating. The Mn(2+)S4 tetrahedron density and the orange emission intensity increased upon enhancing the dodecanethiol content. These results provide an alternative way to optimize the white emission spectrum from nanocrystals of Mn-doped ZnS-ZnO complex structures through modulation of the coordination environment of Mn ions.

  15. Synthesis, Characterization and Fluorescence Properties of Zn(II) and Cu(II) Complexes: DNA Binding Study of Zn(II) Complex.

    Lavaee, Parirokh; Eshtiagh-Hosseini, Hossein; Housaindokht, Mohammad Reza; Mague, Joel T; Esmaeili, Abbas Ali; Abnous, Khalil


    Zinc(II) and copper(II) complexes containing Schiff base, 2- methoxy-6((E)-(phenylimino) methyl) phenol ligand (HL) were synthesized and characterized by elemental analysis, IR, NMR, and single crystal X-ray diffraction technique. The fluorescence properties and quantum yield of zinc complex were studied. Our data showed that Zn complex could bind to DNA grooves with Kb = 10(4) M(-1). Moreover, Zn complex could successfully be used in staining of DNA following agarose gel electrophoresis. MTT assay showed that Zn complex was not cytotoxic in MCF-7 cell line. Here, we introduce a newly synthesized fluorescence probe that can be used for single and double stranded DNA detection in both solution and agarose gels.

  16. Recognition of amino acids and anions by a Zn(Ⅱ)-methylazacalix[4]pyridine complex


    As a powerful macrocyclic host molecule with unique conformation and cavity structure that are fine-tuned by the bridging nitrogen atoms, methylazacalix[4]pyridine (MACP-4) has been shown to selectively recognize Zn2+ and form stable Zn(Ⅱ)-MACP-4 complexes both in solid state and solution with an association constant up to 5.97 (logKs). The molecular recognition of Zn(Ⅱ)-MACP-4 complexes towards various amino acids and anions with different geometry was investigated by using the spectral titration methods and X-ray analysis. The Zn(Ⅱ)-MACP-4 complex was found to recognize the 17 amino acids tested with the association constant up to 3.97 (logKs). On the other hand, the Zn(Ⅱ)-MACP-4 complex selectively interacted with anions and the maximum association constant of 3.9 (logKs) was obtained.

  17. Microexplosion Recording in Spin-Coated Polymer Films Including ZnO Nanoparticles for Three-Dimensional Optical Memory

    Shiono, Teruhiro; Yamamoto, Hiroaki; Nishino, Seiji


    As a microexplosion recording material, we propose polymer films including ZnO nanoparticles (ZnO polyester composite) for write-once multilayered recording media. These media with the ZnO composite material can be fabricated by a spin-coating method and can be read at the violet wavelength of 0.405 μm. By the electromagnetic analysis of diffraction loss, we clarified the pit design and the optical performance for void formation recording. From the results of experiments performed using three kinds of mode-locked pulsed lasers (pulse widths of 150 fs, 16 ps and 6 ns), with a clear reflection microscope image of submicrometer pits, the microexplosion sensitivity was confirmed to be greatly improved by 14, 38 and 50 times, respectively.

  18. pyridine Zn(II) and Cu(II) Complexes



    Sep 3, 2014 ... The kinetics, mechanism and polymer microstructure studies of ring-opening polymerization (ROP) of lactides (LA) by Zn(II) and Cu(II) ... transparency, ease of processing and ease of microbial decompo- sition or degradation.

  19. Unsteady panel method for complex configurations including wake modeling

    Van Zyl, Lourens H


    Full Text Available implementations of the DLM are however not very versatile in terms of geometries that can be modeled. The ZONA6 code offers a versatile surface panel body model including a separated wake model, but uses a pressure panel method for lifting surfaces. This paper...

  20. Hydrogen motion in the Cu-H complex in ZnO

    Boerrnert, Felix; Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden (Germany)


    The Cu-H complex in ZnO consists of Cu on Zn site and a hydrogen atom bound to a nearby O atom with the O-H bond oriented in the basal plane of the hexagonal lattice to the c axis. The motion of hydrogen in the Cu-H complex is studied by the stress-induced dichroism. Stress applied at room temperature along [10 anti 10] results in an alignment of the Cu-H bond. The reorientation process was found to be thermally activated with the activation energy of 0.52{+-}0.04 eV. The connection of the hydrogen movement in the Cu-H complex with the hydrogen diffusion in ZnO is discussed and consequences for the existence of interstitial hydrogen in ZnO at room temperature are presented.

  1. C H complex defects and their influence in ZnO single crystal

    谢辉; 赵有文; 刘彤; 董志远; 杨俊; 刘京明


    Infrared absorption local vibration mode (LVM) spectroscopy is used to study hydrogen related defects in n-type ZnO single crystal grown by a closed chemical vapor transport (CVT) method under Zn-rich growth conditions, in which carbon is used as a transport agent. Two C–H complex related absorption peaks at 2850 cm−1 and 2919 cm−1 are detected in the sample. The formation of the C–H complex implies an effect of carbon donor passivation and formation suppression of H donor in ZnO. The influence of the complex defects on the electrical property of the CVT-ZnO is discussed based on Hall measurement results and residual impurity analysis.

  2. Chemical behavior of Cu, Zn, Cd, and Pb in a eutrophic reservoir: speciation and complexation capacity.

    Tonietto, Alessandra Emanuele; Lombardi, Ana Teresa; Choueri, Rodrigo Brasil; Vieira, Armando Augusto Henriques


    This research aimed at evaluating cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) speciation in water samples as well as determining water quality parameters (alkalinity, chlorophyll a, chloride, conductivity, dissolved organic carbon, dissolved oxygen, inorganic carbon, nitrate, pH, total suspended solids, and water temperature) in a eutrophic reservoir. This was performed through calculation of free metal ions using the chemical equilibrium software MINEQL+ 4.61, determination of labile, dissolved, and total metal concentrations via differential pulse anodic stripping voltammetry, and determination of complexed metal by the difference between the total concentration of dissolved and labile metal. Additionally, ligand complexation capacities (CC), such as the strength of the association of metals-ligands (logK'ML) and ligand concentrations (C L) were calculated via Ruzic's linearization method. Water samples were taken in winter and summer, and the results showed that for total and dissolved metals, Zn > Cu > Pb > Cd concentration. In general, higher concentrations of Cu and Zn remained complexed with the dissolved fraction, while Pb was mostly complexed with particulate materials. Chemical equilibrium modeling (MINEQL+) showed that Zn(2+) and Cd(2+) dominated the labile species, while Cu and Pb were complexed with carbonates. Zinc was a unique metal for which a direct relation between dissolved species with labile and complexed forms was obtained. The CC for ligands indicated a higher C L for Cu, followed by Pb, Zn, and Cd in decreasing amounts. Nevertheless, the strength of the association of all metals and their respective ligands was similar. Factor analysis with principal component analysis as the extraction procedure confirmed seasonal effects on water quality parameters and metal speciation. Total, dissolved, and complexed Cu and total, dissolved, complexed, and labile Pb species were all higher in winter, whereas in summer, Zn was mostly present in the

  3. The effect of complexing agent on the crystallization of ZnO nanoparticles

    S A Ketabi; A S Kazemi; M M Bagheri-Mohagheghi


    In this work, some structural and optical properties of the zinc oxide (ZnO) nanoparticles were studied. The highly crystalline ZnO nanoparticles were produced by the hydrothermal and sol–gel methods. The analyses of the XRD patterns, STEM images and UV spectroscopy showed that the size of the nanoparticles prepared by oxalic acid was smaller than the ones by urea. The properties of oxalic acid and urea were also investigated to determine the most effective crystallization process of ZnO nanoparticles. It has been shown that pH, decomposition temperature and activity coefficient of the complexing agent have certain effects on crystallization process.

  4. Salen-based [Zn2Ln3] complexes with fluorescence and single-molecule-magnet properties.

    Burrow, Carolyn E; Burchell, Tara J; Lin, Po-Heng; Habib, Fatemah; Wernsdorfer, Wolfgang; Clérac, Rodolphe; Murugesu, Muralee


    A family of four isostructural complexes with a V-shaped pentanuclear [Zn(2)Ln(3)] core of general formula [Zn(2)Ln(3)(m-salen)(3)(N(3))(5)(OH)(2)] [Ln(III) = Tb(III) (1), Eu(III) (2), Ho(III) (3), Dy(III) (4); m-salen = N,N'-ethylenebis(3-methoxysalicylideneamine)] were isolated and structurally characterized. The fluorescence and magnetic measurements of the four compounds were investigated. Complex 1 exhibits strong fluorescence properties, while single-molecule-magnet behavior is seen in complex 4.

  5. Investigation of VO-Zni native donor complex in MBE grown bulk ZnO

    Asghar, M.; Mahmood, K.; Ferguson, I. T.; Raja, M. Yasin A.; Xie, Y. H.; Tsu, R.; Hasan, M.-A.


    In this paper, we have experimentally investigated the theoretical predictions of VO-Zni to be a native donor in ZnO. Intrinsically zinc-rich n-type ZnO thin films having ND ˜ 6.23 × 1018 cm-3 grown by molecular beam epitaxy on Si (0 0 1) substrate were annealed in oxygen environment at 500-800 °C, keeping a step of 100 °C for 1 h, each. Room temperature Hall measurements demonstrated that free donor (VO-Zni) concentration decreased exponentially and Arrhenius plot yielded activation energy to be 1.2 ± 0.01 eV. This value is in agreement with theoretically reported activation energy of VO-Zni donor complex in ZnO. We argue; this observation can be explained by two-step process: (i) incoming oxygen fills VO of VO-Zni complex leaving behind Zni; (ii) Zni releases its energy and moves to a lower energy state with respect to the conduction band minima and/or occupies an inactive location. Consequently, Zni-VO complex loses its donor role in the lattice. Our experimental data supported theoretical predictions of VO-Zni to be a native donor. Results from photoluminescence spectroscopy carried out on Zn-rich ZnO additionally justify the existence of VO-Zni complex.

  6. QTAIM investigation of bis(pyrazol-1-yl)methane derivative and its Zn(II) complexes (ZnLX2, X=Cl, Br or I)

    Dehestani Maryam; Zeidabadinejad Leila


    Topological analyses of the electron density using the quantum theory of atoms in molecules (QTAIM) have been carried out at the B3PW91/6-31g (d) theoretical level, on bis(pyrazol-1-yl)methanes derivatives 9-(4-(di (1H-pyrazol-1-yl)-methyl)phenyl)-9H-carbazole (L) and its zinc(II) complexes: ZnLCl2 (1), ZnLBr2 (2) and ZnLI2 (3). The topological parameters derived from Bader theory were also analyzed; these are characteristics of Zn-bond critical points and ...

  7. Structural and optical characterization of indium-antimony complexes in ZnO

    Türker, M.; Deicher, M., E-mail:; Johnston, K.; Wolf, H.; Wichert, Th. [Universität des Saarlandes, Experimentalphysik (Germany)


    One of the main obstacles to the technical application of the wide-gap semiconductor ZnO represents the difficulty to achieve reliable p-type doping of ZnO with group V elements (N, P, As, Sb) acting as acceptors located on O lattice sites. The theoretically proposed concepts of cluster-doping or codoping may lead to an enhanced and stable p-type conductivity of ZnO. We report on PAC results obtained by codoping experiments of ZnO by ion implantation using the donor {sup 111}In and the group-V acceptor Sb. The formation of In-Sb pairs has been observed. Based on these PAC results, there is no evidence for the formation of In-acceptor complexes involving more than one Sb acceptor. These results has been complemented by photoluminescence measurements.

  8. Tetranuclear Heterometallic {Zn2Eu2} Complexes With 1-Naphthoate Anions: Synthesis, Structure and Photoluminescence Properties.

    Goldberg, Anna; Kiskin, Mikhail; Shalygina, Olga; Kozyukhin, Sergey; Dobrokhotova, Zhanna; Nikolaevskii, Stanislav; Sidorov, Alexey; Sokolov, Sergey; Timoshenko, Victor; Goloveshkin, Alexander; Eremenko, Igor


    A series of new tetranuclear heterometallic Zn(II) -Eu(III) complexes have been synthesized, that is, (bpy)2 Zn2Eu2 (naph)10 (1), (bpy)2 Zn2Eu2 (naph)8 (NO3)2 (2), and (phen)2 Zn2Eu2 (naph)8 (NO3)2 (3), and other ones, where naph(-) is the 1-naphthoate anion, bpy=2,2'-bipyridyl, and phen=1,10-phenanthroline. The solid-phase complexes consist of large supramolecular ensembles due to stacking interactions between the aromatic ligands. Photoluminescence (PL) measurements were carried out to study PL spectra, lifetimes and quantum yields (QY) of the synthesized complexes at different temperatures. The external QY for the solid phases of complexes under UV excitation was found to exceed 20 %. It has been shown that partial replacement of naphthoate ligands in the coordination environment of Eu(3+) by NO3(-) anions influences the PL properties. To investigate the behavior of these complexes in solvent, we dissolved complex 3 in MeCN, put it on a transparent glass as a substrate, and studied the PL properties at room temperature.

  9. Synthesis and evaluation of the potential deleterious effects of ZnO nanomaterials (nanoneedles and nanoflowers) on blood components, including albumin, erythrocytes and human isolated primary neutrophils

    Pastrello, Bruna; Paracatu, Luana Chiquetto; de Carvalho Bertozo, Luiza; Paino, Iêda Maria Martinez; Lisboa-Filho, Paulo Noronha; Ximenes, Valdecir Farias


    The application of zinc oxide (ZnO) nanoparticles in biomaterials has increased significantly in the recent years. Here, we aimed to study the potential deleterious effects of ZnO on blood components, including human serum albumin (HSA), erythrocytes and human isolated primary neutrophils. To test the influence of the morphology of the nanomaterials, ZnO nanoneedles (ZnO-nn) and nanoflowers (ZnO-nf) were synthesized. The zeta potential and mean size of ZnO-nf and ZnO-nn suspensions in phosphate-buffered saline were -10.73 mV and 3.81 nm and -5.27 mV and 18.26 nm, respectively. The incubation of ZnO with HSA did not cause its denaturation as verified by the absence of significant alterations in the intrinsic and extrinsic fluorescence and in the circular dichroism spectrum of the protein. The capacity of HSA as a drug carrier was not affected as verified by employing site I and II fluorescent markers. Neither type of ZnO was able to provoke the activation of neutrophils, as verified by lucigenin- and luminol-dependent chemiluminescence and by the extracellular release of hydrogen peroxide. ZnO-nf, but not ZnO-nn, induced the haemolysis of erythrocytes. In conclusion, our results reinforce the concept that ZnO nanomaterials are relatively safe for usage in biomaterials. A potential exception is the capacity of ZnO-nf to promote the lysis of erythrocytes, a discovery that shows the importance of the morphology in the toxicity of nanoparticles.

  10. Dye-Sensitized Nanocrystalline ZnO Solar Cells Based on Ruthenium(II Phendione Complexes

    Hashem Shahroosvand


    Full Text Available The metal complexes (RuII (phen2(phendione(PF62(1, [RuII (phen(bpy(phendione(PF62 (2, and (RuII (bpy2(phendione(PF62 (3 (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine and phendione = 1,10-phenanthroline-5,6-dione have been synthesized as photo sensitizers for ZnO semiconductor in solar cells. FT-IR and absorption spectra showed the favorable interfacial binding between the dye-molecules and ZnO surface. The surface analysis and size of adsorbed dye on nanostructure ZnO were further examined with AFM and SEM. The AFM images clearly show both, the outgrowth of the complexes which are adsorbed on ZnO thin film and the depression of ZnO thin film. We have studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phendione complexes, which gave power conversion efficiency of (η of 1.54% under the standard AM 1.5 irradiation (100 mW cm−2 with a short-circuit photocurrent density (sc of 3.42 mA cm−2, an open-circuit photovoltage (oc of 0.622 V, and a fill factor (ff of 0.72. Monochromatic incident photon to current conversion efficiency was 38% at 485 nm.

  11. Tuning Complexity by Lithiation: A Family of Intergrowth Structures Using Condensed hypho-Icosahedra in the Li-Doped Ca-Zn System.

    Lin, Qisheng; Zhu, Ran; Miller, Gordon J


    Cluster chemistry of intermetallics with valence electron counts (VECs) in the range of 2.0-3.0 is intriguing. Lithiation of polar intermetallics in this VEC region is found to be an effective chemical route to produce new complex structures with different stability mechanisms. In this work, two new complex intermetallic structures have been discovered in the Ca-Li-Zn system: Ca12LixZn59-x and Ca15LixZn75-x. Ca12LixZn59-x, x ≈ 5.65(3)-14.95(3), forms in the trigonal space group R3̅m, with a = 9.074(1)-9.1699(2) Å, c = 53.353(1)-53.602(1) Å, and Z = 3. In comparison, Ca15LixZn75-x, x ≈ 19.07(2), crystallizes in the space group P63/mmc, with a ≈ 9.183(1) Å, c ≈ 45.191(5) Å), and Z = 2. Both structures are members of a large intergrowth family featuring slabs of dimers (D) and trimers (T) stacking along [001], with the sequences DTDDTDDTD for Ca12LixZn59-x and TDDDTDDD for Ca15LixZn75-x. Each dimer consists of two face-sharing Zn-centered hypho-icosahedra, and each trimer comprises a Li-centered icosahedron sandwiched by two hypho-icosahedra. This intergrowth family includes several known intermetallic structure types involving very electropositive metals, e.g., SrMg5.2, Ba2Li4.21Al4.79, and Sr9Li17.5Al25.5. Because of cluster defects and condensation, both Ca12LixZn59-x and Ca15LixZn75-x are electronically akin to close-packed metals, and their structural stabilities can be interpreted by a Hume-Rothery mechanism rather than the Zintl-Klemm concept.

  12. Green synthesis of ZnO nanoparticles via complex formation by using Curcuma longa extract

    Fatimah, Is; Yudha, Septian P.; Mutiara, Nur Afisa Lintang


    Synthesis of ZnO nanoparticles(NPs) were conducted via Zn(II) complex formation by using Curcuma longa extract as template. Curcuma longa extract has the ability to form zinc ions complex with curcumin as ligating agent. Study on synthesis was conducted by monitoring thermal degradation of the material. Successful formation of zinc oxide nanoparticles was confirmed by employing x-ray diffraction, surface area analysis and transmission electron microscopy(TEM) studies. From the XRD analysis it is denoted that ZnO in hexagonal wurtzite phase was formed and particle size was varied as varied temperature. The data are also confirmed by TEM analysis which shows the particle sie at the range 20-80nm. The NPs exhibited excelent photocatalytic activity for methylene blue degradation and also significant antibacterial activity for Eschericia coli. The activity in methylene blue degradation was also confirmed from fast chemical oxygen demand (COD) reduction.

  13. Green synthesis of ZnO nanoparticles via complex formation by using Curcuma longa extract

    Fatimah, Is, E-mail:; Yudha, Septian P.; Mutiara, Nur Afisa Lintang [Chemistry Department, Islamic University of Indonesia Kampus Terpadu UII, Jl. Kaliurang Km 14, Sleman, Yogyakarta (Indonesia)


    Synthesis of ZnO nanoparticles(NPs) were conducted via Zn(II) complex formation by using Curcuma longa extract as template. Curcuma longa extract has the ability to form zinc ions complex with curcumin as ligating agent. Study on synthesis was conducted by monitoring thermal degradation of the material. Successful formation of zinc oxide nanoparticles was confirmed by employing x-ray diffraction, surface area analysis and transmission electron microscopy(TEM) studies. From the XRD analysis it is denoted that ZnO in hexagonal wurtzite phase was formed and particle size was varied as varied temperature. The data are also confirmed by TEM analysis which shows the particle sie at the range 20-80nm. The NPs exhibited excelent photocatalytic activity for methylene blue degradation and also significant antibacterial activity for Eschericia coli. The activity in methylene blue degradation was also confirmed from fast chemical oxygen demand (COD) reduction.

  14. [Physico-chemical characterisation of Zn-flavonols complexes].

    Muntean, Daniela; Imre, Silvia; Vari, C E


    The aim of flavonols complexation is to improve their specific activity. The flavonols sources were Morus alba L. and Morus nigra L., zinc being the biological active ion. Physico-chemical characterization was made by thin-layer chromatography, UV-VIS spectrophotometry, IR spectrometry and polarography. The complexes results were within acceptability limits, but their obtaining is economically inefficient.

  15. Effect of different complexing agents on the properties of chemical-bath-deposited ZnS thin films

    Liu, Jun; Wei, Aixiang, E-mail:; Zhao, Yu


    Highlights: • To fabricate high quality ZnS films need to promote the ion-by-ion process and restrain cluster-by-cluster process. • The complexation ability of tri-sodium citrate is stronger than that of hydrazine hydrate. • The nucleation density of nuclei determine the performance of ZnS thin films. -- Abstract: Zinc sulfide (ZnS) thin films were deposited on glass substrates using the chemical bath deposition (CBD) technique. The effects of different complexing agents (tri-sodium citrate, hydrazine hydrate) and their concentrations on the structure, composition, morphology, optical properties and growth mechanism of ZnS thin films were investigated. The results indicated that the chemical-bath-deposited ZnS thin films exhibit poor crystallinity and a high Zn/S atomic ratio with an average transmittance of 75% in the range of visible light. The ZnS thin films prepared using hydrazine hydrate as the complexing agent present a more compact surface, a smaller average particle size, and a sharper absorption edge at 300–340 nm compared with those prepared using tri-sodium citrate. Based on our experimental observations and analysis, we conclude that the predominant growth mechanism of ZnS thin films is an ion-by-ion process. The nucleation density of Zn(OH){sub 2} nuclei on the substrate in the initial stage produces the different morphologies and properties of the ZnS thin films prepared using the two complexing agents.

  16. A saponification-triggered gelation of ester-based Zn(II) complex through conformational transformations.

    Kumar, Ashish; Dubey, Mrigendra; Kumar, Amit; Pandey, Daya Shankar


    Novel saponification-triggered gelation in an ester-based bis-salen Zn(II) complex (1) is described. Strategic structural modifications induced by NaOH in 1 tune the dipolar-/π-interactions leading to J-aggregation and the creation of an inorganic gel material (IGM), which has been established by photophysical, DFT and rheological studies.

  17. Preparation and characteristics of chemical bath deposited ZnS thin films: Effects of different complexing agents

    Shin, Seung Wook [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Agawane, G.L.; Gang, Myeng Gil [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Moholkar, A.V. [Department of Physics, Shivaji University, Kolhapur 416-004 (India); Moon, Jong-Ha [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Kim, Jin Hyeok, E-mail: [Photonics Technology Research Institute, Department of Materials Science Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Lee, Jeong Yong, E-mail: [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)


    Highlights: Black-Right-Pointing-Pointer Thick ZnS thin films were successfully prepared by chemical bath deposition in a basic medium using less toxic complexing agents. Black-Right-Pointing-Pointer Effect of different complexing agents such as no complexing agent, Na{sub 3}-citrate and a mixture of Na{sub 3}-citrate and EDTA on the properties of ZnS thin films was investigated. Black-Right-Pointing-Pointer ZnS thin film deposited using two complexing agent showed the outstanding characteristics as compared to those using no and one complexing agent. - Abstract: Zinc sulfide (ZnS) thin films were prepared on glass substrates by a chemical bath deposition technique using aqueous zinc acetate and thiourea solutions in a basic medium (pH {approx} 10) at 80 Degree-Sign C. The effects of different complexing agents, such as a non-complexing agent, Na{sub 3}-citrate, and a mixture of Na{sub 3}-citrate and ethylenediamine tetra-acetate (EDTA), on the structural, chemical, morphological, optical, and electrical properties of ZnS thin films were investigated. X-ray diffraction pattern showed that the ZnS thin film deposited without any complexing agent was grown on an amorphous phase. However, the ZnS thin films deposited with one or two complexing agents showed a polycrystalline hexagonal structure. No secondary phase (ZnO) was observed. X-ray photoelectron spectroscopy showed that all ZnS thin films exhibited both Zn-S and Zn-OH bindings. Field emission scanning electron microscopy (FE-SEM) images showed that ZnS thin films deposited with complexing agents had thicker thicknesses than that deposited without a complexing agent. The electrical resistivity of ZnS thin films was over 10{sup 5} {Omega} cm regardless of complexing agents. The average transmittance of the ZnS thin films deposited without a complexing agent, those with Na{sub 3}-citrate, and those with a mixture of Na{sub 3}-citrate and EDTA was approximately 85%, 65%, and 70%, respectively, while the band gap

  18. Electrical and optical properties of hydrogen-related complexes and their interplay in ZnO

    Koch, Sandro


    The commercial breakthrough of ZnO-based devices is hampered mainly by the unipolar n-type conductivity of this material. Hydrogen, which is known to form both electrically active and inactive complexes in ZnO, is considered as a main cause of this behavior. However, the existing literature is incomplete and partly contradictory. The object of the present thesis is a comprehensive investigation of the properties of two hydrogen-induced shallow donors HBC and HO, the hydrogen molecule H2, and ...

  19. Multifunctional Zn(II) Complexes: Photophysical Properties and Catalytic Transesterification toward Biodiesel Synthesis.

    Gupta, Abhishek Kumar; Dhir, Abhimanew; Pradeep, Chullikkattil P


    Using 4-substituted derivatives of phenol-based compartmental Schiff-base hydroxyl-rich ligand, four multifunctional binuclear Zn(II) complexes have been synthesized and characterized. The photophysical properties of these complexes were explored in the solid state, in solutions, and in poly(methyl methacrylate) (PMMA) matrix, which revealed their good potential as tunable solid state emitters. Some of these complexes acted as efficient catalysts for the transesterification of esters and canola oil showing their potential in biodiesel generation. Mechanistic investigations using ESI-MS revealed that the transesterification catalyzed by these complexes proceeds through two types of acyl intermediates.

  20. Effect of ZnTe/ZnTe:Cu complex back-contact on device characteristics of CdTe solar cells


    ZnTe/ZnTe:Cu complex layers deposited by vacuum co-evaporation have been in- troduced to CdS/CdTe solar cells. The C-V and I-V curves have been investigated and the effects of un-doped ZnTe layer thickness as well as annealing temperatures on I-V characteristics of CdTe solar cells have been studied. The results show that the “roll over” and “cross over” phenomena of dark and light I-V curves can be eliminated by use of ZnTe/ZnTe:Cu layer and the fill factor for a typical sample has increased to 73%, where there is no high resistance transparent layer. The reasons have been discussed combined with the energy band diagram of CdTe solar cells.

  1. Complex formation of CdSe/ZnS/TOPO nanocrystal vs. molecular chaperone in aqueous solution by hydrophobic interaction

    Horiuchi, Hiromi [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan)]. E-mail:; Iwami, Noriya [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Tachibana, Fumi [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Ohtaki, Akashi [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Iizuka, Ryo [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Zako, Tamotsu [Bioengineering Laboratory, RIKEN - Institute of Physical and Chemical Research, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan); Oda, Masaru [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Strategic Research Initiative for Future Nano-Science and Technology, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Yohda, Masafumi [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Strategic Research Initiative for Future Nano-Science and Technology, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Tani, Toshiro [Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan); Strategic Research Initiative for Future Nano-Science and Technology, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Kogane-i, Tokyo 184-8588 (Japan)


    Feasibilities to stabilize CdSe/ZnS/trioctylphosphineoxide (TOPO) nanocrystals (quantum dots, QDs) in aqueous solutions with prefoldin macromolecules in their bioactive states are reported. Prefoldin is a jellyfish-shaped hexameric co-chaperone of the group II chaperonins. As a protein folding intermediate is captured within its central cavity, so CdSe/ZnS/TOPO QDs would also be included within this cavity. It is also found the QDs can be much more dispersed in aqueous solutions and suspended for certain period of time by adding trace amount of t-butanol in the buffer prior to the mixing of the QDs mother solution. While biochemical procedures are evaluated with ordinary fluorescence measurements, possible complex formations are also evaluated with TIRFM single-molecule detection techniques.

  2. Investigation of chemical bath deposition of ZnO thin films using six different complexing agents

    Khallaf, Hani; Chai, Guangyu; Lupan, Oleg; Heinrich, Helge; Park, Sanghoon; Schulte, Alfons; Chow, Lee, E-mail: chow@mail.ucf.ed [Department of Physics, University of Central Florida, Orlando, FL 32816 (United States)


    Chemical bath deposition of ZnO thin films using six different complexing agents, namely ammonia, hydrazine, ethanolamine, methylamine, triethanolamine and dimethylamine, is investigated. As-grown films were mainly ZnO{sub 2} with a band gap around 4.3 eV. Films annealed at 400 deg. C were identified as ZnO with a band gap around 3.3 eV. X-ray diffraction and micro-Raman spectroscopy revealed that as-grown films consist mainly of cubic zinc peroxide that was transformed into hexagonal ZnO after annealing. Rutherford backscattering spectroscopy (RBS) detected excess oxygen content in ZnO films after annealing. Fourier transform infrared spectroscopy of as-grown films showed a broad absorption band around 3300 cm{sup -1} suggesting that the as-grown films may consist of a mixture of zinc peroxide and zinc hydroxide. X-ray photoelectron spectroscopy multiplex spectra of the O 1s peak were found to be consistent with film stoichiometry revealed by RBS. High-resolution transmission electron micrographs showed small variations of the order of 10 nm in film thickness which corresponds to the average grain size. A carrier density as high as 2.24x10{sup 19} cm{sup -3} and a resistivity as low as 6.48 x 10{sup -1} OMEGA cm were obtained for films annealed at 500 deg. C in argon ambient.

  3. Synthesis, Crystal Structure and Electrochemical Studies of Two Novel Zn(Ⅱ) Complexes of Phthalic Acid and Imidazole Derivatives

    LI Wei-Hua; ZHAO Guang-Fa; HUANG Zhao-Ge; LIU Fa-Qian; DING Nai-Xiu; LIU Guang-Ye


    Two novel coordination polymers [Zn(pa)(vim)2]n (1) and [Zn(pa)(eim)2]n (2) (pa=phthalic acid dianion,vim=1-vinyl-1H-imidazole,eim=1-ethyl-1H-imidazole) have been synthesized and their structures characterized by X-ray single crystal diffractometry and elemental analysis.Both of the complexes consist of [Zn(L)2](L=vim for 1;eim for 2) entities linked into polymeric zigzag chains along the crystallographic c-axis by bridging phthalate anions in the μ2-1,2 coordination mode.The coordination around each Zn(II) atom is tetrahedral.There are only van der Waals interactions between the chains in 1,while the three-dimensional network in 2 is assembled by C--H'--O contacts.The electrochemical studies reveal that redoxes of Zn2+/Zn in complexes 1 and 2 are irreversible processes.

  4. The luminescent properties and toxicity controllability investigation of novel ZnO quantum dots with Schiff base complexes modification.

    Yu, Shi Yong; Jing, Hui; Cao, Zhen; Su, Hai Quan


    The Schiff base complexes modified ZnO quantum dots (ZnO-SBC QDs) are successfully synthesized via the reflux and chemical co-precipitation route. For control experiments, we also synthesized the ZnO QDs and amino-modified ZnO QDs (ZnO-NH2 QDs). The structures and morphologies of the samples were characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), FTIR spectroscopy (IR), Fluorescence Spectrometer (FL) and so on. The XRD pattern shows that the three types of QDs possess hexagonal wurtzite structures. The TEM investigation reveals that the as-prepared products have hexagonal morphologies. The plane fringe with 0.26 nm crystalline plane spacing of three types of quantum dots is assigned to the ZnO {002} planes via HR-TEM, which match with the lattice parameter of the hexagonal wurtzite structure of ZnO and also coincide with the data obtained by XRD. By analyzing the fluorescence emission and excitation spectra of ZnO QDs, ZnO-NH2 QDs, ZnO-SBC QDs and Schiff base complexes, we find that the ZnO-SBC QDs still have a perfect fluorescence emission which makes it interesting candidates for luminescence applications such as biochemical sensors and fluorescent labels to mark the cells and DNA. This novel ZnO-SBC QDs under UV irradiation is capable of generating reactive oxygen species by UV irradiation and may be used for the photodynamic therapy. The surface modification with Schiff base complexes makes it difficult to release Zn2+, therefore the toxicity is much more controllable.

  5. Influence of Exciplex formation on the electroluminescent properties of dimeric Zn (II) bis-2-(2'-hydroxyphenyl) benzoxazole complex and monomeric Zn (II) 2-(1'-hydroxynaphthyl) benzothiazole complex

    Prakash, Sattey; Anand, R. S.; Manoharan, S. Sundar


    In this paper we present the factors affecting electroluminescent properties of Zinc complexes of oxazole & thiazole derivatives. Electroluminescent spectra of the Zinc (II) complex of bis-[2-(2'-hydroxyphenyl) benzoxazole], [Zn (HPBO)2]2 and 2-(1'-hydroxynaphthyl) benzothiazole [Zn (HNBT)2] show unusual broadening and shows structural and photophysical similarity with [Zn (HPBT)2]2, a dimeric complex. The [Zn (HPBO)2]2 complex as an emissive layer in the device structure ITO /PEDOT:PSS /TPD (30nm) /[Zn (HPBO)2]2 (60nm) /BCP (6nm) /Ca (3nm) /Al (200nm) shows a broad bluish green emission, with a full width at half maxima (FWHM1˜70nm). The EL spectra is much broader compared to the PL spectra because of exciplex formation at the interfacial region between the emissive layer (EML) & hole transport layer (HTL). We also show the device performance of Zinc 2-(1'-hydroxynaphthyl) benzothiazole [Zn (HNBT)2] complex as emissive layer. Distinctly this device shows a broad greenish yellow emission with a peak maxima at 535nm and 690nm, owing to the exciplex formation between electron transport layer (ETL) and emissive layer (EML), which is in sharp contrast to the exciplex formation across the HTL-EML interface observed for the [Zn (HPBO)2]2 complex.

  6. Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles



    Cu(II) complexes with Schiff bases derived from ethylenediamine (en) and 2-pyridinecarboxaldehyde (pyca), 2,5-dimethoxybenzaldehyde (dmbaH) or 4-imidazolecarboxaldehyde (4Him) were obtained and studied by elemental analysis, UV-VIS and IR spectra. Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers of the studied Cu(II) complexes were deposited on Si(111) or ZnO/Si(111) substrates by a spin coating method and characterized with a scanningelectron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. For Cu(II) layers the most intensive fluorescence bands due to intra-ligand transitions were observed between 462 and 503 nm. The fluorescence intensity of thin layers was corelated to the rotation speed. In the case of the [Cu(II)(en(4Him)₂)Cl₂](2a)/ZnO/Si and [Cu(en(dmbaH)₂)Cl₂](3a)/ZnO/Si layers the quenching of the emission band from ZnO at 440 nm (λex = 330 nm) associated with various intrinsic or extrinsic lattice defects was noted.

  7. Complex hierarchical arrangements of stacked nanoplates in Al-doped ZnO

    Ortega, Y. [Departamento de Fisica de Materiales, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Mikrostrukturanalytik, Christian-Albrechts Universitaet zu Kiel, 24143 Kiel (Germany); Haeussler, D.; Jaeger, W. [Mikrostrukturanalytik, Christian-Albrechts Universitaet zu Kiel, 24143 Kiel (Germany); Piqueras, J.; Fernandez, P. [Departamento de Fisica de Materiales, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, 28040 Madrid (Spain)


    Al-doped micro- and nanostructures have been grown by an evaporation-deposition method with a mixture of ZnS and Al{sub 2}O{sub 3} powders as precursor. It has been found that the presence of Al is the cause of the growth of complex morphologies, as rods formed by stacks of nanoplates and other complex hierarchical structures. The role of Al in the growth process has been investigated by electron microscopy techniques. Al-rich particles in specific sites of a central rod lead to hierarchical growth. Transmission electron microscopy shows that in some cases the Al-rich zones are clusters of spinel ZnAl{sub 2}O{sub 4} nanoparticles adhered to ZnO nanorods. Al incorporation into the structures and the dopant effect on the luminescence behavior of the ZnO structures were investigated by energy dispersive spectroscopy and by cathodoluminescence. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Synthesis, Structural Characterization, and Biological Activity Studies of Ni(II) and Zn(II) Complexes

    Kavitha, Palakuri; Laxma Reddy, K.


    Ni(II) and Zn(II) complexes were synthesized from tridentate 3-formyl chromone Schiff bases such as 3-((2-hydroxyphenylimino)methyl)-4H-chromen-4-one (HL1), 2-((4-oxo-4H-chromen-3-yl)methylneamino)benzoic acid (HL2), 3-((3-hydroxypyridin-2-ylimino)methyl)-4H-chromen-4-one (HL3), and 3-((2-mercaptophenylimino)methyl)-4H-chromen-4-one (HL4). All the complexes were characterized in the light of elemental analysis, molar conductance, FTIR, UV-VIS, magnetic, thermal, powder XRD, and SEM studies. The conductance and spectroscopic data suggested that, the ligands act as neutral and monobasic tridentate ligands and form octahedral complexes with general formula [M(L1–4)2]·nH2O (M = Ni(II) and Zn(II)). Metal complexes exhibited pronounced activity against tested bacteria and fungi strains compared to the ligands. In addition metal complexes displayed good antioxidant and moderate nematicidal activities. The cytotoxicity of ligands and their metal complexes have been evaluated by MTT assay. The DNA cleavage activity of the metal complexes was performed using agarose gel electrophoresis in the presence and absence of oxidant H2O2. All metal complexes showed significant nuclease activity in the presence of H2O2. PMID:24948904

  9. Synthesis, Structural Characterization, and Biological Activity Studies of Ni(II and Zn(II Complexes

    Palakuri Kavitha


    Full Text Available Ni(II and Zn(II complexes were synthesized from tridentate 3-formyl chromone Schiff bases such as 3-((2-hydroxyphenyliminomethyl-4H-chromen-4-one (HL1, 2-((4-oxo-4H-chromen-3-ylmethylneaminobenzoic acid (HL2, 3-((3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one (HL3, and 3-((2-mercaptophenyliminomethyl-4H-chromen-4-one (HL4. All the complexes were characterized in the light of elemental analysis, molar conductance, FTIR, UV-VIS, magnetic, thermal, powder XRD, and SEM studies. The conductance and spectroscopic data suggested that, the ligands act as neutral and monobasic tridentate ligands and form octahedral complexes with general formula [M(L1–42]·nH2O (M = Ni(II and Zn(II. Metal complexes exhibited pronounced activity against tested bacteria and fungi strains compared to the ligands. In addition metal complexes displayed good antioxidant and moderate nematicidal activities. The cytotoxicity of ligands and their metal complexes have been evaluated by MTT assay. The DNA cleavage activity of the metal complexes was performed using agarose gel electrophoresis in the presence and absence of oxidant H2O2. All metal complexes showed significant nuclease activity in the presence of H2O2.

  10. Analysis of solvation and structural contributions in spectral characteristics of dipyrrin Zn(II) complexes.

    Marfin, Yu S; Rumyantsev, E V


    Photophysical characteristics of several alkylated dipyrrin Zn(II) complexes in organic solvents were analyzed. Relations between spectral properties of complexes and physical-chemical parameters of solvents were determined with the use of linear regression analysis method. Each solvent parameter contribution in investigated spectral characteristics was estimated. Spectral properties of complexes under study depend on the specific interactions of zinc with the solvent molecules by specific axial coordination. Increasing of alkyl substitution lead to the bathochromic shifts in spectra due to the positive induction effect of alkyl groups.

  11. Analysis of solvation and structural contributions in spectral characteristics of dipyrrin Zn(II) complexes

    Marfin, Yu. S.; Rumyantsev, E. V.


    Photophysical characteristics of several alkylated dipyrrin Zn(II) complexes in organic solvents were analyzed. Relations between spectral properties of complexes and physical-chemical parameters of solvents were determined with the use of linear regression analysis method. Each solvent parameter contribution in investigated spectral characteristics was estimated. Spectral properties of complexes under study depend on the specific interactions of zinc with the solvent molecules by specific axial coordination. Increasing of alkyl substitution lead to the bathochromic shifts in spectra due to the positive induction effect of alkyl groups.

  12. Effect of nitrogen and intrinsic defect complexes on conversion efficiency of ZnO for hydrogen generation from water.

    Lu, Y H; Russo, S P; Feng, Y P


    Band gap narrowing is important for applications of ZnO, especially for photoelectrochemical water splitting. In this work, we carried out first-principles electronic structure calculations with a hybrid density functional on defected ZnO. It is found that nitrogen substitutional doping alone cannot explain the largely enhanced conversion efficiency observed in nitrogen doped ZnO. Instead, complex defects formed by substitutional nitrogen and intrinsic defects play an important role in the band gap narrowing, in agreement with recent experimental results. We propose ZnO fabricated in a Zn-rich environment with heavy nitrogen doping as a photocatalyst for hydrogen generation from water splitting. A method for controlling the band gap of ZnO is also proposed.

  13. Interaction Energies in Complexes of Zn and Amino Acids: A Comparison of Ab Initio and Force Field Based Calculations.

    Ahlstrand, Emma; Hermansson, Kersti; Friedman, Ran


    Zinc plays important roles in structural stabilization of proteins, enzyme catalysis, and signal transduction. Many Zn binding sites are located at the interface between the protein and the cellular fluid. In aqueous solutions, Zn ions adopt an octahedral coordination, while in proteins zinc can have different coordinations, with a tetrahedral conformation found most frequently. The dynamics of Zn binding to proteins and the formation of complexes that involve Zn are dictated by interactions between Zn and its binding partners. We calculated the interaction energies between Zn and its ligands in complexes that mimic protein binding sites and in Zn complexes of water and one or two amino acid moieties, using quantum mechanics (QM) and molecular mechanics (MM). It was found that MM calculations that neglect or only approximate polarizability did not reproduce even the relative order of the QM interaction energies in these complexes. Interaction energies calculated with the CHARMM-Drude polarizable force field agreed better with the ab initio results, although the deviations between QM and MM were still rather large (40-96 kcal/mol). In order to gain further insight into Zn-ligand interactions, the free energies of interaction were estimated by QM calculations with continuum solvent representation, and we performed energy decomposition analysis calculations to examine the characteristics of the different complexes. The ligand-types were found to have high impact on the relative strength of polarization and electrostatic interactions. Interestingly, ligand-ligand interactions did not play a significant role in the binding of Zn. Finally, analysis of ligand exchange energies suggests that carboxylates could be exchanged with water molecules, which explains the flexibility in Zn binding dynamics. An exchange between carboxylate (Asp/Glu) and imidazole (His) is less likely.

  14. Study on beta-cyclodextrin inclusion of Zn(II) aromatic complex and its analytical application.

    Ding, Lixiu; He, Jiang; Fu, Junkai; Zhang, Jinlong


    A new beta-cyclodextrin (beta-CD) inclusion compound Zn(2H1NA)(2)x 2beta-CD (2H1NA=2-hydroxy-1-naphthoic acid) was prepared. The structure was characterized by (1)H NMR, IR, the fluorescence spectra, thermogravimetric analysis (TG-DTA) and elementary analysis. Meanwhile, the mechanism of the formation of the supramolecular system (2H1NA:Zn(II):beta-CD) was studied and discussed by spectrofluorimetry. The results showed that the naphthalene rings of the Zn(II) aromatic complex Zn(2H1NA)(2) were encapsulated within the beta-CD's cavity to form a 2:1 stoichiometry host-guest compound. The inclusion constant calculated was 1.27 x 10(4)(L/mol)(2). A spectrofluorimetric method for the determination of 2H1NA in bulk aqueous solution in the presence of beta-CD was developed based on the great enhancement of the fluorescence intensity of 2H1NA. The linear relationship was obtained in the range of 9.00 x 10(-7) to 2.50 x 10(-5)mol/L and the detection limit was 8.00 x 10(-7)mol/L. The proposed method was successfully applied to determine 2H1NA in waste water with recoveries of 97-104%.

  15. Heavy metal (Zn and Cu) complexation and molecular size distribution in wastewater treatment plant effluent.

    Chaminda, G G T; Nakajima, F; Furumai, H


    The size distributions of zinc and copper species in the effluent of a wastewater treatment plant were determined by a combination of ultrafiltration and chelating disk cartridge fractionation. The results showed that 75-87% of total Zn and 84-86% of total Cu were strongly complexed or particle-bound in the final effluents. It was also found that the major part of Cu was bound to ligands in the < 500 Da fraction while the trend for Zn was not so clear and exhibited significant seasonal variability. Labile Cu and Zn were detected not only in the smallest fraction (< 500 Da) but also in the larger fractions. It meant that the labile species in the effluent were not equivalent to free metal ions. Conditional stability constants and ligand concentrations were also determined from the measured metal concentrations by square wave anodic stripping voltammetry. Existence of two types of ligand for each metal was inferred from the experimental data. Conditional stability constant obtained for the stronger type Ligand of Zn was higher than that of Cu, although the estimated Ligand concentrations were almost similar.

  16. Electronic and atomic structure of complex defects in Al- and Ga-highly doped ZnO films

    Menéndez-Proupin, Eduardo [Instituto de Energía Solar, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid (Spain); Departamento de Física, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 780-0003 Ñuñoa, Santiago (Chile); Palacios, Pablo, E-mail: [Instituto de Energía Solar, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid (Spain); Dpt. FAIAN, E.T.S.I. Aeronáutica y del Espacio, UPM, Pz. Cardenal Cisneros 3, 28040 Madrid (Spain); Wahnón, Perla [Instituto de Energía Solar, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid (Spain); Dpt. TFO, E.T.S.I. Telecomunicación, UPM, Ciudad Universitaria, 28040 Madrid (Spain)


    Point defects in Ga- and Al-doped ZnO thin films are studied by means of first principles electronic structure calculations. Candidate defects are identified to explain recently observed differences in electrical and spectroscopic behavior of both systems. Substitutional doping in Ga–ZnO explain the metallic behavior of the electrical properties. Complexes of interstitial oxygen with substitutional Ga can behave as acceptor and cause partial compensation, as well as gap states below the conduction band minimum as observed in photoemission experiments. Zn vacancies can also act as compensating acceptors. On the other hand, the semiconducting behavior of Al–ZnO and the small variation in the optical gap compared with pure ZnO, can be explained by almost complete compensation between acceptor Zn vacancies and substitutional Al donors. Interstitial Al can also be donor levels and can be the origin of the small band observed in photoemission experiments below the Fermi level. Combinations of substitutional Al with interstitial oxygen can act simultaneously as compensating acceptor and generator of the mentioned photoemission band. The theoretical calculations have been done using density functional theory (DFT) within the generalized gradient approximation with on-site Coulomb interaction. In selected cases, DFT calculations with semilocal-exact exchange hybrid functionals have been performed. Results explain photoelectron spectra of Ga–ZnO and Al–ZnO at the corresponding doping levels. - Highlights: • Defects in Ga- and Al-heavy-doped ZnO films are studied by quantum calculations. • Defects compatible with electrical, optical, and HAXPES spectra are proposed. • Doping efficiency is reduced by Zn vacancies and O interstitials. • HAXPES bands near the Fermi level are induced by Al{sub i}, and complexes Ga{sub Zn}-O{sub i}, and Al{sub Zn}-O{sub i}.

  17. Unique formation of two high-nuclearity metallamacrocycles from a mononuclear complex [Zn(dmpzdtc)2] (dmpzdtc=3,5-dimethylpyrazole-1-dithiocarboxylate) via CS2 elimination.

    Li, Hong-Xi; Wu, Hua-Zhou; Zhang, Wen-Hua; Ren, Zhi-Gang; Zhang, Yong; Lang, Jian-Ping


    Dissolution of a mononuclear complex [Zn(dmpzdtc)2] in BrCH2CH2Br or DMF saturated with water followed by CS2 elimination led to the formation of two unique high-nuclearity metallamacrocyclic complexes, [Zn4(micro-dmpz)6(micro-OH)2]2 and [Zn4(micro-dmpz)6(micro-OH)2]4.

  18. Zn,Ni ferrite/NiO nanocomposite powder obtained from acetylacetonato complexes

    Vucinic-Vasic, M.; Antic, B.; Kremenovic, A.; Nikolic, A. S.; Stoiljkovic, M.; Bibic, N.; Spasojevic, V.; Colomban, Ph


    The results on the synthesis, microstructure, structure and DC magnetization studies of nanocomposite Zn,Ni ferrite/NiO powder obtained by thermal decomposition of acetylacetonato complexes are reported in this paper. According to the results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) element analysis and multiphase Rietveld refinement, the three samples made are composed of spinel-ferrite (86.7% 96.7%) and NiO (3.3% 13.3%) phases. The compositions of the spinel-ferrite (SP) phase in the investigated samples, S1 S3, are Zn0.72Ni0.24Fe1.98O4, Zn0.56Ni0.29Fe2.07O4 and Zn0.40Ni0.40Fe2.10O4, respectively. Due to the cation deficiency in spinels, created vacancies induce a partial change in the cation valence, \\mathrm {Ni^{2+}} \\to \\mathrm {Ni^{3+}} . The vacancy distribution is found to be random at 8a and 16d cation sites, except in sample S3, where all vacancies are over octahedral sites. The x-ray line broadening due to crystallite size effect is found to be isotropic for all spinels, while the x-ray line broadening due to the strain effect is anisotropic. A correlation between the Zn2+ occupancy of the tetrahedral site and the 650 cm-1 Raman peak intensities is shown. The observed coercivity decrease and shift in hysteresis loop in the samples are caused by the interaction between spinel and NiO phase. The results of M(H) measurements point to the properties of an ensemble of interacting nanoparticles. High saturation magnetization values and superparamagnetic behaviour at room temperature point to the technological significance of the title compounds.

  19. Synthesis, Crystal Structure and Magnetic Properties of a New Zn(Ⅱ)-Nitronyl Nitroxide Complex

    JIANG Kai; YANG Rui-Hua; WANG Li-Ya; WANG Yu-Fang


    A new complex [Zn(NIT-1'-MeBzIm)Cl2(H2O)] (NIT-1'-MeBzIm = 2-{2'-[(1'-methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) has been prepared and structurally characterized by X-ray diffraction method. Crystal data: monoclinic, space group P21/n, Z = 4, C15H21Cl2N4O3Zn, Mr = 441.63, a = 7.2225(10), b = 30.849(4), c = 8.8758(13) (A), β= 103.904(2)°, V = 1919.6(5) A3, Dc = 1.528 g/cm3, μ(MoKα) = 1.579 mm-1, F(000) = 908, R = 0.0436 and wR = 0.1029 for 2456 observed reflections with Ⅰ> 2σ(Ⅰ). X-ray analysis reveals that the Zn(Ⅱ) ion is four-coordinated with a distorted tetrahedron. There also exist H-bonds, π-π piling interactions and weak intermolecular contacts between the NO groups which form a mutual stagger 3-D network configuration. Magnetic investigation reveals that there exists intermolecular antiferro- and ferromagnetic interactions in the title complex.

  20. New insights into cinchonine-aluminium complexes and their application as chiral building blocks: unprecedented ligand-exchange processes in the presence of ZnR2 compounds.

    Kaczorowski, Tomasz; Justyniak, Iwona; Prochowicz, Daniel; Zelga, Karolina; Kornowicz, Arkadiusz; Lewiński, Janusz


    Previous studies have demonstrated that [(CN)(2)AlCl] and [R(2)Al(μ-CN)](2) (CN=deprotonated cinchonine) complexes can effectively act as chiral, semirigid, N,N-ditopic metalloligands for Zn-containing nodes, and provide viable means for constructing new, homochiral, heterometallic, coordination polymers of zigzag and helical topologies. These findings have prompted further investigations on the organometallic analogues of the formula [(CN)(2)AlR], anticipating their utility as N,N-metalloligands for ZnR(2) units. Surprisingly, reactions of [(CN)(2)AlMe]-type metalloligands with ZnR(2) compounds (R=Me or Et) revealed unprecedented ligand-exchange processes, including zinc-to-aluminium and aluminium-to-zinc transmetalations of alkyl groups. The molecular and crystal structure of the resulting compounds was determined by X-ray diffraction analysis. From the reaction of [(CN)(2)AlMe] with ZnMe(2) a new pseudopolymorphic form of a noncovalent porous material based on [Me(2)Al(μ-CN)](2) molecules was isolated. Strikingly, the analogous reaction involving ZnEt(2) led to the generation of a new chiral 4N-tetratopic heterometalloligand [(CN)EtAl(μ-CN)(2)ZnEt]. The latter unit was successfully connected by alkyl-exchanged ZnMe(2) nodes to give an original homochiral heterometallic {[(CN)EtAl(μ-CN)(2)ZnEt]ZnMe(2)}(n) coordination polymer adopting a snake 1D motif. The outcome of the revealed reactions indicates the complicated multistep reaction route that involves redistribution of cinchonine and alkyl ligands among the Al and Zn centers, and a general reaction scheme is proposed. The results are in strong contrast with the previously studied inorganic-organic [(CN)(2)AlCl/ZnCl(2)] system, which exclusively affords a helical coordination polymer based on ZnCl(2) nodes and (CN)(2)AlCl metalloligands and lacks the exchange of CN ligands. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Infrared absorption on a complex comprising three equivalent hydrogen atoms in ZnO

    Herklotz, F.; Hupfer, A.; Johansen, K. M.; Svensson, B. G.; Koch, S. G.; Lavrov, E. V.


    A hydrogen-related defect in ZnO which causes two broad IR absorption bands at 3303 and 3321 cm-1 is studied by means of infrared absorption spectroscopy and first-principles theory. In deuterated samples, the defect reveals two sharp absorption lines at 2466 and 2488 cm-1 accompanied by weaker sidebands at 2462 and 2480 cm-1. Isotope substitution experiments with varying concentrations of H and D together with polarization-sensitive measurements strongly suggest that these IR absorption lines are due to stretch local vibrational modes of a defect comprising three equivalent hydrogen atoms. The zinc vacancy decorated by three hydrogen atoms, VZnH3 , and ammonia trapped at the zinc vacancy, (NH3)Zn, are discussed as a possible origin for the complex.

  2. Heteroleptic complexes of Zn(II) based on 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide: Synthesis, structural characterization, theoretical studies and antibacterial activity

    Azarkish, Mohammad; Akbari, Alireza; Sedaghat, Tahereh; Simpson, Jim


    Four new ternary complexes, [ZnL (2,2‧-bipy)] (1), Zn2L2(4,4‧-bipy)] (2), [ZnL(Imd)]·H2O (3) and [ZnL3(MeImd)] (4), have been synthesized from the reaction of Zn(II) acetate with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H2L) in the presence of a heterocyclic base, 2,2‧-bipyridine, 4,4‧-bipyridine, imidazole or 2-methylimidazole, as an auxiliary ligand. The complexes have been investigated by elemental analysis and FT-IR, UV-Vis and 1HNMR spectroscopy. These data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination sphere was completed by the nitrogen atom(s) of the secondary ligand. The structure of 1 was also confirmed by X-ray crystallography and shown to be a five coordinate complex with coordination geometry between the square-pyramidal and trigonal-bipyramidal. Density functional theory (DFT) calculations including geometry optimization, vibrational frequencies and electronic absorptions have been performed for 1 with the B3LYP functional at the TZP(6-311G*) basis set using the Gaussian 03 or ADF 2009 packages. The optimization calculation showed that the crystallographically determined geometry parameters can be reproduced with that basis set. Experimental IR frequencies and calculated vibration frequencies also support each other. The in vitro antibacterial activities of the ligand and complexes have been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and compared with the standard antibacterial drugs. The results reveal that all of the complexes show much better activity in comparison to the individual thiosemoicarbazone ligand (H2L), against all bacterial strains used, with complex 3 showing the most promising results.

  3. QTAIM investigation of bis(pyrazol-1-ylmethane derivative and its Zn(II complexes (ZnLX2, X=Cl, Br or I

    Dehestani Maryam


    Full Text Available Topological analyses of the electron density using the quantum theory of atoms in molecules (QTAIM have been carried out at the B3PW91/6-31g (d theoretical level, on bis(pyrazol-1-ylmethanes derivatives 9-(4-(di (1H-pyrazol-1-yl-methylphenyl-9H-carbazole (L and its zinc(II complexes: ZnLCl2 (1, ZnLBr2 (2 and ZnLI2 (3. The topological parameters derived from Bader theory were also analyzed; these are characteristics of Zn-bond critical points and also of ring critical points. The calculated structural parameters are the frontier molecular orbital energies highest occupied molecular orbital energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, hardness (η, softness (S, the absolute electronegativity (χ, the electrophilicity index (ω and the fractions of electrons transferred (ΔN from ZnLX2 complexes to L. The numerous correlations and dependencies between energy terms of the Symmetry Adapted Perturbation Theory approach (SAPT, geometrical, topological and energetic parameters were detected and described.

  4. Co (II and Zn (II Metal Complexes of Heterocyclic Schiff Bases: A Synthesis, Spectral and Antimicrobial Study

    Sachin R. Joshi


    Full Text Available The Schiff bases have been synthesised by the reaction of Benzoinoxime primary ligand with heterocyclic compounds such as 2-aminothiazole (SL1 and 8-hydroxyquinoline (SL2 to form the secondary ligand, which than react with the metal halides to form complexes of Co (II and Zn (II. The elemental analysis data shows that the metal to ligand ratio in all Co (II simple is 1:2 for simple complexes and 1:2:2 for metal complex with oxime as a primary ligand and SL1 as a secondary ligand while it is 1:2:1 for metal complex with oxime as a primary ligand and SL3 as a secondary ligand whereas Zn (II complexes of mixed ligand exhibit the stoichiometry 1:2:2. The structural features have been determined from IR, UV-Vis, and XRD data. All the complex shows a distorted octahedral geometry to mononuclear Co (II complexes of mixed ligands, while square planner geometry to mononuclear Co (II complexes of oximes. Zn (II complexes of mixed ligands shows a distorted octahedral geometry, while square planner geometry to mononuclear Zn (II complexes of oximes. All the synthesised compounds were screened for antimicrobial activity.

  5. Synthesis and Fluorescence Properties of Europium, Terbium Doped Zn2+, Cd2+ and Cr3+ Complexes


    Europium and terbium complexes with strong fluorescence intensity and long fluorescence lifetime were prepared.By replacing half of the europium or terbium ion with M (M=Zn2+, Cd2+, and Cr3+) using the doped method, and then incorporating it with 18-crown-6 ether and terephthalic acid, six heteronuclear samples EuZnLL'Cl3·3H2O(1), EuCdLL2'Cl3·5H2O(2), EuCrLL'Cl4·4H2O(3), TbZnLL'Cl3·4H2O(4), TbCdLL'2Cl3·4H2O(5), and TbCrLL'2Cl4·4H2O(6) (L=terephthalic acid, L'=18-Crown-6 ether) were obtained.The elemental analysis, molar conductivities, rare earth complexometry, Fourier Transform Infrared Spectroscopy (FT-IR), ultraviolet (UV), TGA, fluorescence intensity, and fluorescence lifetime of the samples were measured.The results showed that there were good luminescence properties for heteronuclear complexes (1), (2), (4), and (5), which were even stronger than those of the homonuclear complexes Eu2LL'2Cl4·4H2O and Tb2LL'2Cl4·4H2O, but the luminescence properties of EuCrLL'Cl4·4H2O, TbCrLL'Cl4·4H2O were very weak.A possible luminescence mechanism was suggested by the organic-inorganic doped mechanism and the law of intramolecular energy transfer.

  6. Momentum relation and classical limit in the future-not-included complex action theory

    Nagao, Keiichi


    Studying the time development of the expectation value in the future-not-included complex action theory we point out that the momentum relation (relation analogous to $p=\\frac{\\partial L}{\\partial \\dot{q}}$), which was derived via Feynman path integral and was shown to be right in the future-included theory in our previous papers, is not valid in the future-not-included theory. We provide the correct momentum relation in the future-not-included theory, and argue that the future-not-included classical theory is described by a certain real action. In addition we provide another way to understand the time development of the future-not-included theory by utilizing the future-included theory. Furthermore, applying the method used in our previous paper to the future-not-included theory properly by introducing a formal Lagrangian, we derive the correct momentum relation in the future-not-included theory.

  7. Momentum relation and classical limit in the future-not-included complex action theory

    Nagao, Keiichi; Nielsen, Holger Bech


    Studying the time development of the expectation value in the future-not-included complex action theory, we point out that the momentum relation (the relation analogous to p=frac {partial L}{partial dot {q}}), which was derived via the Feynman path integral and was shown to be correct in the future-included theory in our previous papers, is not valid in the future-not-included theory. We provide the correct momentum relation in the future-not-included theory, and argue that the future-not-included classical theory is described by a certain real action. In addition, we provide another way to understand the time development of the future-not-included theory by utilizing the future-included theory. Furthermore, properly applying the method used in our previous paper to the future-not-included theory by introducing a formal Lagrangian, we derive the correct momentum relation in the future-not-included theory.

  8. Fe-tannic acid complex dye as photo sensitizer for different morphological ZnO based DSSCs

    Çakar, Soner; Özacar, Mahmut


    In this paper we have synthesized different morphological ZnO nanostructures via microwave hydrothermal methods at low temperature within a short time. We described different morphologies of ZnO at different Zn(NO3)2/KOH mole ratio. The ZnO nanostructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV-vis spectrophotometry. All ZnO structures have hexagonal wurtzite type structures. The FESEM images showed various morphologies of ZnO such as plate, rod and nanoparticles. Dye sensitized solar cells have been assembled by these different morphological structures photo electrode and tannic acid or Fe-tannic acid complex dye as sensitizer. We have achieved at maximum efficiencies of photovoltaic cells prepared with ZnO plate in all dye systems. The conversion efficiencies of dye sensitized solar cells are 0.37% and 1.00% with tannic acid and Fe-tannic acid complex dye, respectively.

  9. Decomposição térmica de complexos de Zn e Cd com isomaleonitriladitiolato (imnt Thermal decomposition of Zn and Cd complexes with isomaleonitriledithiolate (imnt

    Cristiane M. L. Barbosa


    Full Text Available Thermal decomposition of [Bu4N]2[Zn(imnt2] and [M(NH32(imnt] complexes with M = Zn and Cd, and imnt = (bis 1,1-dicyanoethylene-2,2 dithiolate in inert atmosphere was investigated by thermogravimetric analysis (TG and differential scanning calorimetry (DSC. Pyrolysis studies at different temperatures, 300, 400, 500, and 600 ºC, in N2 atmosphere were performed and the products were characterized by X-ray diffraction (XRD, infrared and Raman spectroscopy, and scanning electron microscopy (SEM. The products were identified as sulfide sub-micron particles, along with amorphous carbon. Particle sizes estimated by SEM were ca. 50 nm for the cationic complexes and 500 nm for the neutral complexes.

  10. Novel Zinc(II) Complexes [Zn(atc-Et)2] and [Zn(atc-Ph)2]: In Vitro and in Vivo Antiproliferative Studies

    Lopes, Erica de O.; de Oliveira, Carolina G.; da Silva, Patricia B.; Eismann, Carlos E.; Suárez, Carlos A.; Menegário, Amauri A.; Leite, Clarice Q. F.; Deflon, Victor M.; Pavan, Fernando R.


    Cisplatin and its derivatives are the main metallodrugs used in cancer therapy. However, low selectivity, toxicity and drug resistance are associated with their use. The zinc(II) (ZnII) thiosemicarbazone complexes [Zn(atc-Et)2] (1) and [Zn(atc-Ph)2] (2) (atc-R: monovalent anion of 2-acetylpyridine N4-R-thiosemicarbazone) were synthesized and fully characterized in the solid state and in solution via elemental analysis, Fourier transform infrared (FTIR), ultraviolet-visible (UV-Vis) and proton nuclear magnetic resonance (1H NMR) spectroscopy, conductometry and single-crystal X-ray diffraction. The cytotoxicity of these complexes was evaluated in the HepG2, HeLa, MDA-MB-231, K-562, DU 145 and MRC-5 cancer cell lines. The strongest antiproliferative results were observed in MDA-MB-231 and HepG2 cells, in which these complexes displayed significant selective toxicity (3.1 and 3.6, respectively) compared with their effects on normal MRC-5 cells. In vivo studies were performed using an alternative model (Artemia salina L.) to assure the safety of these complexes, and the results were confirmed using a conventional model (BALB/c mice). Finally, tests of oral bioavailability showed maximum plasma concentrations of 3029.50 µg/L and 1191.95 µg/L for complexes 1 and 2, respectively. According to all obtained results, both compounds could be considered as prospective antiproliferative agents that warrant further research. PMID:27213368

  11. Marfan syndrome with a complex chromosomal rearrangement including deletion of the FBN1 gene

    Colovati Mileny ES


    Full Text Available Abstract Background The majority of Marfan syndrome (MFS cases is caused by mutations in the fibrillin-1 gene (FBN1, mapped to chromosome 15q21.1. Only few reports on deletions including the whole FBN1 gene, detected by molecular cytogenetic techniques, were found in literature. Results We report here on a female patient with clinical symptoms of the MFS spectrum plus craniostenosis, hypothyroidism and intellectual deficiency who presents a 1.9 Mb deletion, including the FBN1 gene and a complex rearrangement with eight breakpoints involving chromosomes 6, 12 and 15. Discussion This is the first report of MFS with a complex chromosome rearrangement involving a deletion of FBN1 and contiguous genes. In addition to the typical clinical findings of the Marfan syndrome due to FBN1 gene haploinsufficiency, the patient presents features which may be due to the other gene deletions and possibly to the complex chromosome rearrangement.

  12. Probing the orientations of coordination complex molecules onto the surface of ZnO nanoparticles by means of surface enhanced Raman scattering, UV–vis and DFT methods

    Prakash, Om; Gautam, Priyanka; Singh, Ranjan K., E-mail:


    Graphical abstract: - Highlights: • The adsorption geometry of three complex molecules onto the surface of ZnO nanoparticles is investigated by Raman, SERS and UV–vis techniques. • All the three complex molecules are adsorbed in flat-on geometry. • On the adsorption onto the ZnO NPs, the fluorescence background of Raman spectra of Zn complex is quenched. - Abstract: The surface enhanced Raman scattering (SERS) is a highly surface sensitive technique to study inter-surface properties of biological, organic, and inorganic materials. It is a precise technique to determine the adsorption geometry/orientation of the molecules as the intensity enhancement of the SERS bands depends on the adsorption geometry/orientation of molecules on SERS substrate. In the present work, Ni, Cu and Zn complexes of (Z)-N′(1,3,4-thiadiazol-2-yl) acetimidate were synthesized and adsorbed on ZnO nanoparticles. The surface enhanced Raman scattering (SERS), UV–vis and DFT techniques were applied to investigate the possible adsorption geometries of the complexes on ZnO. Consequently, it was found that the orientation of all three complex molecules is flat-on onto the surface of ZnO nanoparticles. The fluorescence background of Raman spectra of Zn complex is quenched and its geometry is isomerized after the adsorption onto the surface of ZnO nanoparticles. The adsorbed Cu complex on ZnO NPs absorbed UV radiations efficiently.

  13. Interaction of Bis-Zn(II) salphen complex with calf thymus-DNA

    Yussof, Aida Mastura Binti Mohd; Karim, Nurul Huda Abd


    Metal salphen family has been extensively studied over the past few years and has been reported to be good DNA stabilizers due to its high binding affinity. Binding studies of metal complex with DNA are useful for understanding the interaction mechanism and to provide an insight about the application and design of a novel effective drug target to DNA. In this study, a bis-zinc (II) salphen metal complex derived from 4-methyl-2,6-diformylphenol and 1,2-diaminobenzene (H2L) via condensation reactions has been synthesised. The zinc(II) macrocyclic complex is characterised using standard spectroscopic and structural techniques such as 1H NMR spectroscopy and FTIR spectroscopy. The binding interaction between the synthesised metal complex with calf thymus-DNA (ct-DNA) has been investigated by preliminary UV/Vis DNA study. From the preliminary UV/Vis DNA study, it shows that Bis-Zn(II) salphen complex has interaction with ct-DNA.

  14. Photodynamic therapy of choroidal neovascularization with enlargement of the spot size to include the feeding complex

    Ilias Georgalas


    Full Text Available Ilias Georgalas, Alexandros A Rouvas, Dimitrios A Karagiannis, Athanasios I Kotsolis, Ioannis D LadasDepartment of Ophthalmology, Medical School of Athens University, Athens, GreeceAbstract: This is a case report of a 83-year-old man with choroidal neovascularization (CNV, due to age-related macular degeneration (AMD in his right eye. Digital fluorescein (FA and indocyanine green angiography (ICG were performed, which disclosed predominantly classic subfoveal CNV and a dilated and tortuous feeding complex. The visual acuity was 20/800. Anti-vascular endothelial growth factor (anti-VEGF treatment was suggested, however, the patient was not keen to receive an intraocular injection. Modified photodynamic therapy (PDT with spot size enlarged, to include not only the CNV lesion but the feeding complex as well, was performed. Ten days after one session of PDT, ICG showed absence of leakage from the CNV and complete occlusion of the feeding complex. The visual acuity gradually improved to 20/100 and remained stable during the following 23 months. No evidence of CNV leakage was seen in the FA and ICG during the follow up period. Adjustment of the PDT spot size to include the detectable by ICG feeding complex might be an additional option in order to close the subfoveal CNV and might be considered as an alternative to intravitreal injection of anti-VEGF in selected cases where anti-VEGF treatment is not available.Keywords: age-related macular degeneration, choroidal neovascularization, photodynamic treatment, feeder vessel

  15. Emission solvatochromic behavior of a pentacoordinated Zn(II) complex: A viable tool for studying the metallodrug–protein interaction

    Ricciardi, Loredana, E-mail: [Department of Chemistry and Chemical Technology, University of Calabria, I-87036 Rende (CS) (Italy); Centre of Excellence “Functional Nanostructured Materials” CEMIF.CAL, LASCAMM and CR INSTM, INSTM Calabria Unit, and CNR-IPCF-UOS Cosenza - Licryl Laboratory, I-87036 Rende (CS) (Italy); Pucci, Daniela; Pirillo, Sante; La Deda, Massimo [Department of Chemistry and Chemical Technology, University of Calabria, I-87036 Rende (CS) (Italy); Centre of Excellence “Functional Nanostructured Materials” CEMIF.CAL, LASCAMM and CR INSTM, INSTM Calabria Unit, and CNR-IPCF-UOS Cosenza - Licryl Laboratory, I-87036 Rende (CS) (Italy)


    A metal complex with antitumoral activity, Zn(Curcumin)(bypiridine)Cl, was characterized from a photophysical point of view, showing a green emission and a positive solvatochromism. These characteristics can be conveniently used to study its interaction with Human Serum Albumin (HSA), a protein carrier of many non-aqueous biologically-active compounds in the blood stream. The intrinsic fluorescence of HSA was quenched by Fluorescence Resonance Energy Transfer toward the Zn(II) complex, and the Stern–Volmer equation was applied to determine the bimolecular quenching rate constant of the interaction. - Highlights: • Albumin binding information is a key characteristic of drug pharmacology. • Fluorescence spectroscopy offers a simple method for revealing drug–protein interaction. • The fluorescence of the Zn(II) complex and its solvatochromisms has allowed studying the binding from a dual perspective.


    Ticuţa Negreanu-Pîrjol


    Full Text Available In this paper we report the synthesis, physical-chemical characterization and antimicrobial activity of some new complex compounds of hetero-aromatic biguanides ligands, chlorhexidine base (CHX and chlorhexidine diacetate (CHXac2 with metallic ions Cu(II and Zn(II, in different molar ratio. The synthesized complexes were characterized by elemental chemical analysis and differential thermal analysis. The stereochemistry of the metallic ions was determined by infrared spectra, UV-Vis, EPR spectroscopy and magnetic susceptibility in the aim to establish the complexes structures. The biological activity of the new complex compounds was identified in solid technique by measuring minimum inhibition diameter of bacterial and fungal culture, against three standard pathogen strains, Escherichia coli ATCC 25922, Staphilococcus aureus ATCC 25923 and Candida albicans ATCC 10231. The results show an increased specific antimicrobial activity for the complexes chlorhexidine:Cu(II 1:1 and 1:2 compared with the one of the Zn(II complexes.

  17. Mass spectrometry and potentiometry studies of Pb(II)-, Cd(II)- and Zn(II)-cystine complexes.

    Furia, Emilia; Aiello, Donatella; Di Donna, Leonardo; Mazzotti, Fabio; Tagarelli, Antonio; Thangavel, Hariprasad; Napoli, Anna; Sindona, Giovanni


    Cd(II)-, Pb(II)- and Zn(II)-cystine complexes were investigated by potentiometric and different mass spectrometric (MS) methodologies. Laser desorption mass spectrometry has provided both the composition and structure of metal-cystine complexes according to the speciation models proposed on the basis of the potentiometric data. Detection of neutral complexes was achieved by protonation or electrochemical reduction during mass spectrometric experiments. The redox activity of metal-cystine complexes was confirmed by laser desorption and charge transfer matrix assisted laser assisted MS experiments, which allowed us to observe the formation of complexes with a reduction of cystine. The stoichiometry of Cd(II)-, Pb(II)- and Zn(II)-cystine complexes was defined by observing the isotopic pattern of the investigated compound. The results suggest that interaction occurs through the carboxylate group of the ligand.

  18. Temperature and dose dependence of defect complex formation with ion implanted Mn/Fe in ZnO

    Mølholt, T E; Gunnlaugsson, H P; Bharuth-Ram, K; Fanciulli, M; Gíslason, H P; Johnston, K; Kobayashi, Y; Langouche, G; Masenda, H; Naidoo, D; Ólafsson, S; Sielemann, R; Weyer, G


    57Fe Mössbauer spectroscopy following ion implantation of radioactive 57Mn+ ( T1/2=85.4 s) has been applied to study the formation of Fe/Mn implantation-induced defects in ZnO at temperatures between 319 and 390 K. The formation of ferric iron–vacancy complexes is found to depend strongly on the implanted dose and to be faster and more efficient at higher temperatures. The results at these temperatures suggest the mobility of the Zn vacancy, together with vacancy trapping at the substitutional Mn/Fe impurities are responsible for the formation of Fe–VZn complexes

  19. Synthesis of ZnWo{sub 4} nanopowders by polymerized complex method

    Ryu, J.H. [Hanyang University, Seoul (Korea); Lim, C.S. [Hanseo University, Seosan (Korea); Auh, K.H. [Hanyang University, Seoul (Korea)


    ZnWO{sub 4} nano-powders were successfully prepared by polymerized complex method using zine nitrate and tungstic acid as starting materials. in order to investigate the thermal decomposition and crystallization process, the polymeric precursors were heat-treated at temperatures from 300 to 600 deg. C for 3 h, and the heat-treated powders were characterized by XRD and FTIR. The surface morphology of the heat-treated powders were observed using SEM and TEM. The crystallite size was measured by X-ray analysis. Crystallization of the ZnWO{sub 4} powders were detected at 400 deg. C and entirely completed at a temperature of 600 deg. C. The particles heat-treated at 400 and 500 deg. C showed primarily co-mixed morphology with spherical and silkworm-like forms, while the particles heat-treated at 600 deg. C showed more homogeneous morphology. The average crystalline were 19.9{approx}24.2 nm showing an ordinary tendency to increase with the temperatures from 400 to 600 deg. C. (author). 14 refs., 1 tab., 7 figs.

  20. Including inputs and control within equation-free architectures for complex systems

    Proctor, Joshua L.; Brunton, Steven L.; Kutz, J. Nathan


    The increasing ubiquity of complex systems that require control is a challenge for existing methodologies in characterization and controller design when the system is high-dimensional, nonlinear, and without physics-based governing equations. We review standard model reduction techniques such as Proper Orthogonal Decomposition (POD) with Galerkin projection and Balanced POD (BPOD). Further, we discuss the link between these equation-based methods and recently developed equation-free methods such as the Dynamic Mode Decomposition and Koopman operator theory. These data-driven methods can mitigate the challenge of not having a well-characterized set of governing equations. We illustrate that this equation-free approach that is being applied to measurement data from complex systems can be extended to include inputs and control. Three specific research examples are presented that extend current equation-free architectures toward the characterization and control of complex systems. These examples motivate a potentially revolutionary shift in the characterization of complex systems and subsequent design of objective-based controllers for data-driven models.

  1. Characterization and performance of Cu/ZnO/Al2O3 catalysts prepared via decomposition of M(Cu,Zn)-ammonia complexes under sub-atmospheric pressure for methanol synthesis from H2 and CO2

    Danjun Wang; Jun Zhao; Huanling Song; Lingjun Chou


    Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M(Cu,Zn)-ammonia complexes (DMAC) at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol (212 g/(Lcat·h); T =513 K,p =3 MPa,S V =12000 h-1).

  2. Trace analysis of cefotaxime at carbon paste electrode modified with novel Schiff base Zn(II) complex.

    Nigam, Preeti; Mohan, Swati; Kundu, Subir; Prakash, Rajiv


    Cefotaxime a third generation cephalosporin drug estimation in nanomolar concentration range is demonstrated for the first time in aqueous and human blood samples using novel Schiff base octahedral Zn(II) complex. The cefotaxime electrochemistry is studied over graphite paste and Zn(II) complex modified graphite paste capillary electrodes in H(2)SO(4) (pH 2.3) using cyclic voltammetry and differential pulse voltammetry. Cefotaxime enrichment is observed over Zn(II) complex modified graphite paste electrode probably due to interaction of functional groups of cefotaxime with Zn(II) complex. Possible interactions between metal complex and cefotaxime drug is examined by UV-vis and electrochemical quartz crystal microbalance (EQCM) techniques and further supported by voltammetric analysis. Differential pulse voltammetry (DPV) with modified electrode is applied for the determination of cefotaxime in acidified aqueous and blood samples. Cefotaxime estimation is successfully demonstrated in the range of 1-500 nM for aqueous samples and 0.1-100 microM in human blood samples. Reproducibility, accuracy and repeatability of the method are checked by triplicate reading for large number of samples. The variation in the measurements is obtained less than 10% without any interference of electrolyte or blood constituents.

  3. Uniaxial stress study of the Cu-H complex in ZnO

    Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden, 01062 Dresden (Germany)


    The influence of uniaxial stress on the vibrational mode of the Cu-H complex at 3192 cm{sup -1} in ZnO is studied. It is shown that the split patterns are consistent with the stretching mode of a bond-centered hydrogen located in the basal plane between substitutional Cu and O. Quantitative analysis of the stress effects reveals two low energy modes with frequencies of 25 and 49 cm{sup -1}. Upon substituting deuterium for hydrogen they shift to 22 and 36 cm{sup -1}, respectively. The origin of the low energy modes is discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Synthesis and characterization of ZnO nanoparticles by thermal decomposition of a curcumin zinc complex

    Mutasim I. Khalil


    Full Text Available ZnO nanoparticles were generated by thermal decomposition of a binuclear zinc (II curcumin complex as single source precursor. Thermal behavior of the precursor showed a considerable weight loss at about 374 °C by an exothermic reaction with a maximum weight loss rate of 14%/min. Complete decomposition of precursor was observed within 49 min with a heating rate of 10 °C/min. Synthesized nanoparticles have been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and selected area electron diffraction microscopy. Results revealed monodispersed hexagonal zincite structure with an average size of 117 ± 4 nm.

  5. Synthesis and characterization of polymeric azido Zn(II) and Ni(II) complexes based on 3-hydroxypyridine

    Mautner, Franz A.; Berger, Christian; Domian, Elisabeth; Fischer, Roland C.; Massoud, Salah S.


    The synthesis and structural characterization of two new complexes catena-[Ni(3-O-py)(3-HO-py)2(μ1,3-N3)(H2O)] (1) and catena-[Zn(μ-3-O-py)(μ1,1-N3)] (2), where 3-HO-py = 3-hydroxypyridine, are reported. The complexes were characterized by the elemental microanalyses, IR, and X-ray crystallography and by UV-Vis spectroscopy for complex 1. Single crystal X-ray crystallography revealed the polymeric nature of the complexes: 1 as 1D with a single EE azide bridging, and 2 as 2D with μ(O,O‧,N) bridging of the deprotonated 3-O-py anions and di-EO azide groups, respectively. In 1 the neutral and deprotonated 3-hydroxypyridine molecules act only as N-terminal ligands. The emission spectral properties of the Zn(II) complex were investigated.

  6. Synthesis of novel binary and ternary Zn2+ complexes with putrescine and phosphocreatine and the metal complexes study in aqueous solution

    Szyfman, Natalie Waissmann; Tenório, Thaís; Ribeiro, Tatiana S.; Felcman, Judith; Mercê, Ana Lucia Ramalho


    Binary and ternary systems of Zn2+ complexes with phosphocreatine (PCr) and putrescine (Put) were investigated in aqueous solution using potentiometric titrations, Raman spectroscopy, Nuclear Magnetic Resonance (1H NMR) and molecular modeling. The stability constants of the complexes and molecular adducts, determined by potentiometry (T = 25.0 °C, I = 0.100 mol L-1, KNO3), are for some of the calculated complexes log KZnPCr = 10.63 ± 0.03, log KZnPut = 5.22 ± 0.08 and for log KZnPCrPut = 16.56 ± 0.02. PCr acts as a bidentate ligand and Put as a monodentate ligand until around pH 11. The Raman and 1H NMR spectra and minimum total molecular energies calculations confirm the coordination modes of all systems. The ternary species are suggested by the values of the stability constants found as, when compared to those of the binary complexes with each ligand, they are neither the sum of the two or a value less than each one separately complexed with Zn2+. An intermolecular interaction was suggested for the ZnPCrPut species. However, for ZnPCrPutH species it was not possible to establish the same kind of interaction due to the long distance between the carboxylate group of phosphocreatine and the NH3+ group of Put.

  7. An amide based dipodal Zn{sup 2+} complex for multications recognition: Nanomolar detection

    Fegade, Umesh [School of Chemical Sciences, North Maharashtra University, Jalgaon 425001, Maharashtra (India); School of Environmental and Earth Sciences, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Sharma, Hemant; Singh, Narinder [Department of Chemistry, Indian Institute of Technology, Ropar, Rupanagar, Punjab (India); Ingle, Sopan; Attarde, Sanjay [School of Environmental and Earth Sciences, North Maharashtra University, Jalgaon 425001, Maharashtra (India); Kuwar, Anil, E-mail: [School of Chemical Sciences, North Maharashtra University, Jalgaon 425001, Maharashtra (India)


    An imine-linked dipodal Zn{sup 2+} complex has been synthesized and elevated its binding affinity towards library of metal ions (Cr{sup 3+}, Mn{sup 2+}, Fe{sup 3+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Cd{sup 2+}, Hg{sup 2+}, Pb{sup 2+} and Bi{sup 3+}). The recognition properties of receptor 4 were performed in DMSO/H{sub 2}O (50:50; v/v) and showed quenching upon interaction with Fe{sup 3+}, Co{sup 2+} and Cu{sup 2+} ions. A photoinduced electron transfer (PET) is potential mechanism behind quenching. The coordination of such cations with the receptor 4 at amide part of carbonyl oxygen hindered the PET process and accordingly Turn-OFF the fluorescence of the receptor 4. The photophysical properties (fluorescence and absorption spectra) and density functional theory (DFT) clearly explains the binding mode between the receptor 4 and the detected cations. The selectivity and sensitivity of the receptor 4 for Fe{sup 3+}, Co{sup 2+} and Cu{sup 2+} ions were acceptable and achieving a detection limit at the nano-molar level. - Highlights: • Zinc chemosensor Schiff base complex bearing carbonyl moieties was constructed through the selective assembly of a chemosensor. • Fluorescence spectra and density functional theory (DFT) clearly explains the binding mode between the receptor 4 and cations. • The 1:1 stoichiometry of the host guest relationship was realized from the Job's plot. • The selectivity and sensitivity of the receptor 4 for Fe{sup 3+}, Co{sup 2+} and Cu{sup 2+} ions were acceptable and achieving a detection limit at the nanomolar level.

  8. Tuning the activity of Zn(II) complexes in DNA cleavage: clues for design of new efficient metallo-hydrolases.

    Bazzicalupi, Carla; Bencini, Andrea; Bonaccini, Claudia; Giorgi, Claudia; Gratteri, Paola; Moro, Stefano; Palumbo, Manlio; Simionato, Alessandro; Sgrignani, Jacopo; Sissi, Claudia; Valtancoli, Barbara


    The hydrolytic ability toward plasmid DNA of a mononuclear and a binuclear Zn(II) complex with two macrocyclic ligands, containing respectively a phenanthroline (L1) and a dipyridine moiety (L2), was analyzed at different pH values and compared with their activity in bis( p-nitrophenyl)phosphate (BNPP) cleavage. Only the most nucleophilic species [ZnL1(OH)]+ and [Zn2L2(OH)2]2+, present in solution at alkaline pH values, are active in BNPP cleavage, and the dinuclear L2 complex is remarkably more active than the mononuclear L1 one. Circular dichroism and unwinding experiments show that both complexes interact with DNA in a nonintercalative mode. Experiments with supercoiled plasmid DNA show that both complexes can cleave DNA at neutral pH, where the L1 and L2 complexes display a similar reactivity. Conversely, the pH-dependence of their cleavage ability is remarkably different. The reactivity of the mononuclear complex, in fact, decreases with pH while that of the dinuclear one is enhanced at alkaline pH values. The efficiency of the two complexes in DNA cleavage at different pH values was elucidated by means of a quantum mechanics/molecular mechanics (QM/MM) study on the adducts between DNA and the different complexed species present in solution.

  9. Antibacterial Properties of a Kind of Schiff Base and Its Neodymium(Ⅲ)and Zn(Ⅱ)Complex(ZnNdL)on Escherichia coli

    LI Chaohong; ZHU Juncheng; QI Zude; HOU Hanna; HU Yanjun; LIU Yi


    The microcalorimetric and electronic microscopy methods were used to study the antibacterial activity of a Schiff base and its complex ZnNdL on Escherichia coil The metabolic power-time curves of the bacteria treated with the compounds were obtained,and the thermokinetic parameters were analyzed.The results show that the compounds(H2L,ZnNdL)have good activity on aerobic multiplying metabolism of E.coli,with the values of IC50 tronic microscopy and scanning electronic micrography were used to study the cell membrane change induced by the dibasic quadridentate Schiff base and its neodymium(Ⅲ)complex.At a low concentration of the compound,the flagellum was inhibited and the cell did not show distinct changes.However,the flagella around the cell membrane were exfoliated,the morphology of E.coli was changed from a rod shape into a spherical shape or a short rod,and the flagella disappeared completely at a high concentration.The drug permeability into cell membrane was investigated by fluorescence quenching of probe dis-C3-(5),which suggested that H2L and ZnNdL could influence on the intra and extra cell membrane.

  10. Synthesis and Crystal Structure of a New Zn(II) Nitronyl Nitroxide Complex [Zn(NIT4Py)(PDA)(H2O)3

    GAO Dong-Zhao; WANG Shu-Ping; CHEN Jin; LI Li-Cun; LIAO Dai-Zheng; JIANG Zong-Hui; YAN Shi-Ping


    A new Zn(II) nitronyl nitroxide complex [Zn(NIT4Py)(PDA)(H2O)3] (NIT4Py = 2-(4'-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, H2PDA = pyridine-2,5-dicarboxylic acid) has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 16.881(8), b = 7.356(4), c = 18.857(9)(A), β= 108.616(6)°, V = 2219.1(19)(A)3, C19H25N4O9Zn, Mr = 518.80, Dc = 1.553 g/cm3, μ(MoKα) = 1.165 mm-1, F(000) = 1076, Z = 4, the final R = 0.0269 and wR = 0.0715 for 3193 observed reflections with I > 2σ(I). The complex exists as discrete mononuclear molecules and the zinc(II) ion is six-coordinated with one radical ligand (NIT4Py), one bidentate pyridine-2,5-dicarboxylate anion and three water molecules. A three-dimensional network structure is formed through the intermolecular interactions.

  11. IRMPD spectroscopic investigation of gas-phase complexes of deprotonated penicillin G with Ba(2+), Zn(2+) and Cd(2+)

    Dunbar, R. C.; Oomens, J.; Orlova, G.; Bohme, D. K.


    The bare deprotonated penicillin G. and its complexes with the Ba(2+), Zn(2+) and Cd(2+) ions, have been formed by electrospray ionization and studied by IRMPD (infrared multiple photon dissociation) spectroscopy using FT-ICR (Fourier-transform ion cyclotron resonance) mass spectrometry with the FEL

  12. Zn (II and Cu (II Halide Complexes of Poly(propylene amine Dendrimer Analysed by Infrared and Raman Spectroscopies

    Ivo Grabchev


    Full Text Available Two nondestructive and complementary spectral methods as infrared and Raman spectroscopies have been used for characterizations of poly(propylene amine dendrimers comprising 1,8-naphthalimide units in the dendrimer periphery and their metal complexes with Cu2+ at Zn2+ ions.

  13. Photofunctional hybrids of rare earth complexes covalently bonded to ZnO core-shell nanoparticle substrate through polymer linkage.

    Shao, Yan-Fei; Yan, Bing


    A novel series of multi-component hybrids are assembled based on rare earth coordinated to rare earth ion (Eu(3+), Tb(3+), Sm(3+), Dy(3+)) complex systems and ZnO nanocomposites through three different ester units (ethyl methacrylate (EMA), 2-hydroxyethyl methacrylate (HEMA) and 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA)) as functional polymer linkages. Methacrylic-group-modified ZnO nanoparticles (designated ZnO-MAA) are synthesized based on the reaction between zinc methacrylate and LiOH with the molar ratio 1 : 3.5 via sol-gel process. The final hybrid materials are prepared by introducing rare earth complexes into ZnO-MAA matrix via addition polymerization reaction in the presence of benzoyl peroxide (BPO) as the initiator. The detailed characterization and luminescence of these hybrid materials are discussed. It is found that ZnO-MAA-HEMA/EMA/HFBMA-RE-phen hybrid systems have effective intramolecular energy transfer process and exhibit longer lifetime and higher quantum efficiency.

  14. Synthesis, Crystal Structure and Fluorescence Property of a Five- and Six-coordinated Trinuclear Zinc(II) Complex:{[ZnL(OAc)]2Zn}·CH3COCH3

    DONG,Wen-Kui; ZHANG,Yan-Ping; ZHAO,Chun-Yu; TANG,Xiao-Lu; L(U),Zhong-Wu; ZOU,Zheng


    A novel linear trinuclear zinc(II) complex, {[ZnL(OAc)]2Zn}·CH3COCH3 (H2L: ethylenedioxybis(5-bromo-2-hydroxybenzylideneamino)), has been synthesized and structurally characterized. X-ray crystal structure of the complex reveals that three zinc(II) ions are coordinated by two tetradentate L2- units and two acetate ions acting as bridging groups. The coordination geometry around the terminal Zn(1) or Zn(1)#1 atom approaches a distorted square pyramid. The coordination sphere of the central Zn(2) atom constitutes a slightly distorted octahedral geometry. The blue-green emission from the zinc(II) complex can be observed, where the maximum emission wavelength is at 464 nm.

  15. Accessory NUMM (NDUFS6) subunit harbors a Zn-binding site and is essential for biogenesis of mitochondrial complex I

    Kmita, Katarzyna; Wirth, Christophe; Warnau, Judith; Guerrero-Castillo, Sergio; Hunte, Carola; Hummer, Gerhard; Kaila, Ville R. I.; Zwicker, Klaus; Brandt, Ulrich; Zickermann, Volker


    Mitochondrial proton-pumping NADH:ubiquinone oxidoreductase (respiratory complex I) comprises more than 40 polypeptides and contains eight canonical FeS clusters. The integration of subunits and insertion of cofactors into the nascent complex is a complicated multistep process that is aided by assembly factors. We show that the accessory NUMM subunit of complex I (human NDUFS6) harbors a Zn-binding site and resolve its position by X-ray crystallography. Chromosomal deletion of the NUMM gene or mutation of Zn-binding residues blocked a late step of complex I assembly. An accumulating assembly intermediate lacked accessory subunit N7BM (NDUFA12), whereas a paralog of this subunit, the assembly factor N7BML (NDUFAF2), was found firmly bound instead. EPR spectroscopic analysis and metal content determination after chromatographic purification of the assembly intermediate showed that NUMM is required for insertion or stabilization of FeS cluster N4. PMID:25902503

  16. Effect of Ligand Substitution around the Dy(III) on the SMM Properties of Dual-Luminescent Zn-Dy and Zn-Dy-Zn Complexes with Large Anisotropy Energy Barriers: A Combined Theoretical and Experimental Magnetostructural Study.

    Costes, Jean Pierre; Titos-Padilla, Silvia; Oyarzabal, Itziar; Gupta, Tulika; Duhayon, Carine; Rajaraman, Gopalan; Colacio, Enrique


    The new dinuclear Zn(II)-Dy(III) and trinuclear Zn(II)-Dy(III)-Zn(II) complexes of formula [(LZnBrDy(ovan) (NO3)(H2O)](H2O)·0.5(MeOH) (1) and [(L(1)ZnBr)2Dy(MeOH)2](ClO4) (3) (L and L(1) are the dideprotonated forms of the N,N'-2,2-dimethylpropylenedi(3-methoxysalicylideneiminato and 2-{(E)-[(3-{[(2E,3E)-3-(hydroxyimino)butan-2-ylidene ]amino}-2,2-dimethylpropyl)imino]methyl}-6-methoxyphenol Schiff base compartmental ligands, respectively) have been prepared and magnetostructurally characterized. The X-ray structure of 1 indicates that the Dy(III) ion exhibits a DyO9 coordination sphere, which is made from four O atoms coming from the compartmental ligand (two methoxy terminal groups and two phenoxido bridging groups connecting Zn(II) and Dy(III) ions), other four atoms belonging to the chelating nitrato and ovanillin ligands, and the last one coming to the coordinated water molecule. The structure of 3 shows the central Dy(III) ion surrounded by two L(1)Zn units, so that the Dy(III) and Zn(II) ions are linked by phenoxido/oximato bridging groups. The Dy ion is eight-coordinated by the six O atoms afforded by two L(1) ligands and two O atoms coming from two methanol molecules. Alternating current (AC) dynamic magnetic measurements of 1, 3, and the previously reported dinuclear [LZnClDy(thd)2] (2) complex (where thd = 2,2,6,6-tetramethyl-3,5-heptanedionato ligand) indicate single molecule magnet (SMM) behavior for all these complexes with large thermal energy barriers for the reversal of the magnetization and butterfly-shaped hysteresis loops at 2 K. Ab initio calculations on 1-3 show a pure Ising ground state for all of them, which induces almost completely suppressed quantum tunnelling magnetization (QTM), and thermally assisted quantum tunnelling magnetization (TA-QTM) relaxations via the first excited Kramers doublet, leading to large energy barriers, thus supporting the observation of SMM behavior. The comparison between the experimental and theoretical

  17. Divacancy complexes induced by Cu diffusion in Zn-doped GaAs

    Elsayed, M.; Krause-Rehberg, R.; Korff, B.; Ratschinski, I.; Leipner, H. S.


    Positron annihilation spectroscopy was applied to investigate the nature and thermal behavior of defects induced by Cu diffusion in Zn-doped p-type GaAs crystals. Cu atoms were intentionally introduced in the GaAs lattice through thermally activated diffusion from a thin Cu capping layer at 1100 °C under defined arsenic vapor pressure. During isochronal annealing of the obtained Cu-diffused GaAs in the temperature range of 450-850 K, vacancy clusters were found to form, grow and finally disappear. We found that annealing at 650 K triggers the formation of divacancies, whereas further increasing in the annealing temperature up to 750 K leads to the formation of divacancy-copper complexes. The observations suggest that the formation of these vacancy-like defects in GaAs is related to the out-diffusion of Cu. Two kinds of acceptors are detected with a concentration of about 1016 - 1017 cm-3, negative ions and arsenic vacancy copper complexes. Transmission electron microscopy showed the presence of voids and Cu precipitates which are not observed by positron measurements. The positron binding energy to shallow traps is estimated using the positron trapping model. Coincidence Doppler broadening spectroscopy showed the presence of Cu in the immediate vicinity of the detected vacancies. Theoretical calculations suggested that the detected defect is VGaVAs-2CuGa.

  18. Synthesis Al complex and investigating effect of doped ZnO nanoparticles in the electrical and optical efficiency of OLEDS

    Shahedi, Zahra; Jafari, Mohammad Reza


    In this study, an organometallic complex based on aluminum ions is synthesized. And it is utilized as fluorescent material in the organic light-emitting diodes (OLEDs). The synthesized complex was characterized using XRD, UV-Vis, FT-IR as well as PL spectroscopy analyses. The energy levels of Al complex were determined by cyclic voltammetry measurements. Then, the effects of ZnO nanoparticles (NPs) of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS, on the electrical and optical performance of the organic light-emitting diodes have been investigated. For this purpose, two samples containing ITO/PEDOT:PSS/PVK/Alq3/PBD/Al with two different concentration and two samples containing ITO/PEDOT:PSS:ZnO/PVK/Alq3/PBD/Al with two different concentration were prepared. Then, hole transport, electron transport and emissive layers were deposited by the spin coating method and the cathode layer (Al) was deposited by the thermal evaporation method. The OLED simulation was also done by constructing the model and choosing appropriate parameters. Then, the experimental data were collected and the results interpreted both qualitatively and quantitatively. The results of the simulations were compared with experimental data of the J-V spectra. Comparing experimental data and simulation results showed that the electrical and optical efficiency of the samples with ZnO NPs is appreciably higher than the samples without ZnO NPs.

  19. PNBE-supported metallopolymer-type optical materials through grafting of Zn-Ln (Ln = Nd, Yb or Er) benzimidazole complex monomers with efficient NIR luminescence

    Liu, Lin; Li, Hongyan; Feng, Weixu; Fu, Guorui; Lü, Xingqiang; Wong, Wai-Kwok; Jones, Richard A.


    Through the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with each of obtained allyl-containing complex monomers [Zn(L)2(Py)Ln(NO3)3] (Ln = La, 1; Nd, 2; Yb, 3; Er, 4 or Gd, 5; HL = 4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol; Py = pyridine), a series of metallopolymers Poly(NBE-co-[Zn(L)2Ln(Py)(NO3)3)]) were obtained, respectively. Especially for Poly(NBE-co-2) and Poly(NBE-co-3), covalently-bonded grafting endows significantly improved physical properties including efficient NIR luminescence (ΦNdL = 0.63% and ΦYbL = 1.43%) in solid state.

  20. Complex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L).

    Liao, Bo-han; Liu, Hong-yu; Zeng, Qing-ru; Yu, Ping-zhong; Probst, Anne; Probst, Jean-Luc


    Complex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L) were studied in a pot experiment by measurement of fresh weights of the plants, determination of surperoxide dismutase (SOD), peroxidase (POD), and lipid peroxidation (MDA) in the plant organs, and observation of injury symptoms. The experimental results demonstrated that all treatments of Cd2+, Zn2+, and/or acid rain significantly decreased fresh weights of kidney bean and caused toxic effects on growth of the plants, especially higher amounts of Cd2+ and Zn2+ and higher acidity of acid rain. Combination of these three pollutant factors resulted in more serious toxic effects than any single pollutant and than combinations of any two pollutants. SOD, POD, and MDA in the plant organs changed with different pollution levels, but MDA content in the leaves showed the best relationship between the pollution levels and toxic effects.

  1. Synthesis and characterization of mono- and bimetallic complexes of Zn(II and Cu(II; new multifunctional unsymmetrical acyclic and macrocyclic phenol-based ligand

    Hamid Golchoubian


    Full Text Available The dicompartmental macrocyclic ligand (L22- was prepared by [1:1] cyclic condensation of N,N′-dimethyacetate-N,N′-ethylene-di(5-methyl-3-formyl-2-hydroxybenzylamine with 1,3-diaminopropane. The ligand includes dissimilar N(amine2O2 and N(imine2O2 coordination sites sharing two phenolic oxygen atoms and containing two methyl acetate pedant arms on the amine nitrogen donor atoms. A series of mono- and bimetallic complexes were synthesized and characterized on the basis of elemental analysis, molar conductance measurement, IR and UV-Vis spectroscopy techniques. It was found that during the cyclization process the copper (II displaced from the N(amine2O2 to the N(imine2O2 coordination site and one of the methyl acetate pedant arms is dissociated. The heterodinuclear complex of [ZnL2Cu(-OAc]+ was prepared by a transmetallation reaction on the [ZnL2Zn(-OAc]+ by Cu(II. The characterization results showed that the two metal ions are bridged by two phenolic oxygen atoms and an acetate group, providing distorted five-coordination geometries for the both metal ions.

  2. Theory Including Future Not Excluded -- Formulation of Complex Action Theory II

    Nagao, Keiichi


    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that if we regard a matrix element defined in terms of the future state at time $T_B$ and the past state at time $T_A$ as an expectation value in the CAT, then we are allowed to have the Heisenberg equation, the Ehrenfest's theorem and the conserved probability current density. In addition we show that the expectation value at the present time $t$ of a future-included theory for large $T_B-t$ and large $t- T_A$ corresponds to that of a future-not-included theory for large $t- T_A$ with a proper inner product. So the CAT with future explicitly present in the formalism and influencing in principle the past is not excluded phenomenologically, because the effects are argued to be very small in the present era. Furthermore we explicitly derive the Hamiltonian for the future state via path integral, and confirm that it is given by the hermitian conjugate of the Hamiltonian for the past state.

  3. Theory including future not excluded: Formulation of complex action theory II

    Nagao, Keiichi; Nielsen, Holger Bech


    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that, if we regard a matrix element defined in terms of the future state at time TB and the past state at time TA as an expectation value in the CAT, then we are allowed to have the Heisenberg equation, Ehrenfest's theorem, and the conserved probability current density. In addition, we show that the expectation value at the present time t of a future-included theory for large TB - t and large t - TA corresponds to that of a future-not-included theory with a proper inner product for large t - TA. Hence, the CAT with future explicitly present in the formalism and influencing in principle the past is not excluded phenomenologically, because the effects are argued to be very small in the present era. Furthermore, we explicitly derive the Hamiltonian for the future state via a path integral, and confirm that it is given by the Hermitian conjugate of the Hamiltonian for the past state.

  4. Evaluation of the complexes of galactomannan of Leucaena leucocephala and Co2+, Mn2+ , Ni2+ and Zn2+

    Mercê Ana Lucia R.


    Full Text Available The binding constants for the complexed species formed in aqueous solution between galactomannan of Leucaena leucocephala and the metal ions Co2+, Mn2+, Ni2+ and Zn2+ were determined by potentiometric titrations. The calculated values showed Ni2+ as the best Lewis acid towards the Lewis base -OH groups of the sugar monomers, with Zn2+ being the poorest. For all systems, a higher percentage of the complexed species was present near pH=7.0, although complexed species existed over a wide range of acidic and basic pH values. The isolated solid complexes were studied by TG-DSC thermal analysis and by EPR spectroscopy. The thermal profiles obtained showed higher thermal resistance to final degradation than the biopolymer alone for the complexed species ML having the smallest log K values. The EPR spectra confirmed the complexation of the metal ions via the Lewis base deprotonated hydroxyl groups (-O and showed that the distances between metal ions in the complexed biopolymer structure depend on the nature of the metal ion. The ability of galactomannans to complex a variety of metal ions in their web like structure and the resistance to high temperatures and a wide range of pH values of these complexes open new perspectives in possible industrial uses whenever these properties are required, such as in bioremediation of waste waters and in the application of slow-release fertilizers.

  5. Zn(II-Chlorido complexes of phytohormone kinetin and its derivatives modulate expression of inflammatory mediators in THP-1 cells.

    Jan Hošek

    Full Text Available Kinetin (N6-furfuryladenine belongs to a group of plant growth hormones involved in cell division, differentiation and other physiological processes. One of the possible ways to obtain biologically active compounds is to complex biologically relevant natural compounds to suitable metal atoms. In this work, two structural groups of Zn(II complexes [Zn(L(n2Cl2]·Solv (1-5 and [Zn(HL(nCl3] · xL(n (6-7; n=1-5, Solv=CH3OH for 1 and 2H2O for 2; x =1 for 6 and 2 for 7; involving a phytohormone kinetin and its derivatives (L(n were evaluated for their ability to modulate secretion of tumour necrosis factor (TNF-α, interleukin (IL-1β and matrix metalloproteinase (MMP-2 in a lipopolysaccharide (LPS-activated macrophage-like THP-1 cell model. The penetration of the complexes to cells was also detected. The mechanism of interactions of the zinc(II complexes with a fluorescent sensor N-(6-methoxy-8-quinolyl-p-toluene sulphonamide (TSQ and sulfur-containing biomolecules (l-cysteine and reduced glutathione was studied by electrospray-ionization mass spectrometry and flow-injection analysis with fluorescence detection. The present study showed that the tested complexes exhibited a low cytotoxic effect on the THP-1 cell line (IC50>40 µM, apart from complex 4, with an IC50=10.9 ± 1.1 µM. Regarding the inflammation-related processes, the Zn(II complexes significantly decreased IL-1β production by a factor of 1.47-2.22 compared with the control (DMSO, but did not affect TNF-α and MMP-2 secretions. However, application of the Zn(II complexes noticeably changed the pro-MMP-2/MMP-2 ratio towards a higher amount of maturated MMP-2, when they induced a 4-times higher production of maturated MMP-2 in comparison with the vehicle-treated cells under LPS stimulation. These results indicated that the complexes are able to modulate an inflammatory response by influencing secretion and activity of several inflammation-related cytokines and enzymes.

  6. Freeze-drying synthesis of an amorphous Zn(2+) complex and its transformation to a 2-D coordination framework in the solid state.

    Itakura, T; Horike, S; Inukai, M; Kitagawa, S


    An amorphous and metastable precursor for a Zn two-dimensional coordination framework was synthesised via freeze drying. The precursor comprises randomly packed discrete clusters of a Zn complex. The amorphous-to-crystalline framework transformation, which was triggered by the gentle application of heat or pressure, was accompanied by a change in the coordination geometry of the Zn(2+) ions from tetrahedral to octahedral symmetry.

  7. New non-toxic transition metal nanocomplexes and Zn complex-silica xerogel nanohybrid: Synthesis, spectral studies, antibacterial, and antitumor activities

    Shebl, Magdy; Saif, M.; Nabeel, Asmaa I.; Shokry, R.


    A new chromone Schiff base and its complexes of Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), and UO2(VI) as well as Zn(II) complex-silica xerogel nanohybrid were successfully prepared in a nano domain with crystalline or amorphous structures. Structures of the Schiff base and its complexes were investigated by elemental and thermal analyses, IR, 1H NMR, electronic, ESR, mass spectra, XRD, and TEM, as well as conductivity and magnetic susceptibility measurements. The spectroscopic data revealed that the Schiff base ligand behaves as a monobasic tridentate ligand. The coordination sites with metal ions are γ-pyrone oxygen, azomethine nitrogen, and oxygen of the carboxylic group. The metal complexes exhibited octahedral geometry, except Cu(II) complex, which has a square planar geometry and UO2(VI) complex, in which uranium ion is hepta-coordinated. Transmission electron microscope (TEM) analysis showed that Ni(II) and Zn(II) complexes have aggregated spheres and rod morphologies, respectively. TEM images of Zn(II) complex-silica xerogel nanohybrid showed a nanosheet morphology with 46 nm average size and confirmed that the complex was uniformly distributed into the silica pores. The obtained nanocomplexes were tested as antimicrobial and antitumor agents. The results showed that Zn(II) nanocomplex and Zn(II) complex-silica xerogel nanohybrid have high activity. The toxicity test on mice showed that Zn(II) complex and Zn(II) complex-silica xerogel nanohybrid have lower toxicity than cisplatin.

  8. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    Stéphane Guichard


    Full Text Available This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM. A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented.

  9. A full model for simulation of electrochemical cells including complex behavior

    Esperilla, J. J.; Félez, J.; Romero, G.; Carretero, A.

    This communication presents a model of electrochemical cells developed in order to simulate their electrical, chemical and thermal behavior showing the differences when thermal effects are or not considered in the charge-discharge process. The work presented here has been applied to the particular case of the Pb,PbSO 4|H 2SO 4 (aq)|PbO 2,Pb cell, which forms the basis of the lead-acid batteries so widely used in the automotive industry and as traction batteries in electric or hybrid vehicles. Each half-cell is considered independently in the model. For each half-cell, in addition to the main electrode reaction, a secondary reaction is considered: the hydrogen evolution reaction in the negative electrode and the oxygen evolution reaction in the positive. The equilibrium potential is calculated with the Nernst equation, in which the activity coefficients are fitted to an exponential function using experimental data. On the other hand, the two main mechanisms that produce the overpotential are considered, that is the activation or charge transfer and the diffusion mechanisms. First, an isothermal model has been studied in order to show the behavior of the main phenomena. A more complex model has also been studied including thermal behavior. This model is very useful in the case of traction batteries in electric and hybrid vehicles where high current intensities appear. Some simulation results are also presented in order to show the accuracy of the proposed models.

  10. A family of acetato-diphenoxo triply bridged dimetallic Zn(II)Ln(III) complexes: SMM behavior and luminescent properties.

    Oyarzabal, Itziar; Artetxe, Beñat; Rodríguez-Diéguez, Antonio; García, JoséÁngel; Seco, José Manuel; Colacio, Enrique


    Eleven dimetallic Zn(II)-Ln(III) complexes of the general formula [Zn(µ-L)(µ-OAc)Ln(NO3)2]·CH3CN (Ln(III) = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7), Ho (8), Er (9), Tm (10), Yb (11)) have been prepared in a one-pot reaction from the compartmental ligand N,N'-dimethyl-N,N'-bis(2-hydroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L). In all these complexes, the Zn(II) ions occupy the internal N2O2 site whereas the Ln(III) ions show preference for the O4 external site. Both metallic ions are bridged by an acetate bridge, giving rise to triple mixed diphenoxido/acetate bridged Zn(II)Ln(III) compounds. The Nd, Dy, Er and Yb complexes exhibit field induced single-ion magnet (SIM) behaviour, with Ueff values ranging from 14.12 to 41.55 K. The Er complex shows two relaxation processes, but only the second relaxation process with an energy barrier of 21.0 K has been characterized. The chromophoric L(2-) ligand is able to act as an "antenna" group, sensitizing the near-infrared (NIR) Nd(III) and Yb(III)-based luminescence in complexes 2 and 11 and therefore, both compounds can be considered as magneto-luminescent materials. In addition, the Sm(III), Eu(III) and Tb(III) derivatives exhibit characteristic emissions in the visible region.

  11. The Interactions between ZnO Nanoparticles (NPs and α-Linolenic Acid (LNA Complexed to BSA Did Not Influence the Toxicity of ZnO NPs on HepG2 Cells

    Yiwei Zhou


    Full Text Available Background: Nanoparticles (NPs entering the biological environment could interact with biomolecules, but little is known about the interaction between unsaturated fatty acids (UFA and NPs. Methods: This study used α-linolenic acid (LNA complexed to bovine serum albumin (BSA for UFA and HepG2 cells for hepatocytes. The interactions between BSA or LNA and ZnO NPs were studied. Results: The presence of BSA or LNA affected the hydrodynamic size, zeta potential, UV-Vis, fluorescence, and synchronous fluorescence spectra of ZnO NPs, which indicated an interaction between BSA or LNA and NPs. Exposure to ZnO NPs with the presence of BSA significantly induced the damage to mitochondria and lysosomes in HepG2 cells, associated with an increase of intracellular Zn ions, but not intracellular superoxide. Paradoxically, the release of inflammatory cytokine interleukin-6 (IL-6 was decreased, which indicated the anti-inflammatory effects of ZnO NPs when BSA was present. The presence of LNA did not significantly affect all of these endpoints in HepG2 cells exposed to ZnO NPs and BSA. Conclusions: the results from the present study indicated that BSA-complexed LNA might modestly interact with ZnO NPs, but did not significantly affect ZnO NPs and BSA-induced biological effects in HepG2 cells.

  12. Structural determination of Zn and Cd-DTPA complexes: MS, infrared, (13)C NMR and theoretical investigation.

    Silva, Vanézia L; Carvalho, Ruy; Freitas, Matheus P; Tormena, Cláudio F; Melo, Walclée C


    The joint application of MS, infrared and (13)C NMR techniques for the determination of metal-DTPA structures (metal=Zn and Cd; DTPA=diethylenetriaminepentacetic acid) is reported. Mass spectrometry allowed determining the 1:1 stoichiometry of the complexes, while infrared analysis suggested that both nitrogen and carboxyl groups are sites for complexation. The (13)C NMR spectrum for the cadmium-containing complex evidenced the existence of free and complexed carboxyl groups, due to a straight singlet at 179.0 ppm (free carboxylic (13)C) and to two broad singlets or a broad doublet at 178.3 ppm (complexed carboxylic (13)C, (2)J(Cd-C(=O))=45.2 Hz). A similar interpretation might be given for the zinc derivative and, with the aid of DFT calculations, structures for both complexes were then proposed.

  13. Quantum-chemical, NMR, FT IR, and ESI MS studies of complexes of colchicine with Zn(II).

    Jankowski, Wojciech; Kurek, Joanna; Barczyński, Piotr; Hoffmann, Marcin


    Colchicine is a tropolone alkaloid from Colchicinum autumnale. It shows antifibrotic, antimitotic, and anti-inflammatory activities, and is used to treat gout and Mediterranean fever. In this work, complexes of colchicine with zinc(II) nitrate were synthesized and investigated using DFT, (1)H and (13)C NMR, FT IR, and ESI MS. The counterpoise-corrected and uncorrected interaction energies of these complexes were calculated. We also calculated their (1)H, (13)C NMR, and IR spectra and compared them with the corresponding experimentally obtained data. According to the ESI MS mass spectra, colchicine forms stable complexes with zinc(II) nitrate that have various stoichiometries: 2:1, 1:1:1, and 2:1:1 with respect to colchichine, Zn(II), and nitrate ion. All of the complexes were investigated using the quantum theory of atoms in molecules (QTAIM). The calculated and the measured spectra showed differences before and after the complexation process. Calculated electron densities and bond critical points indicated the presence of bonds between the ligands and the central cation in the investigated complexes that satisfied the quantum theory of atoms in molecules. Graphical Abstract DFT, NMR, FT IR, ESI MS, QTAIM and puckering studies of complexes of colchicine with Zn(II).

  14. In vitro evaluation of Zn-norfloxacin complex as a potent cytotoxic and antibacterial agent, proposed model for DNA binding.

    Ahmadi, F; Saberkari, M; Abiri, R; Motlagh, H Mohammadi; Saberkari, H


    A tetrahedral Zn(II) complex with the second generation fluoroquinolone, norfloxacin, was prepared and characterized (NOR-Zn complex, NZC). The antibacterial efficiency of the NZC was tested on two Gram-positive and four Gram-negative bacteria by minimum inhibitory concentration method. The cytotoxic potential of NZC on MDA (human breast adenocarcinoma), Caco-2 (human colon adenocarcinoma), and Hela (human cervix carcinoma) cell lines was studied. The DNA interaction property of the NZC has been investigated using UV-vis, fluorescence, Fourier transform infrared, as well as cyclic voltammetry methods. Intrinsic binding constant (K(b)), thermodynamic, and other spectroscopic and voltammetric data indicate that the NZC has more affinity for DNA than for norfloxacin and interacted with DNA via two modes: electrostatic and outside hydrogen binding. The proposed DNA binding mode supports the large enhancement in the cytotoxicity and antibacterial activity of NZC.

  15. Hydrogen bonding interactions and supramolecular networks of pyridine-aryl based thiosemicarbazides and their Zn(II) complexes



    PUBLISHED The synthesis of five pyridyl derived thiosemicarbazides, 1-5, is presented. All five were formed in a single step from 2-hydrazinopyridine with commercially available isothiocyanates using microwave assisted synthesis. Compounds 1-4 were structurally characterised by single crystal diffraction analysis, and showed extended supramolecular hydrogen bonding arrays. Furthermore, the Zn(ii) complexes 6 and 7 have been prepared using ligands 1 and 5, and structurally characterised, ag...

  16. The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

    Irina V. Martynenko


    Full Text Available The formation of nonluminescent aggregates of aluminium sulfonated phthalocyanine in complexes with CdSe/ZnS quantum dots causes a decrease of the intracomplex energy transfer efficiency with increasing phthalocyanine concentration. This was confirmed by steady-state absorption and photoluminescent spectroscopy. A corresponding physical model was developed that describes well the experimental data. The results can be used at designing of QD/molecule systems with the desired spatial arrangement for photodynamic therapy.

  17. Influence of Zn-Cd substitution: spectroscopic and theoretical investigation of 8-hydroxyquinoline complexes.

    Ramalho, Teodorico C; Martins, Tales L C; Borges, Luiz E Pizarro; de Pinho, Marcos Henrique; de Avillez, Roberto Ribeiro; da Cunha, Elaine F F


    It is now well known that zinc is crucial for the synthesis of nucleic acids and, consequently, for cellular division. However, (67)Zn, the NMR-detectable isotope, is one of the isotopes most poorly studied by NMR. The strategy used for NMR studies is the substitution of Zn by (113)Cd. In this work, we employed (13)C, (113)Cd NMR (CPMAS), X-ray and DFT calculation in order to evaluate the Zn-Cd substitution using 8-hydroxyquinoline like prototype compound. Our results show that there are strong structural and electronics effects are involved in the substitution.

  18. Compensation in Al-doped ZnO by Al-related acceptor complexes: synchrotron x-ray absorption spectroscopy and theory.

    T-Thienprasert, J; Rujirawat, S; Klysubun, W; Duenow, J N; Coutts, T J; Zhang, S B; Look, D C; Limpijumnong, S


    The synchrotron x-ray absorption near edge structures (XANES) technique was used in conjunction with first-principles calculations to characterize Al-doped ZnO films. Standard characterizations revealed that the amount of carrier concentration and mobility depend on the growth conditions, i.e. H(2) (or O(2))/Ar gas ratio and Al concentration. First-principles calculations showed that Al energetically prefers to substitute on the Zn site, forming a donor Al(Zn), over being an interstitial (Al(i)). The measured Al K-edge XANES spectra are in good agreement with the simulated spectra of Al(Zn), indicating that the majority of Al atoms are substituting for Zn. The reduction in carrier concentration or mobility in some samples can be attributed to the Al(Zn)-V(Zn) and 2Al(Zn)-V(Zn) complex formations that have similar XANES features. In addition, XANES of some samples showed additional features that are the indication of some α-Al(2)O(3) or nAl(Zn)-O(i) formation, explaining their poorer conductivity.

  19. The origin of room temperature ferromagnetism mediated by Co–VZn complexes in the ZnO grain boundary

    Devi, Assa Aravindh Sasikala


    Ferromagnetism in polycrystalline ZnO doped with Co has been observed to be sustainable in recent experiments. We use first-principle calculations to show that Co impurities favorably substitute at the grain boundary (GB) rather than in the bulk. We reveal that room-temperature ferromagnetism (RTFM) at the Co-doped ZnO GB in the presence of Zn vacancies is due to ferromagnetic exchange coupling of a pair of closely associated Co atoms in the GB, with a ferromagnetic exchange coupling energy of ∼300 meV, which is in contrast to a previous study that suggested the O vacancy-Co complex induced ferromagnetism. Electronic structure analysis was used to predict the exchange coupling mechanism, showing that the hybridization of O p states with Co and Zn d states enhances the magnetic polarization originating from the GB. Our results indicate that RTFM originates from Co clusters at interfaces or in GBs. © 2016 The Royal Society of Chemistry.

  20. Synthesis, characterization, crystal structure, DNA- and HSA-binding studies of a dinuclear Schiff base Zn(II) complex derived from 2-hydroxynaphtaldehyde and 2-picolylamine

    Kazemi, Zahra; Rudbari, Hadi Amiri; Mirkhani, Valiollah; Sahihi, Mehdi; Moghadam, Majid; Tangestaninejad, Sharam; Mohammadpoor-Baltork, Iraj


    A tridentate Schiff base ligand NNO donor (HL: 1-((E)-((pyridin-2-yl)methylimino)methyl)naphthalen-2-ol was synthesized from condensation of 2-hydroxynaphtaldehyde and 2-picolylamine. Zinc complex, Zn2L2(NO3)2, was prepared from reaction of Zn(NO3)2 and HL at ambient temperature. The ligand and complex were characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis (CHN). Furthermore, the structure of dinuclear Zn(II) complex was determined by single crystal X-ray analysis. The complex, Zn2L2(NO3)2, is centrosymmetric dimer in which deprotonated phenolates bridge the two Zn(II) atoms and link the two halves of the dimer. In the structure, Zinc(II) ions have a highly distorted six-coordinate structure bonded to two oxygen atoms from a bidentate nitrate group, the pyridine nitrogen, an amine nitrogen and phenolate oxygens. The interaction of dinuclear Zn(II) complex with fish sperm DNA (FS-DNA) and HSA was investigated under physiological conditions using fluorescence quenching, UV-Vis spectroscopy, molecular dynamics simulation and molecular docking methods. The estimated binding constants for the DNA-complex and HSA-complex were (3.60 ± 0.18) × 104 M-1 and (1.35 ± 0.24) × 104 M-1, respectively. The distance between dinuclear Zn(II) complex and HSA was obtained based on the Förster's theory of non-radiative energy transfer. Molecular docking studies revealed the binding of dinuclear Zn(II) complex to the major groove of FS-DNA and IIA site of protein by formation of hydrogen bond, π-cation and hydrophobic interactions.

  1. DISPLAY-2: a two-dimensional shallow layer model for dense gas dispersion including complex features.

    Venetsanos, A G; Bartzis, J G; Würtz, J; Papailiou, D D


    A two-dimensional shallow layer model has been developed to predict dense gas dispersion, under realistic conditions, including complex features such as two-phase releases, obstacles and inclined ground. The model attempts to predict the time and space evolution of the cloud formed after a release of a two-phase pollutant into the atmosphere. The air-pollutant mixture is assumed ideal. The cloud evolution is described mathematically through the Cartesian, two-dimensional, shallow layer conservation equations for mixture mass, mixture momentum in two horizontal directions, total pollutant mass fraction (vapor and liquid) and mixture internal energy. Liquid mass fraction is obtained assuming phase equilibrium. Account is taken in the conservation equations for liquid slip and eventual liquid rainout through the ground. Entrainment of ambient air is modeled via an entrainment velocity model, which takes into account the effects of ground friction, ground heat transfer and relative motion between cloud and surrounding atmosphere. The model additionally accounts for thin obstacles effects in three ways. First a stepwise description of the obstacle is generated, following the grid cell faces, taking into account the corresponding area blockage. Then obstacle drag on the passing cloud is modeled by adding flow resistance terms in the momentum equations. Finally the effect of extra vorticity generation and entrainment enhancement behind obstacles is modeled by adding locally into the entrainment formula without obstacles, a characteristic velocity scale defined from the obstacle pressure drop and the local cloud height.The present model predictions have been compared against theoretical results for constant volume and constant flux gravity currents. It was found that deviations of the predicted cloud footprint area change with time from the theoretical were acceptably small, if one models the frictional forces between cloud and ambient air, neglecting the Richardson

  2. Synthesis, crystal structure and luminescent properties of some Zn(II) Schiff base complexes: experimental and computational study.

    Eltayeb, Naser Eltaher; Teoh, Siang Guan; Adnan, Rohana; Teh, Jeannie Bee-Jan; Fun, Hoong-Kun


    A series of Zn(II)-Schiff bases I, II and III complexes were synthesized by reaction of o-phenylenediamine with 3-methylsalicylaldehyde, 4-methylsalicylaldehyde and 5-methylsalicylaldehyde. These complexes were characterized using FT-IR, UV-Vis, Diffuse reflectance UV-Vis, elemental analysis and conductivity. Complex III was characterized by XRD single crystal, which crystallizes in the triclinic system, space group P-1, with lattice parameters a=9.5444(2) Å, b=11.9407(2) Å, c=21.1732(3) Å, V=2390.24(7) Å(3), D ( c )=1.408 Mg m(-3), Z=4, F(000)=1050, GOF=0.981, R1=0.0502, wR2=0.1205. Luminescence property of these complexes was investigated in DMF solution and in the solid state. Computational study of the electronic properties of complex III showed good agreement with the experimental data.

  3. Pyrazole bridged dinuclear Cu(II) and Zn(II) complexes as phosphatase models: Synthesis and activity

    Naik, Krishna; Nevrekar, Anupama; Kokare, Dhoolesh Gangaram; Kotian, Avinash; Kamat, Vinayak; Revankar, Vidyanand K.


    Present work describes synthesis of dibridged dinuclear [Cu2L2(μ2-NN pyr)(NO3)2(H2O)2] and [Zn2L(μ-OH)(μ-NNpyr)(H2O)2] complexes derived from a pyrazole based ligand bis(2-hydroxy-3-methoxybenzylidene)-1H-pyrazole-3,5-dicarbohydrazide. The ligand shows dimeric chelate behaviour towards copper against monomeric for zinc counterpart. Spectroscopic evidences affirm octahedral environment around the metal ions in solution state and non-electrolytic nature of the complexes. Both the complexes are active catalysts towards phosphomonoester hydrolysis with first order kcat values in the range of 2 × 10-3s-1. Zinc complex exhibited promising catalytic efficiency for the hydrolysis. The dinuclear complexes hydrolyse via Lewis acid activation, whereby the phosphate esters are preferentially bound in a bidentate bridging fashion and subsequent nucleophilic attack to release phosphate group.

  4. Surface complexation and precipitate geometry for aqueous Zn(II) sorption on ferrihydrite I: X-ray absorption extended fine structure spectroscopy analysis

    Waychunas, G.A.; Fuller, C.C.; Davis, J.A.


    "Two-line" ferrihydrite samples precipitated and then exposed to a range of aqueous Zn solutions (10-5 to 10-3 M), and also coprecipitated in similar Zn solutions (pH 6.5), have been examined by Zn and Fe K-edge X-ray absorption spectroscopy. Typical Zn complexes on the surface have Zn-O distances of 1.97(0.2) A?? and coordination numbers of about 4.0(0.5), consistent with tetrahedral oxygen coordination. This contrasts with Zn-O distances of 2.11(.02) A?? and coordination numbers of 6 to 7 in the aqueous Zn solutions used in sample preparation. X-ray absorption extended fine structure spectroscopy (EXAFS) fits to the second shell of cation neighbors indicate as many as 4 Zn-Fe neighbors at 3.44(.04) A?? in coprecipitated samples, and about two Zn-Fe neighbors at the same distance in adsorption samples. In both sets of samples, the fitted coordination number of second shell cations decreases as sorption density increases, indicating changes in the number and type of available complexing sites or the onset of competitive precipitation processes. Comparison of our results with the possible geometries for surface complexes and precipitates suggests that the Zn sorption complexes are inner sphere and at lowest adsorption densities are bidentate, sharing apical oxygens with adjacent edge-sharing Fe(O,OH)6 octahedra. Coprecipitation samples have complexes with similar geometry, but these are polydentate, sharing apices with more than two adjacent edge-sharing Fe(O,OH)6 polyhedra. The results are inconsistent with Zn entering the ferrihydrite structure (i.e., solid solution formation) or formation of other Zn-Fe precipitates. The fitted Zn-Fe coordination numbers drop with increasing Zn density with a minimum of about 0.8(.2) at Zn/(Zn + Fe) of 0.08 or more. This change appears to be attributable to the onset of precipitation of zinc hydroxide polymers with mainly tetrahedral Zn coordination. At the highest loadings studied, the nature of the complexes changes further

  5. Surface complexation and precipitate geometry for aqueous Zn(II) sorption on ferrihydrite: II. XANES analysis and simulation

    Waychunas, G.A.; Fuller, C.C.; Davis, J.A.; Rehr, J.J.


    X-ray absorption near-edge spectroscopy (XANES) analysis of sorption complexes has the advantages of high sensitivity (10- to 20-fold greater than extended X-ray absorption fine structure [EXAFS] analysis) and relative ease and speed of data collection (because of the short k-space range). It is thus a potentially powerful tool for characterization of environmentally significant surface complexes and precipitates at very low surface coverages. However, quantitative analysis has been limited largely to "fingerprint" comparison with model spectra because of the difficulty of obtaining accurate multiple-scattering amplitudes for small clusters with high confidence. In the present work, calculations of the XANES for 50- to 200-atom clusters of structure from Zn model compounds using the full multiple-scattering code Feff 8.0 accurately replicate experimental spectra and display features characteristic of specific first-neighbor anion coordination geometry and second-neighbor cation geometry and number. Analogous calculations of the XANES for small molecular clusters indicative of precipitation and sorption geometries for aqueous Zn on ferrihydrite, and suggested by EXAFS analysis, are in good agreement with observed spectral trends with sample composition, with Zn-oxygen coordination and with changes in second-neighbor cation coordination as a function of sorption coverage. Empirical analysis of experimental XANES features further verifies the validity of the calculations. The findings agree well with a complete EXAFS analysis previously reported for the same sample set, namely, that octahedrally coordinated aqueous Zn2+ species sorb as a tetrahedral complex on ferrihydrite with varying local geometry depending on sorption density. At significantly higher densities but below those at which Zn hydroxide is expected to precipitate, a mainly octahedral coordinated Zn2+ precipitate is observed. An analysis of the multiple scattering paths contributing to the XANES

  6. Isolation and spectroscopic characterization of Zn(II), Cu(II), and Pd(II) complexes of 1,3,4-thiadiazole-derived ligand

    Karcz, Dariusz; Matwijczuk, Arkadiusz; Boroń, Bożena; Creaven, Bernadette; Fiedor, Leszek; Niewiadomy, Andrzej; Gagoś, Mariusz


    A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv-vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 to metal ions occurs most likely via one of the deprotonated hydroxyl groups of the resorcinyl moiety and one of the N atoms of the thiadiazole heterocycle.

  7. Preparation, characterization and evaluation of antibacterial activity of catechins and catechins-Zn complex loaded β-chitosan nanoparticles of different particle sizes.

    Zhang, Hongcai; Jung, Jooyeoun; Zhao, Yanyun


    This study used β-chitosan nanoparticles (β-CS NPs) of different particle sizes to encapsulate catechins (CAT) or CAT-Zn complex by ionic gelation technology. The antibacterial activity of CAT or CAT-Zn complex loaded β-CS NPs against Escherichia coli and Listeria innocua were investigated based on bacterial growth curve, minimum inhibitory concentration (MIC), and minimum bacterial concentration (MBC). Fourier transform infrared spectrometer (FT-IR) was employed to study the incorporation of CAT or CAT-Zn complex into β-CS NPs. The CAT-Zn complex loaded β-CS NPs had particle size of 208-591 nm, polydispersity index (PDI) of 0.377-0.395, and positive Zeta-potential of 39.17-45.62 mV. The CAT-Zn complex loaded β-CS NPs of smaller particle sizes showed higher antibacterial activity than that of larger particle size ones. The MIC and MBC of CAT-Zn complex loaded β-CS NPs of the smallest particle size against L. innocua and E. coli were 0.031 and 0.063 mg/mL, and 0.063 and 0.125 mg/mL, respectively. This study suggested that encapsulation of CAT-Zn complex in β-CS NPs improved the antibacterial activity of CAT and CAT-Zn complex, and the encapsulators have great potential to be used as antibacterial substances for food and other applications through either direct addition or incorporation into packaging materials.

  8. Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

    Aly, Shawkat Mohammede


    Fluorescence enhancement of organic fluorophores shows tremendous potential to improve image contrast in fluorescence-based bioimaging. Here, we present an experimental study of the interaction of two cationic porphyrins, meso-tetrakis(1-methylpyridinium-4-yl)porphyrin chloride (TMPyP) and meso-tetrakis(4-N,N,N-trimethylanilinium)porphyrin chloride (TMAP), with cationic surfactant-stabilized zinc oxide nanoparticles (ZnO NPs) based on several steady-state and time-resolved techniques. We show the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic porphyrins. For TMPyP, we observe a sixfold increase in the fluorescence intensity of TMPyP upon addition of ZnO NPs. Our experimental results indicate that the electrostatic binding of TMPyP with the surface of ZnO NPs increases the symmetry of the porphyrin macrocycle. This electronic communication hinders the rotational relaxation of the meso unit and/or decreases the intramolecular CT character between the cavity and the meso substituent of the porphyrin, resulting in the enhancement of the intensity of the fluorescence. For TMAP, on the other hand, the different type and nature of the positive charge resulting in the development of the CT band arise from the interaction with the surface of ZnO NPs. This observation is confirmed by the femtosecond transient absorption spectroscopy, which provides clear spectroscopic signatures of photoinduced electron transfer from TMAP to ZnO NPs. © 2014 American Chemical Society.

  9. Identification of Fe3+-Li+ complexes in ZnO by means of high-frequency EPR/ENDOR spectroscopy

    Kutin, Yu. S.; Mamin, G. V.; Orlinskii, S. B.


    Theoretical prediction of a high Curie temperature in ZnO doped with Mn, Fe, and other transition metals has stimulated the investigation of these materials by many research groups. Although charge-compensated Fe3+ centers in ZnO:Fe have been observed by means of EPR and have been known for decades, conclusions on the chemical nature of these defects are still contradictory. Originally, these centers were treated as Fe3+-Li+ complexes with both ions occupying adjacent cationic sites. Recently, however, the centers were interpreted as a substitutional Fe3+ ion with a vacancy at an adjacent zinc or oxygen site (Fe-VZn or Fe-VO). In order to determine the chemical nature of the impurity associated with Fe3+, electron-nuclear double resonance (ENDOR) spectroscopy was used. ENDOR measurements reveal NMR transitions corresponding to nuclei with g-factor gN = 2.171 and spin I = 3/2. This unambiguously shows presence of Li as a charge compensator and also resolves contradictions with the theoretical prediction of the Fe-VO formation energy. The electric field gradients at the 7Li nuclei (within the Fe3+-Li+ complexes) were estimated to be significantly lower than the gradient at undistorted Zn sites.

  10. Syntheses, structural characterization, luminescence and optical studies of Ni(II) and Zn(II) complexes containing salophen ligand

    More, M. S.; Pawal, S. B.; Lolage, S. R.; Chavan, S. S.


    Some Ni(II) (1a-d) and Zn(II) (2a-d) salophen complexes were prepared by the treatment of 5-bromosalicylaldehyde, 5-(trimethylsilylethynyl)salicylaldehyde, 5-(4-nitrophenyl)ethynylsalicylaldehyde or 5-(4-methoxyphenyl)ethynylsalicylaldehyde with nickel acetate or zinc acetate followed by addition of 2,3-diamino-5-bromopyridine. All complexes were characterized by elemental analyses, IR, 1H NMR and mass spectral studies. X-ray powder diffraction of representative complexes 1c and 2b and SEM studies of 1b and 2d are used to elucidate the crystal structure and morphology of the complexes. The electrochemical behavior reveals that the redox responses of Ni(II) complexes shifted to more negative potential in order to increase the π-conjugation in the complexes. Room temperature luminescence is observed for all complexes corresponding to π→π* ILCT transition with some MLCT character in DMF and is finely tuned by the degree of extended π-conjugation and variation of the substituent group with different electronic effects in the complexes. The second harmonic generation (SHG) efficiency of the complexes was screened by Kurtz-powder technique indicating that all complexes possesses promising potential for the application as a useful nonlinear optical material.

  11. Synthesis, Crystal Structure and Thermoanalysis of Complex of Zn(Ⅱ) with Aminomethanesulfonic Acid-5-bromosalicylaldelyde Schiff Base

    DENG Yi-Fang; KUANG Dai-Zhi; ZHANG Chun-Hua; CHEN Man-Sheng; PENG Yun-Lin; YANG Ying-Qun; LI Wei


    The title complex [Zn(L)(phen)(CH3OH)] (L= C8H6BrO4NS, aminomethanesulfonic acid 5-bromo-salicylaldelyde schiff base; phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 1.8712(3), b = 1.38008(19), c = 0.83685(12) nm, β = 97.791 (2)°, Mr = 569.72, V = 2.1411(5)nm3,Z= 4, Dc = 1.767 g/cm3, μ = 3.151 mm-1, F(000) = 1144, the final R = 0.0402 and wR = 0.0885. The central Zn(Ⅱ) is six-coordinated by one nitrogen and two oxygen atoms from the Schiff base, two nitrogen atoms from 1,10-phenanthroline and one oxygen from methanol to form a distorted octahedral coordination geometry.

  12. Thiocyanate-Ligated Heterobimetallic {PtM} Lantern Complexes Including a Ferromagnetically Coupled 1D Coordination Polymer.

    Guillet, Jesse L; Bhowmick, Indrani; Shores, Matthew P; Daley, Christopher J A; Gembicky, Milan; Golen, James A; Rheingold, Arnold L; Doerrer, Linda H


    A series of heterobimetallic lantern complexes with the central unit {PtM(SAc)4(NCS)} have been prepared and thoroughly characterized. The {Na(15C5)}[PtM(SAc)4(NCS)] series, 1 (Co), 2 (Ni), 3 (Zn), are discrete compounds in the solid state, whereas the {Na(12C4)2)}[PtM(SAc)4(NCS)] series, 4 (Co), 5 (Ni), 6 (Zn), and 7 (Mn), are ion-separated species. Compound 7 is the first {PtMn} lantern of any bridging ligand (carboxylate, amide, etc.). Monomeric 1-7 have M(2+), necessitating counter cations that have been prepared as {(15C5)Na}(+) and {(12C4)2Na}(+) variants, none of which form extended structures. In contrast, neutral [PtCr(tba)4(NCS)]∞ 8 forms a coordination polymer of {PtCr}(+) units linked by (NCS)(-) in a zigzag chain. All eight compounds have been thoroughly characterized and analyzed in comparison to a previously reported family of compounds. Crystal structures are presented for compounds 1-6 and 8, and solution magnetic susceptibility measurements are presented for compounds 1, 2, 4, 5, and 7. Further structural analysis of dimerized {PtM} units reinforces the empirical observation that greater charge density along the Pt-M vector leads to more Pt···Pt interactions in the solid state. Four structural classes, one new, of {MPt}···{PtM} units are presented. Solid state magnetic characterization of 8 reveals a ferromagnetic interaction in the {PtCr(NCS)} chain between the Cr centers of J/kB = 1.7(4) K.

  13. Synthesis and catalytic activity of Ln(III) complexes with an unsymmetrical Schiff base including multigroups

    YAO; Kemin; (


    [1]Elder, R. C., Tridentate and unsymmetrical tetradentate Schiff base ligands from salicylaldehydes and dimeric nickel(II) complexes, Aust. J. Chem., 1978, 31:35-45.[2]Atkins, R., Brewer, G., Kokot, G. et al., Copper(II) and nickel(II) complexesof unsymmetrical tetradentate Schiff base ligand, Inorg. Chem., 1985, 24: 127-134.[3]Meng Qingjin, Wang Ruixue, Bu Xiuren et al., New Ni (II) complexes with mixedtrimeric double Schiff ligands, Chemical Journal of Chinese Universities (in Chinese), 1990, 10: 1126-1130.[4]Yao Kemin, Zhou Wen, Lu Gui et al., Synthesis, mechanism and NMR spectra of lanthanide complexes with a novel unsymmetrical Schiff base, Science in China, Series B, 1999, 42(2): 164-169.[5]Yao Kemin, Li Ning, Huang Qiaohong et al., Synthesis and catalytic activity of novel heteronuclear Ln(III)-Cu(II) complexes with noncyclic polyether-amino acid Schiff base, Science in China, Series B, 1999, 42 (1) : 54-81.[6]Li Ning, Yao Kemin, Lou Kaiyan, Synthesis of La(III), Y(III) complexes with polyglycol aldehyde-amino acid Schiff base and their high resolution solid state 13C NMR spectra, Science in China, Series B, 1999, 42(6): 599-604.[7]Lam Berf, J. B., Shurvell, H. F., Verbet, L. et al., Organic Structural Analysis, New York: Macmillan Publishing Co. Inc., 1975, 234-250.[8]Yao Kemin, Cai Lezhen, Shen Liangfang et al., Synthesis and characterization of lanthanide perchlorates with noncyclic polyethylene glycols and their 13C-NMRspectra, Polyhedron, 1992,11(7): 2245-2251.[9]Dewar, M. J. S., Zoebisch, E. G., Healy, E. F., AM1: A new general purpose quantum mechanical molecular model, J. Amer. Chem. Soc., 1985, 107: 3902-3909.[10]Feifer, P., Avnjr, D., Chemistry in noninteger dimensions between two and three, I. Fractal theory of heterogeneous surfaces, J. Chem. Phys., 1983, 79(7): 3558-3565.[11]Yang Haifeng, Wang Hui, Duan Jinxia et al., Ab initio research of organic ligand Schiff base 4-[(2-hydroxyphenyl) imine]-2

  14. Photophysical properties of a novel organic-inorganic hybrid material: Eu(III)-β-diketone complex covalently bonded to SiO(2) /ZnO composite matrix.

    Li, Ya-Juan; Yan, Bing


    In this article, dibenzoylmethane (DBM) was first grafted with the coupling reagent 3-(triethoxysilyl)-propyl isocyanate (TESPIC) to form precursor DBM-Si, and ZnO quantum dot was modified with 3-mercaptopropyltrimethoxysilane (MPS) to form SiO(2) /ZnO nanocomposite particle. Then the precursor DBM-Si and the terminal ligand 1,10-phenthroline (phen) were coordinated to Eu(3+) ion to obtain ternary hybrid material phen-Eu-DBM-SiO(2) /ZnO after hydrolysis and copolycondensation between the tetraethoxysilane (TEOS), water molecules and the SiO(2) /ZnO network via the sol-gel process. In addition, for comparison, the binary hybrid material with SiO(2) /ZnO network and ternary hybrid material with pure Si-O network were also synthesized, denoted as Eu-DBM-SiO(2) /ZnO and phen-Eu-DBM-Si, respectively. The results reveal that hybrid material with SiO(2) /ZnO network phen-Eu-DBM-SiO(2) /ZnO exhibits the stronger red light, the longer lifetimes and higher quantum efficiency than hybrid material with pure Si-O network phen-Eu-DBM-Si, suggesting that SiO(2) /ZnO is a favorable host matrix for the luminescence of rare earth complexes.

  15. Two Zn(II) coordination complexes assembled by trithiocyanuric acid and two different N-donor auxiliary ligands.

    He, Xiao Xiao; Guo, Ya Mei


    The dipyridyl-type building blocks 4-amino-3,5-bis(pyridin-3-yl)-1,2,4-triazole (3-bpt) and 4,4'-bipyridine (bpy) have been used to assemble with Zn(II) in the presence of trithiocyanuric acid (ttcH3) to afford two coordination compounds, namely bis[4-amino-3,5-bis(pyridin-3-yl)-1,2,4-triazole-κN(3)]bis(trithiocyanurato-κ(2)N,S)zinc(II), [Zn(C3H2N3S3)2(C12H10N6)2]·2H2O, (1), and catena-poly[[[bis(trithiocyanurato-κ(2)N,S)zinc(II)]-μ-4,4'-bipyridine-κ(2)N:N'] 4,4'-bipyridine monosolvate], {[Zn2(C3H2N3S3)4(C10H8N2)3]·C10H8N2}n, (2). Single-crystal X-ray analysis indicates that complex (1) is a mononuclear structure, while complex (2) presents a one-dimensional chain coordination motif. In both complexes, the central Zn(II) cation adopts an octahedral geometry, coordinated by four N- and two S-donor atoms. Notably, trithiocyanurate (ttcH2(-)) adopts the same bidentate chelating coordination mode in each complex and exists in the thione tautomeric form. The 3-bpt co-ligand in (1) adopts a monodentate coordination mode and serves as a terminal pendant ligand, whereas the 4,4'-bipyridine (bpy) ligand in (2) adopts a bidentate-bridging coordination mode. The different coordination characters of the different N-donor auxiliary ligands lead to structural diversity for complexes (1) and (2). Further analysis indicates that the resultant three-dimensional supramolecular networks for (1) and (2) arise through intermolecular N-H...S and N-H...N hydrogen bonds. Both complexes have been further characterized by FT-IR spectroscopy and elemental analyses.

  16. Synthesis, spectroscopic, photoluminescence properties and biological evaluation of novel Zn(II) and Al(III) complexes of NOON tetradentate Schiff bases

    Abdel Aziz, Ayman A.; Badr, Ibrahim H. A.; El-Sayed, Ibrahim S. A.


    Novel mononuclear Zn(II) and Al(III) complexes were synthesized from the reactions of Zn(OAc)2·2H2O and anhydrous AlCl3 with neutral N2O2 donor tetradentate Schiff bases; N,N'bis(salicylaldehyde)4,5-dimethyl-1,2-phenylenediamine (H2L1) and N,N'bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (H2L2). The new complexes were fully characterized by using micro analyses (CHN), FT-IR, 1H NMR, UV-Vis spectra and thermal analysis. The analytical data have been showed that, the stoichiometry of the complexes is 1:1. Spectroscopic data suggested tetrahedral and square pyramidal geometries for Zn(II) and Al(III) complexes, respectively. The synthesized Zn(II), and Al(III) complexes exhibited intense fluorescence emission in the visible region upon UV-excitation in methylene chloride solution at ambient temperature. This high fluorescence emission was assigned to the strong coordination of the ligands to the small and the highly charged Zn(II) and Al(III) ions. Such strong coordination seems to extend the π-conjugation of the complexes. Thermal analysis measurements indicated that the complexes have good thermal stability. As a potential application the biological activity (e.g., antimicrobial action) of the prepared ligands and complexes was assessed by in-vitro testing of their effect on the growth of various strains of bacteria and fungi.

  17. Synthesis, spectroscopic, photoluminescence properties and biological evaluation of novel Zn(II) and Al(III) complexes of NOON tetradentate Schiff bases.

    Abdel Aziz, Ayman A; Badr, Ibrahim H A; El-Sayed, Ibrahim S A


    Novel mononuclear Zn(II) and Al(III) complexes were synthesized from the reactions of Zn(OAc)(2).2H(2)O and anhydrous AlCl(3) with neutral N2O2 donor tetradentate Schiff bases; N,N'bis(salicylaldehyde)4,5-dimethyl-1,2-phenylenediamine (H(2)L(1)) and N,N'bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (H(2)L(2)). The new complexes were fully characterized by using micro analyses (CHN), FT-IR, (1)H NMR, UV-Vis spectra and thermal analysis. The analytical data have been showed that, the stoichiometry of the complexes is 1:1. Spectroscopic data suggested tetrahedral and square pyramidal geometries for Zn(II) and Al(III) complexes, respectively. The synthesized Zn(II), and Al(III) complexes exhibited intense fluorescence emission in the visible region upon UV-excitation in methylene chloride solution at ambient temperature. This high fluorescence emission was assigned to the strong coordination of the ligands to the small and the highly charged Zn(II) and Al(III) ions. Such strong coordination seems to extend the π-conjugation of the complexes. Thermal analysis measurements indicated that the complexes have good thermal stability. As a potential application the biological activity (e.g., antimicrobial action) of the prepared ligands and complexes was assessed by in-vitro testing of their effect on the growth of various strains of bacteria and fungi.

  18. Transport of Pb and Zn by carboxylate complexes in basinal ore fluids and related petroleum-field brines at 100°C: the influence of pH and oxygen fugacity

    Giordano Thomas H


    Full Text Available It is well established through field observations, experiments, and chemical models that oxidation (redox state and pH exert a strong influence on the speciation of dissolved components and the solubility of minerals in hydrothermal fluids. log –pH diagrams were used to depict the influence of oxygen fugacity and pH on monocarboxylate- and dicarboxylate-transport of Pb and Zn in low-temperature (100°C hydrothermal ore fluids that are related to diagenetic processes in deep sedimentary basins, and allow a first-order comparison of Pb and Zn transport among proposed model fluids for Mississippi Valley-type (MVT and red-bed related base metal (RBRBM deposits in terms of their approximate pH and conditions. To construct these diagrams, total Pb and Zn concentrations and Pb and Zn speciation were calculated as a function of log and pH for a composite ore-brine with concentrations of major elements, total sulfur, and total carbonate that approximate the composition of MVT and RBRBM model ore fluids and modern basinal brines. In addition to acetate and malonate complexation, complexes involving the ligands Cl-, HS-, H2S, and OH- were included in the model of calculated total metal concentration and metal speciation. Also, in the model, Zn and Pb are competing with the common-rock forming metals Ca, Mg, Na, Fe, and Al for the same ligands. Calculated total Pb concentration and calculated total Zn concentration are constrained by galena and sphalerite solubility, respectively. Isopleths, in log –pH space, of the concentration of Pb and concentration of Zn in carboxylate (acetate + malonate complexes illustrate that the oxidized model fluids of T. H. Giordano (in Organic Acids in Geological Processes, ed. E. D. Pittman and M. D. Lewan, Springer-Verlag, New York, 1994, pp. 319–354 and G. M. Anderson (Econ. Geol., 1975, 70, 937–942 are capable of transporting sufficient amounts of Pb (up to 10 ppm and Zn (up to 100 ppm in the form of carboxylate

  19. Electrochemical and theoretical complexation studies for Zn and Cu with individual polyphenols

    Esparza, I. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Salinas, I. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Santamaria, C. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain); Garcia-Mina, J.M. [INABONOS, Poligono Arazuri, 31160 Orcoyen, Navarra (Spain); Fernandez, J.M. [Departamento de Quimica y Edafologia, Universidad de Navarra, c/ Irunlarrea s/n, 31080 Pamplona, Navarra (Spain)]. E-mail:


    Zn and Cu interactions with three selected flavonoids (catechin, quercetin and rutin) have been electrochemically monitored. It has been shown that catechin takes one atom of metal per molecule; quercetin takes two atoms, and rutin is able to take up to three atoms. Not all ligands bind metals equally strong, and weakly bonded metals can be distinguished. Zn shows a sluggish kinetics and, at the same time, the highest conditional formation constants. The method could be applied to a real sample. Theoretical models are proposed for the most favourable compounds.

  20. Detection of DNA via the fluorescence quenching of Mn-doped ZnSe D-dots/doxorubicin/DNA ternary complexes system.

    Gao, Xue; Niu, Lu; Su, Xingguang


    This manuscript reports a method for the detection of double-stranded DNA, based on Mn:ZnSe d-dots and intercalating agent doxorubicin (DOX). DOX can quench the photoluminescence (PL) of Mn:ZnSe d-dots through photoinduced electron transfer process, after binding with Mn:ZnSe d-dots. The addition of DNA can result in the formation of the Mn:ZnSe d-dots-DOX-DNA ternary complexes, the fluorescence of the Mn:ZnSe d-dots-DOX complexes would be further quenched by the addition of DNA, thus allowing the detection of DNA. The formation mechanism of the Mn:ZnSe d-dots-DOX-DNA ternary complexes was studied in detail in this paper. Under optimal conditions, the quenched fluorescence intensity of Mn:ZnSe d-dots-DOX system are perfectly described by Stern-Volmer equation with the concentration of hsDNA ranging from 0.006 μg mL(-1) to 6.4 μg mL(-1). The detection limit (S/N = 3) for hsDNA is 0.5 ng mL(-1). The proposed method was successfully applied to the detection of DNA in synthetic samples and the results were satisfactory.

  1. Synthesis, characterization and antibacterial activities of Zn(II and Cd(II complexes of a quinazoline-4(3H-one Schiff base

    Brahman Dhiraj


    Full Text Available Zn(II and Cd(II complexes of a Schiff base derived from quinazoline-4(3H one and 2-formylphenoxy acetic acid were prepared and characterized by elemental and different spectroscopic (IR, UV-Visible and NMR analyses. The elemental analysis indicated the formation of the complexes: [ML(AcO].H2O, where M stands for Zn(II and Cd(II and L stands for quinazoline-4(3H-one Schiff base. The molar conductivities of the prepared complexes revealed their non-electrolytic nature. The complexes were also investigated for their antimicrobial activities by using turbidometric assay method.

  2. Theoretical study of electronic absorptions in aminopyridines - TCNE CT complexes by quantum chemical methods, including solvent.

    Mach, Pavel; Juhász, György; Kyseľ, Ondrej


    The geometric and electronic structure of donor-acceptor complexes of TCNE with aniline, o-, m- and p- aminopyridines and pyridine has been studied in gas phase and in solution using CC2, TDDFT and CIS methods. Concerning interaction energy between particular donor and TCNE acceptor it is fairly described by both CC2 (MP2) and DFT-D approaches. Transition energies in gas phase calculated by CC2 approach are in good agreement with available experimental data for aniline. TDDFT calculations with LC-BLYP functional (with standard value of range separation factor μ = 0.47) gives transition energies too high although not as high as CIS. The red solvent shifts, calculated by PCM model with CIS method are qualitative correct, but error in the range of 0.1-0.2 eV should be expected.

  3. Complex pattern of colon cancer recurrence including a kidney metastasis: A case report

    Helfried Waleczek; Moritz N Wente; Jürgen Kozianka


    We report a case of a 77-year-old female with a local recurrence of cancer after right hemicolectomy which infiltrated the pancreatic head affording pancreatoduodenectomy, who developed 3 years later recurrent tumor masses localized in the mesentery of the jejunum and in the lower pole of the left kidney. Partial nephrectomy and a segment resection of the small bowel were performed. Histological examination of both specimens revealed a necrotic metastasis of the primary carcinoma of the colon. Although intraluminal implantation of colon cancer cells in the renal pelvic mucosa from ureteric metastasis has been described, metastasis of a colorectal cancer in the kidney parenchyma is extremely rare and can be treated in an organ preserving manner. A complex pattern of colon cancer recurrence with unusual and rare sites of metastasis is reported.

  4. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    Guichard, Stéphane; Bigot, Dimitri; Malet-Damour, Bruno; Libelle, Teddy; Boyer, Harry


    This paper deals with the empirical validation of a building thermal model using a phase change material (PCM) in a complex roof. A mathematical model dedicated to phase change materials based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase understanding of the thermal behavior of the whole building with PCM technologies. To empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model have been identified for optimization. The use of a generic optimization program called GenOpt coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons o...

  5. Soft X-ray Spectroscopy of a Complex Heterojunction in High-Efficiency Thin-Film Photovoltaics: Intermixing and Zn Speciation at the Zn(O,S)/Cu(In,Ga)Se 2 Interface

    Mezher, Michelle; Garris, Rebekah; Mansfield, Lorelle M.; Blum, Monika; Hauschild, Dirk; Horsley, Kimberly; Duncan, Douglas A.; Yang, Wanli; Bär, Marcus; Weinhardt, Lothar; Ramanathan, Kannan; Heske, Clemens


    The chemical structure of the Zn(O,S)/Cu(In,Ga)Se2 interface in high-efficiency photovoltaic devices is investigated using X-ray photoelectron and Auger electron spectroscopy, as well as soft X-ray emission spectroscopy. We find that the Ga/(Ga+In) ratio at the absorber surface does not change with the formation of the Zn(O,S)/Cu(In,Ga)Se2 interface. Furthermore, we find evidence for Zn in multiple bonding environments, including ZnS, ZnO, Zn(OH)2, and ZnSe. We also observe dehydrogenation of the Zn(O,S) buffer layer after Ar+ ion treatment. Similar to high-efficiency CdS/Cu(In,Ga)Se2 devices, intermixing occurs at the interface, with diffusion of Se into the buffer, and the formation of S-In and/or S-Ga bonds at or close to the interface.

  6. Including Quantum Effects in the Dynamics of Complex (i.e., Large)Molecular Systems

    Miller, William H.


    The development in the 1950's and 60's of crossed molecular beam methods for studying chemical reactions at the single-collision molecular level stimulated the need and desire for theoretical methods to describe these and other dynamical processes in molecular systems. Chemical dynamics theory has made great strides in the ensuing decades, so that methods are now available for treating the quantum dynamics of small molecular systems essentially completely. For the large molecular systems that are of so much interest nowadays (e.g. chemical reactions in solution, in clusters, in nano-structures, in biological systems, etc.), however, the only generally available theoretical approach is classical molecular dynamics (MD) simulations. Much effort is currently being devoted to the development of approaches for describing the quantum dynamics of these complex systems. This paper reviews some of these approaches, especially the use of semiclassical approximations for adding quantum effects to classical MD simulations, also showing some new versions that should make these semiclassical approaches even more practical and accurate.

  7. Reality and Hermiticity from maximizing overlap in the future-included complex action theory

    Nagao, Keiichi


    In the complex action theory whose path runs over not only past but also future we study a normalized matrix element of an operator $\\hat{\\cal O}$ defined in terms of the future state at the latest time $T_B$ and the past state at the earliest time $T_A$ with a proper inner product which makes a non-normal Hamiltonian at first given normal. We present a theorem which states that provided that the operator $\\hat{\\cal O}$ is $Q$-Hermitian, i.e. Hermitian with regard to the proper inner product the normalized matrix element becomes real and time-develops under a $Q$-Hermitian Hamiltonian for the past and future states selected such that the absolute value of the transition amplitude from the past state to the future state is maximized. Furthermore, we give a possible procedure to formulate the $Q$-Hermitian Hamiltonian in terms of $Q$-Hermitian coordinate and momentum operators, and construct a conserved probability current density.

  8. Copy number gain at Xp22.31 includes complex duplication rearrangements and recurrent triplications.

    Liu, Pengfei; Erez, Ayelet; Nagamani, Sandesh C Sreenath; Bi, Weimin; Carvalho, Claudia M B; Simmons, Alexandra D; Wiszniewska, Joanna; Fang, Ping; Eng, Patricia A; Cooper, M Lance; Sutton, V Reid; Roeder, Elizabeth R; Bodensteiner, John B; Delgado, Mauricio R; Prakash, Siddharth K; Belmont, John W; Stankiewicz, Pawel; Berg, Jonathan S; Shinawi, Marwan; Patel, Ankita; Cheung, Sau Wai; Lupski, James R


    Genomic instability is a feature of the human Xp22.31 region wherein deletions are associated with X-linked ichthyosis, mental retardation and attention deficit hyperactivity disorder. A putative homologous recombination hotspot motif is enriched in low copy repeats that mediate recurrent deletion at this locus. To date, few efforts have focused on copy number gain at Xp22.31. However, clinical testing revealed a high incidence of duplication of Xp22.31 in subjects ascertained and referred with neurobehavioral phenotypes. We systematically studied 61 unrelated subjects with rearrangements revealing gain in copy number, using multiple molecular assays. We detected not only the anticipated recurrent and simple nonrecurrent duplications, but also unexpectedly identified recurrent triplications and other complex rearrangements. Breakpoint analyses enabled us to surmise the mechanisms for many of these rearrangements. The clinical significance of the recurrent duplications and triplications were assessed using different approaches. We cannot find any evidence to support pathogenicity of the Xp22.31 duplication. However, our data suggest that the Xp22.31 duplication may serve as a risk factor for abnormal phenotypes. Our findings highlight the need for more robust Xp22.31 triplication detection in that such further gain may be more penetrant than the duplications. Our findings reveal the distribution of different mechanisms for genomic duplication rearrangements at a given locus, and provide insights into aspects of strand exchange events between paralogous sequences in the human genome.

  9. Disclosure-and-resolution programs that include generous compensation offers may prompt a complex patient response.

    Murtagh, Lindsey; Gallagher, Thomas H; Andrew, Penny; Mello, Michelle M


    Under "disclosure-and-resolution" programs, health systems disclose adverse events to affected patients and their families; apologize; and, where appropriate, offer compensation. Early adopters of this approach have reported reduced liability costs, but the extent to which these results stem from effective disclosure and apology practices, versus compensation offers, is unknown. Using survey vignettes, we examined the effects of different compensation offers on individuals' responses to disclosures of medical errors compared to explanation and apology alone. Our results show that although two-thirds of these individuals desired compensation offers, increasing the offer amount did not improve key outcomes. Full-compensation offers did not decrease the likelihood of seeking legal advice and increased the likelihood that people perceived the disclosure and apology as motivated by providers' desire to avoid litigation. Hospitals, physicians, and malpractice insurers should consider this complex interplay as they implement similar initiatives. They may benefit from separating disclosure conversations and compensation offers and from excluding physicians from compensation discussions.

  10. Blastoid Variant Mantle Cell Lymphoma with Complex Karyotype Including 11q Duplication

    Özge Özer


    Full Text Available We describe a case of blastoid mantle cell lymphoma with a complex karyotype. The blastoid variant is a rare type of non-Hodgkin lymphoma exhibiting an aggressive clinical course. Mantle cell lymphoma is a distinct entity of mature B-cell neoplasms genetically characterized by the presence of t(11;14. In the present case, conventional analysis revealed structural abnormalities of chromosomes 2, 4, 6, 10, 13, and 19, along with 3 additional marker chromosomes. The derivative 1 chromosome determined in the case was a result of t(1p;11q. Our interesting finding was the presence of a different translocation between 11q and chromosome 1 in addition to t(11;14. Thus, the resulting 11q duplication was believed to additionally increase the enhanced expression of cyclin D1 gene, which is responsible in the pathogenesis of the disease. Fluorescence in situ hybridization method by the t(11;14 probe revealed clonal numerical abnormalities of chromosomes 11 and 14 in some cells. The detection of multiple abnormalities explains the bad prognosis in the present case. On the basis of our findings, we can easily conclude that results of cytogenetic analyses of similar mantle cell lymphoma patients would provide clues about new responsible gene regions and disease prognosis. In conclusion, it has been suggested that the presence of multiple chromosomal aberrations in addition to the specific t(11;14 may have a negative impact on clinical course and survival rate.

  11. Synthesis of fatty monoester lubricant base oil catalyzed by Fe-Zn double-metal cyanide complex

    Ravindra K Raut; Mehejabeen Shaikh; Srinivas Darbha


    Fatty monoester lubricant base oils as high as 96.7 mol% were prepared by reacting methyl oleate with long-chain alcohols viz., 2-ethyl-1-hexanol (C8−OH), 1-decanol (C10OH) and 1-dodecanol (C12OH) in the presence of a solid Fe-Zn double-metal cyanide (DMC) complex catalyst. Unlike many other acid catalysts, DMC doesn't produce undesired ether side products. The catalyst was reusable in four recycling experiments with little loss in catalytic activity and ester yield. The long-chain esters prepared in the study have the desired physical properties for their application as lubricant base oils.

  12. Unsaturated b-ketoesters and their Ni(II, Cu(II and Zn(II complexes



    Full Text Available A new series of b-ketoesters in which the keto group is attached to the olefinic linkage were synthesized by the reaction of methyl acetoacetate and aromatic aldehydes under specified conditions. The existence of these compounds predominantly in the intramolecularly hydrogen bonded enol form was well demonstrated from their IR, 1H-NMR and mass spectral data. Details on the formation of their [ML2] complexes with Ni(II, Cu(II and Zn(II and the nature of the bonding are discussed on the basis of analytical and spectral data.

  13. The Arabidopsis thaliana vernalization response requires a polycomb-like protein complex that also includes VERNALIZATION INSENSITIVE 3.

    Wood, Craig C; Robertson, Masumi; Tanner, Greg; Peacock, W James; Dennis, Elizabeth S; Helliwell, Chris A


    In Arabidopsis thaliana, the promotion of flowering by cold temperatures, vernalization, is regulated via a floral-repressive MADS box transcription factor, FLOWERING LOCUS C (FLC). Vernalization leads to the epigenetic repression of FLC expression, a process that requires the polycomb group (PcG) protein VERNALIZATION 2 (VRN2) and the plant homeodomain protein VERNALIZATION INSENSITIVE 3 (VIN3). We demonstrate that the repression of FLC by vernalization requires homologues of other Polycomb Repressive Complex 2 proteins and VRN2. We show in planta that VRN2 and VIN3 are part of a large protein complex that can include the PcG proteins FERTILIZATION INDEPENDENT ENDOSPERM, CURLY LEAF, and SWINGER. These findings suggest a single protein complex is responsible for histone deacetylation at FLC and histone methylation at FLC in vernalized plants. The abundance of the complex increases during vernalization and declines after plants are returned to higher temperatures, consistent with the complex having a role in establishing FLC repression.

  14. Synthesis, Characterization, Activity of Yttrium(Ⅲ) Antibacterial and Antifungal Complexes Including 1,10-P henanth roli ne

    蔡梦军; 陈建定; Taha, Mohamed


    Two rare metal coordination complexes of yttrium(Ⅲ) including 1,10-phenanthroline, Y(phen)2(NO3)3 and (phenH)2[Y2(pydc)3(NO3)2.6H2O] (phen= 1,10-phenanthroline, pydc=2,6-pyridinedicarboxylate), and a proton transfer compound (phenH+)2(pydc2-) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra (IR), nuclear magnetic resonance (NMR) and thermal analysis. The proposed structures of yttrium complexes were exhibited. The in vitro biological activities of the newly synthesized complexes have also been investigated against Bacillus coli, Staphylococcus aureus and Candida albicans. The results showed that yttrium(Ⅲ) complexes including 1,10-phenanthroline exhibited better antibacterial/antifungal activity than their ligands and corresponding compounds.

  15. Antibacterial Activities of Newly Synthesized Azo Anils And its Oxalato-Bridged Binuclear {Cu(II and Zn(II} Complexes

    M. Ameen


    Full Text Available Novel oxalato-bridged binuclear metal {Cu(II and Zn(II} complexes; [{(L1M(II}2OX] (L1= 2-({2-hydroxy-5-[(4-nitrophenyldiazenyl]benzylidene}aminobenzoic acid, OX = oxalate and [{(L2M(II}2OX], (L2 = 2-{[(2-hydroxyphenylimino]methyl}-4-[(4-nitrophenyldiazenyl] phenol, OX = oxalate were synthesized. Azo anils and corresponding Metal {Cu((II and Zn(II} complexes were characterised by Elemental Combustion System, Atomic Absorption Spectroscopy (AAS, Fourier Transform Infrared (FTIR spectroscopy, UV-Visible, Spectroscopy and 13C-1H-Nuclear Magnetic Resonance spectroscopy. Elemental Analyses, FTIR and UV-Vis were used for structural characterization of metal complexes and distorted octahedral geometry for M(II complexes came into being. The antibacterial activities of azo anils ligands, oxalate ion, CuCl2.2H2O, Zn(CH3COO2.2H2O and metal {Cu(II and Zn(II} complexes against gram-positive (Bacillis subtilis and gram-negative (Escherichia coli were evaluated. The antibacterial activities were performed to asses inhibition potential of ligand and their metal {Cu(II and Zn(II} complexes. The results revealed that antibacterial activities of azo anils become more pronounced when free ligands were coordinated to central metal atom.

  16. Synthetic Source Inversion Tests with the Full Complexity of Earthquake Source Processes, Including Both Supershear Rupture and Slip Reactivation

    Song, Seok Goo; Dalguer, Luis A.


    Recent studies in dynamic source modeling and kinematic source inversion show that earthquake rupture may contain greater complexity than we previously anticipated, including multiple slipping at a given point on a fault. Finite source inversion methods suffer from the nonuniqueness of solutions, and it may become more serious if we aim to resolve more complex rupture models. In this study, we perform synthetic inversion tests with dynamically generated complex rupture models, including both supershear rupture and slip reactivation, to understand the possibility of resolving complex rupture processes by inverting seismic waveform data. We adopt a linear source inversion method with multiple windows, allowing for slipping from the nucleation of rupture to the termination at all locations along a fault. We regularize the model space effectively in the Bayesian framework and perform multiple inversion tests by considering the effect of inaccurate Green's functions and station distributions. We also perform a spectral stability analysis. Our results show that it may be possible to resolve both a supershear rupture front and reactivated secondary slipping using the linear inversion method if those complex features are well separated from the main rupture and produce a fair amount of seismic energy. It may be desirable to assume the full complexity of an earthquake rupture when we first develop finite source models after a major event occurs and then assume a simple rupture model for stability if the estimated models do not show a clear pattern of complex rupture processes.

  17. Surface characterization of ZnO/ZnMn{sub 2}O{sub 4} and Cu/Mn{sub 3}O{sub 4} powders obtained by thermal degradation of heterobimetallic complexes

    Barrault, Joeel, E-mail: [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France); Makhankova, Valeriya G., E-mail: [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Khavryuchenko, Oleksiy V.; Kokozay, Vladimir N. [Department of Inorganic Chemistry, Kyiv National Taras Shevchenko University, Volodymyrska str. 64, Kyiv 01601 (Ukraine); Ayrault, Philippe [CNRS-Universite de Poitiers, LACCO/Laboratoire de catalyse en Chimie Organique, UMR6503, ENSIP, 1 rue Marcel Dore, 86022 Poitiers cedex (France)


    From the selective transformation of the heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes with 2,2 Prime -bipyridyl by thermal degradation at relatively low (350 Degree-Sign C) temperature, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Morphology of the powder surface was examined by scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX). Surface composition was determined by X-ray photoelectron spectroscopy (XPS). Specific surface of the powders by nitrogen adsorption was found to be 33{+-}0.2 and 9{+-}0.06 m{sup 2} g{sup -1} for Zn-Mn and Cu-Mn samples, respectively, which is comparable to those of commercial products. - Graphical abstract: From the selective transformation of heterometallic (Zn-Mn or Cu-Mn) carboxylate complexes, it was possible to get either well defined spinel ZnMn{sub 2}O{sub 4} over zinc oxide or well dispersed copper particles surrounded by a manganese oxide (Mn{sub 3}O{sub 4}) in a core-shell like structure. Highlights: Black-Right-Pointing-Pointer Thermal degradation of heterometallic complexes results in fine disperse particles. Black-Right-Pointing-Pointer Core-shell Cu/Mn{sub 3}O{sub 4} particles are obtained. Black-Right-Pointing-Pointer ZnMn{sub 2}O{sub 4} spinel layer covers ZnO particles.

  18. NMR structure of d(CGCA3T3GCG)2:tren-microgonotropen-b:Zn(II) complex and solution studies of metal ion complexes of tren-microgonotropen-b interacting with DNA.

    Blaskó, A; Browne, K A; Bruice, T C


    The solution structure of a 1:1 complex of zinc tren-microgonotropen-b [6b:Zn(II)] with d(CGCAAATTTGCG)2 has been determined by 2D nuclear Overhauser effect 1H NMR spectroscopy and restrained molecular modeling. The exchangeable and nonexchangeable proton resonances of d(CGCA3T3GCG)2:6b:Zn(II) indicate that the Zn(II) is interacting in the A+T-rich region of the dsDNA and the tren region of 6b, while 31P NMR shows interaction of the Zn(II) with the phosphate backbone. Proton chemical shift differences between d(CGCA3T3GCG)2:6b:Zn(II) and d(CGCA3T3GCG)2:6b are in agreement with the polyamino substituent of 6b [-(CH2)4N(CH2CH2)N-(CH2CH2NH2)2] forming a four-coordinated Zn(II) complex similar to that found in the X-ray structure of 'tren-chloride':Zn(II). The P9 and P10 phosphate oxygens that are held by hydrogen bonding to the tren substituent of 6b in the DNA:6b complex become ligands to the tren-complexed Zn(II) in DNA:6b:Zn(II). To do so there is a 2 A decrease in the adjacent phosphate-to-phosphate distance at the Zn(II) binding site. This motion brings about an increased bend of 14.6 degrees in the helical axis of d(CGCA3T3GCG)2:6b:Zn(II) compared to that found in d(CGCA3T3GCG)2:6b. Single stranded cleavage of linear DNA fragments was not observed in the presence of 6b and Fe(II), Co(II), Ni(II), Cu(II), Zn(II), La(III) or Ce(III); this is likely due to the metal ion being sequestered as in the structure of d(CGCA3T3GCG)2:6b:Zn(II) complex. Supercoiled DNA was susceptible to cleavage by 6b:Cu(II) in the presence of O2 and a reducing agent.

  19. Synthesis and characterization of mixed ligand complexes of Zn(II) and Co(II) with amino acids: Relevance to zinc binding sites in zinc fingers

    P Rabindra Reddy; M Radhika; P Manjula


    Mixed ligand complexes of Zn(II) and Co(II) with cysteine, histidine, cysteinemethylester, and histidinemethylester have been synthesized and characterized by elemental analysis, conductivity, magnetic susceptibility measurements, and infrared, 1H NMR, TGA and FAB mass spectra. In these complexes, histidine, and histidinemethylester act as bidentate ligands involving amino and imidazole nitrogens in metal coordination. Similarly, cysteine, and cysteinemethylester also act as bidentate ligands coordinating through thiol sulphur and amino nitrogen. Tetrahedral geometry has been proposed for Zn(II) and Co(II) complexes based on experimental evidence.

  20. N,N’-diisopropylthiourea and N,N’-dicyclohexyl-thiourea zinc(II complexes as precursors for the synthesis of ZnS nanoparticles

    J. Raftery


    Full Text Available The single X-ray crystal structures of zinc (II complexes of N,N’-diisopropylthiourea and N,N’ dicyclohexylthiourea weredetermined.These complexes, similar to other alkylthioureas, were found to be effective as precursors for the preparation of hexadecylamine-capped ZnS nanoparticles. The complexes are air-stable, easy to prepare and inexpensive. They pyrolyse cleanly to give high-quality ZnS nanoparticles, which show quantum confinement effects in their absorption spectra and close to band-edge emission. Their broad diffraction patterns are typicalof nanosized particles while their transmission electronmicroscopy images showed agglomerates of needle-like platelet nanoparticles.

  1. Correlation between slow magnetic relaxation and the coordination structures of a family of linear trinuclear Zn(II)-Ln(III)-Zn(II) complexes (Ln = Tb, Dy, Ho, Er, Tm and Yb).

    Maeda, Moe; Hino, Shiori; Yamashita, Kei; Kataoka, Yumiko; Nakano, Motohiro; Yamamura, Tomoo; Kajiwara, Takashi


    Six linear trinuclear [Ln{Zn(L)(AcO)}(2)]BPh(4) complexes (H(2)L denotes the Schiff-base ligand formed by a condensation reaction between ethylenediamine and two equivalents of o-vanillin), including Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5) and Yb (6) were synthesized and were confirmed to be isostructural via X-ray crystallographic analyses. The Ln(III) ion in each complex is deca-coordinated by four equatorial oxygen donors from the methoxo groups of the Schiff-base ligands, two oxygen donors from the acetate anions and four axial oxygen donors from the phenoxo groups of the Schiff-base ligands. AC susceptibility measurements, with an oscillating frequency of 10 to 10,000 Hz, revealed that 1, 2, 4 and 6 show slow magnetic relaxation under a 1000 Oe DC bias field, which occurs via a single process, as confirmed by the semi-circular Cole-Cole plots. These complexes are considered to be field-induced single-molecule magnets under these conditions. The presence or absence of the slow magnetic relaxation process is discussed by correlating the characteristic magnetic anisotropy of each Ln(III) ion with the ligand field anisotropy.

  2. Biological activities of Zn(II)-S-methyl-cysteine complex as antiradical, inhibitor of acid phosphatase enzyme and in vivo antidepressant effects.

    Escudero, Graciela E; Martini, Nancy; Jori, Khalil; Jori, Nadir; Maresca, Nahuel R; Laino, Carlos H; Naso, Luciana G; Williams, Patricia A M; Ferrer, Evelina G


    The antidepressant effect of simple Zn(II) salts has been proved in several animal models of depression. In this study, a coordination metal complex of Zn(II) having a sulfur containing ligand is tested as antidepressant for the first time. Forced swimming test method on male Wistar rats shows a decrease in the immobility and an increase in the swimming behavior after treatment with [Zn(S-Met)2] (S-Met=S-methyl-l-cysteine) being more effective and remarkable than ZnCl2. The thiobarbituric acid and the pyranine consumption (hydroxyl and peroxyl radicals, respectively) methods were applied to evaluate the antioxidant activity of S-Met and [Zn(S-Met)2] showing evidence of attenuation of hydroxyl but not peroxyl radicals activities. UV-vis studies on the inhibition of acid phosphatase enzyme (AcP) demonstrated that S-methyl-l-cysteine did not produce any effect but, in contrast, [Zn(S-Met)2] complex behaved as a moderate inhibitor. Finally, bioavailability studies were performed by fluorescence spectroscopy denoting the ability of the albumin to transport the complex.

  3. The effect of pH on the complexation of Cd, Ni and Zn by dissolved organic carbon from leachate-polluted groundwater

    Christensen, J. B.; Christensen, Thomas Højlund


    Complexation of cadmium (Cd), nickel (Ni) and zinc (Zn) by dissolved organic carbon (DOC) in leachate-polluted groundwater was measured using a resin equilibrium method. Metal-DOC complexation was measured at di€erent DOC concentrations over a range of pH values . The results were compared...

  4. Difference of Electron Capture and Transfer Dissociation Mass Spectrometry on Ni2+-, Cu2+-, and Zn2+-Polyhistidine Complexes in the Absence of Remote Protons

    Asakawa, Daiki; De Pauw, Edwin


    Electron capture dissociation (ECD) and electron transfer dissociation (ETD) in metal-peptide complexes are dependent on the metal cation in the complex. The divalent transition metals Ni2+, Cu2+, and Zn2+ were used as charge carriers to produce metal-polyhistidine complexes in the absence of remote protons, since these metal cations strongly bind to neutral histidine residues in peptides. In the case of the ECD and ETD of Cu2+-polyhistidine complexes, the metal cation in the complex was reduced and the recombination energy was redistributed throughout the peptide to lead a zwitterionic peptide form having a protonated histidine residue and a deprotonated amide nitrogen. The zwitterion then underwent peptide bond cleavage, producing a and b fragment ions. In contrast, ECD and ETD induced different fragmentation processes in Zn2+-polyhistidine complexes. Although the N-Cα bond in the Zn2+-polyhistidine complex was cleaved by ETD, ECD of Zn2+-polyhistidine induced peptide bond cleavage accompanied with hydrogen atom release. The different fragmentation modes by ECD and ETD originated from the different electronic states of the charge-reduced complexes resulting from these processes. The details of the fragmentation processes were investigated by density functional theory.

  5. Synthesis, Characterisation, and Biological Evaluation of Zn(II Complex with Tridentate (NNO Donor Schiff Base Ligand

    Nayaz Ahmed


    Full Text Available The present paper deals with the synthesis and characterization of metal complex of tridentate Schiff base ligand derived from the inserted condensation of 2-aminobenzimidazole (1H-benzimidazol-2-amine with salicylaldehyde (2-hydroxybenzaldehyde in a 1 : 1 molar ratio. Using this tridentate ligand, complex of Zn(II with general formula ML has been synthesized. The synthesized complex was characterized by several techniques using molar conductance, elemental analysis, FT-IR, and mass and 1HNMR spectroscopy. The elemental analysis data suggest the stoichiometry to be 1 : 1 [M : L]. The complex is nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen, imidazole nitrogen of benzimidazole ring, and azomethine nitrogen atom. Spectral studies suggest tetrahedral geometry for the complex. The pure compound, synthesized ligand, and metal complex were screened for their antimicrobial activity.

  6. Antiviral Activity of Substituted Chalcones and their Respective Cu(ii, Ni(ii and Zn(ii Complexes

    K. G. Mallikarjun


    Full Text Available Complexes of Cu(II, Ni(II and Zn(II with of 3-(phenyl-1-(2’-hydroxynaphthyl – 2 – propen – 1 – one (PHPO , 3 - (4-chlorophenyl - 1- (2’-hydroxynaphthyl–2–propen – 1 – one (CPHPO, 3 - (4 -methoxyphenyl -1-(2’-hydroxynapthyl-2-propen-1-one(MPHPO,3 - (3,4-dimethoxyphenyl –1-(2’-hydroxynaphthyl – 2 - propen– 1 – one (DMPHPO have been prepared and the purity of the samples were checked by elemental analysis. The ligands and their Cu(II, Ni(II and Zn(II complexes were tested on the infectivity of tobacco ring spot virus(TRSV using cowpea (Vigna Sinensis as a local lesions assay host. All the compounds were tested at different concentrations (250 ppm to 1500 ppmon the infectivity of the virus by applying them either with virus inoculum or 24 h before of after virus inoculation to the test plants. The compounds were found to have varied effects on virus infectivity depending on compounds concentration and method of application. The statistical significance of the data was determined by using analysis of variance.

  7. Syntheses, crystal structures and antioxidant study of Zn(II) complexes with morin-5'-sulfonic acid (MSA).

    Pieniążek, Elżbieta; Kalembkiewicz, Jan; Dranka, Maciej; Woźnicka, Elżbieta


    The study of modified synthetic procedure of water soluble morin-5'-sulfonic acid sodium salt (NaMSA) involving less aggressive chemicals and carried out at mild conditions was described. The NaMSA salt is a convenient source of anionic morin-5'-sulfonic ligand (MSA) in ion exchange reactions. The coordination ability of MSA ligand towards the zinc cations was investigated in aqueous solution and in solid state. Novel zinc complexes of morin-5'-sulfonate were obtained by a reaction of Zn(NO3)2 with morin-5'-sulfonate in water. Resulting compounds were characterized by single-crystal X-ray diffraction analysis, as well as spectral and thermal methods. The coordination interaction, hydrogen bond and π-π stacking lead to the formation of a 1D chain or 3D coordination polymers. The antioxidant activity of the Zn(II)-MSA complexes was evaluated by means of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. In this work, we have shown that the studied compounds are more effective free radical scavengers than the natural flavonoids like plain morin.

  8. Synthesis, crystal structure and computational chemistry research of a Zinc(II complex: [Zn(Pt(Biim2

    Teng Fei


    Full Text Available The title metal-organic coordination complex [Zn(pt(Biim2] (pt=phthalic acid, benzene-1,2-dicarboxylate, Biim=2,2'-biimidazole 1 has been obtained by using hydrothermal synthesis and characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/n with a = 8.5466(15 Å, b = 11.760(2 Å, c = 20.829(4 Å, β = 95.56(2º, V = 2083.5(6 Å3, Mr =497.78, Dc = 1.587 g/cm3, μ(MoKα = 1.226 mm−1, F(000 = 1016, Z = 4, the final R = 0.0564 and wR = 0.1851 for 3656 observed reflections (I > 2σ(I. The elemental analysis, IR, TG and the theoretical calculation were also investigated.

  9. Urea/thiourea derivatives and Zn(II)-DPA complex as receptors for anionic recognition—A brief account

    Priyadip Das; Prasenjit Mahato; Amrita Ghosh; Amal K Mandal; Tanmay Banerjee; Sukdeb Saha; Amitava Das


    This review covers few examples of anion complexation chemistry, with a special focus on urea/thiourea-based receptors and Zn(II)-dipicolyl amine-based receptors. This article specially focuses on structural aspects of the receptors and the anions for obtaining the desire specificity along with an efficient receptor-anion interaction. Two types of receptors have been described in this brief account; first one being the strong hydrogen bond donor urea/thiourea derivatives, which binds the anionic analytes through hydrogen bonded interactions; while, the second type of receptors are coordination complexes, where the coordination of the anion to the metal centre. In both the cases the anion binding modulate the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and thereby the spectroscopic response. Appropriate choice of the signalling unit may allow probing the anion binding phenomena through visual detection.

  10. A Hirshfeld surface analysis, crystal structure and spectroscopic properties of new Zn(II) complex with N-aminoethylpiperazine ligand

    El Glaoui, Maroua; El Glaoui, Maher; Jelsch, Christian; Aubert, Emmanuel; Lefebvre, Frédéric; Ben Nasr, Chérif


    A new organic-inorganic hybrid material, 1-amonioethylpiperazine-1, 4-diium tetrachloridozincate(II) chloride, (C6H18N3)[ZnCl4]Cl, has been synthesized and characterized by various physicochemical techniques including UV-visible absorption, Infra-Red (IR), Raman and NMR spectroscopies. The compound crystallizes in the monoclinic system and P21 space group with Z = 2 and the following unit cell dimensions: a = 7.1728 (6), b = 12.4160 (11), c = 8.0278 (7) Å, β = 97.513 (1)°, V = 708.80 (11) Å3. In this structure, the Zn2+ ion, surrounded by four chlorides, adopts a distorted tetrahedral coordination geometry. The structure of this compound consists of monomeric 1-amonioethylpiperazine-1, 4-diium trications and monomeric [ZnCl4]2- and Cl- anions. These entities are interconnected by means of hydrogen bonding contacts [Nsbnd H⋯Cl, Csbnd H⋯Cl], forming a three-dimensional network. Intermolecular interactions were investigated by Hirshfeld surfaces. More than three quarters of the interaction surface in the crystal packing is constituted by attractive and favored H⋯Cl hydrogen bonds. The 13C and 15N CP-MAS NMR spectra are discussed and the vibrational absorption bands were identified by infrared and Raman spectroscopy.

  11. Effect of adsorbed metals ions on the transport of Zn- and Ni-EDTA complexes in a sand and gravel aquifer

    Kent, D.B.; Davis, J.A.; Anderson, L.C.D.; Rea, B.A.; Coston, J.A.


    Adsorption, complexation, and dissolution reactions strongly influenced the transport of metal ions complexed with ethylenediaminetetraacetic acid (EDTA) in a predominantly quartz-sand aquifer during two tracer tests conducted under mildly reducing conditions at pH 5.8 to 6.1. In tracer test M89, EDTA complexes of zinc (Zn) and nickel (Ni), along with excess free EDTA, were injected such that the lower portion of the tracer cloud traveled through a region with adsorbed manganese (Mn) and the upper portion of the tracer cloud traveled through a region with adsorbed Zn. In tracer test S89, Ni- and Zn-EDTA complexes, along with excess EDTA complexed with calcium (Ca), were injected into a region with adsorbed Mn. The only discernable chemical reaction between Ni-EDTA and the sediments was a small degree of reversible adsorption leading to minor retardation. In the absence of adsorbed Zn, the injected Zn was displaced from EDTA complexes by iron(III) [Fe(III)] dissolved from the sediments. Displacement of Zn by Fe(III) on EDTA became increasingly thermodynamically favorable with decreasing total EDTA concentration. The reaction was slow compared to the time-scale of transport. Free EDTA rapidly dissolved aluminum (Al) from the sediments, which was subsequently displaced slowly by Fe. In the portion of tracer cloud M89 that traveled through the region contaminated with adsorbed Zn, little displacement of Zn complexed with EDTA was observed, and Al was rapidly displaced from EDTA by Zn desorbed from the sediments, in agreement with equilibrium calculations. In tracer test S89, desorption of Mn dominated over the more thermodynamically favorable dissolution of Al oxyhydroxides. Comparison with results from M89 suggests that dissolution of Al oxyhydroxides in coatings on these sediment grains by Ca-EDTA was rate-limited whereas that by free EDTA reached equilibrium on the time-scale of transport. Rates of desorption are much faster than rates of dissolution of Fe

  12. Theoretical investigations of the structures and electronic spectra of Zn(II) and Ni(II) complexes with cyclohexylamine-N-dithiocarbamate

    Yu, Xiaohan; Wang, Na; He, Hongqing; Wang, Li


    The ground-state structures of two ligands cyclohexylamine-N-dithiocarbamate (L) and PPh3 and four complexes [Zn(L)2] (A), [Ni(L)2] (B), [Zn(L)2PPh3] (C), and [Ni(L)2PPh3] (D) are optimized by M06, B3LYP, and B3PW91 methods with the same mixed basis set. As compared with the experimental data of other complexes containing the Ni-P bond, the result obtained by M06/6-31+G(d)-LANL2DZ method is finally regarded as accurate and reliable for this project. Based on the optimized geometries, the compositions of molecular orbitals are analyzed and the absorption spectra are simulated. When one more ligand PPh3 is coordinated, the lowest-lying transition energy presents red-shift; while it shows blue-shift when the metal coordination center change from Ni to Zn with the same ligands. The detailed transition characters related with the absorption spectrum are assigned. In all the key transitions, it is hard to find the contribution from Zn atom. On the contrary, the d orbital of Ni atom contributes a lot for the HOMO and LUMO of complexes B and D. Consequently, the transition characters of Zn(II) and Ni(II) complexes are different.

  13. Influence of Chemical Effect on the Kβ/Kα Intensity Ratios and Kβ Energy Shift of Co, Ni, Cu, and Zn Complexes

    G. Apaydma, V. Ayhkg; Z. Biyiklioglu; E. Tirasoglu; H. Kantekin


    Chemical effects on the Kβ/Kα intensity ratios and ΔE energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a 241 Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed the effects of different ligands on the Kβ/Kα intensity ratios and ΔE energy differences for Co, Ni, Cu, and Zn complexes. We tried to investigate chemical effects on central atoms using the behaviors of different ligands in these complexes. The experimental values of Kβ/Kα were compared with the theoretical and other experimental values of pure Co, Ni, Cu, and Zn.

  14. Zn(2+)-cyclen-based complex enable a selective detection of single-stranded thymine-rich DNA in aqueous buffer.

    Zhu, Zece; Wang, Sheng; Wei, Danqing; Yang, Chuluo


    It is a big challenge to develop fluorescent probes for selective detection of DNA with specific sequences in aqueous buffers. We report a new tetraphenylethene-based Zn(2+)-cyclen complex (TPECyZn), and a chemo-sensing ensemble of the Zn complex with phenol red. TPECyZn showed significant fluorescence enhancement upon binding to thymine-rich DNA in HEPES buffers. But its selectivity was not high enough to eliminate the interference from some random DNA. By constructing the chemo-sensing ensemble of TPECyZn with phenol red, the background fluorescence was eliminated due to the energy transfer from TPECyZn to phenol red. Moreover, this chemo-sensing ensemble revealed high selectivity in detecting thymine-rich single-stranded DNA over other DNA in aqueous buffer. It can detect poly deoxythymidylic acid sequence as short as 2 nt. This detection in aqueous media makes this probe feasible in real application. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Chiral discrimination asserted by enantiomers of Ni (II), Cu (II) and Zn (II) Schiff base complexes in DNA binding, antioxidant and antibacterial activities.

    Khan, Noor-ul Hasan; Pandya, Nirali; Prathap, K Jeya; Kureshy, Rukhsana Ilays; Abdi, Sayed Hasan Razi; Mishra, Sandhya; Bajaj, Hari Chandra


    Chiral Schiff base ligands (S)-H(2)L and (R)-H(2)L and their complexes (S-Ni-L, R-Ni-L, S-Cu-L, R-Cu-L, S-Zn-L and R-Zn-L) were synthesized, characterized and examined for their DNA binding, antioxidant and antibacterial activities. The complexes showed higher binding affinity to calf thymus DNA with binding constant ranging from 2.0×10(5) to 4.5×10(6) M(-1). All the complexes also exhibited remarkable superoxide (56-99%) and hydroxyl scavenging (45-89%) activities as well as antibacterial activities against gram (+) and gram (-) bacteria. However, none of the complexes showed antifungal activity. Conclusively, S enantiomers of the complexes were found to be relatively more efficient for DNA interaction, antioxidant and antibacterial activities than their R enantiomers. This study reveals the possible utilization of chiral Schiff base complexes for pharmaceutical applications.

  16. Synthesis, characterization, photoluminescence, and electrochemical studies of novel mononuclear Cu(II) and Zn(II) complexes with the 1-benzylimidazolium ligand

    Bibi, Sherino; Mohammad, Sharifah; Manan, Ninie Suhana Abdul; Ahmad, Jimmy; Kamboh, Muhammad Afzal; Khor, Sook Mei; Yamin, Bohari M.; Abdul Halim, Siti Nadiah


    Two new mononuclear coordination complexes [Cu(bim)4Cl2]ṡ2H2O (1) and [Zn(bim)2Cl2] (2) containing the 1-benzylimidazole (bim) ligand were successfully synthesized. Both complexes were characterized by IR, UV-vis, and fluorescence spectroscopies, single crystal and powder X-ray diffraction measurements, and thermogravimetric analysis. Self-assembly during the recrystallization process resulted in the formation of octahedral and tetrahedral Cu(II) and Zn(II) complexes, respectively. The single crystals obtained are representative of the bulk material, as shown by the powder X-ray diffraction patterns. Cyclic voltammetry measurements showed that complex 1 undergoes a quasi-reversible redox reaction, while complex 2 undergoes reduction alone, and no oxidation peak was observed; this is due to the stability of the reduced form of complex 2.

  17. Bifunctional Zn(II)Ln(III) dinuclear complexes combining field induced SMM behavior and luminescence: enhanced NIR lanthanide emission by 9-anthracene carboxylate bridging ligands.

    Palacios, María A; Titos-Padilla, Silvia; Ruiz, José; Herrera, Juan Manuel; Pope, Simon J A; Brechin, Euan K; Colacio, Enrique


    There were new dinuclear Zn(II)-Ln(III) complexes of general formulas [Zn(μ-L)(μ-OAc)Ln(NO3)2] (Ln(III) = Tb (1), Dy (2), Er (3), and Yb (4)), [Zn(μ-L)(μ-NO3)Er(NO3)2] (5), [Zn(H2O)(μ-L)Nd(NO3)3]·2CH3OH (6), [Zn(μ-L)(μ-9-An)Ln(NO3)2]·2CH3CN (Ln(III) = Tb (7), Dy (8), Er (9), Yb(10)), [Zn(μ-L)(μ-9-An)Yb(9-An)(NO3)3]·3CH3CN (11), [Zn(μ-L)(μ-9-An)Nd(9-An)(NO3)3]·2CH3CN·3H2O (12), and [Zn(μ-L)(μ-9-An)Nd(CH3OH)2(NO3)]ClO4·2CH3OH (13) prepared from the reaction of the compartmental ligand N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H2L), with ZnX2·nH2O (X = NO3(-) or OAc(-)) salts, Ln(NO3)3·nH2O, and, in some instances, 9-anthracenecarboxylate anion (9-An). In all these complexes, the Zn(II) ions invariably occupy the internal N3O2 site whereas the Ln(III) ions show preference for the O4 external site, giving rise to a Zn(μ-diphenoxo)Ln bridging fragment. Depending on the Zn(II) salt and solvent used in the reaction, a third bridge can connect the Zn(II) and Ln(III) metal ions, giving rise to triple-bridged diphenoxoacetate in complexes 1-4, diphenoxonitrate in complex 5, and diphenoxo(9-anthracenecarboxylate) in complexes 8-13. Dy(III) and Er(III) complexes 2, 8 and 3, 5, respectively, exhibit field induced single molecule magnet (SMM) behavior, with Ueff values ranging from 11.7 (3) to 41(2) K. Additionally, the solid-state photophysical properties of these complexes are presented showing that ligand L(2-) is able to sensitize Tb(III)- and Dy(III)-based luminescence in the visible region through an energy transfer process (antenna effect). The efficiency of this process is much lower when NIR emitters such as Er(III), Nd(III), and Yb(III) are considered. When the luminophore 9-anthracene carboxylate is incorporated into these complexes, the NIR luminescence is enhanced which proves the efficiency of this bridging ligand to act as antenna group. Complexes 2, 3, 5, and 8 can be considered as dual materials

  18. Intense intrashell luminescence of Eu-doped single ZnO nanowires at room temperature by implantation created Eu-Oi complexes.

    Geburt, Sebastian; Lorke, Michael; da Rosa, Andreia L; Frauenheim, Thomas; Röder, Robert; Voss, Tobias; Kaiser, Uwe; Heimbrodt, Wolfram; Ronning, Carsten


    Successful doping and excellent optical activation of Eu(3+) ions in ZnO nanowires were achieved by ion implantation. We identified and assigned the origin of the intra-4f luminescence of Eu(3+) ions in ZnO by first-principles calculations to Eu-Oi complexes, which are formed during the nonequilibrium ion implantation process and subsequent annealing at 700 °C in air. Our targeted defect engineering resulted in intense intrashell luminescence of single ZnO:Eu nanowires dominating the photoluminescence spectrum even at room temperature. The high intensity enabled us to study the luminescence of single ZnO nanowires in detail, their behavior as a function of excitation power, waveguiding properties, and the decay time of the transition.

  19. Synthesis and spectroscopic and computational characterization of Zn4O(alicyclic or aromatic carboxylate)6 complexes as potential MOF precursors.

    Otvös, Sándor B; Berkesi, Ottó; Körtvélyesi, Tamás; Pálinkó, István


    Potential metal-organic-framework precursors, Zn(4)O complexes with various alicyclic or aromatic carboxylate ligands, were prepared, in many cases quantitatively, from ZnO and the relevant carboxylic acids in the presence of trace amounts of water. The complexes obtained were characterized with various classical (titration) and instrumental (IR and NMR spectroscopies) methods and molecular modeling (PM3 and PM6 semiempirical quantum chemical methods and HF/6-31G** ab initio calculations). Structural peculiarities reflected in the success or failure in the synthesis could be rationalized with the combination of IR and NMR spectroscopies and molecular modeling.

  20. Effect of 60Co gamma irradiation on dielectric and complex impedance properties of Dy3+ substituted Ni-Zn nanoferrites

    Veena, M.; Somashekarappa, A.; Shankaramurthy, G. J.; Jayanna, H. S.; Somashekarappa, H. M.


    Nanocrystalline Ni1-xZnxFe2-yDyyO4 (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0.0 and 0.1) ferrites were synthesized by combustion method. Ni-Zn-Dy nanoferrites were investigated by X-ray diffraction, scanning electron microscopy, dielectric and impedance properties, before and after γ-irradiation process by 60Co γ-radiation with a dose rate of 310 kGy. The lattice parameter of irradiated samples increased attributed to the conversion of smaller size Fe3+ ions to larger size Fe2+ ions on ionizing effect of gamma radiation. Experimental results reveal that reduction in dielectric constant (ε‧), loss tangent (tan δ), real (Z‧) and imaginary (Z‧‧) impedance and increase in ac conductivity (σac) have been increased with increasing in frequency. It was found that ε‧, tan δ, σac increase, Z‧‧ and Z‧‧ reach a maximum value and thereafter decrease with further Zn ion substitution. The values of ε‧, tan δ and σac decrease with Dy3+ substitution and enhanced after irradiation. The complex impedance analysis suggesting predominant contribution to conduction was through the grain boundary.

  1. The Dispersion Characteristics of the Complex Permeability of NiZnCu Ferrite and its Composite Materials

    Rastislav Dosoudil


    Full Text Available The paper deals with the frequency dependence of complex permeability for the Ni0.27Zn0.63Cu0.1Fe2O4 sintered ferrite produced by conventional ceramic method and its composite materials made of this ferrite (in the form of powder and non-magnetic polymer matrix (polyvnyl chloride - PVC. The experimental and theoretical curves of the complex permeability were compared. The contribution of both domain wall motion and spin rotational mangetisation processes on th complex permeability in high-frequency region (up to 1 GHz is discussed. In the case of composite materials, the simple magnetic circuit approach is taken into account. In composites, the real part of the complex permeability in the frequency region above 100 MHz is larger than that of the prepared sintered ferrite. This is attibuted to the shift of the spin and domain wall resonance frequencies toward the higher frequency region by introducing demagnetising fields of magnetic particles in the composite.

  2. A range of complex probabilistic models for RNA secondary structure prediction that includes the nearest-neighbor model and more.

    Rivas, Elena; Lang, Raymond; Eddy, Sean R


    The standard approach for single-sequence RNA secondary structure prediction uses a nearest-neighbor thermodynamic model with several thousand experimentally determined energy parameters. An attractive alternative is to use statistical approaches with parameters estimated from growing databases of structural RNAs. Good results have been reported for discriminative statistical methods using complex nearest-neighbor models, including CONTRAfold, Simfold, and ContextFold. Little work has been reported on generative probabilistic models (stochastic context-free grammars [SCFGs]) of comparable complexity, although probabilistic models are generally easier to train and to use. To explore a range of probabilistic models of increasing complexity, and to directly compare probabilistic, thermodynamic, and discriminative approaches, we created TORNADO, a computational tool that can parse a wide spectrum of RNA grammar architectures (including the standard nearest-neighbor model and more) using a generalized super-grammar that can be parameterized with probabilities, energies, or arbitrary scores. By using TORNADO, we find that probabilistic nearest-neighbor models perform comparably to (but not significantly better than) discriminative methods. We find that complex statistical models are prone to overfitting RNA structure and that evaluations should use structurally nonhomologous training and test data sets. Overfitting has affected at least one published method (ContextFold). The most important barrier to improving statistical approaches for RNA secondary structure prediction is the lack of diversity of well-curated single-sequence RNA secondary structures in current RNA databases.

  3. Synthesis, Biological, and Quantum Chemical Studies of Zn(II and Ni(II Mixed-Ligand Complexes Derived from N,N-Disubstituted Dithiocarbamate and Benzoic Acid

    Anthony C. Ekennia


    Full Text Available Some mixed-ligand complexes of Zn(II and Ni(II derived from the sodium salt of N-alkyl-N-phenyl dithiocarbamate and benzoic acid have been prepared. The complexes are represented as ZnMDBz, ZnEDBz, NiMDBz, and NiEDBz (MD: N-methyl-N-phenyl dithiocarbamate, ED: N-ethyl-N-phenyl dithiocarbamate, and Bz: benzoate; and their coordination behavior was characterized on the basis of elemental analyses, IR, electronic spectra, magnetic and conductivity measurements, and quantum chemical calculations. The magnetic moment measurement and electronic spectra were in agreement with the four proposed coordinate geometries for nickel and zinc complexes and were corroborated by the theoretical quantum chemical calculations. The quantum chemically derived thermodynamics parameters revealed that the formation of N-methyl-N-phenyl dithiocarbamate complexes is more thermodynamically favourable than that of the N-ethyl-N-phenyl dithiocarbamate complexes. The bioefficacy of the mixed-ligand complexes examined against different microbes showed moderate to high activity against the test microbes. The anti-inflammatory and antioxidant studies of the metal complexes showed that the ethyl substituted dithiocarbamate complexes exhibited better anti-inflammatory and antioxidant properties than the methyl substituted dithiocarbamate complexes.

  4. Acid–base equilibria of the Zn(II and Fe(III complexes with condensation products of 2-acetylpyridine and the dihydrazide of oxalic and malonic acid



    Full Text Available Acid–base equilibria of Zn(II and Fe(III complexes with N',N'2-bis[(1E-1-(2-pyridylethylidene]ethanedihydrazide (ligand L1 and N',N'2-bis[(1E-1-(2-pyridylethylidene]propanedihydrazide (ligand L2, i.e., [Fe(L1Cl2(H2O], [Fe(L2Cl(H2O]2+, [Zn(L1(H2O3]+ and [Zn(L2(H2O2]2+, which expressed cytotoxic activity, were investigated in aqueous media. The equilibrium constants were determined potentiometrically at 25 °C at a constant ionic strength of 0.10 mol/dm3 (Na2SO4. The results showed that at pH < 8 both the Fe(III complexes studied here have three, while [Zn(L1(H2O3]+ and [Zn(L2(H2O2]2+ have one and two titratable protons, respectively. Based on the obtained values for the equilibrium constants, protonation schemes of the examined complexes are proposed.

  5. Formation of a unique zinc carbamate by CO2 fixation: implications for the reactivity of tetra-azamacrocycle ligated Zn(II) complexes.

    Notni, Johannes; Schenk, Stephan; Görls, Helmar; Breitzke, Hergen; Anders, Ernst


    The macrocyclic ligand [13]aneN 4 ( L1, 1,4,7,10-tetra-azacyclotridecane) was reacted with Zn(II) perchlorate and CO 2 in an alkaline methanol solution. It was found that, by means of subtle changes in reaction conditions, two types of complexes can be obtained: (a) the mu 3 carbonate complex 1, {[Zn( L1)] 3(mu 3-CO 3)}(ClO 4) 4, rhombohedral crystals, space group R3 c, with pentacoordinate zinc in a trigonal bipyramidal enviroment, and (b) an unprecedenced dimeric Zn(II) carbamate structure, 2, [Zn( L2)] 2(ClO 4) 2, monoclinic crystals, space group P2 1/ n. The ligand L2 (4-carboxyl-1,4,7,10-tetra-azacyclotridecane) is a carbamate derivative of L1, obtained by transformation of a hydrogen atom of one of the NH moieties into carbamate by means of CO 2 uptake. In compound 2, the distorted tetrahedral Zn(II) coordinates to the carbamate moiety in a monodentate manner. Most notably, carbamate formation can occur upon reaction of CO 2 with the [Zn L1] (2+) complex, which implicates that a Zn-N linkage is cleaved upon attack of CO 2. Since complexes of tetra-azamacrocycles and Zn(II) are routinely applied for enzyme model studies, this finding implies that the Zn-azamacrocycle moiety generally should no longer be considered to play always only an innocent role in reactions. Rather, its reactivity has to be taken into account in respective investigations. In the presence of water, 2 is transformed readily into carbonate 1. Both compounds have been additionally characterized by solid-state NMR and infrared spectroscopy. A thorough comparison of 1 with related azamacrocycle ligated zinc(II) carbonates as well as a discussion of plausible reaction paths for the formation of 2 are given. Furthermore, the infrared absorptions of the carbamate moiety have been assigned by calculating the vibrational modes of the carbamate complex using DFT methods and the vibrational spectroscopy calculation program package SNF.

  6. Study of the structure and luminescent properties of terbium complex intercalated Zn/Al layered double hydroxide

    Gao, Xiaorui; Xie, Juan; Yin, Yaobing; Hao, Yongjing; Lian, Yiwei


    Terbium complex of ethylenediaminetetraacetate ([Tb(EDTA)]-) intercalated Zn/Al layered double hydroxide (LDH), as an inorganic-organic green-emitting phosphor, was synthesized through an ion exchange method. X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR) spectra exhibit a successful intercalation of [Tb(EDTA)]- anions between the hydroxide sheets of the LDH. The basal spacing of 14.5 Å indicate a vertical arrangement of [Tb(EDTA)]- anions with the maximal dimension in the gallery is adopted. The luminescent properties of this material were studied by excitation and emission spectra. The results show that the strongest emission peak of Tb3+ ion occurs at 544 nm. This material may supply a candidate of green light emitting phosphor.

  7. Zn/Ga−DFO iron–chelating complex attenuates the inflammatory process in a mouse model of asthma

    Haim Bibi


    Conclusion: In this mouse model of allergic asthma, Zn/Ga−DFO attenuated allergic airway inflammation. The beneficial effects of treatment were in accord with iron overload abatement in asthmatic lungs by Zn/Ga−DFO. The findings in both cellular and tissue levels supported the existence of a significant anti-inflammatory effect of Zn/Ga−DFO.

  8. Hydrothermal Synthesis, Crystal Structure and Electrochemical Properties of Complex Zn(phen)(m-CBA)2(H2O)

    LUO Bing-Chu; LI Chang-Hong; PENG Yun-Lin; KUANG Yun-Fei


    A novel complex Zn(phen)(m-CBA)2(H2O) with m-chlorobenzoic acid (m-CBA), 1,10-phenanthroline (phen) and zinc chloride has been hydrothermally synthesized and characterized. Crystal data for this complex: triclinic, space group P-1, a = 0.8361(5), b = 1.2455(7), c = 1.3107(7) nm, α = 115.637(8), β = 91.014(9), γ = 104.857(8)°, V = 1.1763(11) nm3, Dc = 1.623 g/cm3, Z = 2, F(000) = 584, GOOF = 1.078, the final R = 0.0453 and wR = 0.1192. Structure analysis shows that the zinc ion coordinates with two nitrogen atoms of one 1,10-phenanthroline molecule, three oxygen atoms from two m-chlorobenzoic acid molecules and one water molecule, giving a distorted square-pyramidal coordination geometry. The cyclic voltametric behavior of the complex was also investigated.

  9. Synthesis, characterization, DFT and biological studies of isatinpicolinohydrazone and its Zn(II), Cd(II) and Hg(II) complexes

    El-Gammal, O. A.; Rakha, T. H.; Metwally, H. M.; Abu El-Reash, G. M.


    Isatinpicolinohydrazone (H2IPH) and its Zn(II), Cd(II) and Hg(II) complexes have been synthesized and investigated using physicochemical techniques viz. IR, 1H NMR, 13C NMR, UV-Vis spectrometric methods and magnetic moment measurements. The investigation revealed that H2IPH acts as binegative tetradentate in Zn(II), neutral tridentate in Cd(II) and as neutral bidentate towards Hg(II) complex. Octahedral geometry is proposed for all complexes. The bond length, bond angle, chemical reactivity, energy components (kcal/mol), binding energy (kcal/mol) and dipole moment (Debyes) for all the title compounds were evaluated by DFT and also MEP for the ligand is shown. Theoretical infrared intensities of H2IPH and also the theoretical electronic spectra of the ligand and its complexes were calculated. The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. The in vitro antibacterial studies of the complexes proved them as growth inhibiting agents. The DDPH antioxidant of the compounds have been screened. Antitumor activity, carried out in vitro on human mammary gland (breast) MCF7, have shown that Hg(II) complex exhibited potent activity followed by Zn(II), Cd(II) complexes and the ligand.

  10. Ni(II) and Zn(II) complexes of 2-((thiophen-2-ylmethylene)amino)benzamide: synthesis, spectroscopic characterization, thermal, DFT and anticancer activities.

    Tyagi, Prateek; Chandra, Sulekh; Saraswat, B S


    The paper presents the synthesis of Ni(II) and Zn(II) complexes of general composition M(L)X₂ and M(L)₂X₂ (M=Ni(II), Zn(II), X=Cl(-1), OAc(-1)) with Schiff base obtained through the condensation of 2-aminobenzamide with thiophene-2-carbaldehyde. The characterization of newly formed complexes was done by (1)H NMR, UV-VIS, TGA, IR, mass spectrophotometry and molar conductivity studies. The thermal studies suggested that the complexes are more stable as compared to ligand. In DFT studies the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. On the basis of the spectral studies a distorted octahedral geometry has been assigned for Ni(II) complexes and tetrahedral geometry for Zn(II) complexes. The effect of these complexes on proliferation of human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (HepG2) were studied and compared with those of free ligand.

  11. Conductometric Studies of Thermodynamics of Complexation of Co2+, Ni2+, Cu2+, and Zn2+ Cations with Aza-18-crown-6 in Binary Acetonitrile-Methanol Mixtures

    Mehdi Taghdiri


    Full Text Available The complexation reactions between aza-18-crown-6 (A18C6 and Co2+, Ni2+, Cu2+, and Zn2+ ions were studied conductometrically in different acetonitrile-methanol mixtures at various temperatures. The formation constants of the resulting 1 : 1 complexes were calculated from the computer fitting of the molar conductance-mole ratio data at different temperatures. Selectivity of A18C6 for Co2+, Ni2+, Cu2+, and Zn2+ cations is sensitive to the solvent composition. At 20°C and in acetonitrile solvent, the stability of the resulting complexes varied in the order but the order was reversed byadding 20% methanol. The enthalpy and entropy changes of the complexation reactions were evaluated from the temperature dependence of formation constants. It was found that the stability of the resulting complexes decreased with increasing methanol in the solvent mixture. The TΔS° versus ΔH° plot of thermodynamic data obtained shows a fairly good linear correlation indicating the existence of enthalpy-entropy compensation in the complexation reactions. In addition, binding energies of Ni2+, Cu2+, and Zn2+ complexes with A18C6 were calculated at B3LYP/6-31G level of theory.

  12. 基于石墨烯-ZnO纳米线的复合电极在GaN LED中的应用%Graphene-ZnO Nanowires Based Complex Electorde Used as Transparency Conductive Layer in GaN LED

    许坤; 王一帆; 解意洋; 丁佩; 杜银霄


    By using one-dimensional ZnO nanowires and two-dimensional graphene composite struc-ture to integrate onto p-GaN surface, the current expansion and the efficiency improvement of LED light extraction were both achieved. Comparing the devices with or without ZnO nanowires, it was found that ZnO nanowires could increase the light extraction efficiency of GaN LED by 30%. The key parameters, such as opening voltage, working voltage and reverse leakage current of the two type of devices were analyzed, and the results verified that the structure used in GaN LED didn’t de-teriorate the electrical properties of LED. The complex structure adopted in this paper for GaN LED can not only achieve a good Ohmic contact without the using of ITO, but also enhance the extraction of light.%使用一维ZnO纳米线和二维石墨烯复合结构集成到p-GaN表面来同时实现电流扩展和提高LED光提取效率。通过两组有无ZnO纳米线器件的对比,发现ZnO纳米线使器件的光提取效率提高了30%。通过分析两组器件的开启电压、工作电压和反向漏电流等关键参数,验证了本结构应用于GaN LED不会恶化其电性能。本文所采用的复合结构用于GaN LED,同时达到了良好欧姆接触、避免使用ITO和增强出光的效果。

  13. Line probe assay for differentiation within Mycobacterium tuberculosis complex. Evaluation on clinical specimens and isolates including Mycobacterium pinnipedii

    Kjeldsen, Marianne Kirstine; Bek, Dorte; Rasmussen, Erik Michael;


    A line probe assay (GenoType MTBC) was evaluated for species differentiation within the Mycobacterium tuberculosis complex (MTBC). We included 387 MTBC isolates, 43 IS6110 low-copy MTBC isolates, 28 clinical specimens with varying microscopy grade, and 30 isolates of non-tuberculous mycobacteria....... The assay was 100% specific and identified all 387 isolates and 98% of all IS6110 low-copy strains in concordance with the gold standard. The 2% discrepancy was caused by 1 isolate showing a faint restriction fragment length polymorphism (RFLP) pattern. The assay could provide specifies identification in 13...

  14. Synthesis and characterization of Ni(II) and Zn(II) complexes of (furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamate (ftpedtc): X-ray structures of [Zn(ftpedtc)2(py)] and [Zn(ftpedtc)Cl(1,10-phen)

    Jamuna Rani, Palanisamy; Thirumaran, Subbiah; Ciattini, Samuele


    Seven complexes of a new dithiocarbamate ligand (ftpedtc = (furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamate) namely [Ni(ftpedtc)2] (1), [Ni(ftpedtc)(NCS)(PPh3)] (2), [Ni(ftpedtc)(PPh3)2]ClO4 (3), [Zn(ftpedtc)2] (4), [Zn(ftpedtc)2(py)] (5), [Zn(ftpedtc)2(1,10-phen)] (6) and [Zn(ftpedtc)2(2,2‧-bipy] (7) have been prepared. The complexes were characterized by IR, UV-Vis and NMR (1H and 13C) spectroscopy. Single crystal X-ray structural analysis was carried out for complexes 5 and [Zn(ftpedtc)Cl(1,10-phen)] (8). Electronic spectral studies suggest square planar geometry for nickel complexes. The 13C NMR peaks of the group N13CS2 are found in all the cases, at around 205.0 ppm, which indicates the bidentate character of the dithiocarbamate ligand. X-ray structures of 5 and 8 show bidentate coordination by dithiocarbamate ligands and a distorted trigonal bipyramidal geometry for zinc, defined by NS4 and ClN2S2 donor sets, respectively. The packing in 8 involves π-π stacking interactions involving the 1,10-phenanthroline ring systems with the distance between ring centroids being 3.587 Å.

  15. Syntheses, structures and properties of Zn(II) and Cu(II) complexes based on N2-2-methylenepyridinyl 1,2,3-triazole ligand

    Chen, Yunfeng; Wu, Jun; Ma, Shan; Zhou, Shilei; Meng, Xianggao; Jia, Lihui; Pan, Zhiquan


    Four new Zn(II) and Cu(II) coordinated polymers ([ZnL2N3]ClO4 (1), [Cu2L2(CH3CN)]Cl4 (2) [CuL](NO3)2 (3), [Cu(H2O)L](SO4) (4) L = 2-((4-phenyl-2H-1,2,3-triazol-2-yl)methyl) pyridine (ptmp)) have been reported. All the compounds have been characterized by IR spectrum, elemental analyses and X-ray crystallography diffraction. Single-crystal X-ray diffraction analyses show that one-dimensional polymers are formed in these four complexes. Chain-like structures are formed in complex 1, 2 and 3, which are connected by azide, chloride and nitrate anions, respectively. In complex 4, one-dimensional left-handed polymer is formed by a μ2-SO4 bridge. The fluorescent and electrochemical properties of these four complexes were investigated. It was found that these three Cu(II) complexes displayed a quenching of fluorescence, while Zn(II) complex exhibited a clear enhanced fluorescence.

  16. Use of the mTOR inhibitor everolimus in a patient with multiple manifestations of tuberous sclerosis complex including epilepsy

    James W. Wheless


    Full Text Available Tuberous sclerosis complex (TSC is a genetic disease in which overactivation of mechanistic target of rapamycin (mTOR signaling leads to the growth of benign hamartomas in multiple organs, including the brain, and is associated with a high rate of epilepsy and neurological deficits. The mTOR inhibitor everolimus has been used in the treatment of subependymal giant cell astrocytomas and renal angiomyolipomas in patients with TSC. This article describes the case of a 13-year-old girl with TSC-associated epilepsy with refractory generalized seizures who initiated treatment with everolimus and experienced subsequent improvement in several TSC manifestations, including a reduction in seizure frequency from clusters of two or three daily to one every 2 to 4 weeks after 1.5 years of treatment.

  17. The bipyridine adducts of N-phenyldithiocarbamato complexes of Zn(II) and Cd(II); synthesis, spectral, thermal decomposition studies and use as precursors for ZnS and CdS nanoparticles.

    Onwudiwe, Damian C; Strydom, Christien A


    Bipyridine adducts of N-phenyldithiocarbamato complexes, [ML(1)2L(2)] (M=Cd(II), Zn(II); L(1)=N-phenyldithiocarbamate, L(2)=2,2' bipyridine), have been synthesized and characterised. The decomposition of these complexes to metal sulphides has been investigated by thermogravimetric analysis (TGA). The complexes were used as single-source precursors to synthesize MS (M=Zn, Cd) nanoparticles (NPs) passivated by hexadecyl amine (HDA). The growth of the nanoparticles was carried out at two different temperatures: 180 and 220 °C, and the optical and structural properties of the nanoparticles were studied using UV-Vis spectroscopy, photoluminescence spectroscopy (PL), transmission emission microscopy (TEM) and powdered X-ray diffraction (p-XRD). Nanoparticles, whose average diameters are 2.90 and 3.54 nm for ZnS, and 8.96 and 9.76 nm for CdS grown at 180 and 220 °C respectively, were obtained.

  18. Syntheses, crystal structures and DNA-binding studies of Cu(II) and Zn(II) complexes bearing asymmetrical aroylhydrazone ligand

    Li, Yueqin; Yang, Zhiwei; Zhou, Minya; He, Jing; Wang, Xuehong; Wu, Yanlong; Wang, Zhuye


    Zn(II) and Cu(II) complexes with benzophenone benzoyl hydrazone (HBBH) and benzophenone salicylylhydrazone (HBSH) have been synthesized and characterized by different physico-chemical and spectroscopic techniques (UV-vis, IR and NMR). The molecular structures of these complexes [Zn(BBH)2, Cu(BBH)2 and Cu(BSH)2Cl2H2O] have also been determined by single X-ray diffraction technique. In Zn(BBH)2 and Cu(BBH)2 complexes, each ligand coordinates to metal through enol tautomeric form by azomethine-N and carbonylate-O resulting a 4-coordinate distorted tetrahedral geometry. While in Cu(BSH)2Cl2H2O, each ligand coordinates to metal through keto tautomeric form resulting distorted octahedral geometry in which two chlorine atoms occupy the axial positions. The DNA interaction propensity of the complexes with Herring sperm DNA, studied at physiological pH by spectrophotometric, spectrofluorometric, viscometric techniques and cyclic voltammetry, revealed intercalation as the possible binding mode. Fascinatingly, Cu(BSH)2Cl2H2O was found to exhibit greater binding strength than the others. A strong hyperchromism effect and a slight red shift were exhibited by all complexes. The intrinsic binding constants are of moderate values and are about 3.28 × 104 M-1, 4.73 × 104 M-1 and 5.80 × 104 M-1, respectively. Cyclic voltammetry studies of the complexes binding with DNA indicate quasireversible oxidation and reduction potentials. The results suggest that the binding affinity of complexes lies in the order Cu(BSH)2Cl2H2O > Cu(BBH)2 > Zn(BBH)2.

  19. Metal flux and dynamic speciation at (bio)interfaces. Part VI: The roles of simple, fulvic and aggregate complexes on computed metal flux in freshwater ligand mixtures; comparison of Pb, Zn and Ni at planar and microspherical interfaces

    Zhang, Zeshi; Buffle, Jacques


    The computations of metal flux in aquatic systems, at consuming interfaces like microorganism surfaces are of major importance in ecotoxicology and dynamic risk assessment. In this paper, the flux of Zn(II) and Ni(II), at a planar consuming interface in a typical natural freshwater, are studied. The system includes (a) simple ligands (OH -, CO32-); (b) fulvics; (c) aggregates, as complexants, i.e., those which play the major roles in controlling the metal distribution and/or metal flux in aquatic media. The above two metals are chosen because they participate, respectively, to intermediate and very slow chemical reactions with complexing sites, and are thus complementary to Pb(II) and Cu(II) (two metals with very fast reactions) studied in Parts III-V of this series. The effects of the various physico-chemical factors, in particular, the diffusion layer thickness, the stability constants and complexing site distribution of fulvics and the size distribution of aggregates, are studied in details. The contribution to the flux, of each complex type, is computed. This paper also compares the dynamic behaviour of Pb(II), Zn(II) and Ni(II) as well as the labilities and flux contributions of their various complexes at planar and microspherical interfaces. This enables to make predictions on biouptake by microorganisms.

  20. Ca(II, Zn(II and Au(III sulfamethoxazole sulfa-drug complexes: Synthesis, spectroscopic and anticancer evaluation studies

    Fatima A.I. Al-Khodir


    Full Text Available Herein in this article, three new Ca(II, Zn(II and Au(III complexes of sulfamethoxazole (SZ (sulfa-drug have been synthesized for the first time. The sulfa-drugs have a great attentions because of their therapeutic applications against bacterial infections. The SZ complexes were discussed with the help of elemental analyses, molar conductance and spectroscopic instruments e.g. IR, 1H-NMR, and electronic spectra. Investigations of the infrared spectra of the SZ and their metal complexes indicated the vibrations due to the sulfonamido (SO2 and –NH and isoxazole (C=N groups are shifted with respect to the free molecule in line with their coordination to the metal. In case of calcium(II an zinc(II complexes, the coordination site of SZ are the sulfonyl oxygen and SO2-NH sulfonamide nitrogen, but in gold(III complex, the gold metal ions coordinates through the sulfonyl oxygen and isoxazole nitrogen. These complexes are formulated as: [Ca(SZ(Cl2].8H2O (1, [Zn(SZ(Cl2].2H2O (2 and [Au(SZ(Cl2].Cl (3. The molar conductance data reveals that both Ca(II and Zn(II complexes are non-electrolyte but gold(III complex is electrolyte. The morphological nano structures of SZ complexes were checked using X-ray powder diffraction (XRD, scanning electron microscope (SEM and transmission electron microscopy (TEM. The gold(III complex was recorded good anticancer behavior against Human colon carcinoma (HCT-116 cells and human hepatocellular carcinoma (HepG-2 cells.

  1. Supramolecular phosphatases formed by the self-assembly of the bis(Zn²⁺-cyclen) complex, copper(II), and barbital derivatives in water.

    Zulkefeli, Mohd; Hisamatsu, Yosuke; Suzuki, Asami; Miyazawa, Yuya; Shiro, Motoo; Aoki, Shin


    In our previous paper, we reported that a dimeric Zn(2+) complex with a 2,2'-bipyridyl linker (Zn2L(1)), cyanuric acid (CA), and a Cu(2+) ion automatically assemble in aqueous solution to form 4:4:4 complex 3, which selectively catalyzes the hydrolysis of mono(4-nitrophenyl)phosphate (MNP) at neutral pH. Herein, we report that the use of barbital (Bar) instead of CA for the self-assembly with Zn2L(1) and Cu(2+) induces 2:2:2 complexation of these components, and not the 4:4:4 complex, to form supramolecular complex 6 a, the structure and equilibrium characteristics of which were studied by analytical and physical measurements. The finding show that 6 a also accelerates the hydrolysis of MNP, similarly to 3. Moreover, inspired by the crystal structure of 6 a, we prepared barbital units that contain functional groups on their side chains in an attempt to produce supramolecular phosphatases that possess functional groups near the Cu2(μ-OH)2 catalytic core so as to mimic the catalytic center of alkaline phosphatase (AP).

  2. Ultraviolet stimulation of hydrogen peroxide production using aminoindazole, diaminopyridine, and phenylenediamine solid polymer complexes of Zn(II)

    Hayes, Jennifer A.; Schubert, David M.; Amonette, James E.; Nachimuthu, Ponnusamy; Disselkamp, Robert S.


    Hydrogen peroxide is a valuable chemical commodity whose production relies on expensive methods. If an efficient, sustainable, and inexpensive solar-mediated production method could be developed from the reaction between dioxygen and water then its use as a fuel may be possible and gain acceptance. Hydrogen peroxide at greater than 10 M possesses a high specific energy, is environmentally clean, and is easily stored. However, the current method of manufacturing H2O2 via the anthraquinone process is environmentally unfriendly making the unexplored nature of its photochemical production from solar irradiation of interest. Here the concentration and quantum yield of hydrogen peroxide produced in an ultraviolet (UV-B) irradiated environment using aromatic and nitrogen-heterocyclic ring complexes of zinc(II) as solid substrates was studied. The amino-substituted isomers of the substrates indazole, pyridine, and phenylenediamine solid polymer complexes are examined. Samples exposed to the ambient atmosphere (e.g., aerated) were irradiated with a low power lamp with emission from 280-360 nm. Irradiation of various zinc complexes revealed Zn-5-aminoindazole to have the greatest first-day production of 63 mM/day with a 37% quantum yield. Para-phenylenediamine (PPAM) showed the greatest long-term stability and thus suggests H2O2 is produced photocatalytically. Isomeric forms of the catalyst’s organic components (e.g., amino groups) did have an effect on the production. Irradiation of diaminopyridine isomers indicated 2,3-diamino and 3,4-diamino structures were the most productive, each generating 32 mM/day hydrogen peroxide. However, the 2,5-diamino isomer showed no peroxide production. A significant decrease in hydrogen peroxide production in all but PPAM was noticed in the samples, suggesting the possibility of a catalyst poisoning mechanism. The samples ability to produce H2O2 is rationalized by proposing a reaction mechanism and examining the stability of the resonance

  3. On the impedance of galvanic cells—XVII. The mechanism of the Zn2+/Zn(Hg) electrode reaction

    Sluyters-Rehbach, M.; Ijzermans, A.B.; Timmer, B.; Griffioen, J.B.; Sluyters, J.H.


    A theory is presented of the complex behaviour of the streaming zinc amalgam electrode in a Zn2+ solution. It is assumed that the Zn2+/Zn+ and the Zn+/Zn(Hg) electrode reactions occur at potentials where at the dropping amalgam electrode the Zn2+-resp. Zn-concentration at the electrode surface is vi

  4. Construction and NIR luminescent property of hetero-bimetallic Zn Nd complexes from two chiral salen-type Schiff-base ligands

    Bi, Wei-Yu; Lü, Xing-Qiang; Chai, Wen-Li; Song, Ji-Rong; Wong, Wai-Yeung; Wong, Wai-Kwok; Jones, Richard A.


    Two new near-infrared (NIR) luminescent Zn-Nd complexes [ZnL 1Nd(OAc)(NO 3) 2] ( 3) and [ZnL 2Nd(DMF) 2(NO 3) 3] ( 4) have been obtained with two salen-type Schiff-base ligands H 2L 1 and H 2L 2, ( H 2L 1 = N, N'-bis(3-methoxysalicylidene)-(1s, 2s)-(-)1,2-dipheneylethylenediamine and H 2L 2 = N, N'-bis(3-methoxysalicylidene)-(s)-2,2-diamine-1,1'-binaphthyl) from the reaction of different chiral diamines with o-vanillin. The X-ray crystal structure analysis reveals that both of them crystallize in the chiral space groups with P2(1), a = 10.1669(6), b = 19.3775(11), c = 17.4639(10) Å, β = 94.8710(10)°, V = 3428.1(3) Å 3, Z = 4 for 3, and C2, a = 22.1914(13), b = 9.7886(6), c = 22.0138(13) Å, β = 118.9590(10)°, V = 4372.5(4) Å 3, Z = 4 for 4. Complexes 3- 4 are both dinuclear Zn-Nd structures, while suitable choice of chiral Schiff-base ligands could induce the different complexions of ligands and metal ions, and the functional control of ligand character shows a potentially effective way to the fine-tuning properties of NIR luminescence from Nd ions.

  5. Solid-state Photochemical [2+2] Cycloaddition Reaction of Hydrogen-Bonded Zn(II) Metal Complex Containing Several Parallel C=C Bonds



    A 2D hydrogen-bonded dinuclear Zn(II) complex, [{Zn(H₂O) ₃ (bpe) ₂} ₂ (bpe)](NO₃) ₄・3bpe・14H₂O,1 (bpe = 4,4_-bipyridylethylene) containing coordination complex cations, [{Zn(H₂O) ₃ (bpe) ₂} ₂ (μ-bpe)] ⁴⁺and free bpe and lattice water molecules shows face-to-face, π ・ ・ ・ π stacking of two of the four free bpemolecules with coordinated bpe ligands. Out of eight bpe molecules, six are aligned in parallel fashion withshort C・ ・ ・ C distances of 3.663–3.814Å and they undergo photochemical [2+2] cycloaddition reaction. The photoreaction conducted on ground sample of 1 in the solid-state affords rctt-tetrakis(4-pyridyl)cyclobutane (rctt-tpcb) product in 75% yield. The molecular movement of free bpe molecules was tested by conducting thephotoreaction in ground sample and heated sample of single crystals. The photoreactivity study of 1 indicates that the free bpe molecules are locked between the cationic [{Zn(H₂O) ₃ (bpe) ₂} ₂ (bpe)] ⁴⁺ layers.

  6. Synthesis and Crystal Structure of a New One-dimensional Zn(II) Nitronyl Nitroxide Complex Bridged by Pyridine-2,4-dicarboxylate Anion

    GAO Dong-Zhao; LI Li-Cun; LIAO Dai-Zheng; JIANG Zong-Hui; YAN Shi-Ping


    A new one-dimensional (1-D) Zn(II) nitronyl nitroxide complex bridged by pyri- dine-2,4-dicarboxylate anion, [Zn(NIT4Py)(2,4-PDA)(H2O)2]n (NIT4Py = 2-(4'-pyridyl)-4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide and 2,4-PDA = pyridine-2,4-dicarboxylate anion), has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 16.834(2), b = 7.4376(10), c = 18.295(3) (A), β = 102.848(2)°, V = 2233.2(5)(A)3, C19H23N4O8Zn, Mr = 500.78, Dc = 1.489 g/cm3, μ(MoKα) = 1.152 mm-1, F(000) = 1036, Z = 4, the final R = 0.0390 and wR = 0.0915 for 3234 observed reflections. In the complex, each zinc(II) ion is six-coordinated by one nitrogen atom of the radical ligand (NIT4Py), one nitrogen atom and two oxygen atoms of two 2,4-PDA anions and two oxygen atoms of two water molecules. Each 2,4-PDA anion bridges two Zn(II) ions via a tridentate mode into a 1-D chain, and these 1-D chains are further linked into a 2-D network via hydrogen-bonding interactions.

  7. Determination of the structure, morphology and complex refractive index in ZnO-nanopencils/P3HT hybrid structures

    Motaung, DE


    Full Text Available Well crystallized flower-shaped ZnO-structures composed of a perfectly hexagonal-shaped ZnO structure were successfully synthesized using a simple microwave assisted hydrothermal method. The NPs with a hexagonal stem and a tapering tip grows out...

  8. Complex permeability spectra of PbO and Ta2O5 added nanocrystalline MgCuZn ferrites

    V, Seetha Rama Raju


    PbO and Ta2O5 added MgCuZn ferrites are prepared by the Microwave-Hydrothermal (M-H) processing. The nanocrystalline ferrites are sintered to a temperature of 900 °C/4 h. SEM pictures reveal that, the addition of PbO causes a small amount of grain growth, whereas the addition of Ta2O5 causes a fine-grained microstructure. The complex permeability spectra (μ*=μ‧-iμ″) of the prepared samples were measured in the frequency range from 1 MHz to 1.8 GHz, the μ* spectra are analyzed into two magnetization processes with focus on the particle size of ferrite samples. In addition to the spin rotation relaxation in 130-200 MHz, it is initially identified the contribution from reversible domain wall bowing rising at 6-40 MHz. The magnetic state of the ferrite is also influenced by the addition of PbO and Ta2O5. The spin rotation mechanism of the present ferrites is enhanced by the preparation of nanocrystalline samples.

  9. Syntheses and Crystal Structures of Two Novel 1-D Metal Complexes with Dicyanamide:[Zn(pheen)(dca)2]n and [Cu(quin)2(dca)2]n

    吴阿清; 郑发鲲; 蔡丽珍; 郭国聪; 黄锦顺


    The two complexes [Zn(phen)(dca)2]n 1 (phen = 1,10-phenanthroline, dca = di-cyanamide) and [Cu(quin)2(dca)2]n 2 (quin = quinoline) were synthesized by self-assembly reactions of Zn(CH3COO)2·4H2O with Nadca and phen ligands, and CuCl2(2H2O with Nadca and quin ligands, respectively. Their crystal structures were determined by single-crystal X-ray diffraction analyses. Crystallographic data for complex 1: (C16H8N8Zn)n, Mr = 377.67, monoclinic, space group P21/c, a = 10.1322(5), b = 11.0218(6), c = 14.1351(6) (A), β = 101.077(2)°, V = 1549.1(1) (A)3, Z = 4 , Dc = 1.619 g/cm3, μ(MoKα) = 1.602 mm-1, F(000) = 760, R = 0.0698 and wR = 0.1558; and for complex 2: (C22H14N8Cu)n, Mr = 453.95, orthorhombic, space group Cmc21, a = 16.679(4), b = 9.153(2), c = 12.937(3) (A), V = 1975.0(7) (A)3, Z = 4, Dc = 1.527 g/cm3, μ(MoKα) = 1.134 mm-1, F(000) = 924, R = 0.0486 and wR = 0.0981. The structures of complexes 1 and 2 consist of infinite zigzag chains, and their metal atoms have slightly distorted square pyramidal coordination environments with two N atoms of phen or quin ligands and three nitrile N atoms of dca ligands. The secondary long Zn-N bonds and π-π stacking interactions make the chains into a three-dimensional network in complex 1.

  10. Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

    MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.; Berrie, Barbara H. (NGA); (Bordeaux)


    To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K+, Zn2+, Pb2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic–inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm–1 for Pb(II) and ca. 1580 cm–1 for Zn(II) are consistent with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. These complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.

  11. Investigation on Al(III) and Zn(II) complexes containing a calix[4]arene bearing two 8-oxyquinoline pendant arms used as emitting materials for OLEDs

    Bagatin, Izilda A. [Instituto de Quimica, Universidade de Sao Paulo, Cx. P.: 26077, CEP 05513-970, Sao Paulo, SP (Brazil)], E-mail:; Legnani, Cristiano [Divisao de Metrologia em Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, CEP 25250-020, Duque de Caxias, RJ (Brazil); Cremona, Marco [Divisao de Metrologia em Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, CEP 25250-020, Duque de Caxias, RJ (Brazil); Pontificia Universidade Catolica do Rio de Janeiro, Depto de Fisica, C.P.38071, Rio de Janeiro (Brazil)


    A comparison between [Al{center_dot}1]{sup 3+} and [Zn{center_dot}1]{sup 2+} complexes (1 = 5,11,17,23-tetra-tert-butyl-25,27-bis[(quinoline-8-oxy)propyloxy]-26, 28-dihydroxy-calix[4]arene) has been made using electrochemical techniques and the experimental results obtained in the fabrication of organic light emitting devices (OLEDs). The electrochemically determined values of the ionization potential I{sub p} and electron affinity E{sub a} parameters for the [Al{center_dot}1]{sup 3+} (I{sub p} = 5.82eV, E{sub a} = 2.80eV) and [Zn{center_dot}1]{sup 2+} (I{sub p} = 5.67eV, E{sub a} = 2.32eV) evidenced that the [Al{center_dot}1]{sup 3+} complex is a better electron transporting layer with respect to the Zn complex one. The fabricated OLEDs based on these supramolecular complexes show a superior quality with the [Al{center_dot}1]{sup 3+} systems expected from the energy level diagrams.

  12. DNA binding and cleavage studies of new sulfasalazine-derived dipeptide Zn(II) complex: Validation for specific recognition with 5 Prime -TMP

    Tabassum, Sartaj, E-mail: [Department of Chemistry, Aligarh Muslim University, Aligarh, UP 202002 (India); Al-Asbahy, Waddhaah M.; Afzal, Mohd.; Shamsi, Manal; Arjmand, Farukh [Department of Chemistry, Aligarh Muslim University, Aligarh, UP 202002 (India)


    A new water soluble complex [Zn(glygly)(ssz)(H{sub 2}O)]{center_dot}6H{sub 2}O, 1 derived from dipeptide (glycyl glycine) and sulfasalazine was synthesized and characterized by spectroscopic (IR, UV-vis, NMR, ESI-MS) and analytical methods. The in vitro DNA binding studies of complex 1 with calf-thymus DNA were carried out by employing various biophysical methods and molecular docking technique which reveals strong electrostatic binding via phosphate backbone of DNA helix, in addition to partial intercalation. To gain further insight into the molecular recognition at the target site, interaction studies of complex 1 with 5 Prime -TMP and 5 Prime -GMP were carried out by UV-vis titration which was validated by {sup 1}H and {sup 31}P NMR with 5 Prime -TMP, which implicate the preferential selectivity of 1 towards N3 of thymine. Complex 1 is accessible to minor groove of DNA and cleaved pBR322 DNA via hydrolytic pathway (validated by T4 ligase assay). - Graphical abstract: Synthesis, characterization, DNA binding and cleavage studies of [Zn(glygly)(ssz)(H{sub 2}O)]{center_dot}6H{sub 2}O (1) containing glycyl glycine and sulfasalazine ligand. Complex 1 recognize minor groove of DNA and show hydrolytic DNA cleavage. Highlights: Black-Right-Pointing-Pointer Novel Zn(II) complex 1 bearing bioactive glycyl glycine and sulfasalazine ligand scaffold. Black-Right-Pointing-Pointer Cleavage activity of 1 was enhanced in presence of activators: H{sub 2}O{sub 2}>MPA>GSH>Asc. Black-Right-Pointing-Pointer Complex 1 recognize minor groove as depicted in the cleavage pattern and molecular docking. Black-Right-Pointing-Pointer Complex 1 cleaves pBR322 DNA via hydrolytic mechanism and validated by T4 DNA ligase experiments.


    Yahmin Yahmin


    Full Text Available The structure and binding energies of 12-crown-4 and benzo-12-crown-4 complexes with Li+, Na+, K+, Zn2+, Cd2+, and Hg2+were investigated with ab initio calculations using Hartree-Fock approximation and second-order perturbation theory. The basis set used in this study is lanl2mb. The structure optimization of cation-crown ether complexes was evaluated at HF/lanl2mb level of theory and interaction energy of the corresponding complexes was calculated at MP2/lanl2mb level of theory (MP2/lanl2mb//HF/lanl2mb. Interactions of the crown ethers and the cations were discussed in term of the structure parameter of crown ether. The binding energies of the complexes show that all complex formed from transition metal cations is more stable than the complexes formed from alkali metal cations.   Keywords: 12-crown-4, benzo-12-crown-4, alkali metals, transition metals

  14. Interface Study of ITO/ZnO and ITO/SnO2 Complex Transparent Conductive Layers and Their Effect on CdTe Solar Cells

    Tingliang Liu


    Full Text Available Transparent ITO/ZnO and ITO/SnO2 complex conductive layers were prepared by DC- and RF-magnetron sputtering. Their structure and optical and electronic performances were studied by XRD, UV/Vis Spectroscopy, and four-probe technology. The interface characteristic and band offset of the ITO/ZnO, ITO/SnO2, and ITO/CdS were investigated by Ultraviolet Photoelectron Spectroscopy (UPS and X-ray Photoelectron Spectroscopy (XPS, and the energy band diagrams have also been determined. The results show that ITO/ZnO and ITO/SnO2 films have good optical and electrical properties. The energy barrier those at the interface of ITO/ZnO and ITO/SnO2 layers are almost 0.4 and 0.44 eV, which are lower than in ITO/CdS heterojunctions (0.9 eV, which is beneficial for the transfer and collection of electrons in CdTe solar cells and reduces the minority carrier recombination at the interface, compared to CdS/ITO. The effects of their use in CdTe solar cells were studied by AMPS-1D software simulation using experiment values obtained from ZnO, ITO, and SnO2. From the simulation, we confirmed the increase of Eff, FF, Voc, and Isc by the introduction of ITO/ZnO and ITO/SnO2 layers in CdTe solar cells.

  15. Quantum Chemical Studies on the Prediction of Structures, Charge Distributions and Vibrational Spectra of Some Ni(II), Zn(II), and Cd(II) Iodide Complexes

    Bardakci, Tayyibe; Kumru, Mustafa; Altun, Ahmet


    Transition metal complexes play an important role in coordination chemistry as well as in the formation of metal-based drugs. In order to obtain accurate results for studying these type of complexes quantum chemical studies are performed and especially density functional theory (DFT) has become a promising choice. This talk represents molecular structures, charge distributions and vibrational analysis of Ni(II), Zn(II), and Cd(II) iodide complexes of p-toluidine and m-toluidine by means of DFT. Stable structures of the ligands and the related complexes have been obtained in the gas phase at B3LYP/def2-TZVP level and calculations predict Ni(II) complexes as distorted polymeric octahedral whereas Zn(II) and Cd(II) complexes as distorted tetrahedral geometries. Charge distribution analysis have been performed by means of Mulliken, NBO and APT methods and physically most meaningful method for our compounds is explained. Vibrational spectra of the title compounds are computed from the optimized geometries and theoretical frequencies are compared with the previously obtained experimental data. Since coordination occurs via nitrogen atoms of the free ligands, N-H stretching bands of the ligands are shifted towards lower wavenumbers in the complexes whereas NH_2 wagging and twisting vibrations are shifted towards higher wavenumbers.

  16. Complexation of heavy metals by phytochelatins: voltammetric study of the binding of Cd2+ and Zn2+ ions by the phytochelatin (gamma-Glu-Cys)3Gly assisted by multivariate curve resolution.

    Cruz, Boris H; Díaz-Cruz, José Manuel; Ariño, Cristina; Esteban, Miquel


    The complexation of Cd2+, Zn2+, and both together with the phytochelatin (gamma-Glu-Cys)3Gly is studied by differential pulse polarography, and data are analyzed by multivariate curve resolution by alternating least squares (MCR-ALS). MCR-ALS yields the respective unitary voltammograms and concentration profiles of the resolved components, which contain information on the relative stabilities and stoichiometries of the formed complexes. The analysis of these results shows, for the Cd2+/(gamma-Glu-Cys)3Gly system, the presence of different kinds of bound Cd2+. For the Zn2+/ (gamma-Glu-Cys)3Gly system, the poor definition of the reduction signals of the complexes prevents a clear discrimination among differently bound Zn2+ ions. Atentative complexation/ electrochemical model is proposed for when both metal ions, Cd2+ and Zn2+, compete toward complexation, and some of the corresponding equilibrium constants are estimated.

  17. Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

    Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur


    New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

  18. Process of electroless plating Cu-Sn-Zn ternary alloy


    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  19. Application of Fe(VI) in the treatment of Zn(II)-NTA complexes in aqueous solutions.

    Yang, J; Tiwari, D; Yu, M; Pachuau, L; Kim, W; Lee, S


    The higher oxidation state of iron, i.e. Fe(VI), was exploited to treat the synthetic wastewater containing Zn(II)-NTA. The decomposition of Zn(II)-NTA by Fe(VI) was investigated with the help of analytical data obtained for the change in Fe(VI) concentration, dissolved organic carbon (DOC) and total soluble Zn(II) concentration as a function of time at various concentrations of Zn(II)-NTA and at constant Fe(VI) concentration. The UV-Visible data was used to explain the reaction kinetics for redox reactions between Fe(VI) and Zn(II)-NTA. The pseudo-first-order rate constant was calculated keeping the Zn(II)-NTA concentration in excess and hence the overall second-order-rate constant was obtained. Fe(VI) reduction was almost unaffected with the 1000 times increase in ionic strength (NaNO3), as well as in the presence of completely oxidized background electrolytes. However, Fe(VI) reduction was greatly affected in the presence of both SO3(2-) and NO2(-) especially at higher concentrations, indicating a competitive reduction took place between Zn(II)-NTA and Na2SO3 or NaNO2 in the Fe(VI) treatment. These results were again supported by the dissolved organic carbon observations since relatively very low removal of the dissolved organic carbon occurred in the presence of Na2SO3 and NaNO2.

  20. A theoretical and experimental investigation of the spectroscopic properties of a DNA-intercalator salphen-type Zn(II) complex.

    Biancardi, Alessandro; Burgalassi, Azzurra; Terenzi, Alessio; Spinello, Angelo; Barone, Giampaolo; Biver, Tarita; Mennucci, Benedetta


    The photophysical and DNA-binding properties of the cationic zinc(II) complex of 5-triethylammonium methyl salicylidene ortho-phenylenediiminato (ZnL(2+)) were investigated by a combination of experimental and theoretical methods. DFT calculations were performed on both the ground and the first excited states of ZnL(2+) and on its possible mono- and dioxidation products, both in vacuo and in selected solvents mimicked by the polarizable continuum model. Comparison of the calculated absorption and fluorescence transitions with the corresponding experimental data led to the conclusion that visible light induces a two-electron photooxidation process located on the phenylenediiminato ligand. Kinetic measurements, performed by monitoring absorbance changes over time in several solvents, are in agreement with a slow unimolecular photooxidation process, which is faster in water and slower in less polar solvents. Moreover, structural details of ZnL-DNA binding were obtained by DFT calculations on the intercalation complexes between ZnL and the d(ApT)2 and d(GpC)2 dinucleoside monophosphate duplexes. Two main complementary binding interactions are proposed: 1) intercalation of the central phenyl ring of the ligand between the stacked DNA base pairs; 2) external electrostatic attraction between the negatively charged phosphate groups and the two cationic triethylammonium groups of the Schiff-base ligand. Such suggestions are supported by fluorescence titrations performed on the ZnL/DNA system at different ionic strengths and temperatures. In particular, the values of the DNA-binding constants obtained at different temperatures provided the enthalpic and entropic contributions to the binding and confirmed that two competitive mechanisms, namely, intercalation and external interaction, are involved. The two mechanisms are coexistent at room temperature under physiological conditions.

  1. Modeling of the Vela complex including the Vela supernova remnant, the binary system gamma2 Velorum, and the Gum nebula

    Sushch, Iurii; Neronov, Andrii


    We study the geometry and dynamics of the Vela complex including the Vela supernova remnant (SNR), the binary system gamma2 Velorum and the Gum nebula. We show that the Vela SNR belongs to a subclass of non-Sedov adiabatic remnants in a cloudy interstellar medium (ISM), the dynamics of which is determined by the heating and evaporation of ISM clouds. We explain observable characteristics of the Vela SNR with a SN explosion with energy 1.4 x 10^50 ergs near the step-like boundary of the ISM with low intercloud densities (~ 10^{-3} cm^{-3}) and with a volume-averaged density of clouds evaporated by shock in the north-east (NE) part about four times higher than the one in the south-west (SW) part. The observed asymmetry between the NE and SW parts of the Vela SNR could be explained by the presence of a stellar wind bubble (SWB) blown by the nearest-to-the Earth Wolf-Rayet (WR) star in the gamma2 Velorum system. We show that the size and kinematics of gamma2 Velorum SWB agree with predictions of numerical calcula...

  2. Determination of the structure, morphology and complex refractive index in ZnO-nanopencils/P3HT hybrid structures

    Motaung, David E., E-mail: [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-structured Materials, Council for Scientific Industrial Research, P. O. Box 395, Pretoria, 0001 (South Africa); Malgas, Gerald F., E-mail: [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-structured Materials, Council for Scientific Industrial Research, P. O. Box 395, Pretoria, 0001 (South Africa); Arendse, Christopher J. [Deparment of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Mavundla, Sipho E. [School of Engineering, Department of Chemical Engineering, University of South Africa, Florida campus, Private Bag X6, Florida 1710 (South Africa)


    Well crystallized flower-shaped ZnO-structures composed of a perfectly hexagonal-shaped ZnO structure were successfully synthesized using a simple microwave assisted hydrothermal method. The NPs with a hexagonal stem and a tapering tip grows out of the base of the flower-shapes. ZnO-NPs were incorporated into the nanomorphology of P3HT and two variations of P3HT:C{sub 60} and P3HT:PCBM blended films in order to facilitate charge separation and transport. Thermo-gravimetric analysis revealed that ZnO-NPs are more stable and are of high purity. A complete PL quenching was demonstrated upon incorporating ZnO-NPs on the surface of P3HT and blended films indicating a charge transfer along the ZnO/P3HT and ZnO/P3HT:fullerenes induced by the aligned nanorods which are working as effective electron collectors by shortening the average electron diffusion distance in the P3HT and fullerenes network. Spectroscopic ellipsometry demonstrated that infiltrating of ZnO-NPs, results in the improved refractive index, extinction coefficient and shifts to lower photon energies. Such shifts can be inferred to the improved light absorption through the waveguide effect from the NPs and an increased interfacial area between the ZnO-NPs and P3HT. An improvement in the mobility and conductivity of P3HT films was observed with an incorporation of ZnO. -- Highlights: Black-Right-Pointing-Pointer Flower-shaped ZnO-structures were synthesized via microwave hydrothermal method. Black-Right-Pointing-Pointer ZnO-nanopencils were incorporated on the P3HT and blended surface. Black-Right-Pointing-Pointer Formation of hexagonal and cone-like structures on the P3HT surface demonstrated an improved morphology. Black-Right-Pointing-Pointer The interfacial area and charge transport improved. Black-Right-Pointing-Pointer The absorption spectra, refractive index and extinction coefficient shifted to lower photon energies.

  3. Isolation and X-ray structures of four Rh(PCP) complexes including a Rh(I) dioxygen complex with a short O-O bond

    Hayashi, Yukiko


    The reaction of RhCl3·H2O with tBu2P(CH2)5PtBu 2 afforded several complexes including [RhIII(H)Cl{ tBu2- P(CH2)2CH(CH2) 2PtBu2}] (1), [RhIIIHCl 2{tBu2P(CH2)5P tBu2}]2 (2), [RhICl{ tBu2P(CH2)2CH=CHCH2P tBu2}] (3) and [RhICl{tBu 2PCH2C(O)CH=CHCH2PtBu2}] (4). X-ray crystal structures of 3 and 4 showed that the C=C bond on the C 5 unit of tBu2P(CH2) 5PtBu2 is bound to Rh(I) in a η2 configuration. In 4, the Rh atom has a trigonal pyramidal coordination geometry. The X-ray crystal structure of 2 consists of two rhodium( III) centers bridged by two tBu2P(CH2)5P tBu2 ligands with two phosphorus atoms, one from each ligand, trans to one another. The crystal structure of the rhodium oxygen adduct with 1,3-bis(di-t-butylphosphinomethyl) benzene [RhO2{ tBu2PCH2(C6H3)CH 2PtBu2}] (5) was also investigated. In this species the O2 is η2 coordinated to the Rh(I) center with asymmetric Rh-O bond lengths (2.087(7) and 1.998(8) Å). The O-O bond distance is short (1.337(11) Å) with νO-O of 990.5 cm -1. DFT calculations on complex 5 yielded two η2- O2 structures that differed in energy by only 0.76 kcal/mol. The lower energy one (5a) had near C2 symmetry, and had nearly equal Rh-O bond lengths, while the higher energy structure (5b) had near Cs symmetry and generally good agreement with the experimental structure. The calculated UV-Vis and IR spectra of complex 5 are in excellent agreement with experiment. © 2012 Elsevier Ltd. All rights reserved.

  4. Synthesis, spectroscopic and DNA binding ability of Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

    Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed


    A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L)2]·l2H2O, [Ni(L)Cl·(H2O)2].5H2O, [Cu(L)Cl] and [Zn(L)(CH3COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, (1)H &(13)C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (Kb). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Biologically active new Fe(II, Co(II, Ni(II, Cu(II, Zn(II and Cd(II complexes of N-(2-thienylmethylenemethanamine

    C. SPÎNU


    Full Text Available Iron(II, cobalt(II, nickel (II, copper (II, zinc(II and cadmium(II complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N-(2-thienylmethylenemethanamine (TNAM formed by the condensation of 2-thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand. Magnetic susceptibility data coupled with electronic, ESR and Mössbauer spectra suggest a distorted octahedral structure for the Fe(II, Co(II and Ni(II complexes, a square-planar geometry for the Cu(II compound and a tetrahedral geometry for the Zn(II and Cd(II complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II, Zn(II and Cd(II complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

  6. Crystal Structures and Theoretical Calculation of Zn(Ⅱ) and Cu(Ⅱ) Supramolecular Complexes Based on Macrocyclic Triamine Ligand 1 ,4,7-Triazacyclodecane (tacd)

    QUO,Hui; ZHU,Hai-Yan; HE,Xian-Ling; SU,Zhen-Ping; LI,Jun; ZHANG,Feng-Xing


    Two supramolecular complexes [Zn(tacd)2](C6H8O4)·6H2O (1) and [Cu(tacd)2]Cl2·4H2O (2) were synthesized and characterized by elemental analysis, IR spectra, TGA and single-crystal X-ray diffraction analysis. The crystal structure showed that the metal ions in complexes 1 and 2 had similar coordination circumstance. But for the complex 2, it formed a novel two-dimensional supramolecular network with 12-membered rings and four-membered rings via hydrogen bond interaction. The thermal gravimetric analyses indicated that the two complexes had similar steps of weight-loss. On the basis of experiment, the two complexes were calculated by DFT-B3LYP/6-31G(d) in Gaussian 03. The results of calculation are in good agreement with the experiment.

  7. Fluorescent sensing and electrocatalytic properties of three Zn(II)/Co(II) coordination complexes containing two different dicarboxylates and two various bis(pyridyl)-bis(amide) ligands

    Lin, Hongyan; Rong, Xing; Liu, Guocheng; Wang, Xiang; Wang, Xiuli; Duan, Surui


    Three new transition metal(II) coordination complexes constructed from two different dicarboxylates (1,3-H2BDC = 1,3-benzenedicarboxylic acid, 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid) and two bis(pyridyl)-bis(amide) ligands (3-bpcd = N,N‧-bis(3-pyridyl)cyclohexane-1,4-dicarboxamide, 3-bpod = N,N‧-bis(3-pyridyl)octandiamide), [Zn(1,3-BDC)(3-bpcd)0.5(H2O)]·H2O (1), [Zn(1,3-BDC)(3-bpod)0.5(H2O)] (2) and [Co(1,4-NDC)(3-bpod)1.5(H2O)] (3) have been synthesized in the hydrothermal environments and structurally characterized by IR, TG and single crystal X-ray diffraction. Complexes 1 and 2 possess the similar 1D ladder-like chain based on [Zn(1,3-BDC)]n zigzag chain and the bidentate ligands 3-bpcd/or 3-bpod. Complex 3 shows a 2D layered structure with a 5-connected {410} topology, which consists of 1D linear [Co(1,4-NDC)]n chain and [Co(3-bpod)1.5]n chain with alternating arrangement of 3-bpod ligands and Co2(3-bpod)2 dinuclear loops. The adjacent 1D chains for 1-2 or the 2D layers for 3 are further extended into 2D or 3D supramolecular frameworks through the hydrogen bonding interactions. Additionally, the solid state fluorescent properties for the title complexes 1-3, the fluorescent sensing behaviors of complexes 1-2 and the electrochemical behaviour of complex 3 have been investigated.

  8. Interplay of bifurcated hydrogen bonds in making of inclusion/pseudo-inclusion complexes of Ni(II), Cu(II) and Zn(II) of a salophen type ligand: Crystal structures and spectral aspects

    Ambili, K. U.; Sithambaresan, M.; Kurup, M. R. Prathapachandra


    Three novel photoluminescent materials were synthesized by treating Ni(II), Cu(II) and Zn(II) acetate salts with a Schiff base prepared from 3-ethoxysalicylaldehyde and 2-aminobenzylamine. Among the prepared complexes, Ni(II) and Cu(II) complexes are inclusion compounds while Zn(II) complex is a pseudo-inclusion compound. They were characterized by elemental analysis, IR, UV-visible and EPR spectra. Single crystal XRD studies of these complexes suggest that Ni(II) and Cu(II) are in a distorted square planar environment while the spatial arrangement of donor atoms in Zn(II) complex is best described as distorted square based pyramid although significant distortion towards trigonal bipyramid is noticed. Stabilized crystal packing of the complexes is established via supramolecular interactions. The metal chelate rings as the π system for C-H···π interactions found in Cu(II) and Zn(II) complexes explicit the concept of metalloaromaticity. TG-DTG studies reveal that all the complexes are thermally stable. Both ligand and complexes exhibit intense photoluminescence in near UV region. However, Zn(II) complex giving an intense blue-green emission spectrum at maximum wavelength of 518 nm with shoulder peaks, could be used for optoelectronic applications.

  9. (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

    Zeynizadeh, Behzad; Faraji, Fariba [Urima Univ., Urima (Iran, Islamic Republic of)


    (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, {alpha}-diketones and {alpha},{beta}-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent.

  10. The synthesis of N-Zn, N-Cu complexes involving 2-amino pyridine and ethylenediamine ligands and application to the Henry reaction

    Luo Mei; Tang Hai Ming; Li Qian Rong; Sun Jie; Yang Shan Zhong; Li Xue Liang


    The synthesis and characterization of a series of N-Zn, N-Cu complexes with 2-amino pyridine and ethylenediamine ligands (1a-b and 2a-b) have been described. They were synthesized with a simple, one-pot method, and the crystal structures of 1a, 1b, 2a and 2b were determined by X-ray crystallography. The complexes were also characterized by NMR, IR, and elemental analysis. They were used as the catalysts in an application to the Henry reaction, and high yields were obtained under the optimum conditions.

  11. Multiheteromacrocycles that Complex Metal Ions. Ninth Progress Report (includes results of last three years), 1 May 1980 -- 30 April 1983

    Cram, D. J.


    The overall objective of this research is to design, synthesize, and evaluate cyclic and polycyclic host organic compounds for the abilities to complex and lipophilize guest metal ions, their complexes, and their clusters. Host organic compounds consist of strategically placed solvating, coordinating, and ion-pairing sites tied together by covalent bonds through hydrocarbon units around cavities shaped to be occupied by guest metal ions, or by metal ions plus their ligands. Specificity in complexation is sought by matching the following properties of host and guest: cavity and metal ion sizes; geometric arrangements of binding sites; numbers of binding sites; characters of binding sites; and valences. The hope is to synthesize new classes of compounds useful in the separation of metal ions, their complexes, and their clusters.

  12. Cu(II), Zn(II) andMn(II) complexes of poly(methyl vinyl ether-alt-maleic anhydride). Synthesis, characterization and thermodynamic parameters

    Hidayet Mazi; Ali Gulpinar


    The complexes of poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) with Zn(II), Mn(II) and Cu(II) ions were synthesized from the reaction of the aqueous solution of copolymer and metal(II) chlorides at different temperatures ranging from 25° to 40°C. Elemental analysis of themetal-polymer complexes suggests that the metal to ligand ratio is 1:1. The formation constants of each complex were determined by the mol-ratio method. UV-Vis studies showed that the complex formation tendency increased in the following order: Zn(II) > Cu(II) > Mn(II). This order was confirmed by the Irving-William series and Pearson’s classification. The IR spectral data indicated the metal ions to be coordinated through the hydroxyl groups of the hydrolysed maleic anhydride. The intrinsic viscosity and thermal properties of the copolymer and metal-polymer complexes and their thermal stability are discussed.

  13. Synthesis, crystal structure, spectroscopic, thermogravimetric and theoretical characterization of Ni(II) and Zn(II) complexes with 4-chloro-2-nitrobenzenesulfonamide

    Estiu, G.; Chacón Villalba, M. E.; Camí, G. E.; Echeverria, G. A.; Soria, D. B.


    Two new complexes of Ni and Zn with 4-chloro-2-nitrobenzenesulfonamide (ClNbsa) have been synthesized and characterized. The structure of the [Ni(ClNbsa)2(NH3)4] complex was determined by X-ray diffraction methods. It crystallizes in the monoclinic P21/c space group with a = 12.8679(3) Å, b = 7.7254(1) Å, c = 12.2478(2) Å, β = 109.899(2)°, V = 1144.85 (4)Å3 and Z = 4 molecules per unit cell. The coordination geometry of the Nickel (II) ion in the complex can be described as a distorted octahedron with two N-sulfonamide and four NH3 groups in opposite vertices. Due to the poor solubility of the Zn(II) complex, their cell parameters were determined by indexing the powder X-ray pattern using the successive dichotomy method implemented in the Fullprof Suite software package. A triclinic cell was determined with cell parameters a = 18.3724(1) Å, b = 7.9468(8) Å, c = 10.2212(9) Å α = 63.061(6) β = 108.754(6) γ = 109.153(6) and V = 1229.97(2)Å3. Nuclear magnetic resonance (NMR) spectroscopy of 1H and 13C have been used for support the structure of the Zn complex. Vibrational and electronic spectroscopy have been used to characterize the compounds, using theoretical calculations for the assignment of the experimental bands. The thermal behavior was investigated by thermogravimetric analyses (TG) and differential thermal analysis (DT).

  14. Synthesis, Optical and Thermal Properties of Cu ( Ⅰ)、 Zn (Ⅱ)Complexes of Schiff Base%Cu(Ⅱ)、Zn(Ⅱ)Schiff碱配合物的合成及其光热性质

    贤景春; 窦甜甜; 王顺文


    用5-硝基水杨醛与色氨酸缩合制备了一种Schiff碱配体,将其与过渡金属Cu(Ⅱ)、Zn(Ⅱ)进行作用合成出两种新型的配合物.采用元素分析、差热-热重、IR、UV、摩尔电导率等对配体和配合物进行了表征,并测定了化合物的荧光性质和对超氧离子的催化歧化作用.%In this paper a new 5-nitro-salicylaldehyde-tryptophane Schiff base ligand and its complex containing Cu( Ⅱ ) ,Zn(Ⅱ ) were synthesized. The compositions and structures of the ligand and its complexes have been characterized by The elemental analyses, thermal analyses,IR spectra, UV spectra and molar conductivity. The fluorescence property and The Dismutation to O2- free radical has also been investigated.

  15. Thiosemicarbazone Cu(II) and Zn(II) complexes as potential anticancer agents: syntheses, crystal structure, DNA cleavage, cytotoxicity and apoptosis induction activity.

    Shao, Jia; Ma, Zhong-Ying; Li, Ang; Liu, Ya-Hong; Xie, Cheng-Zhi; Qiang, Zhao-Yan; Xu, Jing-Yuan


    Four novel thiosemicarbazone metal complexes, [Cu(Am4M)(OAc)]·H2O (1), [Zn(HAm4M)Cl2] (2), [Zn2(Am4M)2Br2] (3) and [Zn2(Am4M)2(OAc)2]·2MeOH (4) [HAm4M=(Z)-2-(amino(pyridin-2-yl)methylene)-N-methylhydrazinecarbothioamide], have been synthesized and characterized by X-ray crystallography, elemental analysis, ESI-MS and IR. X-ray analysis revealed that complexes 1 and 2 are mononuclear, which possess residual coordination sites for Cu(II) ion in 1 and good leaving groups (Cl(-)) for Zn(II) ion in 2. Both 3 and 4 displayed dinuclear units, in which the metal atoms are doubly bridged by S atoms of two Am4M(-) ligands in 3 and by two acetate ions in bi- and mono-dentate forms, respectively, in 4. Their antiproliferative activities on human epithelial cervical cancer cell line (HeLa), human liver hepatocellular carcinoma cell line (HepG-2) and human gastric cancer cell line (SGC-7901) were screened. Inspiringly, IC50 value (11.2±0.9 μM) of complex 1 against HepG-2 cells was nearly 0.5 fold of that against human hepatic cell lines LO2, showing a lower toxicity to human liver cells. Additionally, it displayed a stronger inhibition on the viability of HepG-2 cells than cisplatin (IC50=25±3.1 μM), suggesting complex 1 might be a potential high efficient antitumor agent. Furthermore, fluorescence microscopic observation and flow cytometric analysis revealed that complex 1 could significantly suppress HepG-2 cell viability and induce apoptosis. Several indexes, such as DNA cleavage, reactive oxygen species (ROS) generation, comet assay and cell cycle analysis indicated that the antitumor mechanism of complex 1 on HepG-2 cells might be via ROS-triggered apoptosis pathway. Copyright © 2014. Published by Elsevier Inc.

  16. The meloxicam complexes of Co(II) and Zn(II): Synthesis, crystal structures, photocleavage and in vitro DNA-binding

    Sanatkar, Tahereh Hosseinzadeh; Hadadzadeh, Hassan; Simpson, Jim; Jannesari, Zahra


    Two neutral mononuclear complexes of Co(II) and Zn(II) with the non-steroidal anti-inflammatory drug meloxicam (H2mel, 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxammide-1,1-dioxide), [Co(Hmel)2(EtOH)2] (1), and [Zn(Hmel)2(EtOH)2] (2), were synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy and their solid-state structures were studied by single-crystal diffraction. The complexes have a distorted octahedral geometry around the metal atom. The experimental data indicate that the meloxicam acts as a deprotonated bidentate ligand (through the amide oxygen and the nitrogen atom of the thiazolyl ring) in the complexes, and a strong intramolecular hydrogen bond between the amide N-H function and the enolate O atom stabilizes the ZZZ conformation of meloxicam ligands. Absorption, fluorescence spectroscopy and cyclic voltammetry have been used to investigate the binding of the complexes with fish sperm DNA (FS-DNA). Additionally, the photocleavage studies have been also used to investigate the binding of the complexes with plasmid DNA. The interaction of the complexes with DNA was monitored by a blue shift and hyperchromism in the UV-Vis spectra attributed to an electrostatic binding mode. A competitive study with ethidium bromide (EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. The experimental results show that the complexes can cleave pUC57 plasmid DNA.

  17. New macrocyclic schiff base complexes incorporating a homopiperazine unit: Synthesis of some Co(II), Ni(II),Cu(II) and Zn(II) complexes and crystal structure and theoretical studies

    Keypour, Hassan; Rezaeivala, Majid; Ramezani-Aktij, Ameneh; Bayat, Mehdi; Dilek, Nefise; Ünver, Hüseyin


    A new macrocyclic Schiff base ligand, L, was synthesized by condensation reaction of 1,4-bis(2-formylphenyl)homopiperazine and 1,4-diaminobutane in acetonitrile. The Schiff base ligand was characterized by using elemental analyses, FT-IR, 1H, 13C NMR and mass spectroscopic techniques. The metal (II) complexes [ML], were synthesized from the reaction of MCl2.nH2O (M: Co, Ni, Cu and Zn) with Schiff base ligand, L and characterized by elemental analyses and FT-IR. X-ray crystal structure of [CoLCl]+ distorted square pyramidal geometry with an N4Cl core, arising from coordination by the four donor nitrogen atoms from the macrocyclic framework and one Cl atom. It crystallizes triclinic space group, P-1 with a = 7.1777(1) Å, b = 11.0357 (2) Å, c = 15.1520(2) Å, V = 1183.14(3), Z = 2, Dc = 1.556 g cm-3, μ (MoKα) = 0.156 mm-1. Also, the bonding situation between the [MCl]+ and Ligand (L) fragments in [MLCl]ClO4 (M = Co(II), Ni(II), Cu(II), Zn(II)) complexes were carried out by energy-decomposition analysis (EDA). The results showed that there is an increasing trend in the case of ΔEelstat of the complexes by changing the M from Co(II) to Zn(II).

  18. Synthesis, Characterization and DNA-Binding Properties of The Novel Mononuclear Zn(II, Cd(II, and Mn(II Complexes with Pantoprazole.

    Wessam N. El-Sayed


    Full Text Available A   novel   mononuclear   Mn(II,   Zn(II   and   Cd(II   complexes of pantoprazole   (PA   was synthesized  and characterized  by elemental analysis,  molar conductivity,  magnetic susceptibility   measurements,   IR,  UV-visible  spectral  studies,  and  thermal  analysis.  The electronic spectra along with magnetic data suggest octahedral geometry for Mn(II, Zn(II and Cd(II complexes.  PA acts as an anionic bi-dentate ligand being coordinated by (S=O oxygen and benzimdazolyl nitrogen atoms. The interaction of the complexes with calf thymus DNA (CT-DNA was monitored by blue shift and hyperchromism in the UV-vis spectra. The observed  intrinsic  binding  constants  together  with  structural  analysis  of  the  complexes indicate  the groove  binding. The binding constants were determined at 303°K, 308°K and 313°K.  A thermodynamic analysis showed that the reaction is spontaneous with ΔG being negative. The enthalpy ΔH and the entropy ΔS of reactions were all determined.

  19. Cyanide bridged hetero-metallic polymeric complexes: Syntheses, vibrational spectra, thermal analyses and crystal structures of complexes [M(1,2-dmi)2Ni(μ-CN)4]n (M = Zn(II) and Cd(II))

    Kürkçüoğlu, Güneş Süheyla; Sayın, Elvan; Şahin, Onur


    Two cyanide bridged hetero-metallic complexes of general formula, [M(1,2-dmi)2Ni(μ-CN)4]n (1,2-dmi = 1,2-dimethylimidazole and M = Zn(II) or Cd(II)) have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal analyses and elemental analyses. The crystallographic analyses reveal that the complexes, [Zn(1,2-dmi)2Ni(μ-CN)4] (1) and [Cd(1,2-dmi)2Ni(μ-CN)4] (2), have polymeric 2D networks. In the complexes, four cyanide groups of [Ni(CN)4]2- coordinated to the adjacent M(II) ions and distorted octahedral geometries of complexes are completed by two nitrogen atoms of trans 1,2-dmi ligands. The structures of 1 and 2 are similar and linked via intermolecular hydrogen bonding, C-H⋯Ni interactions to give rise to 3D networks. Vibration assignments are given for all the observed bands and the spectral features also supported to the crystal structures of heteronuclear complexes. The FT-IR and Raman spectra of the complexes are very much consistent with the structural data presented.

  20. Preparation of a Nanosized As2O3/Mn0.5Zn0.5Fe2O4 Complex and Its Anti-Tumor Effect on Hepatocellular Carcinoma Cells

    Jia Zhang


    Full Text Available Manganese-zinc-ferrite nanoparticles (Mn0.5Zn0.5Fe2O4, MZF-NPs prepared by an improved co-precipitation method and were characterized by transmission electron microscopy (TEM, X-ray diffraction (XRD and energy dispersive spectrometry (EDS. Then thermodynamic testing of various doses of MZF-NPs was performed in vitro. The cytotoxicity of the Mn0.5Zn0.5Fe2O4 nanoparticles in vitro was tested by the MTT assay. A nanosized As2O3/Mn0.5Zn0.5Fe2O4 complex was made by an impregnation process. The complex’s shape, component, envelop rate and release rate of As2O3 were measured by SEM, EDS and atom fluorescence spectrometry, respectively. The therapeutic effect of nanosized As2O3/Mn0.5Zn0.5Fe2O4 complex combined with magnetic fluid hyperthermia (MFH on human hepatocelluar cells were evaluated in vitro by an MTT assay and flow cytometry. The results indicated that Mn0.5Zn0.5Fe2O4 and nanosized As2O3/Mn0.5Zn0.5Fe2O4 complex were both prepared successfully. The Mn0.5Zn0.5Fe2O4 nanoparticles had powerful absorption capabilities in a high-frequency alternating electromagnetic field, and had strong magnetic responsiveness. Moreover, Mn0.5Zn0.5Fe2O4 didn’t show cytotoxicity in vitro. The therapeutic result reveals that the nanosized As2O3/Mn0.5Zn0.5Fe2O4 complex can significantly inhibit the growth of hepatoma carcinoma cells.

  1. The Rhynchosia totta complex (Phaseoleae, Fabaceae in Southern Africa, including the description of a new variety and new species

    Annah N. Moteetee


    Full Text Available Background: The Rhynchosia totta complex is one of three taxonomically complicated African groups in the genus Rhynchosia. Numerous southern African species and infraspecific taxa (at least 19 names, 17 species and 2 varieties have been described by various authors in the past, but were later reduced into synonymy with  R. totta. Currently, only the typical variety is recognised in Southern Africa.Objectives:  To investigate and update the circumscription of the taxa within the  R. totta complex in southern Africa and to update their synonymies and distribution ranges. Methods: Specimens of R. totta at GRA, JRAU, K, NH and PRE were studied and compared, and measurements of characters recorded. Populations were also observed during field studies.Results: The examination of numerous specimens, as well as field investigations, has prompted the recognition of four varieties (one described here as new: R. totta var. longicalyx and a new species (R. pedunculata in southern Africa.Conclusions: A great variation in leaf structure and vestiture occurs within the R. totta complex, with the extreme forms easily recognisable. However, the total number of varieties are limited to four [R. totta vars. totta,  longicalyx,  rigidula and venulosa] and a new species described to accommodate specimens with a distinctly prostrate habit and upwardly directed leaves.

  2. A series of Zn-4f heterometallic coordination polymers and a zinc complex containing a flexible mixed donor dicarboxylate ligand.

    Feng, Xun; Feng, Yu-Quan; Liu, Lang; Wang, Li-Ya; Song, Hong-Liang; Ng, Seik-Weng


    A new zinc compound, together with a corresponding series of Zn-4f heterometallic coordination polymers, namely, [Zn(H2PBDA)(PBDA)]n (1), {[Ln2(PBDA)2·2H2O] [Zn2(PBDA)2Cl2]}n [H2PBDA = 3-(pyridin-3-yl-oxy) benzene-1,2-dicarboxylic acid, and Ln = Pr(2), Nd(3), Eu(4), Gd(5), Dy(6), Ho(7), Er(8)] have been hydrothermally synthesized and characterized systematically. Polymers 2-8 feature two-dimensional (2D) 4,4 networks, containing the original 1D heterometallic double stranded chains composed of [Ln2Zn2(PBDA)2] entities. The extensive hydrogen bonding and π-π stacking interactions were observed to stabilize the extended architectures. The luminescence emission spectra of the polymers vary depending on the lanthanide(III) ion present. Informative magnetic susceptibility measurements show that the same carboxylate bridging fashion of the PBDA ligand results in the different magnetic properties occurring within the heterometallic coordination polymers. In addition, polymer 6 exhibits an interesting slow magnetic relaxation behavior at lower temperatures.

  3. Ultrafast pump-probe spectroscopy of Zinc Phthalocynine (ZnPc) and light harvesting complex II (LHC II)

    Ombinda-Lemboumba, Saturnin


    Full Text Available The presentation discusses basic principles of pump-probe technique, possible transient absorption signals, LHC II and ZnPc, experimental setup, chirp measurement and correction methods. The results of the study, conclusion and future work are also...

  4. ZnS, CdS and HgS Nanoparticles via Alkyl-Phenyl Dithiocarbamate Complexes as Single Source Precursors

    Peter A. Ajibade


    Full Text Available The synthesis of II-VI semiconductor nanoparticles obtained by the thermolysis of certain group 12 metal complexes as precursors is reported. Thermogravimetric analysis of the single source precursors showed sharp decomposition leading to their respective metal sulfides. The structural and optical properties of the prepared nanoparticles were characterized by means of X-ray diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM UV-Vis and photoluminescence spectroscopy. The X-ray diffraction pattern showed that the prepared ZnS nanoparticles have a cubic sphalerite structure; the CdS indicates a hexagonal phase and the HgS show the presence of metacinnabar phase. The TEM image demonstrates that the ZnS nanoparticles are dot-shaped, the CdS and the HgS clearly showed a rice and spherical morphology respectively. The UV-Vis spectra exhibited a blue-shift with respect to that of the bulk samples which is attributed to the quantum size effect. The band gap of the samples have been calculated from absorption spectra and werefound to be about 4.33 eV (286 nm, 2.91 eV (426 nm and 4.27 eV (290 nm for the ZnS, CdS and HgS samples respectively.

  5. Theoretical studies on densities, stability and detonation properties of 2D polymeric complexes Cu(DAT)₂Cl₂ and its new analogues Zn(DAT)₂Cl₂.

    Shu, Yuanjie; Li, Huarong; Gao, Shijie; Xiong, Ying


    A novel environmentally friendly octahedrally coordinated 2D polymeric complexes bis(1,5-diaminotetrazole) -dichlorozinc(II) (Zn(DAT)2Cl2) was first designed based on the the crystal data of bis(1,5-diaminotetrazole)- dichlorocopper(II) (Cu(DAT)2Cl2). Density functional theory (DFT) was used to predict the optimized geometries at TPSSTPSS/6-311G(d, p) level. Densities and detonation properties were evaluated using the electron cloud enclosed volume and VLW equation of state (VLW EOS), respectively. Calculation results show that the density of Zn(DAT)2Cl2 (2.117 g · cm(-1)) is a bit more than that of Cu(DAT)2Cl2 (2.106 g · cm(-1)). The calculated high positive heat of formation (HOF) predicts that the stabilities of the title compounds decrease in the order Zn(DAT)2Cl2 > Cu(DAT)2Cl2, which agrees with the result of bond dissociation energies (BDE). Even though they have the same molecule structures, their first scission steps are different. Furthermore, the title two compounds show good detonation velocities and pressures compared with that of bis-(5-nitro-2H-tetrazolato-N (2)) tetraamminecobalt(III) perchlorates (BNCP), and they are potential candidates for high-energy-density materials (HEDM).

  6. Synthesis and luminescent properties of novel Cu (II), Zn (II) polymeric complexes based on 1,10-phenanthroline and biphenyl groups

    Yan He; Chaofan Zhong; Yu Zhou; Hailiang Zhang


    A fully conjugated ligand 4,4'-bis(1,10-phenanthroline-[5,6-d]imidazole-2-yl)-biphenyl (BPIBP) based on 1,10-phenanthroline and biphenyl groups was firstly synthesized. The corresponding polymeric complexes, BPIBP (1) with Cu(II) (2) and Zn(II) (3), were synthesized and characterized by FT-IR, elemental Analysis, conductivity measurement. UV-Vis and fluorescence spectra at room temperature revealed that both the polymeric complexes 2 and 3 emit blue luminescence at 453 and 452 nm (em, max) in DMSO solution and blue/green luminescence at 527 and 536 nm (em, max) in solid state respectively, and the maximum wavelengths of the polymeric complexes 2 and 3 are red shifted, compared with the ligand 1. Thermal property measurements show that they have good thermal stability.

  7. Chitosan supported Zn(II) mixed ligand complexes as heterogeneous catalysts for one-pot synthesis of amides from ketones via Beckmann rearrangement

    Anuradha; Kumari, Shweta; Layek, Samaresh; Pathak, Devendra D.


    Chitosan supported Zn(II) mixed ligand complexes have been synthesized and characterized by FT-IR, UV-Vis, TGA, XRD, FESEM, EDX, AAS and Elemental Analysis. These complexes have been found to be efficient and recyclable heterogeneous catalysts for the one-pot synthesis of amides via Beckmann rearrangement. All three complexes can be easily filtered out from the reaction medium and reused up to five times without significant loss of catalytic activity. The reported protocol is economical and novel in the sense that amides can be easily synthesized in only one-step. All products were obtained as white to off-white crystalline solids and fully characterized by 1H NMR, FT-IR and Mass Spectra.

  8. Crystal Structure, Fluorescence Property and Theoretical Calculation of the Zn(II) Complex with o-Aminobenzoic Acid and 1,10-Phenanthroline

    Zhang, Zhongyu; Bi, Caifeng; Fan, Yuhua; Zhang, Xia; Zhang, Nan; Yan, Xingchen; Zuo, Jian [Ocean Univ. of China, Qingdao (China)


    A novel complex [Zn(phen)(o-AB){sub 2}] [phen: 1,10-phenanthroline o-AB: o-aminobenzoic acid] was synthesized and characterized by elemental analysis and X-ray diffraction single-crystal analysis. The crystal crystallizes in monoclinic, space group P2(1)/c with a = 7.6397(6) A, b = 16.8761(18) A, c = 17.7713(19) A, α = 90 .deg., β = 98.9570(10) .deg., γ = 90 .deg., V = 2.2633(4) nm{sup 3}, Z = 4, F(000) = 1064, S = 1.058, Dc = 1.520 g·cm{sup -3}, R{sub 1} = 0.0412, wR{sub 2} = 0.0948, μ = 1.128 mm{sup -1}. The Zn(II) is six coordinated by two nitrogen and four oxygen atoms from the 1,10-phenanthroline and o-aminobenzoic acid to furnish a distorted octahedron geometry. The complex exhibits intense fluorescence at room temperature. Theoretical studies of the title complex were carried out by density functional theory (DFT) B3LYP method. CCDC: 898291.

  9. Supramolecular complexes of Co(II), Ni(II) and Zn(II) p-hydroxybenzoates with caffeine: Synthesis, spectral characterization and crystal structure

    Taşdemir, Erdal; Özbek, Füreya Elif; Sertçelik, Mustafa; Hökelek, Tuncer; Çelik, Raziye Çatak; Necefoğlu, Hacali


    Three novel complexes Co(II), Ni(II) and Zn(II) containing p-hydroxybenzoates and caffeine ligands were synthesized and characterized by elemental analysis, FT-IR and UV-vis Spectroscopy, molar conductivity and single crystal X-ray diffraction methods. The thermal properties of the synthesized complexes were investigated by TGA/DTA. The general formula of the complexes is [M(HOC6H4COO)2(H2O)4]·2(C8H10N4O2)·8H2O (where: M: Co, Ni and Zn). The IR studies showed that carboxylate groups of p-hydroxybenzoate ligands have monodentate coordination mode. The M2+ ions are octahedrally coordinated by two p-hydroxybenzoate ligands, four water molecules leading to an overall MO6 coordination environment. The medium-strength hydrogen bondings involving the uncoordinated caffeine ligands and water molecules, coordinated and uncoordinated water molecules and p-hydroxybenzoate ligands lead to three-dimensional supramolecular networks in the crystal structures.

  10. Major histocompatibility complex harbors widespread genotypic variability of non-additive risk of rheumatoid arthritis including epistasis

    Wei, Wen-Hua; Bowes, John; Plant, Darren; Viatte, Sebastien; Yarwood, Annie; Massey, Jonathan; Worthington, Jane; Eyre, Stephen


    Genotypic variability based genome-wide association studies (vGWASs) can identify potentially interacting loci without prior knowledge of the interacting factors. We report a two-stage approach to make vGWAS applicable to diseases: firstly using a mixed model approach to partition dichotomous phenotypes into additive risk and non-additive environmental residuals on the liability scale and secondly using the Levene’s (Brown-Forsythe) test to assess equality of the residual variances across genotype groups per marker. We found widespread significant (P < 2.5e-05) vGWAS signals within the major histocompatibility complex (MHC) across all three study cohorts of rheumatoid arthritis. We further identified 10 epistatic interactions between the vGWAS signals independent of the MHC additive effects, each with a weak effect but jointly explained 1.9% of phenotypic variance. PTPN22 was also identified in the discovery cohort but replicated in only one independent cohort. Combining the three cohorts boosted power of vGWAS and additionally identified TYK2 and ANKRD55. Both PTPN22 and TYK2 had evidence of interactions reported elsewhere. We conclude that vGWAS can help discover interacting loci for complex diseases but require large samples to find additional signals. PMID:27109064

  11. The MRX Complex Ensures NHEJ Fidelity through Multiple Pathways Including Xrs2-FHA-Dependent Tel1 Activation.

    Daichi Iwasaki


    Full Text Available Because DNA double-strand breaks (DSBs are one of the most cytotoxic DNA lesions and often cause genomic instability, precise repair of DSBs is vital for the maintenance of genomic stability. Xrs2/Nbs1 is a multi-functional regulatory subunit of the Mre11-Rad50-Xrs2/Nbs1 (MRX/N complex, and its function is critical for the primary step of DSB repair, whether by homologous recombination (HR or non-homologous end joining. In human NBS1, mutations result truncation of the N-terminus region, which contains a forkhead-associated (FHA domain, cause Nijmegen breakage syndrome. Here we show that the Xrs2 FHA domain of budding yeast is required both to suppress the imprecise repair of DSBs and to promote the robust activation of Tel1 in the DNA damage response pathway. The role of the Xrs2 FHA domain in Tel1 activation was independent of the Tel1-binding activity of the Xrs2 C terminus, which mediates Tel1 recruitment to DSB ends. Both the Xrs2 FHA domain and Tel1 were required for the timely removal of the Ku complex from DSB ends, which correlates with a reduced frequency of imprecise end-joining. Thus, the Xrs2 FHA domain and Tel1 kinase work in a coordinated manner to maintain DSB repair fidelity.

  12. Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, and In Vitro Biological Activities

    Jeslin Kanaga Inba, P.; B. Annaraj; Thalamuthu, S.; Neelakantan, M.A.


    A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2,2′-(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, ...

  13. Kinetics of Thermal Decomposition for ComplexZn(C16H18FN3O3)2(NO3)2]*2H2O


    The thermal decomposition reaction of the [Zn(NFA)2(NO3)2]*2H2O(NFA=C16H18FN3O3,norfloxacin) was studied in a static atmosphere using TG-DTG and DTA methods. The thermal decomposition processes of the complex were determined and its kinetics was investigated. The kinetic parameters were obtained from analysis of the TG-DTG curves by differential and integral methods. The most pro- bable mechanism for the second stage was suggested by comparision of the kinetic parameters.

  14. Preparation of zinc oxide coatings by using newly designed metal–organic complexes of Zn: Effect of molecular structure of the precursor and surfactant over the crystallization, growth and luminescence

    Brahma, Sanjaya, E-mail: [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Shivashankar, S.A. [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012 (India)


    Graphical abstract: ZnO coating comprised of tapered ZnO nanorods using Zn(acac){sub 2} bipy as the precursor. Highlights: • Newly designed precursors were used for the fabrication of ZnO coating. • ZnO coatings (1.5–2 μm) were achieved quickly (1–5 min) by a simple microwave process. • The coatings are uniform having high density of nucleation and excellent growth rate. • Luminescence could be tuned by varying molecular structure of the precursor. • Possible growth mechanism is described in detail. -- Abstract: We report large scale deposition of tapered zinc oxide (ZnO) nanorods on Si(1 0 0) substrate by using newly designed metal–organic complex of zinc (Zn) as the precursor, and microwave irradiation assisted chemical synthesis as a process. The coatings are uniform and high density ZnO nanorods (∼1.5 μm length) grow over the entire area (625 mm{sup 2}) of the substrate within 1–5 min of microwave irradiation. ZnO coatings obtained by solution phase deposition yield strong UV emission. Variation of the molecular structure/molecular weight of the precursors and surfactants influence the crystallinity, morphology, and optical properties of ZnO coatings. The precursors in addition with the surfactant and the solvent are widely used to obtain desired coating on any substrate. The growth mechanism and the schematics of the growth process of ZnO coatings on Si(1 0 0) are discussed.

  15. Two different zinc(II)-aqua complexes held up by a metal-oxide based support: Synthesis, crystal structure and catalytic activity of [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (HMTAH = protonated hexamethylenetetramine)

    T Arumuganathan; A Srinivasarao; T Vijay Kumar; Samar K Das


    An inorganic−organic hybrid material, [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (1) (where HMTAH = protonated hxamethylenetetramine) has been synthesized and structurally characterized. The compound 1 crystallizes in a monoclinic space group 2/. The crystal data of 1: = 43.12(3), = 12.399(10), = 16.285(13), = 111.131(11), = 8. Its crystal structure shows that two different Zn(II)-aqua complexes, [Zn(H2O)5]2+ and [Zn(H2O)4]2+ are covalently coordinated to a heptamolybdateanion [Mo7O24]6- resulting in an anionic species of polyoxometalate supported zinc-aqua complexes, [{Zn(H2O)}{Zn(H2O)4}{Mo7O24}]2-, that is stabilized with two protonated hexamethylenetetramine cations in the title compound 1. In the crystal structure, both lattice water molecules are found to interact with the heptamolybdate cluster anion and the protonated hexamethylenetetramine cation resulting in an intricate three-dimensional hydrogen bonding network. Interestingly, compound 1 exhibits catalytic activity towards oxidation of some primary alcohols.

  16. A highly selective fluorescent 'turn-on' chemosensor for Zn(2+) based on a benzothiazole conjugate: their applicability in live cell imaging and use of the resultant complex as a secondary sensor of CN(-).

    Khairnar, Nilesh; Tayade, Kundan; Sahoo, Suban K; Bondhopadhyay, Banashree; Basu, Anupam; Singh, Jasminder; Singh, Narinder; Gite, Vikas; Kuwar, Anil


    A benzothiazole derivative linked "off-on" multi-responsive and selective chemosensor has been synthesized and evaluated for cation recognition properties. The receptor shows a high sensitivity and selectivity for Zn(2+) through a 'turn-on' fluorescence response over the other tested cations with a detection limit as low as 0.67 μM. The receptor was successfully applied for the detection of Zn(2+) in live HeLa cells. Then, the Zn(2+) complex of receptor was also used for cyanide detection and recognition.

  17. Probing the magnetic and magnetothermal properties of M(II)-Ln(III) complexes (where M(II) = Ni or Zn; Ln(III) = La or Pr or Gd).

    Ahmed, Naushad; Das, Chinmoy; Vaidya, Shefali; Srivastava, Anant Kumar; Langley, Stuart K; Murray, Keith S; Shanmugam, Maheswaran


    We establish the coordination potential of the Schiff base ligand (2-methoxy-6-[(E)-2'-hydroxymethyl-phenyliminomethyl]-phenolate (H2L)) via the isolation of various M(II)-Ln(III) complexes (where M(II) = Ni or Zn and Ln(III) = La or Pr or Gd). Single crystals of these five complexes were isolated and their solid state structures were determined by single crystal X-ray diffraction. Structural determination revealed molecular formulae of [NiGd(HL)2(NO3)3] (1), [NiPr(HL)2(NO3)3] (2) and [Ni2La(HL)4(NO3)](NO3)2 (3), [Zn2Gd(HL)4(NO3)](NO3)2 (4), and [Zn2Pr(HL)4(NO3)](NO3)2 (5). Complexes and were found to be neutral heterometallic dinuclear compounds, whereas 3-5 were found to be linear heterometallic trinuclear cationic complexes. Direct current (dc) magnetic susceptibility and magnetization measurements conclusively revealed that complexes 1 and 4 possess a spin ground state of S = 9/2 and 7/2 respectively. Empirically calculated ΔχMT derived from the variable temperature susceptibility data for all complexes undoubtedly indicates that the Ni(II) ion is coupled ferromagnetically with the Gd(III) ion, and antiferromagnetically with the Pr(III) ion in 1 and 2 respectively. The extent of the exchange interaction for was estimated by fitting the magnetic susceptibility data using the parameters (g = 2.028, S = 9/2, J = 1.31 cm(-1) and zJ = +0.007), supporting the phenomenon observed in an empirical approach. Similarly using a HDVV Hamiltonian, the magnetic data of 3 and 4 were fitted, yielding parameters g = 2.177, D = 3.133 cm(-1), J = -0.978 cm(-1), (for 3) and g = 1.985, D = 0.508 cm(-1) (for 4). The maximum change in magnetic entropy (-ΔSm) estimated from the isothermal magnetization data for was found to be 5.7 J kg(-1) K(-1) (ΔB = 7 Tesla) at 7.0 K, which is larger than the -ΔSm value extracted from 4 of 3.5 J kg(-1) K(-1) (ΔB = 7 Tesla) at 15.8 K, revealing the importance of the exchange interaction in increasing the overall ground state of a molecule for

  18. Co(II), Ni(II), Cu(II) and Zn(II) complexes of a bipyridine bis-phenol conjugate: generation and properties of coordinated radical species.

    Arora, Himanshu; Philouze, Christian; Jarjayes, Olivier; Thomas, Fabrice


    Four bis-phenolate complexes [Zn(II)L], [Ni(II)L], [Cu(II)L] and [Co(II)L] (where [H(2)L = 2,2'-[2,2']bipyridinyl-6-yl-bis-4,6-di-tert-butylphenol] have been synthesized. The copper(II) and nickel(II) complexes have been characterized by X-ray diffraction, showing a metal ion within a square planar geometry, slightly distorted towards tetrahedral. The cyclic voltametry (CV) curve of [Zn(II)L] consists of a single bi-electronic reversible wave at 0.06 V vs. Fc/Fc(+). The electrochemically generated dication is a diradical species [Zn(II)L˙˙](2+) that exhibits the typical phenoxyl π-π* band at 395 nm. It is EPR-silent due to magnetic interactions between the phenoxyl moieties. The CV curves of [Ni(II)L] and [Cu(II)L] exhibit two distinct ligand-centred one-electron oxidation waves. The first one is observed at E(1/2)(1) = 0.38 and 0.40 V for the nickel and copper complex, respectively, and corresponds to the formation of M(II)-coordinated phenoxyl radicals. Accordingly, [Ni(II)L˙](+) exhibits a strong absorption band at 960 nm and an (S = ½) EPR signal centred at g(iso) = 2.02. [Cu(II)L˙](+) is EPR-silent, in agreement with a magnetic coupling between the metal and the radical spin. In contrast with the other complexes, [Co(II)L] was found to react with dioxygen (mostly in the presence of pyridine), giving rise to a stable (S = ½) superoxo radical complex [Co(III)L(Py)(O(2)˙)]. One-electron oxidation of [Co(II)L] at -0.01 V affords a diamagnetic cobalt(III) complex [Co(III)L](+) that is inert towards O(2) binding, whereas two-electron oxidation leads to the paramagnetic phenoxyl radical species [Co(III)L˙](+) whose EPR spectrum features an (S = ½) signal at g(iso) = 2.00.

  19. Cytotoxicity of Cu(II) and Zn(II) 2,2'-bipyridyl complexes: dependence of IC50 on recovery time.

    Shi, Yi; Toms, Bonnie B; Dixit, Namrata; Kumari, Niraj; Mishra, Lallan; Goodisman, Jerry; Dabrowiak, James C


    We measure the cytotoxicity of three metal complexes containing the 2,2'-bypyridine ligand, Cu(bpy)(NCS)(2), 1, [Cu(bpy)(2)(H(2)O)](PF(6))(2), 2, and Zn(bpy)(2)(NCS)(2), 3, toward neuroblastoma cells (SK-N-SH) and ovarian cancer cells (OVCAR-3) using two different cell assays. The cells were exposed to various concentrations of the compounds for 1 h and the percent inhibition of cell growth, I, measured for various times after exposure, i.e., as a function of the recovery time t. After developing the theory showing the relationship between I and t, the cytotoxicity data were analyzed to reveal that the two copper complexes, 1 and 2, cause the cells to divide at a slower rate than the controls during the recovery period, but the zinc complex, 3, had little or no effect on cell division during the recovery period. The usual metric for reporting cytotoxicity is IC(50), which is the concentration of agent required to inhibit cell growth to 50% of the control population. However, since IC(50) can depend on the recovery time, t, as is the case for 1 and 2, reporting IC(50) for a single recovery time can hide important information about the long-time effects of a cytotoxic agent on the health of the cell population. Mechanistic studies with the compounds revealed that the copper complexes, 1 and 2, cleave closed circular pBR322 DNA in the presence of ascorbate, while the zinc complex, 3, does not facilitate DNA cleavage under the same conditions. This difference in DNA cleavage activity may be related to the fact that Cu(II) is redox active and can readily change its oxidation state, while Zn(II) is redox inert and cannot participate in a redox cycle with ascorbate to break DNA.

  20. Vibrational spectra of the ML/sub 2/Cl/sub 2/ complexes (M=Zn,Cd,Co,Ni; L=5-methyl-1-phenylhexahydro-1,3-5-triazine-2-thion)

    Zakharova, O.S.; Dobreva, D.D.; Ignatova, L.A.; Kravchenko, V.V.; Petrov, K.I. (Moskovskij Inst. Tonkoj Khimicheskoj Tekhnologii (USSR))


    IR absorption spectra of the complexes ML/sub 2/Cl/sub 2/ (M=Zn, Cd, Co, Ni, L=5 - methyl-1-phenylhexahydro-1, 3, 5-triazine-2-thion) in the range from 4000 to 200 cm/sup -1/ and Raman laser spectra of the complexes ML/sub 2/Cl/sub 2/ (M=Zn, Cd) in crystal state are recorded. Qualitative interpretation of vibrational frequencies in the spectra has been carried out. It is established that ligand molecules are coordinated via sulphur atom. The structure of the complexes is briefly outlined.

  1. Coordination Compounds of Niobium(IV) Oxide Dihalides Including the Synthesis and the Crystallographic Characterization of NHC Complexes.

    Bortoluzzi, Marco; Ferretti, Eleonora; Marchetti, Fabio; Pampaloni, Guido; Pinzino, Calogero; Zacchini, Stefano


    The 1:1 molar reactions of NbOX3 with SnBu3H, in toluene at 0 °C in the presence of oxygen/nitrogen donors, resulted in the formation of NbOX2L2 (X = Cl, L2 = dme, 2a; X = Br, L2 = dme, 2b; X = Cl, L = thf, 2c; X = Cl, L = NCMe, 2d; dme = 1,2-dimethoxyethane, thf = tetrahydrofuran), in good yields. The 1:2 reactions of freshly prepared 2d and 2b with the bulky NHC ligands 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, Imes, and 1,3-bis(2,6-dimethylphenyl)imidazol-2-ylidene, Ixyl, respectively, afforded the complexes NbOCl2(Imes)2, 3, and NbOBr2(Ixyl)2, 4, in 50-60% yields. The reactions of 2b with NaOR, in tetrahydrofuran, gave NbOCl(OR) (R = Ph, 5; R = Me, 6) in about 60% yields. All the products were characterized by analytical and spectroscopic techniques; moreover DFT calculations were carried out in order to shed light on synthetic and structural features. Compounds 3 and 4, whose molecular structures have been ascertained by X-ray diffraction, represent very rare examples of crystallographically characterized niobium-NHC systems.

  2. Supramolecular architectures in luminescent Zn(II) and Cd(II) complexes containing imidazole derivatives: Crystal structures, vibrational and thermal properties, Hirshfeld surface analysis and electrostatic potentials

    Di Santo, Alejandro; Echeverría, Gustavo A.; Piro, Oscar E.; Pérez, Hiram; Ben Altabef, Aida; Gil, Diego M.


    Three novel zinc and cadmium complexes with 1-methylimidazole and 2-methylimidazole as ligands, mono-nuclear dichloro-bis(1-methylimidazole) zinc(II) and dibromo-bis(2-methylimidazole)cadmium(II) monohydrate complexes, and poly-nuclear bis(1-methylimidazole)-di-(μ2-bromo)cadmium(II) complex, namely, compounds 1-3, respectively, have been synthesized. The complexes were characterized by IR and Raman spectroscopies, thermal analysis and fluorescence. All the compounds exhibit interesting luminescent properties in solid state originated from intra-ligand (π→π*) transitions. Crystal structures of 1-3 were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in P21/n space group, the Zn(II) ion lies at a crystal general position in a tetrahedral environment, and the mono-nuclear units are weakly bonded to one another by Csbnd H⋯Cl hydrogen bonds. Compound 2 crystallizes in Pnma space group, and mirror-related tetrahedral units around Cd(II) ion are H-bonded through a water molecule. Compound 3 crystallizes in P21/c space group, and the Cd(II) ion presents a centrosymmetric octahedral coordination. Neighboring and equatorial edge-sharing octahedra conform a polymeric arrangement that extends along the crystal a-axis. Weak hydrogen bonds are the major driving forces in the crystal packing of the three complexes. Hirshfeld surface analysis reveals a detailed scrutiny of intermolecular interactions experienced by each complex. The surfaces mapped over dnorm property highlight the X···H (X = Cl, Br) as the main intermolecular contacts for the three complexes, being also relevant the presence of O⋯H contacts for complex 2. The surfaces mapped over Shape index and curvedness properties for the two Cd complexes allow identify π … π stacking interactions which are absent in the Zn complex. 2D fingerprint plots have been used to quantify the relative contribution of the intermolecular contacts to crystal stability of compounds, showing

  3. Structural characterization of 1,8-naphthalimides and in vitro microbiological activity of their Cu(II) and Zn(II) complexes

    Grabchev, Ivo; Yordanova, Stanislava; Bosch, Paula; Vasileva-Tonkova, Evgenia; Kukeva, Rositsa; Stoyanov, Stanimir; Stoyanova, Radostina


    Two new 1,8-naphthalimide derivatives (NI1 and NI2) have been synthesized and characterized. The photophysical properties of the new compounds have been investigated in organic solvents of different polarity. It has been shown that both compounds are solvent depended. Cu(II) and Zn(II) complexes of NI2 were obtained and characterized by IR-NMR, fluorescence and EPR spectroscopy. The influence of different metal cations on the fluorescence intensity has been investigated in acetonitrile solution. Antimicrobial composite PLA-metal complexes materials have been obtained for the first time. Microbiological activity of both metal complexes has been investigated in vitro against different Gram-positive and Gram-negative bacteria and two yeasts. The various antimicrobial activities and the minimum inhibitory concentrations (MICs) of both complexes have been determined. The microbiological activity of composite materials PLA-metal complexes in thin polymeric film has also been investigated. The results suggest that the new metal complexes could find application in designing new antimicrobial preparations to control the spread of infections.

  4. Synthesis and multi-response research of a highly selective fluorescent chemosensor for Zn2+

    Li, Ming; Wang, Rujie


    A new 1,2,3-triazole receptor bearing quinoline groups have been prepared via “click” reaction. The compound shows significant fluorescent response to Zn2+ over other cations in CH3CN solvent. Besides, electrochemical properties including cyclic voltammetry (CV) and differential-pulse voltammetry (DPV) tests are operated to reveal the complex also has good electrochemical response toward Zn2+.

  5. Synthesis and characterization of new unsymmetrical 'side-off' tetra and hexa coordinate homobinuclear Cu(II) and heterobinuclear Cu(II)-Zn(II) complexes: Magnetic, electrochemical and kinetic studies

    Shanmuga Bharathi, K.; Sreedaran, S.; Kalilur Rahiman, A.; Narayanan, V.

    A new class of phenol based unsymmetrical side-off tetra and hexa coordinate homobinuclear Cu(II) and heterobinuclear Cu(II)-Zn(II) complexes have been synthesized and characterized by elemental and spectral analysis. The electronic spectra of all the complexes show "Red shift" in LMCT band, for the ligand H2L2 compared to that of the ligand H2L1 due to the relatively higher electron donating nature of their substitutents. The homobinuclear Cu(II) complexes (1 and 2) illustrate an antiferromagnetic interaction (μeff: 1.58 and 1.60 BM) at 298 K with a broad EPR signal. Variable temperature magnetic moment study of the binuclear copper (II) complexes shows that the extent of antiferromagnetic coupling is greater in the case of H2L2 complexes than H2L1 complexes (-2 J values: 192 cm-1 and 184 cm-1 respectively). The heterobinuclear Cu(II)-Zn(II) complexes (3 and 4) have a magnetic moment value close to the spin only value with four hyperfine EPR signals. Electrochemical studies of the complexes reveal that all the binuclear complexes show two irreversible one-electron transfer reduction waves in the cathodic region. There is an "anodic shift" in the first reduction potential of the complexes, of the ligand H2L1 when compared to that of the ligand H2L2 due to the presence of relatively higher electron donating N-substituents in the later case than in the former case. The catecholase activity of the complexes reveals that the homobinuclear Cu(II) complexes show higher catalytic activity than the corresponding heterobinuclear Cu(II)-Zn(II) complexes. In the hydrolysis of 4-nitrophenylphosphate, the heterobinuclear Cu(II)-Zn(II) complexes show better catalytic activity than the corresponding homobinuclear Cu(II) complexes.

  6. Structural, physicochemical characterization, theoretical studies of carboxamides and their Cu(II), Zn(II) complexes having antibacterial activities against E. coli

    Aktan, Ebru; Gündüzalp, Ayla Balaban; Özmen, Ümmühan Özdemir


    The carboxamides; N,N‧-bis(thiophene-2-carboxamido)-1,3-diaminopropanol (L1) and N,N‧-bis(furan-2-carboxamido)-1,3-diaminopropanol (L2) were synthesized and characterized using 1H NMR, 13C NMR, LC-MS and FT-IR spectrum. The molecular geometries of these molecules were optimized by DFT/B3LYP method with 6-311G(d,p) basis set in Gaussian 09 software. The geometrical parameters, frontier molecular orbitals (FMOs) and molecular electrostatic potential (MEP) mapped surfaces were calculated by the same basis set. Dinuclear Cu(II) and Zn(II) complexes having general formula as [MLCl]2Cl2.nH2O (in which M = Cu(II),Zn(II); n = 0,2) were also synthesized and characterized using LC-MS and FT-IR spectrum, thermogravimetric analysis (TGA/DTA curves), magnetic moments and molar conductivities. Coordination was found to be through carbonyl oxygen and two chlorine atoms as bridging in distorted tetrahedral geometry. The optimized structures, geometrical parameters, frontier molecular orbitals (FMOs) and dipole moments of metal complexes were also obtained by DFT/B3LYP method with LanL2DZ basis set. Antibacterial activities of the compounds were screened against E. coli using microdilution method (MIC's in μg/mL). The activity results show that the corresponding compounds exhibit good to moderate antibacterial effects when compared with sulfamethoxazole and sulfisoxazole antibiotics as positive controls. Also, metal complexes have remarkable increase in their activities than parent ligands against E. coli which is mostly effected by [Cu(L2)Cl]2Cl2 complex as potential antibacterial agent.

  7. Molecular dynamics study of Zn(aβ and Zn(aβ2.

    Lurong Pan

    Full Text Available The aggregation of Aβ-peptide (Aβ is widely considered to be the critical step in the pathology of Alzheimer's disease. Small, soluble Aβ oligomers have been shown to be more neurotoxic than large, insoluble aggregates and fibrils. Recent studies suggest that biometal ions, including Zn(II, may play an important role in the aggregation process. Experimentally determining the details of the binding process is complicated by the kinetic lability of zinc. To study the dynamic nature of the zinc-bound Aβ complexes and the potential mechanisms by which Zn(II affects Aβ oligomerization we have performed atomistic molecular dynamics (MD simulations of Zn(Aβ and Zn(Aβ2. The models were based on NMR data and predicted coordination environments from previous density functional theory calculations. When modeled as 4-coordinate covalently bound Zn(Aβ n complexes (where n = 1 or 2, zinc imposes conformational changes in the surrounding Aβ residues. Moreover, zinc reduces the helix content and increases the random coil content of the full peptide. Although zinc binds at the N-terminus of Aβ, β-sheet formation is observed exclusively at the C-terminus in the Zn(Aβ and most of the Zn(Aβ2 complexes. Furthermore, initial binding to zinc promotes the formation of intra-chain salt-bridges, while subsequent dissociation promotes the formation of inter-chain salt-bridges. These results suggest that Zn-binding to Aβ accelerates the aggregation of Aβ by unfolding the helical structure in Aβ peptide and stabilizing the formation of vital salt-bridges within and between Aβ peptides.

  8. Biofilm production and evaluation of antifungal susceptibility amongst clinical Candida spp. isolates, including strains of the Candida parapsilosis complex.

    Melo, Analy S; Bizerra, Fernando C; Freymüller, Edna; Arthington-Skaggs, Beth A; Colombo, Arnaldo L


    Candida cells can form biofilms that frequently are sources of infections and are less susceptible to antifungal drugs. Some authors have reported that Candida orthopsilosis and Candida metapsilosis isolates are not able to produce biofilms in vitro and there are no studies available on biofilm susceptibility for these species to antifungals. The aims of this study were to (i) quantify Candida spp. biofilms in vitro, and (ii) test the in vitro susceptibilities of Candida spp. biofilms to fluconazole (FLC) and amphotericin B (AMB). Isolates studied included four Candida albicans, six C. tropicalis, seven C. parapsilosis, eight C. orthopsilosis, and five C. metapsilosis. We compared two different methods to evaluate biofilm production, i.e., crystal violet (CV) staining and XTT-reduction assays (XTT). Scanning electron microscopy (SEM) was used to observe high, medium and low biofilm producing isolates screened by these two methods. To determine the minimum biofilm eradication concentration (MBEC) for FLC and AMB, XTT-reduction assay was used to measure cell metabolic activity. Biofilm quantification by CV and XTT showed that C. tropicalis isolates were the highest biofilm producer, followed by C. albicans, C. parapsilosis, C. orthopsilosis and C. metapsilosis. Examination of SEM images revealed that the extent of biofilms formed by high, medium, and low producers was highly correlated to the results generated by CV assay. Biofilm of all the isolates evaluated were resistant to FLC (MBEC(80) ≥ 256 ug/ml) but, in general, susceptible to AMB, except for six C. parapsilosis strains (MBEC(80) ≥ 8 ug/ml).

  9. Eco-friendly and Efficient Synthesis, Characterisation and Antibacterial Studies of Unsymmetrical Bidentate Schiff Bases and their Zn(II Complexes

    K. P.Srivastava


    Full Text Available A rapid, efficient, clean and environmentally benign exclusive synthesis of Schiff bases as new ligands and their complexes with Zn(II have been developed using condensation of pyridoxalwith amoxicillin (L1, cephalexin (L2, sulphamethoxazole (L3 and trimethoprim (L4 efficiently in analcoholic suspension medium using alkali catalyst with excellent yields under microwaves irradiation. This method provides several advantages such as environmental friendliness, simple work-up procedure, short reaction times, non-hazardous and excellent yield of products.The results are compared with conventional methods for their yield and reaction time. The Schiff base ligands and the complexes were characterized by micro-analytical, thermo-gravimetric, magnetic and spectroscopic studies.All the Schiff bases were bidentate (NO donor ligands. All complexes were found to be six co-ordinate dihydrates and ML2[1:2 (metal: ligand ratio] type. The complexes are coloured and stable in air. All the complexes under investigation possess antibacterial activity. The antibacterial activity showed the following trend:

  10. Synthesis, interactions, molecular structure, biological properties and molecular docking studies on Mn, Co, Zn complexes containing acetylacetone and pyridine ligands with DNA duplex.

    Thamilarasan, V; Sengottuvelan, N; Stalin, N; Srinivasan, P; Chakkaravarthi, G


    Three metal complexes (1-3) of the type [Mn(acac)2(py)·H2O] (1), [Co(acac)2(py)·H2O] (2) and [Zn(acac)2(py)·H2O] (3), [Where acac=acetylacetone, py=pyridine] were synthesized and characterized by spectral (UV-vis, FT-IR, ESI-mass) analysis. The structure of complex 2 has been determined by single crystal X-ray diffraction studies and the configuration of ligand-coordinated to metal(II) ion was well described as distorted octahedral coordination geometry. The interaction of the complexes with CT-DNA has been explored by absorption, fluorescence, circular dichromism spectroscopy, viscosity measurements and molecular docking studies. The intrinsic binding constant Kb of complexes 1-3 with CT-DNA obtained from UV-vis absorption spectral studies were 2.1×10(4), 2.1×10(5) and 1.98×10(4)M(-1), respectively, which revealed that the complexes could interact with CT-DNA through groove binding. The results indicated that the complexes (1-3) were able to bind to DNA with different binding affinity, in the order: 2>1>3. The interaction of the compounds with bovine serum albumins were also investigated using fluorescence methods and the gel electrophoresis assay demonstrates weak cleavage ability of the pBR322 plasmid DNA in the presence of the metal complexes (1-3) with various activators. Further, the in vitro cytotoxic effect of the complexes were examined on cancerous cell line, with human breast cancer cells MCF-7.

  11. Novel photoluminescent mesogenic Schiff-base ligands bearing [N{sub 4}O{sub 4}] donors and their bimetallic Zn(II) complexes

    Bhattacharjee, Chira R., E-mail:; Datta, Chitraniva; Das, Gobinda; Mondal, Paritosh


    Novel photoluminescent salicylaldimine ligands condensed from 3{sup /}, 3{sup /}, 4{sup /}, 4{sup /}-tetraminobiphenyl and 4-substituted long alkoxy salicylaldehyde possessing two sets of tetradentate [N{sub 2}O{sub 2}] donor site and their binuclear zinc(II) complexes have been synthesized. The mesogenic and photophysical properties were investigated. The compounds were characterized by FT-IR, {sup 1}H and {sup 13}C NMR, UV-vis, elemental analyses, solution electrical conductivity measurements and FAB mass spectrometry. The mesomorphic behavior of these compounds was probed by differential scanning calorimetry and polarized optical microscopy. The ligand with six carbon chain length showed monotropic nematic mesomorphism at 128 Degree-Sign C. However, the ligand with alkoxy tail of carbon length 12 showed enantiotropic SmC phase. The complexes are devoid of any mesomorphism. The low molar conductance values in CH{sub 2}Cl{sub 2} indicate that the complexes are non-electrolytes. At 330 nm excitation, the ligand emits green light at {approx} 516 nm ({Phi} = 30%) and {approx} 549 nm ({Phi} = 16%) in solution and solid state, respectively. At similar excitation wavelength, the complexes exhibit blue light in solution at {approx} 452 nm ({Phi} = 20%) and green light in solid state {approx} 555 nm ({Phi} = 11%). The DFT calculations were performed using DMol3 program at BLYP/DNP level to ascertain the stable electronic structure of the complex. - Graphical abstract: Green emissive mesogenic compartmental salen type Schiff base compound with four terminal chains and their binuclear Zn(II) complex are described. The ligand exhibits nematic/SmC mesomorphism however complexes did not exhibit mesogenicity. Highlights: Black-Right-Pointing-Pointer New photoluminescent compartmental Schiff-base. Black-Right-Pointing-Pointer Nematic and SmC mesomorphism. Black-Right-Pointing-Pointer Green emissive ligand. Black-Right-Pointing-Pointer Distorted square planner geometry. Black

  12. Synthesis and catalytic activity of Ln(III) complexes with an unsymmetrical Schiff base including multi()C = N-groups

    姚克敏; 李宁; 沈联芳


    A synthetic method for a new unsymmetrical Schiff base and its Ln (III) complexes including multi C == N- groups is reported. The complexes are characterized by elemental analysis, IR spectra, 1H and 13C NMR, especially 2D-COSY1H, 1H NMR spectra. The general formula of the obtained complexes is [Ln3(TBLY)(NO3)3]@nH2O (Ln = La, n = 3; Ln = Nd, n = 5; Ln = Gd, Dy, Yb, Y, n = 7), whereTBLY = tetraglycol aldehyde-2,4-dihydroxy benzaldehyde bis-lysine Schiff base. In addition, the evidence for existence of C == CH-NH- group is supported bythe AM1 method. The complexes obtained may be used as a catalyst. Conversion rate of 80% with the viscosity-average molecular weight 220000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst has been obtained.

  13. Dilution-triggered SMM behavior under zero field in a luminescent Zn2Dy2 tetranuclear complex incorporating carbonato-bridging ligands derived from atmospheric CO2 fixation.

    Titos-Padilla, Silvia; Ruiz, José; Herrera, Juan Manuel; Brechin, Euan K; Wersndorfer, Wolfgang; Lloret, Francesc; Colacio, Enrique


    The synthesis, structure, magnetic, and luminescence properties of the Zn2Dy2 tetranuclear complex of formula {(μ3-CO3)2[Zn(μ-L)Dy(NO3)]2}·4CH3OH (1), where H2L is the compartmental ligand N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine, are reported. The carbonate anions that bridge two Zn(μ-L)Dy units come from the atmospheric CO2 fixation in a basic medium. Fast quantum tunneling relaxation of the magnetization (QTM) is very effective in this compound, so that single-molecule magnet (SMM) behavior is only observed in the presence of an applied dc field of 1000 Oe, which is able to partly suppress the QTM relaxation process. At variance, a 1:10 Dy:Y magnetic diluted sample, namely, 1', exhibits SMM behavior at zero applied direct-current (dc) field with about 3 times higher thermal energy barrier than that in 1 (U(eff) = 68 K), thus demonstrating the important role of intermolecular dipolar interactions in favoring the fast QTM relaxation process. When a dc field of 1000 Oe is applied to 1', the QTM is almost fully suppressed, the reversal of the magnetization slightly slows, and U(eff) increases to 78 K. The dilution results combined with micro-SQUID magnetization measurements clearly indicate that the SMM behavior comes from single-ion relaxation of the Dy(3+) ions. Analysis of the relaxation data points out that a Raman relaxation process could significantly affect the Orbach relaxation process, reducing the thermal energy barrier U(eff) for slow relaxation of the magnetization.

  14. Synthesis, characterization, fluorescence and biological studies of Mn(II, Fe(III and Zn(II complexes of Schiff bases derived from Isatin and 3-substituted-4-amino-5-mercapto-1,2,4-triazoles

    Sangamesh A. Patil


    Full Text Available A series of Mn(II, Fe(III and Zn(II complexes have been synthesized with Schiff bases derived from isatin and 3-substituted-4-amino-5-mercapto-1,2,4-triazole. The elemental, spectroscopic (Infrared, nuclear magnetic resonance, ultraviolet-visible, fast atom bombardment-mass, fluorescence and electrochemistry and magnetic studies suggested that the metal complexes possess octahedral geometry. The Schiff bases and their metal complexes exhibit fluorescent properties. The antimicrobial studies of Schiff bases and their metal complexes against various bacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis and fungal (Aspergillus niger, and Penicillium chrysogenum species by the minimum inhibitory concentration method revealed that the metal complexes possess more healing antibacterial activities than the Schiff bases. DNA cleavage property of Mn(II, Fe(III and Zn(II complexes revealed the important role of metal ion in the biological system.

  15. Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole: synthesis, structures and their high catalytic activity for efficient cyclic carbonate synthesis.

    Vignesh Babu, Heeralal; Muralidharan, Krishnamurthi


    The syntheses of Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole (DIP(2)pyr)H 1 and their catalytic activities in CO(2) fixation are reported. The structures of these complexes were characterized by IR, (1)H, (13)C NMR and single crystal X-ray diffraction techniques. The catalytic activities of these complexes for the cycloaddition of CO(2) to an epoxide under one atmosphere of pressure and mild temperature conditions to yield cyclic carbonate have been studied. Among the four complexes synthesized, the Zn(II) and Cu(II) complexes were found to be versatile whereas the Cu(II) complex was more selective in the conversion. They were highly effective for the conversion of monosubstituted terminal epoxides, disubstituted terminal and internal epoxides to their corresponding cyclic carbonates with good to high yields.

  16. Synthesis, characterization and biological activity of Cu(II), Ni(II) and Zn(II) complexes of biopolymeric Schiff bases of salicylaldehydes and chitosan.

    de Araújo, Eliene Leandro; Barbosa, Hellen Franciane Gonçalves; Dockal, Edward Ralph; Cavalheiro, Éder Tadeu Gomes


    Schiff bases have been prepared from biopolymer chitosan and salicylaldehyde, 5-methoxysalicylaldehyde, and 5-nitrosalicylaldehyde. Ligands were synthesized in a 1:1.5mol ratio, and their Cu(II), Ni(II) and Zn(II) complexes in a 1:1mol ratio (ligand:metal). Ligands were characterized by (1)H NMR and FTIR, resulting in degrees of substitution from 43.7 to 78.7%. Complexes were characterized using FTIR, electronic spectra, XPRD. The compounds were confirmed by the presence of an imine bond stretching in the 1630-1640cm(-1) and νMetal-N and νMetal-O at Schiff base complexes presented lower thermal stability and crystallinity than the starting chitosan. Residues were the metallic oxides as confirmed by XPRD, whose amounts were used in the calculation of the percentage of complexed metal ions. Surface morphologies were analyzed with SEM-EDAX. Preliminary cytotoxicity tests were performed using MTT assay with HeLa cells. Despite the differences in solubility, the free bases presented relatively low toxicity.

  17. Tetra- and hexadentate Schiff base ligands and their Ni(II), Cu(II) and Zn(II) complexes. Synthesis, spectral, magnetic and thermal studies.

    Ismail, Tarek M A; Saleh, Akila A; El Ghamry, Mosad A


    Tetradentate N(2)O(2), N(4) Schiff bases, 1,2-bis(4-oxopent-2-ylideneamino) benzene (BOAB), 1-(4-oxopent-2-ylideneamino-2-[(2-hydroxyphenyl)ethylideneamino] benzene (OAHAB), 7,16-bis(4-chlorobenzylidene)-6,8,15,17-tetra-methyl-7,16-dihydro -5,9,14,18-tetraza-dibenzo[a,h] cyclo tetradecene (BCBDCT), 7,16-bis(2-hydroxy-benzylidene)-6,8,15,17-tetramethyl-7,16-dihydro-5,9,14,18-tetraza-dibenzo [a,h] cyclo tetradecene (BHBDCT) and hexadentate N(4)O(2) Schiff bases, 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(2-hydroxybenzylidene) pentane (BHAPHP), 2,4-bis {2-[1-(2-hydroxyphenyl) ethylideneamino] phenylimino}-3-(4-chlorobenzylidene) pentane (BHAPCP) were prepared and characterized by elemental analysis, IR, UV-Vis, (1)H NMR and mass spectra. The solid complexes of the prepared Schiff base ligands with Ni(II), Cu(II) and Zn(II) ions were isolated and characterized by elemental and thermal analyses, IR, electronic and ESR spectra as well as conductance and magnetic susceptibility measurements. The results showed that most complexes have octahedral geometry but few can attain the tetrahedral arrangement. The TG analyses suggest high stability for most complexes followed by thermal decomposition in different steps. The kinetic and thermodynamic parameters for decomposition steps in Cu(II) complexes thermograms have been calculated.

  18. Spectroscopic, DNA binding ability, biological activity, DFT calculations and non linear optical properties (NLO) of novel Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes with ONS Schiff base

    Abdel Aziz, Ayman A.; Elantabli, Fatma M.; Moustafa, H.; El-Medani, Samir M.


    The reaction of Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) with the synthesized N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol Schiff base ligand (H2L) at room temperature resulted in the formation of the five complexes; [Co(HL)2]H2O, 1; [M(HL)2] (M = Cu, Zn and Cd), (2-4) and [Hg(HL)Cl], 5. The ligand and its complexes were characterized based on elemental analyses, IR, 1H NMR, magnetic measurement, molar conductance, and thermal analysis. Coats and Redfern method was used to compute the kinetic and thermodynamic parameters. Antimicrobial activities of H2L and its complexes have been studied. The binding of Co(II), Cu(II) and Zn(II) complexes to calf thymus DNA (CT-DNA) has been investigated using UV-Vis and fluorescence absorption spectra. The results indicated that the ligand and its complexes may bind to DNA by intercalation modes, with a much higher binding affinity of the complexes than that of the ligand. The equilibrium geometries of the studied complexes are investigated theoretically at the B3LYP/LANL2DZ level of theory, and it was found that these geometries are non-linear. The calculated EHOMO and ELUMO energies of the studied complexes can be used to calculate the global properties. The calculated nonlinear optical parameters (NLO); first order hyperpolarizibility (β) of the studied complexes show promising optical properties.

  19. Synthesis, characterization and DNA binding/cleavage, protein binding and cytotoxicity studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of aminonaphthoquinone.

    Kosiha, A; Parthiban, C; Elango, Kuppanagounder P


    The Co(II), Ni(II), Cu(II) and Zn(II) complexes of an aminonaphthoquinone ligand (L) have been prepared and characterized using analytical and spectral techniques. The structures of L and its Zn(II) complex are confirmed by single crystal X-ray diffraction study. The results indicate that Co(II), Ni(II) and Zn(II) complexes possess tetrahedral geometry while Cu(II) complex exhibits square planar structure. The interaction of L and its complexes with CT-DNA reveal that they could interact with CT-DNA through intercalation. The DNA cleavage studies of the L and its complexes indicate that the Cu(II) and Ni(II) complexes cleave the circular form of the DNA relatively to a greater extent than the other complexes. The results of the interaction of these compounds with bovine serum albumin (BSA) indicate that the complexes exhibit a strong binding to BSA over the L. The in vitro anticancer activities indicate that these compounds exhibit substantial activity against human breast (MCF7) and lung cancer (A549) cell lines. The characteristics of apoptosis in cell morphology have been observed using AO/EB and DAPI staining and the results suggest that an apoptotic mode of cell death with these compounds. The overall results and discussion indicate that coordination of metal ions with the ligand enhances the biological activity.

  20. Influence of zinc concentration on structure, complex permittivity and permeability of Ni–Zn ferrites at high frequency

    Jiang, Nan-Nan; Yang, Yang; Zhang, Yu-Xiang [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710119 (China); Zhou, Jian-Ping, E-mail: [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710119 (China); Liu, Peng [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710119 (China); Deng, Chao-Yong [Department of Electronic Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang 550025 (China)


    Polycrystalline soft magnetic nickel–zinc ferrites with chemical composition Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4}, where x=0, 0.2, 0.4, 0.6, 0.65, 0.7, 0.75, and 0.8, were prepared by solid state reaction method. We researched the effect of zinc concentration on the lattice parameter, crystal morphology and electromagnetic properties at high frequency. Results show that ε′ and ε″ decline with increasing frequency until they reach almost constants over 3 MHz to 1 GHz. The dielectric constant achieves a maximum when the Zn concentration is 0.8. The value of ε′ slightly declines with increasing frequency in the range of 2–18 GHz. The spectra of the permeability displays a relaxation resonance for the ferrites with x=0, 0.2, and 0.4 in 3 MHz to 1 GHz frequency range. The permeability is ruled by Snoek's law, which results in the values of μ′ decreased fast below 2 GHz and smaller than 1 above 2 GHz. The value of μ′ reaches maximum and μ″ shows minimum for the samples around x=0.75 in 2–18 GHz range. The magnetic permeability μ′ decreases in an external magnetic field, and shows two resonance peaks corresponding to domain wall and spin rotation resonance. The resonance peaks shift to higher frequency with increasing the external magnetic field. But the permeability has no clear response for magnetic field when zinc concentration is much higher. - Graphical abstract: (a) Resonance frequencies for the domain wall and spin components as a function of external magnetic field and (b) illustration of magnetization process. - Highlights: • A detailed study on permittivity and permeability of Ni–Zn ferrites in 3 MHz to 18 GHz. • Magnetic field inspires two resonance peaks in permeability. • The resonance peaks shift to higher frequency with the magnetic field.

  1. Obtaining strong ferromagnetism in diluted Gd-doped ZnO thin films through controlled Gd-defect complexes

    Roqan, I. S., E-mail:; Venkatesh, S.; Zhang, Z.; Hussain, S.; Bantounas, I.; Flemban, T. H.; Schwingenschlogl, U. [Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Franklin, J. B.; Zou, B.; Petrov, P. K.; Ryan, M. P.; Alford, N. M. [Department of Materials and London Centre for Nanotechnology, Imperial College London, London SW7 2AZ (United Kingdom); Lee, J.-S. [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)


    We demonstrate the fabrication of reproducible long-range ferromagnetism (FM) in highly crystalline Gd{sub x}Zn{sub 1−x}O thin films by controlling the defects. Films are grown on lattice-matched substrates by pulsed laser deposition at low oxygen pressures (≤25 mTorr) and low Gd concentrations (x ≤ 0.009). These films feature strong FM (10 μ{sub B} per Gd atom) at room temperature. While films deposited at higher oxygen pressure do not exhibit FM, FM is recovered by post-annealing these films under vacuum. These findings reveal the contribution of oxygen deficiency defects to the long-range FM. We demonstrate the possible FM mechanisms, which are confirmed by density functional theory study, and show that Gd dopants are essential for establishing FM that is induced by intrinsic defects in these films.

  2. Temperature and time dependence on ZnS microstructure and phases obtained through hydrothermal decomposition of diethyldithiocarbamate complexes.

    Siqueira, Guilherme Oliveira; Matencio, Tulio; da Silva, Herculano Vieira; de Souza, Yara Gonçalves; Ardisson, José Domingos; de Lima, Geraldo Magela; de Oliveira Porto, Arilza


    Zinc sulphide was obtained through hydrothermal decomposition of [Zn(S2CNEt2)] under different experimental conditions such as temperatures and reaction times. Hydrothermal reactions were carried out in a stainless steel autoclave at 160, 180 and 200 °C for 3, 6 and 24 hours. The obtained products were characterized using X-ray diffraction, scanning and high resolution transmission electron microscopies. Particle size and microstrain were determined by Rietveld refinement of experimental X-ray diffraction patterns. The obtained crystal size values were in the range of 6.1 to 30 nm and as the temperature and reaction times increase the particle size also increases. Band gap values are in the range of 3.34 to 3.60 eV and are highly dependent on the crystal microstrain. The catalyst activities were studied through the degradation of methylene blue dye solutions under ultraviolet radiation.

  3. Obtaining strong ferromagnetism in diluted Gd-doped ZnO thin films through controlled Gd-defect complexes

    Roqan, Iman S.


    We demonstrate the fabrication of reproducible long-range ferromagnetism (FM) in highly crystalline GdxZn1-xO thin films by controlling the defects. Films are grown on lattice-matched substrates by pulsed laser deposition at low oxygen pressures (≤25 mTorr) and low Gd concentrations (x ≤ 0.009). These films feature strong FM (10 μB per Gd atom) at room temperature. While films deposited at higher oxygen pressure do not exhibit FM, FM is recovered by post-annealing these films under vacuum. These findings reveal the contribution of oxygen deficiency defects to the long-range FM. We demonstrate the possible FM mechanisms, which are confirmed by density functional theory study, and show that Gd dopants are essential for establishing FM that is induced by intrinsic defects in these films.

  4. Synthesis and Molecular Structure of A Bimetallic Salen Complex Containing Zn and La: A Disordered Nitrate Group Dancing between Two Metal Centers

    Leon Dyers Jr; Donald Van Derveer; Xiu R Bu


    A new bimetallic complex containing Zn and La was prepared from a salen ligand possessing methoxyl groups at the 3, 3'-positions. The structural feature is that one of nitrate groups is disordered and displaced between two metal centers. Crystal system: Triclinic space group:P-1, Z=2. a=0.82714(17) nm, b=1.3484(3) (1) nm, and c=1.3898(3) (1) nm, α=79.89(3)°, β=76.67(3)°, and γ=72.43(3)°. V=1.428.6(5) nm3, Dx=1.812 g·cm-3. (Δρ)max=1.510×10-3 enm3, (Δρ)min=-1.503×10-3 enm3. Accordingly, two water molecules occupy the metal centers in the apical positions via the syn-geometry.

  5. Crystal structure of a mixed-ligand dinuclear Ba-Zn complex with 2-meth-oxy-ethanol having tri-phenyl-acetate and chloride bridges.

    Utko, Józef; Sobocińska, Maria; Dobrzyńska, Danuta; Lis, Tadeusz


    The dinuclear barium-zinc complex, μ-chlorido-1:2κ(2) Cl:Cl-chlorido-2κCl-bis-(2-meth-oxy-ethanol-1κO)bis-(2-meth-oxy-ethanol-1κ(2) O,O')bis-(μ-tri-phenyl-acetato-1:2κ(2) O:O')bariumzinc, [BaZn(C20H15O2)2Cl2(C3H8O2)4], has been synthesized by the reaction of barium tri-phenyl-acetate, anhydrous zinc chloride and 2-meth-oxy-ethanol in the presence of toluene. The barium and zinc metal cations in the dinuclear complex are linked via one chloride anion and carboxyl-ate O atoms of the tri-phenyl-acetate ligands, giving a Ba⋯Zn separation of 3.9335 (11) Å. The irregular nine-coordinate BaO8Cl coordination centres comprise eight O-atom donors, six of them from 2-meth-oxy-ethanol ligands (four from two bidentate O,O'-chelate inter-actions and two from monodentate inter-actions), two from bridging tri-phenyl-acetate ligands and one from a bridging Cl donor. The distorted tetra-hedral coordination sphere of zinc comprises two O-atom donors from the tri-phenyl-acetate ligands and two Cl donors (one bridging and one terminal). In the crystal, O-H⋯Cl, O-H⋯O and C-H⋯Cl inter-molecular inter-actions form a layered structure, lying parallel to (001).

  6. Extended photoresponse and multi-band luminescence of ZnO/ZnSe core/shell nanorods.

    Yang, Qin; Cai, Hua; Hu, Zhigao; Duan, Zhihua; Yang, Xu; Sun, Jian; Xu, Ning; Wu, Jiada


    Aligned ZnO/ZnSe core/shell nanorods (NRs) with type-II energy band alignment were fabricated by pulsed laser deposition of ZnSe on the surfaces of hydrothermally grown ZnO NRs. The obtained ZnO/ZnSe core/shell NRs are composed of wurtzite ZnO cores and zinc blende ZnSe shells. The bare ZnO NRs are capable of emitting strong ultraviolet (UV) near band edge (NBE) emission at 325-nm light excitation, while the ZnSe shells greatly suppress the emission from the ZnO cores. High-temperature processing results in an improvement in the structures of the ZnO cores and the ZnSe shells and significant changes in the optical properties of ZnO/ZnSe core/shell NRs. The fabricated ZnO/ZnSe core/shell NRs show optical properties corresponding to the two excitonic band gaps of wurtzite ZnO and zinc blende ZnSe and the effective band gap between the conduction band minimum of ZnO and the valence band maximum ZnSe. An extended photoresponse much wider than those of the constituting ZnO and ZnSe and a multi-band photoluminescence including the UV NBE emission of ZnO and the blue NBE emission of ZnSe are observed.

  7. Complexes of photosensitizer and CdSe/ZnS quantum dots passivated with BSA: optical properties and intracomplex energy transfer

    Kuznetsova, Vera; Orlova, Anna; Martynenko, Irina; Kundelev, Evgeny; Maslov, Vladimir; Fedorov, Anatoly; Baranov, Alexander; Gun'ko, Yurii


    Here we report our investigations of the formation conditions and photophysical properties of complexes between luminescent semiconducting nanoparticles (quantum dots, QDs) and the photosensitizer chlorin e6, which is widely used for the photodynamic therapy. In our complexes, bovine serum albumin (BSA), the most abundant protein in blood serum, was used as a linker between QDs and chlorin e6 molecules. The influence of BSA on the optical properties of Ce6 and QDs in complexes was properly examined using spectral-luminescent methods. It was found that BSA passivated QD surface and substantially QD quantum yield of luminescence was increased. In addition, BSA prevented the aggregation of chlorin e6 molecules in complexes with QDs. We demonstrated that the use of BSA as a linker allows to create functional QD-chlorin e6 complexes with effective photoexcitation energy transfer from QDs to the molecules.

  8. Novel Ni(II) and Zn(II) complexes coordinated by 2-arylaminomethyl-1H-benzimidazole: Molecular structures, spectral, DFT studies and evaluation of biological activity

    Abdel-Ghani, Nour T.; Abo El-Ghar, Maha F.; Mansour, Ahmed M.


    [NiL1,2Cl2(OH2)3]·zH2O and [ZnL1,2(CH3CO2)2] (L1 = (1H-benzimidazol-2-ylmethyl)-N-phenyl amine, z = 0 and L2 = 2-[(1H-Benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester, z = 1) complexes have been synthesized and characterized by a variety of physico-chemical techniques. The central Ni(II) ion is coordinated by only the pyridine-type nitrogen (Npy) of benzimidazole ring, three water molecules and two chlorido ligands forming a distorted octahedral geometry. Five coordinated zinc complexes were obtained, where the coordination sphere of zinc ion is made up of secondary amino group (NHsec), Npy and two acetate groups, one acts as a unidentate and the other as a bidentate. A theoretical DFT/UB3LYP method combined with LANL2DZ basis set shows that all the metal-ligand bonds are of the L → M type. Electronic structures have been calculated using TD-DFT method. The antibacterial activity of NiL2 complexes decreases by the introduction of COOCH3 group in the ortho-position of the aniline moiety.

  9. Synthesis, Characterization and Antitumor Activities of Co, Ni, Cu, Zn Complexes with 1,4,7,10- tetrakis (4- nitrobenzyl )- 1,4,7,10- tetraazacyclododecane Macrocyclic Ligand

    孔德源; 谢雨礼; 谢毓元; 黄小荧


    New tetraazamacrocyclic ligand with 1, 4, 7, 10-tetrakis (4-nitrobenzyl) pendent groups (C36H40N8O8, Mr= 712.76) crystallized in the monoclinic system, P21/n space group with unit cell parameters: a=7. 834(2), b=22. 902(6), c =10. 147(3)A, β=106.53(2)°, V=1745(1)A3, Z=2, Dc=1. 356 g/cm3, λ(MoKa)=0. 71069 A ; μ=0. 92cm-1, F(000)=752, T=296K. The final R and Rw values are 0.065 and 0.066, respectively. The Cu( Ⅱ ), Ni( Ⅱ ), Co( Ⅱ ), Zn( Ⅱ ) complexes with this new ligand have been synthesized and characterized by elemental analyses, IR, UV, ESI-MS and molar conductance. The macrocyclic ligand molecular structure is centrosymmetrical. All complexes are in accordance with the general forN8O8). The central metal ions coordinate to four nitrogen atoms of azamacrocycle and two oxygen atoms of one nitrate ion. Preliminary pharmacological tests against P-388and A-549 tumor cell lines showed that all these complexes had considerable activities in vitro.

  10. Rapid growth of nanotubes and nanorods of würtzite ZnO through microwave-irradiation of a metalorganic complex of zinc and a surfactant in solution

    Sanjaya Brahma; Kalya Jagannatha Rao; Srinivasarao Shivashankar


    Large quantities of single-crystalline ZnO nanorods and nanotubes have been prepared by the microwave irradiation of a metalorganic complex of zinc, in the presence of a surfactant. The method is simple, fast, and inexpensive (as it uses a domestic microwave oven), and yields pure nanostructures of the hexagonal würtzite phase of ZnO in min, and requires no conventional templating. The ZnO nanotubes formed have a hollow core with inner diameter varying from 140–160 nm and a wall of thickness, 40–50 nm. The length of nanorods and nanotubes varies in the narrow range of 500–600 nm. These nanostructures have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The ZnO nanorods and nanotubes are found by SAED to be single-crystalline. The growth process of ZnO nanorods and nanotubes has been investigated by varying the surfactant concentration and microwave irradiation time. Based on the various results obtained, a tentative and plausible mechanism for the formation of ZnO nanostructures is proposed.

  11. Spectroscopic, magnetic and thermal studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of 3-acetylcoumarin-isonicotinoylhydrazone and their antimicrobial and anti-tubercular activity evaluation

    Hunoor, Rekha S.; Patil, Basavaraj R.; Badiger, Dayananda S.; Vadavi, Ramesh S.; Gudasi, Kalagouda B.; Chandrashekhar, V. M.; Muchchandi, I. S.


    Co(II), Ni(II), Cu(II) and Zn(II) complexes with a new heterocyclic Schiff base derived by the condensation of isonicotinoylhydrazide and 3-acetylcoumarin have been synthesized. 1H, 13C and 2D HETCOR NMR analyses confirm the formation of title compound and existence of the same in two isomeric forms. The metal complexes were characterized on the basis of various spectroscopic techniques like electronic, EPR, IR, 1H and 13C NMR studies, elemental analysis, magnetic properties and thermogravimetric analysis, and also by the aid of molar conductivity measurements. It is found that the Schiff base behaves as a monobasic tridentate ligand coordinating in the imidol form with 1:1 metal to ligand stoichiometry. Trigonal bipyramidal geometry has been assigned for Ni(II) and Cu(II) complexes, while tetrahedral for Co(II) and Zn(II) complexes. The compounds were subjected to antimicrobial and anti-tubercular activity screening using serial broth dilution method and Minimum Inhibitory Concentration (MIC) is determined. Zn(II) complex has shown significant antifungal activity with an MIC of 6.25 μg/mL while Cu(II) complex is noticeable for antibacterial activity at the same concentration. Anti-TB activity of the ligand has enhanced on complexation with Co(II) and Ni(II) ions.

  12. Synthesis of Pure and Pt-Doped ZnO Particles Through Aerosol Route Using Nitrate and PDDA-Pt(IV) Complex Solution%利用浮质方法将硝酸盐和PDDA-Pt(IV)复合溶液合成纯净及Pt掺杂的ZnO颗粒

    V.M.Djinovic; L.T.; Maneieb; G.A.; Bogdanovic; P.J.; Vulie; G.; del; Rosario; T.J.; Sabo; O.B.; Milosevie


    @@ Pure and Pt-doped ZnO nanophase particles were synthesized using the ultrasonic spray pyrolysis. Particles were obtained through decomposition of zincnitrate and new developed Pt(IV) complex with 1,3-propylenediamine-N,N'-diacetate ligand (pdda) belonging to the tetradentate class.

  13. Synthesis and Characterization of a New Bidentate Ligand 5-Substituted-(2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione and its Metal Complexes of Ag(I, Cu(II and Zn(II

    Shabbir A. A. Kazi


    Full Text Available A new ligand (2-methyl-5-nitro-1-imidazomethyl-1,3,4-oxadiazole-2-thione (L and its Ag(I,Cu(II and Zn(II complexes were synthesized. The authenticity of the ligand and its transition metal complexes were established by elemental analyses, conductance and magnetic susceptibility measurements, as well as spectroscopic (IR, 1H NMR, electronic, mass and ESR and thermal studies. The IR spectral studies revealed the existence thiol-thione tautamerism in the ligand molecule. The magnetic and electronic spectral studies suggest an octahedral geometry for Cu(II and Zn(II complexes. The ligand acts as a bidentate coordinating through the N-3 nitrogen and the exocyclic sulfur atoms of oxadiazole rings. Antimicrobial screening of the ligand and its metal complexes were determined against the bacteria Escherichia coli and Salmonella paratyphiA.

  14. Synthesis, characterization, and antioxidant/cytotoxic activity of new chromone Schiff base nano-complexes of Zn(II), Cu(II), Ni(II) and Co(II)

    Saif, M.; El-Shafiy, Hoda F.; Mashaly, Mahmoud M.; Eid, Mohamed F.; Nabeel, A. I.; Fouad, R.


    A chromone Schiff base complexes of Zn(II) (1), Cu(II) (2), Ni(II) (3) and Co(II) (4) were successfully prepared in nano domain with crystalline or amorphous structures. The spectroscopic data revealed that the Schiff base ligand behaves as a monoanionic tridentate ligand. The metal complexes exhibited octahedral geometry. Transmission electron microscope (TEM) analysis showed that Cu(II) complex have aggregated nanospheres morphology. The obtained nano-complexes were tested as antioxidant and antitumor agents. The H2L and its Cu(II) complex (2) were found to be more potent antioxidant (IC50(H2L) = 0.93 μM; IC50(Cu(II) complex) = 1.1 μM than standard ascorbic acid (IC50 = 2.1 μM) as evaluated by DPPH• method. The H2L and its complexes (1-4) were tested for their in vitro cytotoxicity against Ehrlich Ascites Carcinoma cell line (EAC). The Cu(II) nano-complex (2) effectively inhibited EAC growth with IC50 value of 47 μM in comparison with its parent compound and other prepared complexes. The high antioxidant activity and antitumor activity of Cu(II) nano-complex (2) were attributed to their chemical structure, Cu(II) reducing capacity, and nanosize property. The toxicity test on mice showed that Zn(II) (1) and Cu(II) (2) nano-complex have lower toxicity than the standard cis-platin.

  15. Supplementing Zn, Mn, and Cu from amino acid complexes and Co from cobalt glucoheptonate during the peripartal period benefits postpartal cow performance and blood neutrophil function.

    Osorio, J S; Trevisi, E; Li, C; Drackley, J K; Socha, M T; Loor, J J


    The physiologic and metabolic stresses that dairy cows experience during the transition into early lactation can promote oxidative stress, inflammation, and immune dysfunction. Optimal supply of micronutrients such as trace minerals (e.g., Zn, Mn, Cu, and Co) via more bioavailable forms (e.g., AA complexes) might minimize these negative effects. Multiparous Holstein cows were enrolled at 60 d before dry-off (~110 d before calving) and remained on experiment until 30 d in milk (DIM). Cows were offered a common diet supplemented entirely with inorganic trace minerals (INO) from -110 to -30 d before calving. From -30 to calving cows received a common prepartal [1.5 Mcal/kg of dry matter (DM), 15% crude protein] diet, and from calving to 30 DIM a common postpartal (1.76 Mcal/kg of DM, 18% crude protein) diet. Both diets were partially supplemented with an INO mix of Zn, Mn, and Cu to supply 35, 45, and 6 mg/kg, respectively, of the total diet DM. Cows were assigned to treatments in a randomized complete block design to receive an oral bolus with a mix of INO (n=21) or organic AA complexes (AAC; n=16) of Zn, Mn, Cu, and Co to achieve supplemental levels of 75, 65, 11, and 1mg/kg, respectively, in the total diet DM. Inorganic trace minerals were provided in sulfate form and AAC were supplied via Availa Zn, Availa Mn, Availa Cu, and COPRO (Zinpro Corp., Eden Prairie, MN). Liver tissue was harvested on -30, -15, 10, and 30 d, and blood samples for biomarker analyses were obtained more frequently from -30 to 30 DIM. Short-term changes in blood ketones were measured via Precision Xtra (Abbott Diabetes Care, Alameda, CA) every other day from 1 to 15 d postpartum. Prepartal DM intake was lower in AAC cows. In contrast, a tendency for a diet by time (D × T) interaction resulted in greater postpartal DM intake of approximately 2 kg/d in cows fed AAC. Milk and milk protein yield had a D × T interaction because AAC cows produced approximately 3.3 kg/d more milk and 0.14 kg

  16. Synthesis of new photosensitive H2BBQ(2+)[ZnCl4](2-)/[(ZnCl)2(μ-BBH)] complexes, through selective oxidation of H2O to H2O2.

    Stylianou, M; Hadjiadamou, I; Drouza, C; Hayes, S C; Lariou, E; Tantis, I; Lianos, P; Tsipis, A C; Keramidas, A D


    A new two-electron photosensitizer, H2BBQ(2+)[ZnCl4](2-)/[(ZnCl)2(μ-BBH)] (BBQ stands for 2,5-bis[bis(pyridin-2-ylmethyl)amino]-1,4-quinone and BBH stands for 2,5-bis[bis(pyridin-2-ylmethyl)amino]-1,4-hydroquinone), has been synthesized and the oxidation state of the ligand was determined by X-ray crystallography and NMR spectroscopy. Under light illumination the H2BBQ(2+)[ZnCl4](2-) + ZnCl2 is reduced quantitatively to [(ZnCl)2(μ-BBH)] (pH ∼ 5) oxidizing H2O to H2O2 as is evident by trap experiments. Electrochemistry gave a reversible two-electron ligand-centered redox wave for [(ZnCl)2(μ-BBH)]. UV-Vis, luminescence and EPR spectroscopies reveal the slow formation of a stable quinone diradical, intermediate of the reaction. DFT calculations are in agreement with the proposed mechanism. Based on this property an aqueous {[(ZnCl)2(μ-BBH)]||H2O2} solar rechargeable galvanic cell has been constructed.

  17. Immunometabolic Status during the Peripartum Period Is Enhanced with Supplemental Zn, Mn, and Cu from Amino Acid Complexes and Co from Co Glucoheptonate.

    Fernanda Batistel

    Full Text Available The peripartum (or transition period is the most-critical phase in the productive life of lactating dairy cows and optimal supply of trace minerals through more bioavailable forms could minimize the negative effects associated with this phase. Twenty Holstein cows received a common prepartal diet and postpartal diet. Both diets were partially supplemented with an inorganic (INO mix of Zn, Mn, and Cu to supply 35, 45, and 6 ppm, respectively, of the diet dry matter (DM. Cows were assigned to treatments in a randomized completed block design, receiving an daily oral bolus with INO or organic trace minerals (AAC Zn, Mn, Cu, and Co to achieve 75, 65, 11, and 1 ppm supplemental, respectively, in the diet DM. Liver tissue and blood samples were collected throughout the experiment. The lower glutamic-oxaloacetic transaminase concentration after 15 days in milk in AAC cows indicate lower hepatic cell damage. The concentration of cholesterol and albumin increased, while IL-6 decreased over time in AAC cows compared with INO indicating a lower degree of inflammation and better liver function. Although the acute-phase protein ceruloplasmin tended to be lower in AAC cows and corresponded with the reduction in the inflammatory status, the tendency for greater serum amyloid A concentration in AAC indicated an inconsistent response on acute-phase proteins. Oxygen radical absorbance capacity increased over time in AAC cows. Furthermore, the concentrations of nitric oxide, nitrite, nitrate, and the ferric reducing ability of plasma decreased with AAC indicating a lower oxidative stress status. The expression of IL10 and ALB in liver tissue was greater overall in AAC cows reinforcing the anti-inflammatory response detected in plasma. The greater overall expression of PCK1 in AAC cows indicated a greater gluconeogenic capacity, and partly explained the greater milk production response over time. Overall, feeding organic trace minerals as complexed with amino acids

  18. Immunometabolic Status during the Peripartum Period Is Enhanced with Supplemental Zn, Mn, and Cu from Amino Acid Complexes and Co from Co Glucoheptonate

    Batistel, Fernanda; Osorio, Johan S.; Ferrari, Annarita; Trevisi, Erminio; Socha, Michael T.; Loor, Juan J.


    The peripartum (or transition) period is the most-critical phase in the productive life of lactating dairy cows and optimal supply of trace minerals through more bioavailable forms could minimize the negative effects associated with this phase. Twenty Holstein cows received a common prepartal diet and postpartal diet. Both diets were partially supplemented with an inorganic (INO) mix of Zn, Mn, and Cu to supply 35, 45, and 6 ppm, respectively, of the diet dry matter (DM). Cows were assigned to treatments in a randomized completed block design, receiving an daily oral bolus with INO or organic trace minerals (AAC) Zn, Mn, Cu, and Co to achieve 75, 65, 11, and 1 ppm supplemental, respectively, in the diet DM. Liver tissue and blood samples were collected throughout the experiment. The lower glutamic-oxaloacetic transaminase concentration after 15 days in milk in AAC cows indicate lower hepatic cell damage. The concentration of cholesterol and albumin increased, while IL-6 decreased over time in AAC cows compared with INO indicating a lower degree of inflammation and better liver function. Although the acute-phase protein ceruloplasmin tended to be lower in AAC cows and corresponded with the reduction in the inflammatory status, the tendency for greater serum amyloid A concentration in AAC indicated an inconsistent response on acute-phase proteins. Oxygen radical absorbance capacity increased over time in AAC cows. Furthermore, the concentrations of nitric oxide, nitrite, nitrate, and the ferric reducing ability of plasma decreased with AAC indicating a lower oxidative stress status. The expression of IL10 and ALB in liver tissue was greater overall in AAC cows reinforcing the anti-inflammatory response detected in plasma. The greater overall expression of PCK1 in AAC cows indicated a greater gluconeogenic capacity, and partly explained the greater milk production response over time. Overall, feeding organic trace minerals as complexed with amino acids during the

  19. Cleavage of an RNA model catalyzed by dinuclear Zn(II) complexes containing rate-accelerating pendants. Comparison of the catalytic benefits of H-bonding and hydrophobic substituents.

    Mohamed, Mark F; Brown, R Stan


    The transesterification of a simple RNA model, 2-hydroxypropyl p-nitrophenyl phosphate (2, HpNPP) promoted by seven dinuclear Zn(II) catalysts (3,4,5,6,7,8,9:Zn(II)2:(-OCH3)) based on the bis[bis(2-substituted-pyridinyl-6-methyl)]amine ligand system was investigated in methanol under sspH-controlled conditions at 25.0 ± 0.1 °C. The two metal complexing ligands were joined together via the amino N connected to a m-xylyl linker (3, 4, 5, 6, 7) where the 2-pyridinyl substituent = H, CH3, (CH)4, NH2, and NH(C═O)CH3, respectively, and a propyl linker (8, 9) where the ring substituent = H and CH3. All of the dinuclear complexes except 8:Zn(II)2 exhibit saturation kinetics for the kobs versus [catalyst] plots from which one can determine catalyst:substrate binding constants (KM), the catalytic rate constants for their decomposition (kcat), and the second order catalytic rate constants (k2cat = kcat/KM). In the case of 8:Zn(II)2, the plots of kobs versus [catalyst] as a function of sspH are linear, and the catalytic rate constants (k2cat) are defined as the gradients of the plots. Analysis of all of the data at the sspH optimum for each reaction indicates that the presence of the amino and acetamido H-bonding groups and the CH3 group provides similar increases of the kcat terms of 25−50 times that exhibited by the parent complex 3:Zn(II)2. However, in terms of substrate catalyst binding (KM), there is no clear trend that H-bonding groups or the CH3 group provides stronger binding than the parent complex. In terms of the overall second order catalytic rate constant, the CH3, amino, and NH(C═O)CH3 groups provide 20, 10, and 68 times the k2cat observed for the parent complex. In the case of 9:Zn(II)2, the presence of the methyl groups provides a 1000-fold increase in activity (judged by k2cat) over the parent complex 8:Zn(II)2. The results are interpreted to indicate that H-bonding effects may be important for catalysis and less so for substrate binding, but the

  20. Metal-ion directed synthesis of N2O2 type chelate complexes of Ni(II), Cu(II) and Zn(II): spectral, thermal and single crystal studies.

    Yadav, Seema; Ahmad, Musheer; Siddiqi, K S


    A set of Ni(II), Cu(II) and Zn(II) complexes of Schiff base have been synthesized by one pot condensation reaction of 2-hydroxy-4-methoxybenzophenone with 1,3-diaminopropane in 1:2:1 molar ratio. They have been characterized by elemental analysis, conductance measurement, thermal analysis (TGA/DTA), FT-IR, (1)H-NMR, EPR spectra, ESI-MS and electronic spectral studies. In order to establish the geometry, a single crystal X-ray structure for [Ni(L)] complex was determined. It crystallizes in monoclinic system having unit cell parameters a=14.015(5)Å, b=13.391(5)Å, c=14.931(5)Å and α=90.000(5)(o), β=112.237(5)(o), γ=90.000(5)(o) with P 2(1)/c space group. No π-π stacking interaction was obtained in molecular packing diagram. A square-planar geometry has been confirmed for Ni(II) complex. Furthermore, on the basis of elemental analysis, IR, UV-visible and EPR data a square-planar geometry for Cu(II) and a distorted octahedral geometry for the Zn(II) complex has been established. In case of Zn(II) complex NO(3)(-) group was found to be coordinated in monodentate fashion. The low molar conductivity values of the complexes measured in chloroform and DMSO suggest their non-ionic nature.

  1. Dioxygen oxidation of hydrocarbons by a methane monooxygenase-like system: diiron complex-O2-Zn/HOAc-MV2+

    魏俊发; 何地平; 俞贤达


    The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe2Dhist(OAc)2]BPh4·3H2O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styrene is oxygenated predominantly to styrene oxide (1 396 mol/100 mol of the Fe2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclohexanone (2670). EPR studies indicate that the hypervalent ironoxo spiecs FeⅣFeⅣ(?)O, derived from FeⅢFeⅢ core via reduction, O2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C(?)C or C—H bond giving each product. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distributions. The Mn2 analog cmplex、Fe-Zn hetero

  2. Investigation of defect properties of Li in ZnO - A first-principles study of vibrational frequencies, transition rates and diffusion profiles of Li and Li-complexes in ZnO

    Wold, Roger


    ZnO is a promising material for modern technological applications. Due to its large direct bandgap (3.4 eV) and large exciton binding energy (60 meV), the compound is suggested as a material for optoelectronic devices, such as light emitting diodes, lasers etc. Moreover, the piezoelectric and pyroelectric properties make ZnO a promising candidate for sensors, actuators and energy generators. ZnO is also suggested for spintronics, and in other application areas in science like biotechnology an...

  3. Ternary complexes metal [Co(II), Ni(II), Cu(II) and Zn(II)]--ortho-iodohippurate (I-hip)--acyclovir. X-ray characterization of isostructural [(Co, Ni or Zn)(I-hip)(2)(ACV)(H(2)O)(3)] with stacking as a recognition factor.

    Barceló-Oliver, M; Terrón, A; García-Raso, A; Fiol, J J; Molins, E; Miravitlles, C


    Four ternary metal--ortho-iodohippurate (I-hip)--acyclovir (ACV) complexes, [M(I-hip)(2)(ACV)(H(2)O)(3)] where M is Co(II) (1), Ni(II) (2), Cu (3) and Zn(II) have been obtained by reaction between the corresponding binary complexes M(II)(I-hip)(2)xnH(2)O and ACV. Three ternary complexes (M=Co, Ni and Zn) and the corresponding Zn(II)--ortho-iodohippurate binary derivative have been structurally characterized by X-ray diffraction: The studies show these three ternary complexes are isostructural and present, in solid state, an interesting stacking between the nucleobase and the aryl ring of the hippurate moiety, which probably promotes the formation of ternary complexes. Moreover, the two different ligands interact between them by means of ancillary hydrogen bonds with water molecules coordinated to the metal ion. It must be mentioned that these two recognition factors, hydrogen bonds plus stacking, could explain the reason for the isostructurality of these ternary derivatives with so different three metal ions, with diverses trends in coordination numbers and geometries. In solid state, there are two enantiomeric molecules that are related by an inversion center as the crystal-building unit (as a translational motif) for the ternary complexes.

  4. Synthesis and characterization of Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate Schiff base derived from vanillin and DL-α-aminobutyric acid

    Nair, M. Sivasankaran; Joseyphus, R. Selwin


    Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base derived from vanillin and DL-α-aminobutyric acid were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements, powder XRD and biological activity. The analytical data show the composition of the metal complex to be [ML(H 2O)], where L is the Schiff base ligand. The conductance data indicate that all the complexes are non-electrolytes. IR results demonstrate the tridentate binding of the Schiff base ligand involving azomethine nitrogen, phenolic oxygen and carboxylato oxygen atoms. The IR data also indicate the coordination of a water molecule with the metal ion in the complex. The electronic spectral measurements show that Co(II) and Ni(II) complexes have tetrahedral geometry, while Cu(II) complex has square planar geometry. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, whereas Ni(II) and Zn(II) complexes are crystalline in nature. Magnetic measurements show that Co(II), Ni(II) and Cu(II) complexes have paramagnetic behaviour. Antibacterial results indicated that the metal complexes are more active than the ligand.

  5. Synthesis and Crystal Structures of Ni(II)/(III) and Zn(II) Complexes with Schiff Base Ligands

    Koo, Bon Kweon [Catholic Univ., of Daegu, Daegu (Korea, Republic of)


    Coordination polymers are of great interest due to their intriguing structural motifs and potential applications in optical, electronic, magnetic, and porous materials. The most commonly used strategy for designing such materials relies on the utilization of multidentate N- or Odonor ligands which have the capacity to bridge between metal centers to form polymeric structures. The Schiff bases with N,O,S donor atoms are an useful source as they are readily available and easily form stable complexes with most transition metal ions. Schiff bases are also important intermediates in synthesis of some bioactive compounds and are potent anti-bacterial, anti-fungal, anticancer and antiviral compounds. In this work, the Schiff bases, Hapb and Hbpb, derived from 2-acetylpyridene or 2-benzoylpyridine and benzhydrazide were taken as trifunctional (N,N,O) monobasic ligand (Scheme 1). This ligand is of important because the π-delocalization of charge and the configurational flexibility of their molecular chain can give rise to a great variety of coordination modes. Although many metal.Schiff base complexes have been reported, the 1D, 2D, and 3D networks of coordination polymers linked through the bridging of ligands such as dicyanamide, N(CN){sub 2}{sup -} as coligand have been little published. In the process of working to extend the dimensionality of the metal-Schiff base complexes using benzilic acid as a bridging ligand, we obtained three simple metal (II)/(III) complexes of acetylpyridine/2-benzoyl pyridine based benzhydrazide ligand. Therefore, we report here the synthesis and crystal structures of the complexes.

  6. Effect of impurity Zn~(2+) on nickel electrodeposition in solution containing ammonia complex%氨络合物体系中杂质Zn~(2+)对电沉积镍的影响

    曹华珍; 秦爱玲; 郑国渠; 杜征峥


    通过霍尔槽试验研究氨络合物体系中杂质Zn~(2+)对镍电沉积的影响,采用电化学工作站测试不同Zn~(2+)浓度时的循环伏安曲线、稳态极化曲线及电流时间暂态曲线.结果表明:杂质Zn~(2+)的含量为0.1 g/L时,在小于2.78 A/dm的电流密度范围内可正常沉积出金属镍;杂质Zn~(2+)含量大于0.5 g/L时,在较大的电流密度范围内均无法正常沉积出金属镍;过电位小于640 mV时,Zn~(2+)的存在不影响阴极反应的传递系数,且不改变阴极反应机理;当过电位大于640 mV,且杂质Zn~(2+)的浓度大于0.5 g/L时,阴极反应的传递系数减小,阴极反应机理发生改变;杂质Zn~(2+)浓度大于0.5 g/L时,严重影响镍电结晶过程的成核速率,这是其抑制金属镍电沉积的主要原因.因此,采用镍氨络合物体系电积金属镍,应控制杂质Zn~(2+)的含量小于0.1 g/L.%In nickel ammonia system, the influence of impurity Zn~(2+) on the nickel electrodeposition was studied intensively by Hull Cell experiments, and the cyclic voltammetry, cathodic polarization and chronoamperometric curves were tested at different Zn~(2+) concentration by electrochemistry working station. The results show that nickel can be deposited normally when the concentration of impurity Zn~(2+) is 0.1 g/L and the cathodic current density is less than 2.78 A/dm. When the concentration of impurity Zn~(2+) is greater than 0.5 g/L, nickel can't be deposited normally in a wide range of current density. The cathodic transfer coefficient α and reaction mechanism will not change with the addition of impurity Zn~(2+) when the overpotential is less than 640 mV. The cathodic transfer coefficient α decreases and the reaction mechanism changes when the overpotential is greater than 640 mV and the concentration of impurity Zn~(2+) is greater than 0.5 g/L. The nucleation rate during nickel electrocrystallization is restrained greatly when the impurity Zn~(2+) concentration is greater than 0

  7. Cation recognition of thiacalix[2]thianthrene and p-tert-butylthiacalix[2]thianthrene and their conformers and complexes with Zn(II), Cd(II) and Hg(II): a theoretical investigation.

    Kaenkaew, Saowapak; Sae-Khow, Ornchuree; Ruangpornvisuti, Vithaya


    The structures of thiacalix[2]thianthrene, p-tert-butylthiacalix[2]thianthrene and their complexes with Zn(2+), Cd(2+) and Hg(2+) were obtained using B3LYP/LanL2DZ and HF/LanL2DZ calculations. The structures of the most stable conformers of thiacalix[2]thianthrene and p-tert-butylthiacalix[2]thianthrene optimized at either the B3LYP/LanL2DZ or HF/LanL2DZ level are in good agreement with their corresponding X-ray crystallographic structures. The binding energies of cations, Zn(2+), Cd(2+) and Hg(2+) to thiacalix[2]thianthrene and to p-tert-butylthiacalix[2]thianthrene conformers, and the thermodynamic properties of their associations were obtained. The relative selectivities of both thiacalix[2]thianthrene and thiacalix[2]thianthrene conformer are in same order: Zn(2+) > Hg(2+) > Cd(2+).

  8. Performances of Dye-sensitized Solar Cell Based on ZnO Photoanode Sensitized with Cadmium Complexes Cd (phen) 2 (NO3) (NO2)%金属配合物Cd(phen)2(NO3)(NO2)对ZnO光阳极的敏化特性

    张凌云; 杨玉林; 范瑞清; 张艳娇; 王平; 李亮


    采用具有紫外光区吸收的金属配合物Cd(phen)2(NO3)(NO2)和N719对ZnO光阳极进行共敏化.结果表明,配合物能够对ZnO光阳极进行共敏化,同时被电解液还原再生,共敏化增加电池对光的吸收,电池光电流密度增加63%,共敏化降低了电池各个界面电阻,有利于电子在界面的传输,电池的光电转换效率提高了37%.%The ZnO photoanode was co-sensitized with cadmium complexe Cd (phen) 2 (NO3) (NO2) absorbed in the ultraviolet light region and dye N719.The performances of co-sensitized dye-sensitized solar cell (DSSC) and the properties of cadmium complexe were investigated by the cyclic voltammetry measurement,UV-Visible absorption spectroscopy,fluorescence spectrum,electrochemical impedance spectroscopy and photocurrent-photovoltage curve.The results show that cadmium complexe is suitable for sensitization of ZnO photoanode,and the complexe can be reduced by the electrolyte.The light absorption of DSSC is enhanced and the current density is improved 63% by co-sensitization.The decreased resistance of interface of DSSC is in favor of the electron transport.The conversion efficiency of DSSC based on ZnO photoanode is improved 37% by co-sensitization.

  9. Synthesis, spectral characterization and biological activity of Zn(II complex with 2′-[1-(2-hydroxyphenylethylidene]benzenesulfanohydrazide

    Nura Suleiman Gwaram


    Full Text Available Zinc(II complex with 2′-[1-(2-hydroxyphenyl ethylidene] benzenesulfanohydrazide, was synthesized, and structurally characterized by elemental analysis CHN, TGA, UV, FT-IR, 1H NMR and 13C NMR spectroscopy. Its preventive effect on ulcer activity induced by absolute ethanol in Sprague–Dawley rats was studied in vivo. Gastric ulcers were induced in rats by administrating absolute ethanol. Twenty four Spragu–Dawley rats (12 males and 12 females were assigned equally into the following 4 groups (n = 6: negative control; positive control; low dose, which received low oral doses of the compound; and high dose, which received high oral doses of the compounds . These animals were subjected to overnight fasting (food but not water prior to dosing. Gastric wall mucus, ulcer areas and histology of gastric walls were assessed in addition gastric homogenate was determined for superoxide dismutase (SOD, glutathione (GSH and malondialdehyde (MDA. Pre-treatment of rats with compound significantly prevented ethanol-induced gastric wall depletion and restored non-sulfhydryl (NP-SH content in glandular stomachs. The Zinc(II complex also exhibits high levels of SOD, and GSH enzymes as well as a reduced amount of lipid peroxidation enzyme, malondialdehyde. This study describes a model to produce extensive gastric necrosis in rats by induction with absolute ethanol. The administration of zinc(II complex with benzensulfanohydrazone at 30 min before induction with absolute ethanol reduced or totally eliminated lesions.

  10. Study of Complex Formation Between Iodoquinol (IQ and Co2+ , Mn2+, Cd2+, Pb2+ and Zn2+ Cations in Binary Aqueous / Non-aqueous Solvent Using Spectrophotometry

    A. Nezhadali


    Full Text Available The complexation reactions between iodoquinol and Co2+, Mn2+, Cd2+, Pb2+ and Zn2+ cations were studied in different DMF/H2O binary mixtures at the ionic strength of 0.1(using NaNO3.The spectrophotometric method was used for the determination of formation constants and the stoichiometries. The stoichiometry of the complexes is established 1:1 by Job's and mole ratio methods. It was found that the stability constants of the complex formed between the ligand (IQ and the cations in the all cases increase with increasing of the non-aqueous solvent. In the most cases the maximum formation constants between Zn2+ ion and IQ were obtained respect to the other cations.

  11. 自然光下ZnO/共轭高分子复合微粒的催化性能%Catalytic Property of ZnO/Conjugated Polymer Complex Particles Under Natural Light

    马占营; 敏世雄; 佘世雄; 苏碧桃


    以PVC和ZnCl2为前驱物,利用一种简单、快速的方法制备了ZnO/共轭高分子(P)复合微粒,并通过XRD、IR和UV-Vis等技术对其进行了表征. 结果表明,其中的P为具有活性基团和不同长度共轭链的高分子,且与 ZnO以Zn-O-C相键合;该复合材料的吸收拓宽至整个紫外-可见光区. 前驱物(m(ZnCl2)∶m(PVC)=3∶1)经200 ℃热处理15 min制得的ZnO/P复合微粒5 min内可将亚甲基(MB)彻底脱色,并且该复合催化剂重复使用6次后对MB的脱色率依然可达90%以上.

  12. Supramolecular Design of Coordination Complexes of Zn(Ⅱ) and Vapor Adsorption for MeOH%锌(Ⅱ)配合物的超分子设计及对甲醇蒸气的吸附性能

    吴娟; 赵博文; 黄超; 陈冬梅; 朱必学


    采用饱和蒸气扩散技术,将2,4-二羟基苯甲醛缩异烟酰腙(H2dhbi)配体分别与Zn(ClO4)2·6H2O和Zn(NO3)2·6H2O进行配位作用,得到2种不同配位模式的金属-有机框架材料[(dhbi)2Zn2·8H2O]n(1)和{[(dhbi)2(H2O)2Zn2]·4DMF]}n(2).利用X射线单晶衍射、热分析技术(TG-DTA)和X射线粉末衍射( PXRD)等方法进行了结构表征.进一步将配位聚合物1和2用于对甲醇分子的吸附性能研究,结果表明,化合物1是一种理想的微孔材料,其对甲醇分子的吸附能力为化合物2的近5倍,采用PLATON对材料的孔隙体积进行计算得到化合物1和2的孔隙率分别为38.2%和5.5%.%By employing the N'-( 2 , 4-dihydroxybenzylidene )-isonicotinohydrazide ligand to assemble with zinc ions in different solvents, the two metal-organic frameworks ( MOFs) 1 and 2 were obtained, namely [(dhbi)2Zn2·8H2O]n(1) was obtained from the ligand assemble with Zn(ClO4)2·6H2O,{[(dhbi)2(H2O)2Zn2]·4DMF]}n(2) was obtained from the ligand assemble with Zn(NO3)2 ·6H2O using diffusion technology of saturated vapor. Single crystal diffraction was used to characterize their struc-tures. Thermogravimetric analysis ( TG-DTA ) and powder X-ray diffraction ( PXRD ) were used to measure their thermal stability and purity. The results of vapor adsorption for MeOH indicate that complex 1 is a kind of satisfactory microporous material, further the complex 1 shows 38. 1% void volume, and the complex 2 shows 5. 5% void volume according to PLATON calculations.

  13. Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione.

    Singh, Ajay K; Pandey, O P; Sengupta, S K


    Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L=monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2(')(OOCCH3)2(H2O)2](L'=neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, (1)H NMR, and (13)C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

  14. Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione

    Singh, Ajay K.; Pandey, O. P.; Sengupta, S. K.


    Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L = monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2‧(OOCCH3)2(H2O)2](L‧ = neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, 1H NMR, and 13C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200 nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

  15. Osmotic and Activity Coefficients of the {xZnCl2 + (1 - x)ZnSO4}(aq) System at 298.15 K

    Ninkovic, R; Miladinovic, J; Todorovic, M; Grujic, S; Rard, J A


    Isopiestic vapor pressure measurements were made for (xZnCl{sub 2} + (1 - x)ZnSO{sub 4})(aq) solutions with ZnCl{sub 2} molality fractions of x = (0, 0.3062, 0.5730, 0.7969, and 1) at the temperature 298.15 K, using KCl(aq) as the reference standard. These measurements cover the water activity range 0.901-0.919 {le} a{sub w} {le} 0.978. The experimental osmotic coefficients were used to evaluate the parameters of an extended ion-interaction (Pitzer) model for these mixed electrolyte solutions. A similar analysis was made of the available activity data for ZnCl{sub 2}(aq) at 298.15 K, while assuming the presence of equilibrium amounts of ZnCl{sup +}(aq) ion-pairs, to derive the ion-interaction parameters for the hypothetical pure binary electrolytes (Zn{sup 2+}, 2Cl{sup -}) and (ZnCl{sup +},Cl{sup -}). These parameters are required for the analysis of the mixture results. Although significant concentrations of higher-order zinc chloride complexes may also be present in these solutions, it was possible to represent the osmotic coefficients accurately by explicitly including only the predominant complex ZnCl{sup +}(aq) and the completely dissociated ions. The ionic activity coefficients and osmotic coefficients were calculated over the investigated molality range using the evaluated extended Pitzer model parameters.

  16. Phosphorescence and zero-field optically detected magnetic resonance studies of (nd){sup 10} transition-metal complexes. 1. ZnX{sub 2}(phen) (X = Cl, Br, I)

    Ikeda, Shigeru; Yamamoto, Seiichi; Azumi, Tohru [Tohoku Univ., Sendai (Japan)] [and others


    In order to elucidate the effect of (nd){sup 10} central metal ions on the properties of the low-lying excited states of metal complexes, spectroscopic and optically detected magnetic resonance studies on the phenanthroline (phen) localized {sup 3}{pi}{pi}* states of ZnX{sub 2}(phen) (X = Cl, Br, I) were carried out. Comparison of the properties of the spin sublevels of ZnX{sub 2}(phen) with those of the uncoordinated 1, 10-phenanthroline yielded several noteworthy features: (a) the phosphorescence spectra of ZnX{sub 2}(phen) complexes very closely resemble that of the uncoordinated phen molecule, (b) the magnitudes of the zero-field splittings follow the ordering phen > ZnCl{sub 2}(phen) replacing the z sublevel (in-plane component) as the dominant decay channel in uncoordinated phen. These experimental results have been interpreted systematically and satisfactorily by a model invoking Heitler-London type mixing of LLCT (halogen p-orbitals to phen charge transfer) electronic configurations with the phen locally excited electronic configuration. 31 refs., 4 figs., 7 tabs.

  17. Preparation and Optoelectronic Characteristics of ZnO/CuO-Cu2O Complex Inverse Heterostructure with GaP Buffer for Solar Cell Applications

    Yi-Feng Lin


    Full Text Available This study reports the optoelectronic characteristics of ZnO/GaP buffer/CuO-Cu2O complex (COC inverse heterostructure for solar cell applications. The GaP and COC layers were used as buffer and absorber in the cell structure, respectively. An energy gap widening effect and CuO whiskers were observed as the copper (Cu layer was exerted under heat treatment for oxidation at 500 °C for 10 min, and arose from the center of the Cu2O rods. For preparation of the 30 nm-thick GaP buffer by sputtering from GaP target, as the nitrogen gas flow rate increased from 0 to 2 sccm, the transmittance edge of the spectra demonstrated a blueshift form 2.24 to 3.25 eV. Therefore, the layer can be either GaP, GaNP, or GaN by changing the flow rate of nitrogen gas.

  18. A Schiff base complex of Zn(II) as a neutral carrier for highly selective PVC membrane sensors for the sulfate ion.

    Shamsipur, M; Yousefi, M; Hosseini, M; Ganjali, M R; Sharghi, H; Naeimi, H


    Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets.

  19. Design and Synthesis of Chiral Zn2+ Complexes Mimicking Natural Aldolases for Catalytic C–C Bond Forming Reactions in Aqueous Solution

    Susumu Itoh


    Full Text Available Extending carbon frameworks via a series of C–C bond forming reactions is essential for the synthesis of natural products, pharmaceutically active compounds, active agrochemical ingredients, and a variety of functional materials. The application of stereoselective C–C bond forming reactions to the one-pot synthesis of biorelevant compounds is now emerging as a challenging and powerful strategy for improving the efficiency of a chemical reaction, in which some of the reactants are subjected to successive chemical reactions in just one reactor. However, organic reactions are generally conducted in organic solvents, as many organic molecules, reagents, and intermediates are not stable or soluble in water. In contrast, enzymatic reactions in living systems proceed in aqueous solvents, as most of enzymes generally function only within a narrow range of temperature and pH and are not so stable in less polar organic environments, which makes it difficult to conduct chemoenzymatic reactions in organic solvents. In this review, we describe the design and synthesis of chiral metal complexes with Zn2+ ions as a catalytic factor that mimic aldolases in stereoselective C–C bond forming reactions, especially for enantioselective aldol reactions. Their application to chemoenzymatic reactions in aqueous solution is also presented.

  20. Micellar effect on metal-ligand complexes of Co(II, Ni(II, Cu(II and Zn(II with citric acid

    Nageswara Rao Gollapalli


    Full Text Available Chemical speciation of citric acid complexes of Co(II, Ni(II, Cu(II and Zn(II was investigated pH-metrically in 0.0-2.5% anionic, cationic and neutral micellar media. The primary alkalimetric data were pruned with SCPHD program. The existence of different binary species was established from modeling studies using the computer program MINIQUAD75. Alkalimetric titrations were carried out in different relative concentrations (M:L:X = 1:2:5, 1:3:5, 1:5:3 of metal (M to citric acid. The selection of best chemical models was based on statistical parameters and residual analysis. The species detected were MLH, ML2, ML2H and ML2H2. The trend in variation of stability constants with change in mole fraction of the medium is explained on the basis of electrostatic and non-electrostatic forces. Distributions of the species with pH at different compositions of micellar media are also presented.

  1. Sulfur and oxygen isotopic study of Paleozoic sediment-hosted Zn-Pb(-Ag-Au-Ba-F) deposits and associated hydrothermal alteration zones in the Nome Complex, Seward Peninsula, Alaska

    Shanks, W.C. Pat; Slack, John F.; Till, Alison B.; Thurston, Roland; Gemery-Hill, Pamela


    Results of sulfur and oxygen isotope studies of sedimentary exhalative (SEDEX) Zn-Pb(-Ag-Au-Ba-F) deposits hosted in metamorphosed Paleozoic clastic and carbonate rocks of the Nome Complex, Seward Peninsula, Alaska, are consistent with data for similar deposits worldwide. Stable isotopic studies of the Nome Complex are challenging because the rocks have undergone Mesozoic blueschist- and greenschist-facies metamorphism and deformation at temperatures estimated from 390–490 °C. Studies of sulfur and oxygen isotopes in other areas suggest that, in the absence of chemical and mineralogical evidence for metasomatism, the principal effect of metamorphism is re-equilibration between individual minerals at the temperature of metamorphism, which commonly leads to a narrowing of the overall range of isotope values for a suite of rocks, but generally does not significantly modify the average whole rock value for that suite. Sulfur isotope studies of the stratabound and locally stratiform sulfide lenses at the Aurora Creek-Christophosen deposit, which is of possible Late Devonian-early Carboniferous age, show a large range of δ34Ssulfide values from -9.7 to 39.4‰, suggesting multiple sulfur sources and possibly complex processes of sulfide formation that may include bacterial sulfate reduction, thermochemical sulfate reduction, and Rayleigh distillation. Low δ34S values probably represent bacterial sulfide minerals remobilized from the host metasedimentary rocks either during the original seafloor mineralization or are related to a Cretaceous mineralizing event that produced Au-vein and base-metal replacement deposits; the latter process is supported by Pb isotope data. The Wheeler North deposit is similar to Aurora Creek-Christophosen but does not have negative δ34S values. It also probably formed in an euxinic sub-basin.

  2. Complex shaped ZnO nano- and microstructure based polymer composites: mechanically stable and environmentally friendly coatings for potential antifouling applications.

    Hölken, Iris; Hoppe, Mathias; Mishra, Yogendra K; Gorb, Stanislav N; Adelung, Rainer; Baum, Martina J


    Since the prohibition of tributyltin (TBT)-based antifouling paints in 2008, the development of environmentally compatible and commercially realizable alternatives is a crucial issue. Cost effective fabrication of antifouling paints with desired physical and biocompatible features is simultaneously required and recent developments in the direction of inorganic nanomaterials could play a major role. In the present work, a solvent free polymer/particle-composite coating based on two component polythiourethane (PTU) and tetrapodal shaped ZnO (t-ZnO) nano- and microstructures has been synthesized and studied with respect to mechanical, chemical and biocompatibility properties. Furthermore, antifouling tests have been carried out in artificial seawater tanks. Four different PTU/t-ZnO composites with various t-ZnO filling fractions (0 wt%, 1 wt%, 5 wt%, 10 wt%) were prepared and the corresponding tensile, hardness, and pull-off test results revealed that the composite filled with 5 wt% t-ZnO exhibits the strongest mechanical properties. Surface free energy (SFE) studies using contact angle measurements showed that the SFE value decreases with an increase in t-ZnO filler amounts. The influence of t-ZnO on the polymerization reaction was confirmed by Fourier transform infrared-spectroscopy measurements and thermogravimetric analysis. The immersion tests demonstrated that fouling behavior of the PTU/t-ZnO composite with a 1 wt% t-ZnO filler has been decreased in comparison to pure PTU. The composite with a 5 wt% t-ZnO filler showed almost no biofouling.

  3. The Histone Deacetylase Complex 1 Protein of Arabidopsis Has the Capacity to Interact with Multiple Proteins Including Histone 3-Binding Proteins and Histone 1 Variants.

    Perrella, Giorgio; Carr, Craig; Asensi-Fabado, Maria A; Donald, Naomi A; Páldi, Katalin; Hannah, Matthew A; Amtmann, Anna


    Intrinsically disordered proteins can adopt multiple conformations, thereby enabling interaction with a wide variety of partners. They often serve as hubs in protein interaction networks. We have previously shown that the Histone Deacetylase Complex 1 (HDC1) protein from Arabidopsis (Arabidopsis thaliana) interacts with histone deacetylases and quantitatively determines histone acetylation levels, transcriptional activity, and several phenotypes, including abscisic acid sensitivity during germination, vegetative growth rate, and flowering time. HDC1-type proteins are ubiquitous in plants, but they contain no known structural or functional domains. Here, we explored the protein interaction spectrum of HDC1 using a quantitative bimolecular fluorescence complementation assay in tobacco (Nicotiana benthamiana) epidermal cells. In addition to binding histone deacetylases, HDC1 directly interacted with histone H3-binding proteins and corepressor-associated proteins but not with H3 or the corepressors themselves. Surprisingly, HDC1 also was able to interact with variants of the linker histone H1. Truncation of HDC1 to the ancestral core sequence narrowed the spectrum of interactions and of phenotypic outputs but maintained binding to a H3-binding protein and to H1. Thus, HDC1 provides a potential link between H1 and histone-modifying complexes.

  4. Synthesis, Spectral Characterization, Molecular Modeling, and Antimicrobial Studies of Cu(II, Ni(II, Co(II, Mn(II, and Zn(II Complexes of ONO Schiff Base

    Padmaja Mendu


    Full Text Available A series of Cu(II, Ni(II, Co(II, Mn(II, and Zn(II complexes have been synthesized from the schiff base ligand L. The schiff base ligand [(4-oxo-4H-chromen-3-yl methylene] benzohydrazide (L has been synthesized by the reaction between chromone-3-carbaldehyde and benzoyl hydrazine. The nature of bonding and geometry of the transition metal complexes as well as schiff base ligand L have been deduced from elemental analysis, FT-IR, UV-Vis, 1HNMR, ESR spectral studies, mass, thermal (TGA and DTA analysis, magnetic susceptibility, and molar conductance measurements. Cu(II, Ni(II, Co(II, and Mn(II metal ions are forming 1:2 (M:L complexes, Zn(II is forming 1:1 (M:L complex. Based on elemental, conductance and spectral studies, six-coordinated geometry was assigned for Cu(II, Ni(II, Co(II, Mn(II, and Zn(II complexes. The complexes are 1:2 electrolytes in DMSO except zinc complex, which is neutral in DMSO. The ligand L acts as tridentate and coordinates through nitrogen atom of azomethine group, oxygen atom of keto group of γ-pyrone ring and oxygen atom of hydrazoic group of benzoyl hydrazine. The 3D molecular modeling and energies of all the compounds are furnished. The biological activity of the ligand and its complexes have been studied on the four bacteria E. coli, Edwardella, Pseudomonas, and B. subtilis and two fungi pencillium and tricoderma by well disc and fusion method and found that the metal chelates are more active than the free schiff base ligand.

  5. The influence of environmental exposure to complex mixtures including PAHs and lead on genotoxic effects in children living in Upper Silesia, Poland

    Mielzynska, Danuta; Siwinska, Ewa; Kapka, Lucyna


    Environmental exposure is a complex mixture of hazardous compounds with different mechanisms of toxicity. In case of concomitant exposure to carcinogenic substances--such as polycyclic aromatic hydrocarbons (PAHs)--and to heavy metals--such as lead (Pb)--the level of DNA damage may be enhanced...... and to investigate their relation with the environmental exposure to PAHs and Pb. The examined population included 74 children 5-14-year-old who lived in two cities located in the most polluted centre of the Silesia province. Individual exposure to lead was assessed for each child by measuring lead in blood (Pb......B), and to PAH by measuring 1-hydroxypyrene in urine (1-OHP), urinary mutagenicity and DNA adducts in circulating lymphocytes. Biomarkers of genetic effects were assessed by measuring micronuclei (MN) and sister chromatid exchanges (SCE) in children's peripheral lymphocytes. The mean levels of biomarkers...

  6. Synthesis, characterisation and electrochemical behaviour of Cu(II), Co(II), Ni(II) and Zn(II) complexes derived from acetylacetone and p-anisidine and their antimicrobial activity

    N Raman; V Muthuraj; S Ravichandran; A Kulandaisamy


    Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesised using the Schiff base formed by the condensation of acetylacetone and p-anisidine. Microanalysis, molar conductance, magnetic susceptibility, IR, UV-Vis, 1H NMR, CV and EPR studies have been carried out to determine the structure of the complexes. From the data, it is found that all the complexes possess square-planar geometry. The EPR spectrum of the copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. All the title complexes were screened for antimicrobial activity by the well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values were calculated at 37°C for a period of 24 h. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand.

  7. Synthesis, spectral characterization, thermal and photoluminescence properties of Zn(II) and Cd(II)-azido/thiocyanato complexes with thiazolylazo dye and 1,2-bis(diphenylphoshino)ethane.

    Yamgar, B A; Sawant, V A; Bharate, B G; Chavan, S S


    A series of complexes of the type [M(L)(dppe)X2]; where M=Zn(II) or Cd(II); L=4-(2'-thiazolylazo)chlorobenzene (L1), 4-(2'-thiazolylazo)bromobenzene (L2) and 4-(2'-thiazolylazo) iodobenzene (L3); dppe=1,2-bis(diphenylphosphino)ethane; X=N3- or NCS- have been prepared and characterized on the basis of their microanalysis, molar conductance, thermal, IR, UV-vis and 1H NMR spectral studies. IR spectra show that the ligand L is coordinated to the metal atom in bidentate manner via azo nitrogen and thiazole nitrogen. An octahedral structure is proposed for all the complexes. The thermal behavior of the complexes revealed that the thiocyanato complexes are thermally more stable than the azido complexes. All the complexes exhibit blue-green emission with high quantum yield as the result of the fluorescence from the intraligand emission excited state.

  8. Synthesis and spectral studies of macrocyclic Pb(Ⅱ), Zn(Ⅱ), Cd(II)and La(Ⅲ) complexes derived from 1,4-bis(3-aminopropoxy)butane with metal nitrate and salicylaldehyde derivatives

    Salih Ilhan; Hamdi Temel; Salih Pasa


    Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane with metal nitrate and 1,3-bis(2-forrnylphenyl)propane or 1,4-bis(2-formylphenyl)butane and their structures were proposed on the basis of elemental analysis, FTIR, UV-vis, molar conductivity measurements, 1H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1:1. The complexes are 1:2 electrolytes for Pb(II), Zn(II) and Cd(II) complexes and 1:3 electrolytes for La(lIl) as shown by their molar conductivities (Am) in DMSO at 10-3 tool L-l. Due to the existence of free ions in these complexes,such complexes are electrically conductive. The configurations of La(Ⅲ) and Pb(U) were proposed to probably octahedral and Zn(II) and Cd(II) complexes were proposed to probably tetrahedral.

  9. Synthesis, characterization and thermogravimetric analysis of Co(II, Ni(II, Cu(II and Zn(II complexes supported by ONNO tetradentate Schiff base ligand derived from hydrazino benzoxazine

    N. Kavitha


    Full Text Available A new series of Co(II, Ni(II, Cu(II and Zn(II metal complexes of a novel ligand 3-(2-(1-(2,4-DihydroxyPhenylethylidenehydrazinyl-2H-benzo[b][1,4]oxazin-2-one, (DPE-HBO were prepared and characterized. Microwave synthesis of the ligand was also carried out which gave a high increase in its yield within very short time. 3D molecular modeling structure of the ligand is obtained by using ArgusLab software. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analysis, thermal, infrared, electronic spectra, magnetic moments and conductivity measurements. ESR spectrum of Cu(II complex is studied. All the complexes show subnormal magnetic moments. ONNO donor atoms participate in coordination with Cu(II and Zn(II complexes exhibiting octahedral geometry. Co(II and Ni(II complexes behave differently with ONNO donor atoms showing two types of geometries i.e., octahedral and square planar within the same complex.

  10. Synthesis, spectral characterization and biological evaluation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with thiosemicarbazone ending by pyrazole and pyridyl rings

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.


    Here we present the synthesis of the new Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes with chelating ligand (Z)-(2-((1,3-diphenyl-1H-pyrazol-4-yl)methylene) hydrazinyl)(pyridin-2-ylamino)methanethiol. All the complexes were characterized by elemental analysis, IR, 1H NMR, UV-vis, magnetic susceptibility measurements and EPR spectral studies. IR spectra of complexes showed that the ligand behaves as NN neutral bidentate, NSN mononegative tridentate and NSNN mononegative tetradentate. The electronic spectra and the magnetic measurements suggested the octahedral geometry for all complexes as well as the EPR confirmed the tetragonal distorted octahedral for Cu(II) complex. Cd(II) complex showed the highest inhibitory antioxidant activity either using ABTS method. The SOD-like activity exhibited those Cd(II) and Zn(II) complexes have strong antioxidative properties. We tested the synthesized compounds for antitumor activity and showed that the ability to kill liver (HePG2) and breast (MCF-7) cancer cells definitely.

  11. Determination of Formation Constants of Co2+,Ni2+,Cu2+and Zn2+ Complexes with Humic and Fulvic Acids by Potentionmetric Titration Method



    The formation constants of Co2+,Ni2+,Cu2+ and Zn2+ complexes with humic acid(HA) and fulvic acid(FA) in red soil wrer determined by the potentiometric titration method.The constants as a function of composition of the complexation solutions were obtained by two graphical approaches respetively,The formation constants decreased with increasing concentration of metal in the solution,The results provide unambiguous evidence for the heterogeneity of the function groups of humic substances,the formation constants of FA were much smaller than those of HA,and the formation constants of Cu2+ were much greater than those of Co2+ ,Ni2+ and Zn2+,The potentiometric titration methon for determining formation constants are also discussed in the article.

  12. Synthesis and Crystal Structure of a Tetranuclear Carboxylate-bridged Lanthanum(III)-Zinc(II) Complex [La2Zn2(m-CNC6H4COO)10(Py)2(C2H5OH)2


    The title complex was prepared from self-assembly reaction of La(NO3)3×6H2O, Zn(NO3)2×6H2O, m-cyanobenzoic acid (m-CNC6H4COOH) and pyridine (Py) in refluxing ethanol and its structure was determined by single-crystal X-ray diffraction. Crystallographic data: C94H62N12La2O22Zn2, Mr = 2120.12, triclinic space group P _ 1, a = 13.2219(5), b = 13.2713(5), c = 14.1987(6) ?, a = 69.156(1), b = 84.034(1), g = 89.400(1) °, V = 2314.9(2) ?3, Z = 1, Dc = 1.521 g/cm3, F(000) = 1060, m (MoKa) = 14.94 cm-1, the final R = 0.043 and wR = 0.117 for 6381 unique reflections with I > 2s(I). Crystal structure determination shows that the neighboring lanthanum(III) and zinc(II) ions are bridged by three bidentate m-cyanobenzonate ligands in the syn-syn fashion to form a pair of dinuclear [LaZn(m-CNC6H4COO)3(Py)(C2H5OH)] subunits, being linked together by two bidentate and two tridentate m-cyanobenzonate groups in the syn-syn and syn-anti modes, respectively, to construct a tetranuclear La-Zn complex [La2Zn2(m-CNC6H4COO)10(Py)2(C2H5OH)2].

  13. Phosphine-free synthesis of high quality ZnSe, ZnSe/ZnS, and Cu-, Mn-doped ZnSe nanocrystals.

    Shen, Huaibin; Wang, Hongzhe; Li, Xiaomin; Niu, Jin Zhong; Wang, Hua; Chen, Xia; Li, Lin Song


    High quality zinc blende ZnSe and ZnSe/ZnS core/shell nanocrystals have been synthesized by two converse injection methods (i.e. zinc precursor injection or selenium precursor injection) when Se-ODE complex was chosen as the phosphine-free selenium precursor. Absorption spectroscopy, fluorescence spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize the as-synthesized ZnSe and ZnSe/ZnS nanocrystals. The quality of the as-prepared ZnSe nanocrystals reached the same high level compared with the method using phosphine selenium precursors since the quantum yields were between 40 and 60% and photoluminescence (PL) full width at half-maximum (FWHM) was well controlled between 14 and 17 nm. The parameter window for the growth of high quality ZnSe nanocrystals was found to be much broader and monodisperse ZnSe nanocrystals were synthesized successfully even when the reaction temperature was set as low as 240 degrees C. As cores, such zinc blende ZnSe nanocrystals were also used to synthesize ZnSe/ZnS core/shell nanocrystals with high fluorescence quantum yields of 70%. Cu(2+) or Mn(2+) doped ZnSe nanocrystals were also synthesized by simply modifying this phosphine-free method. The emission range has been extended to 500 and 600 nm with the use of Cu(2+) and Mn(2+) dopants compared with the emission coverage of ZnSe at around 400 nm. This is the first totally "green approach" (i.e. phosphine-free synthesis) for the synthesis of high quality ZnSe, ZnSe/ZnS, and Cu(2+) or Mn(2+) doped ZnSe nanocrystals.

  14. A photochemical proposal for the preparation of ZnAl{sub 2}O{sub 4} and MgAl{sub 2}O{sub 4} thin films from β-diketonate complex precursors

    Cabello, G., E-mail: [Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Chillán (Chile); Lillo, L.; Caro, C.; Seguel, M.; Sandoval, C. [Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Chillán (Chile); Buono-Core, G.E. [Instituto de Química, Pontificia Universidad Católica de Valparaíso, Valparaíso (Chile); Chornik, B.; Flores, M. [Deparamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8370415 (Chile)


    Highlights: • ZnAl{sub 2}O{sub 4} and MgAl{sub 2}O{sub 4} thin films were prepared by photo-chemical method. • The Zn(II), Mg(II) and Al(III) β-diketonate complexes were used as precursors. • The photochemical reaction was monitored by UV–vis and FT-IR spectroscopy. • The results reveal spinel oxide formation and the generation of intermediate products. - Abstract: ZnAl{sub 2}O{sub 4} and MgAl{sub 2}O{sub 4} thin films were grown on Si(100) and quartz plate substrates using a photochemical method in the solid phase with thin films of β-diketonate complexes as the precursors. The films were deposited by spin-coating and subsequently photolyzed at room temperature using 254 nm UV light. The photolysis of these films results in the deposition of metal oxide thin films and fragmentation of the ligands from the coordination sphere of the complexes. The obtained samples were post-annealed at different temperatures (350–1100 °C) for 2 h and characterized by FT-Infrared spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force miscroscopy (AFM), and UV–vis spectroscopy. The results indicate the formation of spinel-type structures and other phases. These characteristics determined the quality of the films, which were obtained from the photodeposition of ternary metal oxides.

  15. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) Schiff base complexes derived from o-phenylenediamine and acetoacetanilide

    N Raman; Y Pitchaikani Raja; A Kulandaisamy


    Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) have been synthesised using a Schiff base formed by the condensation of -phenylenediamine with acetoacetanilide in alcohol medium. All the complexes were characterised on the basis of their microanalytical data, molar conductance, magnetic susceptibility, IR, UV-Vis 1H NMR and ESR spectra. IR and UV-Vis spectral data suggest that all the complexes are square-planar except the Mn(II) and VO(II) chelates, which are of octahedral and square pyramidal geometry respectively. The monomeric and neutral nature of the complexes was confirmed by their magnetic susceptibility data and low conductance values. The ESR spectra of copper and vanadyl complexes in DMSO solution at 300 K and 77 K were recorded and their salient features are reported.

  16. Electron spin relaxation in pseudo-Jahn-Teller low-symmetry Cu(II) complexes in diaqua(L-aspartate)Zn(II).H(2)O crystals.

    Hoffmann, S K; Hilczer, W; Goslar, J; Massa, M M; Calvo, R


    Low-temperature (4-55 K) pulsed EPR measurements were performed with the magnetic field directed along the z-axis of the g-factor of the low-symmetry octahedral complex [(63)Cu(L-aspartate)(2)(H2O)2] undergoing dynamic Jahn-Teller effect in diaqua(L-aspartate)Zn(II) hydrate single crystals. Spin-lattice relaxation time T(1) and phase memory time T(M) were determined by the electron spin echo (ESE) method. The relaxation rate 1/T(1) increases strongly over 5 decades in the temperature range 4-55 K. Various processes and mechanisms of T(1)-relaxation are discussed, and it is shown that the relaxation is governed mainly by Raman relaxation processes with the Debye temperature Theta(D)=204 K, with a detectable contribution from disorder in the doped Cu(2+) ions system below 12 K. An analytical approximation of the transport integral I(8) is given in temperature range T=0.025-10Theta(D) and applied for computer fitting procedures. Since the Jahn-Teller distorted configurations differ strongly in energy (delta(12)=240 cm(-1)), there is no influence of the classical vibronic dynamics mechanism on T(1). Dephasing of the ESE (phase relaxation) is governed by instantaneous diffusion and spectral diffusion below 20 K with resulting rigid lattice value 1/T(0)(M)=1.88 MHz. Above this temperature the relaxation rate 1/T(M) increases upon heating due to two mechanisms. The first is the phonon-controlled excitation to the first excited vibronic level of energy Delta=243 cm(-1), with subsequent tunneling to the neighbor potential well. This vibronic-type dynamics also produces a temperature-dependent broadening of lines in the ESEEM spectra. The second mechanism is produced by the spin-lattice relaxation. The increase in T(M) is described in terms of the spin packets forming inhomogeneously broadened EPR lines.

  17. 磨矿方法对某硫化矿浮选的影响%Effects of Grinding Measure on Complex Pb/Zn Ore Flotation

    魏以和; 周高云


    The flotation performances of a complex Pb/zn ore are investigated by three kinds of mill(steel,stainless and ceramic mill)in laboratory batch flotation testa.It is found that the lead recovery is increased while grinding in a ceramic mill,i.e.a non-ferrous,oxidizing environment.but the selectivity is decreased due to the activation ol sphalerite by copper ions produced via the oxidation of ore.On the contrary,the lead recovery is decreased while grinding in a traditionel iron mill,but the selectivity is increased.The low recovery with iron grinding media is probably caused by the coating of iron oxy-hydroxides on sulphide surfaces.Coarse particles are more sensitive to this kind of depression.%为提高效果,用三种磨机(普通钢磨机,不锈钢磨机和瓷磨机)研究某铅锌矿小型试验的浮选行为.结果表明,瓷磨机(即非铁质磨机)的氧化性磨矿环境可提高铅回收率,但由于矿石氧化产生的铜离子对闪锌矿的活化而降低了浮选选择性.相反地,传统铁质磨机磨矿则导致铅收率下降,而选择性提高.铁质磨机磨矿时铅收率降低可能是由铁氧化产物在矿物表面覆盖而造成的.粗粒更易受这种抑制的影响.


    Murray, Shauna; Jørgensen, Mårten Flø; Daugbjerg, Niels;


    Amphidinium operculatum Claparède et Lachmann, the type species of the dinoflagellate genus Amphidinium, has long had an uncertain identity. It has been considered to be either difficult to distinguish from other similar species or a morphologically variable species itself. This has led to the hy......Amphidinium operculatum Claparède et Lachmann, the type species of the dinoflagellate genus Amphidinium, has long had an uncertain identity. It has been considered to be either difficult to distinguish from other similar species or a morphologically variable species itself. This has led...... to the hypothesis that A. operculatum represents a "species complex." Recently, the problem of distinguishing A. operculatum from similar species has become particularly acute, because several morphologically similar species have been found to produce bioactive compounds of potential interest to the pharmaceutical......, and partial large subunit (LSU) rDNA sequence data. Through morphological and molecular phylogenetic analyses, six distinct species were identified, including Amphidinium trulla sp. nov. and Amphidinium gibbosum comb. nov. Amphidinium operculatum was redescribed based on four cultures. Genetic variability...


    BARIC S.


    Full Text Available The phylogenetic relationships of the Austropotamobius pallipes species complex were assessed in several recent genetic studies by analysing sequences of the mitochondrial DNA. Although the Alpine region is known to harbour great extents of morphological and genetic diversity, none of the previous studies included populations from South Tyrol in Northern Italy and Carinthia in Southern Austria. In order to clarify their taxonomic status white-clawed crayfish were sampled from six populations in South Tyrol and three populations in Carinthia. Phylogenetic analyses are based on partial DNA sequences of the mitochondrial DNA 16S rRNA gene, which were supplemented with sequences deposited in GenBank. All surveyed individuals from the six populations in South Tyrol comprised a single haplotype that equalled the already described haplotype S3. This haplotype is distributed in Plansee (Austria as well as several other localities in Italy and Switzerland, and belongs to the A. italicus carinthiacus clade. The investigated specimens from all three Carinthian populations also displayed one single haplotype. However, this haplotype clustered in the A. italicus carsicus clade and has not been published before. Our study clearly shows that neither Austrian crayfish populations from Plansee and Carinthia, nor populations from South Tyrol and Carinthia belong to the same phylogenetic lineage.

  20. In skeletal muscle advanced glycation end products (AGEs) inhibit insulin action and induce the formation of multimolecular complexes including the receptor for AGEs.

    Cassese, Angela; Esposito, Iolanda; Fiory, Francesca; Barbagallo, Alessia P M; Paturzo, Flora; Mirra, Paola; Ulianich, Luca; Giacco, Ferdinando; Iadicicco, Claudia; Lombardi, Angela; Oriente, Francesco; Van Obberghen, Emmanuel; Beguinot, Francesco; Formisano, Pietro; Miele, Claudia


    Chronic hyperglycemia promotes insulin resistance at least in part by increasing the formation of advanced glycation end products (AGEs). We have previously shown that in L6 myotubes human glycated albumin (HGA) induces insulin resistance by activating protein kinase Calpha (PKCalpha). Here we show that HGA-induced PKCalpha activation is mediated by Src. Coprecipitation experiments showed that Src interacts with both the receptor for AGE (RAGE) and PKCalpha in HGA-treated L6 cells. A direct interaction of PKCalpha with Src and insulin receptor substrate-1 (IRS-1) has also been detected. In addition, silencing of IRS-1 expression abolished HGA-induced RAGE-PKCalpha co-precipitation. AGEs were able to induce insulin resistance also in vivo, as insulin tolerance tests revealed a significant impairment of insulin sensitivity in C57/BL6 mice fed a high AGEs diet (HAD). In tibialis muscle of HAD-fed mice, insulin-induced glucose uptake and protein kinase B phosphorylation were reduced. This was paralleled by a 2.5-fold increase in PKCalpha activity. Similarly to in vitro observations, Src phosphorylation was increased in tibialis muscle of HAD-fed mice, and co-precipitation experiments showed that Src interacts with both RAGE and PKCalpha. These results indicate that AGEs impairment of insulin action in the muscle might be mediated by the formation of a multimolecular complex including RAGE/IRS-1/Src and PKCalpha.

  1. Long-term post-stroke changes include myelin loss, specific deficits in sensory and motor behaviors and complex cognitive impairment detected using active place avoidance.

    Jin Zhou

    Full Text Available Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1 sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2 complex active place avoidance learning (APA and simple passive avoidance retention (PA. Electroretinogram (ERG, hemispheric loss (infarction, hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001, sensory (p<0.001, beam balance performance (p<0.01 and hindlimb placement behavior (p<0.01. tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05 but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining. No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01 in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and


    Masoumeh Orojloo


    Full Text Available Synthesis, spectral identification, and magnetic properties of three complexes of Ni(II, Cu(II, and Zn(II are described. All three compounds have the general formula [M(L2(H2O2], where L = deprotonated phenol in the Schiff base 2-((z-(3-methylpyridin-2-yleiminomethylphenol. The three complexes were synthesized in a one-step synthesis and characterized by elemental analysis, Fourier transform infrared spectroscopy, electronic spectra, X-ray diffraction (XRD, and room temperature magnetic moments. The Cu(II and Ni(II complexes exhibited room temperature magnetic moments of 1.85 B.M. per copper atom and 2.96 B.M. per nickel atom. The X-band electron spin resonance spectra of a Cu(II sample in dimethylformamide frozen at 77 K (liquid nitrogen temperature showed a typical ΔMS = ± 1 transition. The complexes ([M(L2(H2O2] were investigated by the cyclic voltammetry technique, which provided information regarding the electrochemical mechanism of redox behavior of the compounds. Thermal decomposition of the complexes at 750 ºC resulted in the formation of metal oxide nanoparticles. XRD analyses indicated that the nanoparticles had a high degree of crystallinity. The average sizes of the nanoparticles were found to be approximately 54.3, 30.1, and 44.4 nm for NiO, CuO, and ZnO, respectively.

  3. Synthesis, characterization, thermal study and biological evaluation of Cu(II), Co(II), Ni(II) and Zn(II) complexes of Schiff base ligand containing thiazole moiety

    Nagesh, G. Y.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.


    The novel Schiff base ligand 2-(4-(dimethylamino)benzylidene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 4-dimethylaminobenzaldehyde and its newly synthesized Cu(II), Co(II), Ni(II) and Zn(II) complexes have been characterized by microanalysis, magnetic susceptibility, molar conductance, thermal analysis, FT-IR, 1H NMR, ESI mass, UV-Visible, ESR spectroscopy and powder X-ray diffraction data. The newly synthesized ligand behaves as a bidentate ON donor. The IR results confirmed the bidentate binding of the ligand involving oxygen atom of amide carbonyl and azomethine nitrogen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. In order to evaluate the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties of all the compounds against Artemia salina. Furthermore, the antioxidant activity of the ligand (L) and its metal complexes were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH), the ligand exhibited potent in vitro - antioxidant activity than its metal complexes.

  4. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

    Nahid Nishat


    Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

  5. Synthesis, characterization and biological activity of some new VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based NNO Schiff base derived from 2-aminothiazole

    Kalanithi, M.; Kodimunthiri, D.; Rajarajan, M.; Tharmaraj, P.


    Coordination compounds of VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) with the Schiff base obtained through the condensation of 2-aminothiazole with 3-formyl chromone were synthesized. The compounds were characterized by 1H, 13C NMR, UV-Vis, IR, Mass, EPR, molar conductance and magnetic susceptibility measurements. The Cu(II) complex possesses tetrahedrally distorted square planar geometry whereas Co(II), Ni(II), and Zn(II) show distorted tetrahedral geometry. The VO(IV) complex shows square pyramidal geometry. The cyclic voltammogram of Cu (II) complex showed a well defined redox couple Cu(II)/Cu(I) with quasireversible nature. The antimicrobial activity against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger was screened and compared to the activity of the ligand. Emission spectrum was recorded for the ligand and the metal(II) complexes. The second harmonic generation (SHG) efficiency was measured and found to have one fourth of the activity of urea. The SEM image of the copper(II) complex implies that the size of the particles is 2 μm.

  6. Synthesis, spectroscopic, antimicrobial and DNA cleavage studies of new Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes with naphthofuran-2-carbohydrazide Schiff base

    Halli, Madappa B.; Sumathi, R. B.


    A series of Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes have been synthesized with newly synthesized Schiff base derived from naphthofuran-2-carbohydrazide and cinnamaldehyde. The elemental analyses of the complexes are confined to the stoichiometry of the type MLCl2 [M = Co(II) and Cu(II)], ML2Cl2 [M = Ni(II), Cd(II), Zn(II) and Hg(II)] respectively, where L is Schiff base ligand. Structures have been proposed from elemental analyses, IR, electronic, mass, 1H NMR, ESR spectral data, magnetic, and thermal studies. The measured low molar conductance values in DMF indicate that the complexes are non-electrolytes. Spectroscopic studies suggest coordination occurs through azomethine nitrogen and carbonyl oxygen of the ligand with the metal ions. The Schiff base and its complexes have been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Salmonella typhi) and antifungal (Aspergillus niger, Aspergillus flavus, Cladosporium and Candida albicans) activities by minimum inhibitory concentration (MIC) method. The DNA cleavage studies by agarose gel electrophoresis method was studied for all the complexes.

  7. Dextrocardia, atrial septal defect, severe developmental delay, facial anomalies, and supernumerary ribs in a child with a complex unbalanced 8;22 translocation including partial 8p duplication.

    Pope, Kathleen; Samanich, Joy; Ramesh, K H; Cannizzaro, Linda; Pan, Qiulu; Babcock, Melanie


    We report on a child with dextrocardia, atrial septal defect (ASD), severe developmental delay, hypotonia, 13 pairs of ribs, left preauricular choristoma, hirsutism, and craniofacial abnormalities. Prenatal cytogenetic evaluation showed karyotype 46,XY,?dup(8p)ish del(8)pter. Postnatal array CGH demonstrated a 6.8 Mb terminal deletion at 8p23.3-p23, an interstitial 31.1 Mb duplication within 8p23.1-p11, and a terminal duplication of 0.24 Mb at 22q13.33, refining the karyotype to 46,XY,der(8)dup(8)(p23.1p11.1)t(8;22)(p23.1;q13.1).ish der(8)dup(8)(p23.1p11.1)t(8;22)(p23.1;q13.1) (D8S504-,MS607 + ,ARSA + ,D8Z1 + , RP115713 + +). Previous reports of distal 8p deletion, 8p duplication, and distal 22q duplication have shown similar manifestations, including congenital heart disease, intellectual impairment, and multiple minor anomalies. We correlate the patient's clinical findings with these particular areas of copy number. This case study supports the use of aCGH to identify subtle chromosomal rearrangement in infants with cardiac malformation as their most significant or only apparent birth defect. Additionally, it illustrates why aCGH is essential in the description of chromosome rearrangements, even those seemingly visible via routine karyotype. This method shows that there is often greater complexity submicroscopically, essential to an adequate understanding of a patient's genotype and phenotype.

  8. Physical nature of interactions in Zn(II) complexes with 2,2'-bipyridyl: quantum theory of atoms in molecules (QTAIM), interacting quantum atoms (IQA), noncovalent interactions (NCI), and extended transition state coupled with natural orbitals for chemical valence (ETS-NOCV) comparative studies.

    Cukrowski, Ignacy; de Lange, Jurgens H; Mitoraj, Mariusz


    In the present account factors determining the stability of ZnL, ZnL2, and ZnL3 complexes (L = bpy, 2,2′-bipyridyl) were characterized on the basis of various techniques: the quantum theory of atoms in molecules (QTAIM), energy decomposition schemes based on interacting quantum atoms (IQA), and extended transition state coupled with natural orbitals for chemical valence (ETS-NOCV). Finally, the noncovalent interactions (NCI) index was also applied. All methods consistently indicated that the strength of the coordination bonds, Zn–O and Zn–N, decreases from ZnL to ZnL3. Importantly, it has been identified that the strength of secondary intramolecular heteropolar hydrogen bonding interactions, CH···O and CH···N, increases when going from ZnL to ZnL3. A similar trend appeared to be valid for the π-bonding as well as electrostatic stabilization. In addition to the above leading bonding contributions, all techniques suggested the existence of very subtle, but non-negligible additional stabilization from the CH···HC electronic exchange channel; these interactions are the weakest among all considered here. From IQA it was found that the local diatomic interaction energy, Eint(H,H), amounts at HF to −2.5, −2.7, and −2.9 kcal mol(–1) for ZnL, ZnL2, and ZnL3, respectively (−2.1 kcal mol(–1) for ZnL at MP2). NOCV-based deformation density channels showed that formation of CH--HC contacts in Zn complexes causes significant polarization of σ(C–H) bonds, which accordingly leads to charge accumulation in the CH···HC bay region. Charge depletion from σ(C–H) bonds was also reflected in the calculated spin–spin (1)J(C–H) coupling constants, which decrease from 177.06 Hz (ZnL) to 173.87 Hz (ZnL3). This last result supports our findings of an increase in the local electronic CH···HC stabilization from ZnL to ZnL3 found from QTAIM, IQA, and ETS-NOCV. Finally, this work unites for the first time the results from four methods that are widely

  9. SERS and DFT investigation of 1-(2-pyridylazo)-2-naphthol and its metal complexes with Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II)

    Szabó, László; Herman, Krisztian; Mircescu, Nicoleta E.; Fălămaş, Alexandra; Leopold, Loredana F.; Leopold, Nicolae; Buzumurgă, Claudia; Chiş, Vasile

    The development of surface-enhanced Raman scattering (SERS) as a prospective analytical methodology for detection of metal ions was shown in recent years by several studies on metal complexes. In this work, 1-(2-pyridylazo)-2-naphthol (PAN) and its Al(III), Mn(II), Fe(III), Cu(II), Zn(II) and Pb(II) complexes were studied by FTIR, FT-Raman and surface enhanced Raman spectroscopies. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculations were performed using the hybrid B3LYP exchange-correlation functional for the PAN molecule and its bidentate complexes. The calculated MEP distributions indicated the atoms with highest electronegativity, the adsorption to the silver surface occurring through these atoms. Based on experimental and theoretical data we were able to identify unique and representative features, useful for the identification of each PAN-metal complex.

  10. Synthesis and spectral studies of Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes of a new macroacyclic ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide



    Full Text Available A new macroacyclic amide ligand N,N’-bis(2-benzothiazolyl-2,6-pyridinedicarboxamide (BPD, formed by the condensation of 2,6-pyridinedicarbonyldichloride with 2-aminobenzothiazole, and its Cu(II, Ni(II, Co(II, Mn(II, Zn(II and Cd(II complexes were synthesized. Their structures were elucidated on the basis of elemental analyses, conductance measurements, magnetic moments, spectral (IR, NMR, UV-Visible, EPR and FAB and thermal studies. The complexes exhibit an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be 1:1 electrolytes. The pentadentate behavior of the ligand was proposed on the basis of spectral studies. The X-band EPR spectra of the Cu(II and Mn(II complexes in the polycrystalline state at room (300 K and liquid nitrogen temperature (77 K were recorded and their salient features are reported.

  11. On the plumbing system of volcanic complexes: field constraints from the Isle of Skye (UK) and FEM elasto-plastic modelling including gravity and tectonics.

    Bistacchi, A.; Pisterna, R.; Romano, V.; Rust, D.; Tibaldi, A.


    The plumbing system that connects a sub-volcanic magma reservoir to the surface has been the object of field characterization and mechanical modelling efforts since the pioneering work by Anderson (1936), who produced a detailed account of the spectacular Cullin Cone-sheet Complex (Isle of Skye, UK) and a geometrical and mechanical model aimed at defining the depth to the magma chamber. Since this work, the definition of the stress state in the half space comprised between the magma reservoir and the surface (modelled either as a flat surface or a surface comprising a volcanic edifice) was considered the key point in reconstructing dike propagation paths from the magma chamber. In fact, this process is generally seen as the propagation in an elastic media of purely tensional joints (mode I or opening mode propagation), which follow trajectories perpendicular to the least compressive principal stress axis. Later works generally used different continuum mechanics methodologies (analytic, BEM, FEM) to solve the problem of a pressure source (the magma chamber, either a point source or a finite volume) in an elastic (in some cases heterogeneous) half space (bounded by a flat topography or topped by a "volcano"). All these models (with a few limited exceptions) disregard the effect of the regional stress field, which is caused by tectonic boundary forces and gravitational body load, and consider only the pressure source represented by the magma chamber (review in Gudmundsson, 2006). However, this is only a (sometimes subordinate) component of the total stress field. Grosfils (2007) first introduced the gravitational load (but not tectonic stresses) in an elastic model solved with FEM in a 2D axisymmetric half-space, showing that "failure to incorporate gravitational loading correctly" affect the calculated stress pattern and many of the predictions that can be drawn from the models. In this contribution we report on modelling results that include: 2D axisymmetric or true

  12. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid

    Faheim, Abeer A.; Abdou, Safaa N.; Abd El-Wahab, Zeinab H.


    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H2L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, 1H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H2L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  13. Complexity

    Gershenson, Carlos


    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  14. Synthesis and characterization of some water soluble Zn(II) complexes with (E)-N-(pyridin-2-ylmethylene)arylamines that regulate tumour cell death by interacting with DNA.

    Basu Baul, Tushar S; Kundu, Sajal; Linden, Anthony; Raviprakash, Nune; Manna, Sunil K; Guedes da Silva, M Fátima C


    The synthesis and spectroscopic properties of nine water soluble zinc(II) complexes of (E)-N-(pyridin-2-ylmethylene)arylamines (L(n)) with the general formula [Zn(X)2(L(n))] (X = Cl(-), Br(-), I(-); (1-8)) and [Zn(μ-N3)(N3)(L(3))]2 (9) are reported. The complexes were characterized by elemental analysis and their spectroscopic properties were studied using UV-Visible, fluorescence, IR and (1)H NMR spectroscopies. The solid state structures of zinc(II) complexes 2-4 and 6-9 were established by single crystal X-ray crystallography. The majority of the structures are mononuclear with tetra-coordinate zinc centres (2-4, 6 and 7) except where L carries an additional donor atom capable of coordinating zinc (8), in which case the zinc atom has a distorted square pyramidal geometry. The centrosymmetric molecule of [Zn(μ-N3)(N3)(L(3))]2 (9) is binuclear with the zinc atoms in a trigonal bipyramidal coordination environment. In general, the dichlorozinc derivatives 1, 3-5 and 8 exhibited moderately elevated in vitro cytotoxic potency towards the human epithelial cervical carcinoma (HeLa) cell line, with 4 as the best performer (IC50 value of 18 μM). Apoptosis-inducing activity, assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, showed that the zinc complexes interacted with DNA and thereby interfered the DNA binding of several transcription factors to its promoter sites, thus inhibiting gene transcription required for the biological activity of cells.

  15. Synthesis and characterization of VO(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based azo-linked Schiff base ligand

    Anitha, C.; Sheela, C. D.; Tharmaraj, P.; Johnson Raja, S.


    Azo-Schiff-base complexes of VO(II), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized and characterized by elemental analysis, IR, UV-Vis, 1H NMR, mass spectra, molar conductance, magnetic susceptibility measurement, electron spin resonance (EPR), CV, fluorescence, NLO and SEM. The conductance data indicate the nonelectrolytic nature of the complexes, except VO(II) complex which is electrolytic in nature. On the basis of electronic spectra and magnetic susceptibility octahedral geometry has been proposed for the complexes. The EPR spectra of copper and oxovanadium complexes in DMSO at 300 and 77 K were recorded and its salient features are reported. The redox behavior of the copper(II) complex was studied using cyclic voltammetry. The in vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella enterica typhi, Bacillus subtilis and Candida strains was studied and compared with that of free ligand by well-diffusion technique. The azo Schiff base exhibited fluorescence properties originating from intraligand (π-π∗) transitions and metal-mediated enhancement is observed on complexation and so the synthesized complexes can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. On the basis of the optimized structures, the second-order nonlinear optical properties (NLO) are calculated by using second-harmonic generation (SHG) and also the surface morphology of the complexes was studied by SEM.

  16. Magnetic exchange in a low-dimensional complex oxide (Cu,Zn){sub 2}V{sub 2}O{sub 7}

    Kataev, V. E-mail:; Pommer, J.; Choi, K.-Y.; Lemmens, P.; Ionescu, A.; Pashkevich, Yu.; Lamonova, K.; Moeller, A.; Freimuth, A.; Guentherodt, G


    Copper-divanadate Cu{sub 2-y}Zn{sub y}V{sub 2}O{sub 7} comprises trans-edge sharing chains of CuO{sub 5} polyhedra where Cu spins S=((1)/(2)) are antiferromagnetically coupled. Zn substitution for Cu induces a structural phase transition which affects strongly the magnetic properties. In particular, a substantial magnetic anisotropy found in one of the structural phases is strongly suppressed in the other one, owing to the changes of the local bonding geometry.

  17. An Efficient, Simple and Green Zn(Phen2Cl2 Complex Catalyzed Synthesis of 4-H-Benzo[b]pyrans in Water at Ambient Temperature

    E. Mosaddegh


    Full Text Available An efficient method for the synthesis of 4-H-benzo[b]pyrans has been developed by the use of Zn(Phen2Cl2(2 mol% as an ecofriendly catalyst. The mixture of an appropriate aldehyde, malononitrile and dimedone in the presence of the Zn(Phen2Cl2 as an inorganic catalyst in water at room temperature resulted excellent yields of the corresponding products in 5 min. Very short experimental time of the reaction, excellent yields, use of water as a green solvent, simple work-up and uses no extra catalyst and purification are the advantages of this method.

  18. Spectral study of the complexation of Nd(III) with glutathione reduced (GSH) in the presence and absence of Zn(II) in aquated organic solvents

    Th David Singh; Ch Sumitra; N Rajmuhon Singh; M Indira Devi


    Studies on the difference in energy parameters and comparative absorption spectrophotometry involving 4-4 transitions on Nd(III) and glutathione reduced (GSH) in the absence and presence of Zn(II) have been carried out in aquated organic solvents (50 : 50) like methanol, dioxane, acetonitrile and dimethylformamide. Variations in the spectral energy parameters - Slater-Condon () factor, Lande spin-orbit coupling constant (4), nephelauxetic ratio (), bonding parameter (1/2) and percent covalency () - are calculated and correlated with binding of Nd(III) with GSH in presence and absence of Zn(II).

  19. Neutral coordination polymers based on a metal-mono(dithiolene) complex: synthesis, crystal structure and supramolecular chemistry of [Zn(dmit)(4,4'-bpy)]n, [Zn(dmit)(4,4'-bpe)]n and [Zn(dmit)(bix)]n (4,4'-bpy = 4,4'-bipyridine, 4,4'-bpe = trans-1,2-bis(4-pyridyl)ethene, bix = 1,4-bis(imidazole-1-ylmethyl)-benzene.

    Madhu, Vedichi; Das, Samar K


    This article describes a unique synthetic route that enables a neutral mono(dithiolene)metal unit, {Zn(dmit)}, to link with three different organic molecules, resulting in the isolation of a new class of neutral coordination polymers. The species {Zn(dmit)} coordinates with 4,4'-bipyridine (4,4'-bpy), trans-1,2-bis(4-pyridyl)ethene (4,4'-bpe) and 1,4-bis(imidazole-1-ylmethyl)-benzene (bix) as linkers giving rise to the formation of coordination polymers [Zn(dmit)(4,4'-bpy)](n) (1), [Zn(dmit)(4,4'-bpe)](n) (2) and [Zn(dmit)(bix)](n) (3) respectively. Compounds 1-3 were characterized by elemental analyses, IR, diffuse reflectance and single crystal X-ray diffraction studies. Compounds 1 and 3 crystallize in the monoclinic space group P2(1)/n, whereby compound 2 crystallizes in triclinic space group P1[combining macron]. In the present study, we chose three linkers 4,4'-bpy, 4,4'-bpe and bix (see , respectively, for their structural drawings), that differ in terms of their molecular dimensions. The crystal structures of compounds 1-3 are described here in terms of their supramolecular diversities that include π-π interactions, not only among aromatic stacking (compounds 1 and 3), but also between an aromatic ring and an ethylenic double bond (compound 2). The electronic absorption spectroscopy of compounds 1-3 support these intermolecular π-π interactions. This journal is © The Royal Society of Chemistry 2011

  20. Controlled Growth of ZnSe Nanocrystals by Tuning Reactivity and Amount of Zinc Precursor

    Lai-Jun Zhang


    Full Text Available Zinc selenide (ZnSe nanocrystals were synthesized via a phosphine-free route using the highly reactive alkylamine-H2Se complex as selenium precursor and zinc precursors with different reactivity. The reactivity of zinc precursor was tuned by using three kinds of zinc carboxylates with different alkyl chain lengths, including zinc acetate, zinc nonanoate, and zinc stearate. The effect of the reactivity and the amount of zinc precursor on nucleation and growth of ZnSe nanocrystals were investigated by ultraviolet-visible absorption and photoluminescence spectra. Result indicates that the growth and optical property of the resulting ZnSe nanocrystals are strongly dependent on the alkyl chain length and the amount of the zinc carboxylates and both shorter alkyl chain length, and more amount of zinc carboxylate will lead to faster growth of ZnSe nanocrystals. This allows that the controlled growth and excellent optical property of high-quality ZnSe nanocrystals can be achieved by combining the different reactivity and the used amount of zinc precursor, such as by using stoichiometric and reactive Zn precursor and Se precursor or by using larger amount of more unreactive Zn precursor relative to the highly reactive alkylamine-H2Se complex precursor.

  1. Effect of Modified Gelatin from Silver Carp Skin Combined with Peptide-Zn Complex on Preservation of Grass Carp%鲢鱼皮改性明胶复合多肽锌对草鱼的保鲜作用

    张玲; 马月; 罗永康; 李博


    The coating preservation of gelatin modified by transglutaminase (TGase) combined with peptide-Zn complex from silver carp skin on grass carp was studied. Sensory evaluation, thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), pH value and total bacterial count were measured to study the quality changes of grass carp with different treatments during cold storage. The results showed that modified gelatin alone and its combination with peptide-Zn complex prepared from silver carp skin protein hydrolysate were both effective in preventing deterioration and preserving the quality of grass carp by significantly inhibiting the increases in TBA value, TVB-N value and pH value and restraining bacterial growth. Modified gelatin was comparable to sodium alginate combined with peptide-Zn complex in terms of efficacy. However, compared with sodium alginate combined with peptide-Zn complex, grass carp had a better quality on the 6th d of storage after being coated with modified gelatin combined with peptide-Zn complex. As a result, the quality of grass carp remained at the first and second grades both for 3 more days. In conclusion, modified gelatin combined with peptide-Zn complex was a more effective coating for preserving the quality of aquatic products when compared with the combination with sodium alginate.%研究鲢鱼皮谷氨酰胺转胺酶(transglutaminase,TGase)改性明胶复合多肽锌对冷藏草鱼段的保鲜效果。通过测定草鱼段在4℃冷藏过程中感官评分、硫代巴比妥酸(thiobarbituric acid,TBA)、挥发性盐基氮(total volatile basic nitrogen,TVB-N)、pH值和菌落总数等指标,评估不同处理条件下草鱼品质的变化情况。结果表明,改性明胶及其复合多肽锌对草鱼均有明显的防腐保鲜作用,有效抑制了草鱼TBA值、TVB-N值、pH值的升高以及菌落总数的增长。与海藻酸钠多肽锌处理的涂膜组草鱼相比,改性明胶单独涂膜组的保鲜

  2. {sup 60}Co gamma-irradiation effects on electrical properties of a rectifying diode based on a novel macrocyclic Zn octaamide complex

    Ocak, Y.S. [Department of Science, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Kilicoglu, T., E-mail: [Department of Physics, Faculty of Art and Science, University of Batman, Batman (Turkey); Department of Physics, Faculty of Art and Science, University of Dicle, Diyarbakir (Turkey); Topal, G. [Department of Chemistry, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Baskan, M.H. [Department of Physics, Faculty of Education, University of Dicle, Diyarbakir (Turkey)


    C{sub 36}H{sub 28}N{sub 12}O{sub 8}ZnCl{sub 2}.9/2H{sub 2}O, Zn-octaamide (ZnOA) macrocyclic compound was synthesized to be used in the fabrication of electronic and photoelectronic devices. The structure of new compound was identified by using {sup 1}H NMR, {sup 13}C NMR, IR, UV-vis and LC-MS spectroscopic methods. The Sn/ZnOA/n-Si/Au structure was engineered by forming a thin macrocyclic organic compound layer on n-Si inorganic substrate and then by evaporating Sn metal on the organic layer. It was seen that the device had a good rectifying behaviour and showed Schottky diode properties. The diode was irradiated under {sup 60}Co gamma-source at room temperature. Characteristic parameters of the diode were determined from its current-voltage (I-V) and capacitance voltage (C-V) measurements before and after irradiation. It was observed that gamma-irradiation had clear effects on I-V and C-V properties. Also, it was seen that the barrier height, the ideality factor and the series resistance values decreased after the applied radiation, while the saturation current value increased.

  3. Synthesis, structural visualization, spectroscopic, and thermal studies of charge transfer Cu(II, Ni(II and Zn(II bromides-carbamide complexes at elevated temperature

    Khlood Abou-Melha


    Full Text Available In the present study, the composition and structure of Cu(II, Ni(II and Zn(II compounds resulted from the chemical reactions of copper(II, nickel(II and zinc(II bromide salts with carbamide in aqueous media at 95 oC have been investigated, using IR, electron spin resonance ESR and x-ray powder diffraction spectroscopy as well as thermal analysis TG/DTG/DSC. The Cu2(OH3Br, [Ni2(NCO2(H2O2(Br2], and ZnCO3.xH2O compounds were achieved by a novel synthetic route through with a low cost precursor like carbamide. The infrared spectra of the results indicate absence of the individual bands of carbamide, but exhibited of the distinguished bands of hydroxyl, isocyanate, NCO, and ionic carbonate, CO32– for Cu(II, Ni(II and Zn(II compounds, respectively. Visualized investigations were performed to confirm crystal structure, validity and stability of the product compounds. A general reaction mechanisms describing the preparation of Cu(II, Ni(II, and Zn(II compounds were discussed.

  4. Hydrothermal Synthesis and Crystal Structure of a Zinc Complex: [Zn2.5(phen)(BDC)2(OH)](phen = 1,10-Phenanthroline, BDC= Benzene-1,4-dicarboxylic Acid)

    WANG Qing-Wei; LI Xiu-Mei; SHI Lin-Fang


    A metal-organic coordination polymer [Zn2.5(phen)(BDC)2(OH)]2 (phen = 1,10-phenanthroline, BDC = benzene-1,4-dicarboxylic acid)1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectro-scopy. The complex crystallizes in the triclinic system, space group P1 with a = 11.199(2), b =11.593(2), c = 11.865(3) A, α= 99.330(1), β=111.506(1),γ = 104.804(1)°, V= 1328.4(5) A3, Dc=1.722 g/cm3, Z = 1, Mr = 1377.82, F(000) = 692, μ(MoKa) = 2.306 mm-1, S = 1.093, R = 0.0281 and wR= 0.0756 for 4179 observed reflections (Ⅰ 20(Ⅰ)). The coordination polyhedron around Zn(Ⅱ)can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.

  5. Complex reconstructive surgery following removal of extra-intracranial meningiomas, including the use of autologous fibrin glue and a pedicled muscle flap

    Antonella Giugno, M.D.


    Conclusions: Reparation of CSF fistulas that arise after meningioma surgery can require a complex reconstructive surgery of the superficial layers; when cranioplasty is not feasible or indicated, a meticulous reconstruction of the extracranial soft tissues is possible also by using vascularized autologous distal muscular tissue, with close interdisciplinary cooperation.

  6. Dynamic regulation of a cell adhesion protein complex including CADM1 by combinatorial analysis of FRAP with exponential curve-fitting.

    Sakurai-Yageta, Mika; Maruyama, Tomoko; Suzuki, Takashi; Ichikawa, Kazuhisa; Murakami, Yoshinori


    Protein components of cell adhesion machinery show continuous renewal even in the static state of epithelial cells and participate in the formation and maintenance of normal epithelial architecture and tumor suppression. CADM1 is a tumor suppressor belonging to the immunoglobulin superfamily of cell adhesion molecule and forms a cell adhesion complex with an actin-binding protein, 4.1B, and a scaffold protein, MPP3, in the cytoplasm. Here, we investigate dynamic regulation of the CADM1-4.1B-MPP3 complex in mature cell adhesion by fluorescence recovery after photobleaching (FRAP) analysis. Traditional FRAP analysis were performed for relatively short period of around 10 min. Here, thanks to recent advances in the sensitive laser detector systems, we examine FRAP of CADM1 complex for longer period of 60 min and analyze the recovery with exponential curve-fitting to distinguish the fractions with different diffusion constants. This approach reveals that the fluorescence recovery of CADM1 is fitted to a single exponential function with a time constant (τ) of approximately 16 min, whereas 4.1B and MPP3 are fitted to a double exponential function with two τs of approximately 40-60 sec and 16 min. The longer τ is similar to that of CADM1, suggesting that 4.1B and MPP3 have two distinct fractions, one forming a complex with CADM1 and the other present as a free pool. Fluorescence loss in photobleaching analysis supports the presence of a free pool of these proteins near the plasma membrane. Furthermore, double exponential fitting makes it possible to estimate the ratio of 4.1B and MPP3 present as a free pool and as a complex with CADM1 as approximately 3:2 and 3:1, respectively. Our analyses reveal a central role of CADM1 in stabilizing the complex with 4.1B and MPP3 and provide insight in the dynamics of adhesion complex formation.

  7. Complex


    Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.

  8. Preparation, characterization and antioxidant activity of Cistanche tubulosa Zn2 + -polysaccharide complex%肉苁蓉多糖锌的制备、表征及抗氧化活性

    黄靖; 邹烨; 王未; 李倩; 吴慧玉; 赵婷; 茆广华; 张敏; 仰榴青


    Cistanche tubulosa polysaccharides was extracted by ultrasonic‐cellulase‐assisted ex‐traction and the refined polysaccharide (UCEP1) was prepared by quaternary ammonium salt precipitation .The Zn 2 + ‐polysaccharide (UCEP1‐Zn) was prepared with ZnSO4 and UCEP1 as raw material ,and its characterization and antioxidant activity were also studied .The results showed that the yield and content of cistanchetubulosa polysaccharides was 22 .31% and 48 .50% ,respectively ,and the content of UCEP1 was 70 .13% .The - OH group and the car‐boxyl group were involved , the chain conformation and variation on morphology were also changed after the formation of UCEP1‐Zn ,and the content of Zn2 + was 7 .57% .The antioxi‐dant activity of UCEP1‐Zn was significantly higher than that of UCEP1 and had the highest ABTS + radical scavenging activity .The study provided a reference for the research and applica‐tion of Cistanche tubulosa polysaccharide ,zinc supplement and zinc complexes .%采用超声酶法辅助提取肉苁蓉粗多糖,并用季铵盐沉淀法对肉苁蓉粗多糖进行精制,获得肉苁蓉精制多糖(UCEP1);以 UCEP1和硫酸锌为原料,制备了肉苁蓉多糖锌配合物(UCEP1‐Zn),对其结构进行了表征,并研究其抗氧化活性.结果表明,肉苁蓉粗多糖收率及含量分别为22.31%和48.50%,UCEP1中多糖含量为70.13%;UCEP1‐Zn 中- OH 和- COO -和 Zn2+发生了配位,其中锌含量为7.57%,且多糖链构象及多糖分子表面形貌发生变化;UCEP1‐Zn 的抗氧化能力显著高于 UCEP1,且对 ABTS +自由基清除活性最好.该研究可为肉苁蓉多糖、新型锌营养素补充剂以及锌功能配合物的研究和利用提供参考.

  9. Complexation and coordination selectivities of the tetradentate ligand 7-[(2-hydroxy-5-sulfophenyl) azo]-8-hydroxyquinoline-5-sulfonic acid with Fe(II), Ni(II), Zn(II), Cd(II) and VO(IV)

    Huang, Hu; Kai, Fumiaki; Hirohata, Masaaki; Nakamura, Masaaki; Matsuzaki, Susumu; Komori, Kenji; Tsunematsu, Yuriko [Kumamoto Univ. (Japan)


    The new title tetradentate ligand (SPAHQS), containing both phenylazo and 8-quinolinol fragments, was prepared. Proton-dissociation processes of the ligand and complexing equilibria with Fe(II), Ni(II), Zn(II), Cd(II), and VO(IV) were analyzed spectrophotometrically. Coordination modes of SPAHQS with these metal ions have been investigated by means of polarography and Raman spectroscopy in aqueous solution. It was established that the coordination selectivity of SPAHQS for such metal ions is mainly dependent on steric factors in the chelate ring formed, not on HSAB properties. 18 refs., 6 figs., 2 tabs.

  10. Spectroscopic and thermal degradation behavior of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes with thiopental sodium anesthesia drug

    Refat, Moamen S.


    A new series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized with thiopental sodium anesthesia drug. The elemental analyses of the complexes are confined to stoichiometry of the formulas [M(TPL)3]ṡnH2O (M = Cr(III) or Fe(III); n = 6 or 5), [M(TPL)2(H2O)2]ṡnH2O (M = Mn(II), Co(II) or Ni(II); n = 0 or 4), and [M(TPL)2] (M = Cu(II) or Zn(II); n = 2 or 0) respectively, where TPL is thiopental chelating agent. Structures have been discussed and suggested upon elemental analyses, infrared, Raman, electronic, electron spin resonance, 1H NMR spectral data and magnetic studies. The X-ray powder diffraction (XRD) was performed of metal complexes. The XRD patterns indicate crystalline nature for the complexes. The measured low molar conductance values in dimethylsulfoxide indicate that the complexes are non-electrolyte nature. Spectroscopic discussion refer that coordination take place through three types: Cdbnd N (pyrimidine moiety) nitrogen and C2sbnd S (2-thiolate group) for Cr(III), Mn(II) and Fe(III), C6dbnd O (amido group) oxygen and C2sbnd S (2-thiolate group) for Co(II) and Ni(II), and Cu(II) and Zn(II) ions coordinated via Cdbnd N (pyrimidine moiety) nitrogen, C2dbnd S (2-thiolate group) and C6dbnd O (amido group) oxygen, respectively. The thermal behavior (TG/DTG/DTA) of the complexes was studied and kinetic parameters were determined by Horowitz-Metzger and Coats-Redfern methods. The thiopental and its complexes have been screened for their antimicrobial (G+ and G-) bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa) and fungi (Aspergillus flavus and Candida albicans) activities by minimum inhibitory concentration (MIC) method.

  11. Synthesis of highly luminescent Mn:ZnSe/ZnS nanocrystals in aqueous media.

    Fang, Zheng; Wu, Ping; Zhong, Xinhua; Yang, Yong-Ji


    High-quality water-dispersible Mn(2+)-doped ZnSe core/ZnS shell (Mn:ZnSe/ZnS) nanocrystals have been synthesized directly in aqueous media. Overcoating a high bandgap ZnS shell around the Mn:ZnSe cores can bring forward an efficient energy transfer from the ZnSe host nanocrystals to the dopant Mn. The quantum yields of the dopant Mn photoluminescence in the as-prepared water-soluble Mn:ZnSe/ZnS core/shell nanocrystals can be up to 35 +/- 5%. The optical features and structure of the obtained Mn:ZnSe/ZnS core/shell nanocrystals have been characterized by UV-vis, PL spectroscopy, TEM, XRD and ICP elementary analysis. The influences of various experimental variables, including the Mn concentration, the Se/Zn molar ratio as well as the kind and amount of capping ligand used in the core production and shell deposition process, on the luminescent properties of the obtained Mn:ZnSe/ZnS nanocrystals have been systematically investigated.

  12. Mechanism of Zn Insertion into Nanostructured δ-MnO 2 : A Nonaqueous Rechargeable Zn Metal Battery

    Han, Sang-Don; Kim, Soojeong; Li, Dongguo; Petkov, Valeri; Yoo, Hyun Deog; Phillips, Patrick J.; Wang, Hao; Kim, Jae Jin; More, Karren L.; Key, Baris; Klie, Robert F.; Cabana, Jordi; Stamenkovic, Vojislav R.; Fister, Timothy T.; Markovic, Nenad M.; Burrell, Anthony K.; Tepavcevic, Sanja; Vaughey, John T.


    Unlike the more established lithium-ion based energy storage chemistries, the complex intercalation chemistry of multivalent cations in a host lattice is not well understood, especially the relationship between the intercalating species solution chemistry and the prevalence and type of side reactions. Among multivalent metals, a promising model system can be based on nonaqueous Zn2+ ion chemistry. Several examples of these systems support the use of a Zn metal anode, and reversible intercalation cathodes have been reported. This study utilizes a combination of analytical tools to probe the chemistry of a nanostructured delta-MnO2 cathode in association with a nonaqueous acetonitrile-Zn(TFSI)(2) electrolyte and a Zn metal anode. As many of the issues related to understanding a multivalent battery relate to the electrolyte electrode interface, the high surface area of a nanostructured cathode provides a significant interface between the electrolyte and cathode host that maximizes the spectroscopic signal of any side reactions or minor mechanistic pathways. Numerous factors affecting capacity fade and issues associated with the second phase formation including Mn dissolution in heavily cycled Zn/delta-MnO2 cells are presented including dramatic mechanistic differences in the storage mechanism of this couple when compared to similar aqueous electrolytes are noted.

  13. Five different types of η(8)-cyclooctatetraenyl-lanthanide half-sandwich complexes from one ligand set, including a "giant neodymium wheel".

    Sroor, Farid M; Hrib, Cristian G; Liebing, Phil; Hilfert, Liane; Busse, Sabine; Edelmann, Frank T


    The lithium-cyclopropylethynylamidinates Li[c-C3H5-C[triple bond, length as m-dash]C-C(NR)2] (1a: R = (i)Pr, 1b: R = cyclohexyl (Cy)) have been used as precursors for the preparation of five new series of half-sandwich complexes. These complexes contain the large flat cyclooctatetraenyl ligand (C8H8(2-), commonly abbreviated as COT), and were isolated as solvated, unsolvated and inverse sandwich complexes. Treatment of the halide precursors [(COT)Pr(μ-Cl)(THF)2]2 with 1b and [(COT)Nd(μ-Cl)(THF)2]2 with 1a and 1b in THF in a 1 : 2 molar ratio, respectively, afforded (COT)Ln[μ-c-C3H5-C[triple bond, length as m-dash]C-C(NR)2]2Li(L) (2: Ln = Pr, R = Cy, L = Et2O; 3: Ln = Nd, R = (i)Pr, L = THF; 4: Ln = Nd, R = Cy, L = THF). Treatment of the dimeric cerium(iii) bis(cyclopropylethynylamidinate) complexes [{c-C3H5-C[triple bond, length as m-dash]C-C(NR)2}2Ce(μ-Cl)(THF)]2 (5: R = (i)Pr; 6: R = Cy) in situ with K2C8H8 in a 1 : 1 molar ratio in THF at room temperature afforded the inverse-sandwich complexes (μ-η(8):η(8)-COT)[Ce{c-C3H5-C[triple bond, length as m-dash]C-C(NR)2}2]2 (7: R = (i)Pr; 8: R = Cy). This reaction represents a new method for encapsulation of a planar (C8H8)(2-) ring in lanthanide complexes containing amidinate ligands in the outer decks. Novel unsolvated dinuclear lanthanide half-sandwich complexes were prepared by using the precursors 1a, 1b and COT(2-). Unlike the complexes 2-4, the reaction of [(COT)Pr(μ-Cl)(THF)2]2 with 1a afforded the unsolvated centrosymmetric complex [(COT)Pr(μ-c-C3H5-C[triple bond, length as m-dash]C-C(N(i)Pr)2)]2 (9). These dimeric structures could be also accessed by reaction of LnCl3 (Ln = Ce or Nd) with 1a or 1b and K2COT in a 1 : 1 : 1 molar ratio as a one-pot reaction to give novel [(COT)Ln(μ-c-C3H5-C[triple bond, length as m-dash]C-C(NR)2)]2 complexes (10: Ln = Ce, R = (i)Pr; 11: Ln = Ce, R = Cy; 12: Ln = Nd, R = (i)Pr). Similar treatment of HoCl3 with 1a or 1b and K2COT as three

  14. DFT vibrational assignments, in vitro antifungal activity, genotoxic and acute toxicity determinations of the [Zn(phen)2(cnge)(H2O)](NO3)2·H2O complex

    Martínez Medina, Juan J.; Torres, Carola A.; Alegre, Walter S.; Franca, Carlos A.; López Tévez, Libertad L.; Ferrer, Evelina G.; Okulik, Nora B.; Williams, Patricia A. M.


    Calculations based on density functional methods were carried out for the [Zn(phen)2(cnge)(H2O)](NO3)2·H2O complex taking into account the presence of two different conformers for the cyanoguanidine ligand. The calculated geometrical parameters and the vibrational IR and Raman spectra were in agreement with the experimental data. On the other hand, the activities of the complex, the ligands and the metal against fungal strains have been measured. The complexation increased the antifungal activity of the metal and the ligand cyanoguanidine, and slightly decreased the antifungal activity of the ligand 1,10-phenanthroline against Candida albicans, C. albicans ATCC 10231 and Candida krusei (not against the others strains of Candida). The ligand 1,10-phenanthroline and the zinc complex showed in some cases higher activity than the common antifungal drug fluconazole. The complexation also increased the post-antifungal effect in the tested strains, except for Candida parapsilosis, even with a better efficiency than those of some conventional antifungal agents. Antifungal studies were coupled with safety evaluations using the Artemia salina and the Ames tests. The zinc complex behaved as a non-mutagenic and non-toxic compound at the tested concentrations. Moreover, the zinc complex could be safer than the ligand when used as an antifungal agent. Therefore, the interaction of zinc(II) with N-containing ligands may provide a promising strategy for the development of novel and more secure drugs with antifungal activity.

  15. Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II, Cd(II, and Hg(II Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

    Morteza Montazerozohori


    Full Text Available Synthesis of zinc(II/cadmium(II/mercury(II thiocyanate and azide complexes of a new bidentate Schiff-base ligand (L with general formula of MLX2 (M = Zn(II, Cd(II, and Hg(II in ethanol solution at room temperature is reported. The ligand and metal complexes were characterized by using ultraviolet-visible (UV-visible, Fourier transform infrared (FT-IR, 1H- and 13C-NMR spectroscopy and physical characterization, CHN analysis, and molar conductivity. 1H- and 13C-NMR spectra have been studied in DMSO-d6. The reasonable shifts of FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm well coordination of Schiff-base ligand and anions in an inner sphere coordination space. The conductivity measurements as well as spectral data indicated that the complexes are nonelectrolyte. Theoretical optimization on the structure of ligand and its complexes was performed at the Becke’s three-parameter hybrid functional (B3 with the nonlocal correlation of Lee-Yang-Parr (LYP level of theory with double-zeta valence (LANL2DZ basis set using GAUSSIAN 03 suite of program, and then some theoretical structural parameters such as bond lengths, bond angles, and torsion angles were obtained. Finally, electrochemical behavior of ligand and its complexes was investigated. Cyclic voltammograms of metal complexes showed considerable changes with respect to free ligand.

  16. Mono and binuclear Ag(I), Cu(II), Zn(II) and Hg(II) complexes of a new azo-azomethine as ligand: synthesis, potentiometric, spectral and thermal studies.

    Ahmed, Ibrahim S; Moustafa, Moustafa M; Abd El Aziz, Mohamed M


    New azo-azomethine dyes were prepared by reaction of p-aminobenzoic acid, o-anisidine, o-nitroaniline, and p-bromoaniline with salicylaldehyde respectively to form azo compounds and then condensation by urea to form 4-(R-arylazo 2-salicylaldene)-urea azo-azomethine derivatives (I(a-d)). The complexes of these ligands with Ag(I), Cu(II), Zn(II) and Hg(II) metal ions were prepared. The structure of the free ligands and their complexes were characterized by using elemental analysis (C, H, N), (1)H NMR, IR and UV-Vis-spectra. The proton dissociation constants of the ligands and the stability constant of their complexes have been determined potentiometrically in 40% (v/v) alcohol-water medium as well as the stoichiometry of complexes were determined conductometrically. The data reveal that the stoichiometries for all complexes were prepared in molar ratios (1:1) and (1:2) (M:L). The electrolytic and nonelectrolytic natures of the complexes were assigned based on molar conductance measurements. The thermogravimetric (TG), and differential thermal analyses (DTA) were studied in nitrogen atmosphere with heating rate 10°C/min. The kinetic and thermodynamic parameters for thermal decomposition of complexes have been calculated by graphical method using Coats-Redfern (CR) method.

  17. Thermodynamic study of complex formation between 3,5-di iodo-hydroxy quinoline and Zn2+, Ni2+ and Co2+ cations in some binary solvents using a conductometric method

    A. Nezhadali


    Full Text Available The complexation reactions between 3,5-di iodo-8-hydroxy quinoline (IQN and Zn2+, Ni2+ and Co2+ were studied in dimethylformamide (DMF-ethanol (EtOH binary solvent systems at different temperatures using a conductometric method. The stoichiometry of complexes was established 1:1. It was found that the stability of complexes formed between cations and this ligand increases with increases temperature. The standard enthalpies and standard entropies of complexes were obtained from the temperature dependence of stability constants. The results obtained by conductometric technique show that there is an inverse relationship between the formation constants of complexes and donor number of solvents. In all cases, the formation constants increased with increasing amounts of EtOH versus DMF in these binary systems. The standard enthalpy and standard entropies of complexes were obtained from the temperature dependence of stability constant. In all cases, ΔH° was positive and ΔS° was negative. The selectivity order for IQN complexes among various neat studied solvents varies in the order: Zn–IQN2+› Ni–IQN2+›Co–IQN2+.

  18. Co-sequestration of Zn(II) and phosphate by γ-Al{sub 2}O{sub 3}: From macroscopic to microscopic investigation

    Ren, Xuemei [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031, Hefei (China); Tan, Xiaoli [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031, Hefei (China); Hayat, Tasawar [Department of Mathematics, Quaid-I-Azam University, Islamabad 44000 (Pakistan); NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alsaedi, Ahmed [NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Wang, Xiangke, E-mail: [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions (China)


    Highlights: • How the Zn and phosphate behave in each other’s presence is elucidated. • Surface speciation of Zn(II) is affected by the presence of phosphate. • Combining macroscopic study with EXAFS can determine the Zn(II) surface speciation. • The enhanced Zn(II) sorption is mainly due to ternary surface complexation at 0.19 mmol P/L and pH 6.5. • Phosphate ions prevent the formation of an Zn–Al LDH phase at pH 8.0. - Abstract: Little information is available concerning co-sorbing oxyanion and metal contaminants in the environment, yet in most metal-contaminated areas, co-contamination by phosphate is common. In this study, the mutual effects of phosphate and Zn(II) on their interaction with γ-Al{sub 2}O{sub 3} are investigated by batch experiments and X-ray absorption fine structure spectroscopy (XAFS) technique. The results show that the co-sorption of phosphate on γ-Al{sub 2}O{sub 3} modifies both the extent of Zn(II) sorption and the local atomic structures of sorbed Zn(II) ions. Multiple mechanisms are involved in Zn(II) retention in the presence of phosphate, including electrostatic interaction, binary and ternary surface complexation, and the formation of Zn(II)-phosphate polynuclear complexes. At pH 6.5, type III ternary surface complexation occurs concurrently with binary Zn-alumina surface complexation at low phosphate concentrations, whereas the formation of type III ternary surface complexes is promoted as the phosphate concentration increases. With further increasing phosphate concentration, Zn(II)-phosphate polynuclear complexes are formed. At pH 8.0, Zn dominantly forms type III ternary surface complexes in the presence of phosphate. The results of this study indicate the variability of Zn complexation on oxide surface and the importance of combining macroscopic observations with XAFS capable of determining metal complex formation mechanism for ternary system.

  19. Synthesis and photodynamic activity of unsymmetrical A3B tetraarylporphyrins functionalized with l-glutamate and their Zn(II) and Cu(II) metal complex derivatives.

    Arredondo-Espinoza, Eder U; López-Cortina, Susana T; Ramírez-Cabrera, Mónica A; Balderas-Rentería, Isaías


    Four novel unsymmetrical A3B porphyrins 1, 2, 3 and 4 were synthesized following Lindsey procedure. Porphyrins 3 and 4 include one and three l-glutamate groups, respectively, and all porphyrins were metallated with Zn(II) (1a-4a) or Cu(II) (1b-4b). Porphyrins and metalloporphyrins presented values of singlet oxygen quantum yields (ΦD) ranging from 0.21 to 0.67. The tetraaryl derivatives in this study showed phototoxicity in SiHa cells with IC50 values ranging from IC50 value. Comparing the phototoxic activity between all porphyrins, functionalization of porphyrins with glutamate increased 100 times phototoxic activity (1 (IC50 4.81±0.34μM) vs. 3 (IC50 0.04±0.02μM) and 2 (IC50 5.19±0.42μM) vs. 4 (IC50 0.05±0.01μM)). This increased activity could be attributed to reduced hydrophobicity and increased ΦΔ, given by functionalization with l-glutamate. Metalloporphyrins 3a (IC50 0.04±0.01μM) and 4a (IC50<0.01μM) presented the best values ​​of phototoxic activity. Therefore, functionalization and zinc metalation increased the phototoxic activity. SiHa cells treated with porphyrins 3, 4, 3a and 4a at a final concentration of 10μM, showed increased activity of caspase-3 enzyme compared to the negative control; indicating the induction of apoptosis. Differential gene expression pattern in SiHa cells was determined; treatments with metalloporphyrins 4a and 4b were performed, respectively, comparing the expression with untreated control. Treatments in both cases showed similar gene expression pattern in upregulated genes, since they share about 25 biological pathways and a large number of genes. According to the new photophysical properties related to the structural improvement and phototoxic activity, these molecules may have the potential application as photosensitizers in the photodynamic therapy.

  20. Hydrothermal Synthesis, Crystal Structure and Fluorescence Properties of a Three-dimensional Triply-bridged Binuclear Zinc(Ⅱ) Complex [Zn2(Mba)3(Phen)2EtOH)]·ClO4%Hydrothermal Synthesis, Crystal Structure and Fluorescence Properties of a Three-dimensional Triply-bridged Binuclear Zinc(Ⅱ) Complex [Zn2(Mba)3(Phen)2EtOH)]·ClO4

    CHEN Zhi-Min; FENG Yong-Lan; YANG Ying-Qun; LI Wei; Zheng-Ji; CHEN Man-Sheng


    The novel complex [Zn2(Mba)3(Phen)2EtOH)]·ClO4 (Hrnba = methoxybenzoic acid, Phen = 1,10-phenanthroline, EtOH = ethanol) was synthesized by hydrothermal reactions, and its structure was determined by X-ray diffraction. The crystal belongs to the triclinic system, space group Pi with a = 1.15362(1), b = 1.3655(3), c = 1.61451(1) nm, α= 72.842(2), β = 83.259(3), y = 72.083(2)°, V = 2.3112(6) nm3, Z = 2,μ(MoKa) = 11.71 cm-1, F(000) = 1120, R = 0.0552 and wR = 0.1157 (I 〉 2σ(I)). The two centric zinc(H) ions in the complex locate in a distorted octahedral coordination geometry and a distorted trigonal bipyramid coordination geometry, respectively. Two bridging bidentate carboxyl groups and a μ2-O carboxyl group from three methoxybenzoic acids act as the bridge to link two Zn(Ⅱ) ions. The asymmetric units are connected by π-π packing interactions between aromatic rings to form a three-dimensional supramolecular network. The experimental results show a good fluorescence property for the complex.

  1. Hydrogen motion in ZnO

    Lavrov, E.V. [Technische Universitaet Dresden, 01062 Dresden (Germany)], E-mail:; Boerrnert, F.; Weber, J. [Technische Universitaet Dresden, 01062 Dresden (Germany)


    The motion of hydrogen in a variety of complexes in ZnO is studied by stress-induced dichroism. The defects investigated are Cu-H and Cu-H{sub 2}, the Zn vacancy passivated by two hydrogen atoms, and a complex resulting in an IR absorption line at 3326cm{sup -1}. The hydrogen movement in these complexes is related to the hydrogen diffusion in ZnO. In addition a new microscopic model for the 3326 cm{sup -1}line is proposed.

  2. The Recombinant Bacteriophage Endolysin HY-133 Exhibits In Vitro Activity against Different African Clonal Lineages of the Staphylococcus aureus Complex, Including Staphylococcus schweitzeri

    Idelevich, Evgeny A.; Schaumburg, Frieder; Knaack, Dennis; Scherzinger, Anna S.; Mutter, Wolfgang; Peters, Georg; Peschel, Andreas


    HY-133 is a recombinant bacteriophage endolysin with bactericidal activity against Staphylococcus aureus. Here, HY-133 showed in vitro activity against major African methicillin-susceptible and methicillin-resistant S. aureus lineages and ceftaroline/ceftobiprole- and borderline oxacillin-resistant isolates. HY-133 was also active against Staphylococcus schweitzeri, a recently described species of the S. aureus complex. The activity of HY-133 on the tested isolates (MIC50, 0.25 μg/ml; MIC90, 0.5 μg/ml; range, 0.125 to 0.5 μg/ml) was independent of the species and strain background or antibiotic resistance. PMID:26833148

  3. ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells

    Bhattacharya, Raghu N.


    The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

  4. A trimetallic strategy towards ZnDyCr and ZnDyCo single-ion magnets.

    Hu, Kong-Qiu; Jiang, Xiang; Wu, Shu-Qi; Liu, Cai-Ming; Cui, Ai-Li; Kou, Hui-Zhong


    Two cyano- and phenoxo-bridged octanuclear complexes ZnDyCo (complex ) and ZnDyCr (complex ) with diamagnetic Zn(ii) and Co(iii) are reported. Dy(iii) is surrounded by nine oxygen atoms of two [Zn(Me2valpn)] (Me2valpn(2-) = dianion of N,N'-2,2-dimethylpropylenebis(3-methoxysalicylideneimine)) and one water molecule. Magnetic studies reveal that both exhibit single-ion magnet (SIM) behavior with the energy barrier of 85.9 K for complex and 100.9 K for complex .

  5. The use of imidazolium ionic liquid/copper complex as novel and green catalyst for chemiluminescent detection of folic acid by Mn-doped ZnS nanocrystals

    Azizi, Seyed Naser; Shakeri, Parmis; Chaichi, Mohammad Javad; Bekhradnia, Ahmadreza; Taghavi, Mehdi; Ghaemy, Mousa


    A novel chemiluminescence (CL) method using water-soluble Mn-doped ZnS quantum dots (QDs) as CL emitter is proposed for the chemiluminometric determination of folic acid in pharmaceutical formulation. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs induced by directly chemical oxidation and its ionic liquid-sensitized effect in aqueous solution were then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic conditions. In the presence of 1,3-dipropylimidazolium bromide/copper a drastic light emission enhancement is observed, related to a strong interaction between Cu2+ and the imidazolium ring. Therefore, a new CL analysis system was developed for the determination of folic acid. Under the optimum conditions, there is a good linear relationship between the relative CL intensity and the concentration of folic acid in the range of 1 × 10-9-1 × 10-6 M of folic acid with a correlation coefficient (R2) of 0.9991. The limit of detection of this system was found to be 1 × 10-10 M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.

  6. 六元扩展卟啉的Zn2+,Cd2+,Hg2+单金属配合物的光电性质的理论研究%Theoretical investingation on electronic transition of [26]hexaphyrin ( and their Zn2+ ,Cd2+and Hg2+ mono-metal complexes

    高影; 韩育志; 赵利维; 林美玉; 孙刚


    The electronic absorption spectra of Zn2+,Cd2+ and Hg2+ mono-metal complexes of [26] hexaphyrind. were systematically investigated using the localized density matrix (LDM) method and time-dependent density functional theory (TD-DFT). The results show that complexes are more co-planarity when HP coordinates with Zn2+ ,Cd2+ and Hg2+ ions. The absorption characteristics represent weak Q-like bands. In addition , the introduction of group 12 transition metals ( E ) leads to red shifts by adding central metal atomic number. The absorption characteristics of strong B-like bands exhibit ligand-to-metal charge transfer characteristics due to contributions from phenyl rings in the meso-carbons. The LDM method is a reliable approach for determining the electronic transition properties of the complexes and substantially reduces the computational cost.%通过定域密度矩阵方法和含时密度泛函方法研究了六元扩展卟啉及其Zn,Cd和Hg单金属配合物的光电性质.通过计算得到扩展卟啉HP同金属Zn2+,Cd2+和Hg2+发生配位时,分子趋于平面化.配合物在Q带有弱得吸收峰,它们随着中心金属的原子序数的增加产生了红移.在B带有强吸收峰,其特征峰主要来自于中心金属离子的d轨道和同金属配位的C原子所处的吡咯环以及吡咯环两侧的meso-C原子上的苯基的参与.对于扩展卟啉极其配合物,定域密度矩阵方法也可以很好的预测光谱和电子跃迁性质.

  7. Mechanism of propylene oxide polymerization on Zn/Co double metal cyanide complex catalyst%锌/钴双金属氰化络合物催化环氧丙烷聚合机理

    刘晓华; 亢茂青; 王心葵


    The characteristic of polymerization of propylene oxide on double metal cyanide(DMC)complex catalyst using diethyl glycol diethyl ether as organic complex and the local structures of Zn and Co ions in the process of propylene oxide polymerization were investigated. The results showed that the polymerization of propylene oxide catalyzed by DMC catalyst was a kind of living polymerization system. The coordination number of Zn and O increased from 3.0 to 5.7 in the process of DMC catalyst activation and in propylene oxide polymerization five 0 atoms coordinated Zn ion could be the real active center in the process of propylene oxide polymerization.%用以二乙二醇二乙醚为有机配体的锌/钴双金属氰化络合物进行了环氧丙烷的聚合,并用扩展X射线精细结构分析方法研究了催化剂激活和环氧丙烷聚合过程中锌离子和钴离子的区域结构变化。结果表明,锌/钴双金属氰化络合物催化环氧丙烷的聚合是一个活性聚合体系。在环氧丙烷聚合过程中锌离子由与3.0个氧原子配位转变为与5.7个氧原子配位,表明聚合活性中心为5.0个氧原子配位的螯合锌离子。

  8. High precision γ spectroscopy of 69,71Zn from (n, γ reactions using EXILL

    Bączyk P.


    Full Text Available Measurement of γ radiation following slow neutron capture on 68Zn and 70Zn using very efficient germanium array EXILL was done at Institute Laue-Langevin in Grenoble. New spectroscopic information for 69Zn (including doorway state and first results for 71Zn (accurate energy of β decaying isomer were obtained. Binding energies for 68Zn, 69Zn and 71Zn were determined with 5-to-70 times higher accuracy than presented in the literature.

  9. New water-soluble copper (II) complexes including 4,7-dimethyl-1,10-phenanthroline and L-tyrosine: synthesis, characterization, DNA interactions and cytotoxicities.

    İnci, Duygu; Aydın, Rahmiye; Yılmaz, Dilek; Gençkal, Hasene Mutlu; Vatan, Özgür; Çinkılıç, Nilüfer; Zorlu, Yunus


    Two new water-soluble copper(II) complexes, [Cu(dmphen)2(NO3)]NO3 (1), [Cu(dmphen)(tyr)(H2O)]NO3·H2O (2) and the diquarternary salt of dmphen (dmphen = 4,7-dimethyl-1,10-phenanthroline and tyr = L-tyrosine), have been synthesized and characterized by elemental analysis, (1)H NMR, (13)C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by absorption, emission spectroscopy and thermal denaturation measurements. The supercoiled pBR322 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by the XTT method. Complexes 1 and 2 exhibit significant cytotoxicity, with lower IC50 values than those of cisplatin.

  10. A new organic-inorganic coordination complex material (C2H5-C6H4-NH2)2ZnBr2: Growth and structural properties

    Harmouzi, Asmaa; Daro, Nathalie; Guionneau, Philippe; Belaaraj, Abdesselam; Khechoubi, El Mostafa


    Single crystals of an organic-inorganic hybrid (C2H5-C6H4-NH2)2ZnBr2 have been grown by the slow-diffusion method and characterized by Single-Crystal X-Ray Diffraction (SC-XRD) at 295 K. This compound crystallizes in the monoclinic system, with the space group C2/c and the following cell parameters: a = 32.336 (3) Å, b = 4.8539 (4) Å, c = 12.2334 (9) Å, β = 97.019 (5)°, V = 1905.7(3) Å3 and Z‧ = 4. The crystal packing is based on well-ordered alternating ZnBr2 inorganic layers and C2H5-C6H4-NH2 organic layers. The crystal structure has been analyzed and discussed in terms of molecular geometry as well as intra and intermolecular interactions. Comparisons with some homologues materials of general formula (R-NH2)2ZnX2 (X = Cl, Br), (R = C2H5-C6H4, C6H5) are also done.

  11. Electrochemical, linear optical, and nonlinear optical properties and interpretation by density functional theory calculations of (4-N,N-dimethylaminostyryl)-pyridinium pendant group associated with polypyridinic ligands and respective multifunctional metal complexes (Ru(II) or Zn(II)).

    Dumur, Frédéric; Mayer, Cédric R; Hoang-Thi, Khuyen; Ledoux-Rak, Isabelle; Miomandre, Fabien; Clavier, Gilles; Dumas, Eddy; Méallet-Renault, Rachel; Frigoli, Michel; Zyss, Joseph; Sécheresse, Francis


    The synthesis, linear optical and nonlinear optical properties, as well as the electrochemical behavior of a series of pro-ligands containing the 4-(4-N,N-dimethylaminostyryl)-1-methyl pyridinium (DASP(+)) group as a push-pull moiety covalently linked to terpyridine or bipyridine as chelating ligands are reported in this full paper. The corresponding multifunctional Ru(II) and Zn(II) complexes were prepared and investigated. The structural, electronic, and optical properties of the pro-ligands and the ruthenium complexes were investigated using density functional theory (DFT) and time-dependent (TD) DFT calculations. A fairly good agreement was observed between the experimental and the calculated electronic spectra of the pro-ligands and their corresponding ruthenium complexes. A quenching of luminescence was evidenced in all ruthenium complexes compared with the free pro-ligands but even the terpyridine-functionalized metal complexes exhibited detectable luminescence at room temperature. Second order nonlinear optical (NLO) measurements were performed by Harmonic Light Scattering and the contribution of the DASP(+) moieties (and their relative ordering) and the metal-polypyridyl core need to be considered to explain the nonlinear optical properties of the metal complexes.

  12. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites

    Hao Zhang; Yuan Cen; Yu Du; Shuangchen Ruan


    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO3)2·6H2O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significant...

  13. 采用谐振腔微扰法的NiZn铁氧体介电常数测量%Measurement of complex permittivity of NiZn-ferrite by resonant cavity perturbation method

    王翠平; 叶柳; 李爱侠; 张子云; 刘晨; 张利飞


    The cavity perturbation technique has been widely used for microwave dielectric properties measurements. It has the great advantages of convenient experimental measurement, small sample dimension, and simple computation formulas. It has a good application value in approximate calculation frequency and the quality factor of resonant cavity, material dielectric constant. The complex permittivity within microwave frequency band of NiZn ferrite was measured by resonator cavity perturbation method. The imaginary part e" and the real part e' of the dielectric constant were obtained, and the effects of content of Ni and Zn on complex permittivity were analyzed.%谐振腔微扰法广泛用于材料微波介电性能的测量,它与常规的测量方法相比,具有样品尺寸小、计算公式简单的优点,在近似计算频率、谐振腔品质因数、材料的介电常数等方面具有较高的应用价值.采用谐振腔微扰法,测量不同配方NiZn铁氧体在微波频段的复介电常数,计算得到介电常数的虚部ε″和实部ε′,进而分析Ni和Zn的含量对NiZn铁氧体材料介电常数的影响.

  14. A Comparison of ZnO and ZnO(-)

    Bauschlicher, Charles W., Jr.; Partridge, Harry; Arnold, James (Technical Monitor)


    Ab initio electronic structure calculations are performed to support and to help interpret the experimental work reported in the proceeding manuscript. The CCSD(T) approach, in conjunction with a large basis set, is used to compute spectroscopic constants for the X(exp 1)Epsilon(+) and (3)II states of ZnO and the X(exp 2)Epsilon(+) state of ZnO(-). The spectroscopic constants, including the electron affinity, are in good agreement with experiment. The ZnO EA is significantly larger than that of O, thus relative to the atomic ground state asymptotes, ZnO(-) has a larger D(sub o) than the (1)Epsilon(+) state, despite the fact that the extra electron goes into an antibonding orbital. The changes in spectroscopic constants can be understood in terms of the X(exp 1)Epsilon(+) formally dissociating to Zn (1)S + O (1)D while the (3)II and (2)Epsilon(+) states dissociate to Zn (1)S + O (3)P and Zn (1) and O(-) (2)P, respectively.


    R.Shakru, N.J.P.Subhashini, Acharyanagarjuna,Shivaraj


    Full Text Available The Schiff base ligands L1 4-allyl-2-{[(5'-methyl-3'-isoxazolylimino]methyl}phenol [AMIIMP] and L2 N-[5'-methyl-3'-isoxazolyl]-[(EPyridine]methylidine]amine[MIPMA] have been synthesized by the condensation of 4-allyl 2- hydroxyl 1-benzaldehyde and Pyridine 3- carboxaldehyde with 3- amino 5-methy isoxazole. The metal chelates of L1 and L2 with Cobalt (II, Nickel (II, Copper (II and Zn (II metal ions have been synthesised and characterized on the basis of elemental analysis, IR, 1H- NMR, Mass, Electronic spectra and magnetic moment studies. From these studies it is found that ligands act as bivalent chelating agents coordinating through oxygen and nitrogen donor atoms in the case of AMIIMP, and pyridine nitrogen and imino nitrogen donar atoms of in the case of MIPMA. The chelates of Co (II, Ni (II and Zn (II appear to be octahedral geometry and Cu (II appears to be tetragonal geometry. Antimicrobial activity of the ligands and their metal complexes against bacteria (Bacillus, Pseudomonas and fungus (R. Solani, A. Niger has been carried out. It is found that the metal complexes have higher activities than those of free ligands.

  16. Localization of eight additional genes in the human major histocompatibility complex, including the gene encoding the casein kinase II {beta} subunit (CSNK2B)

    Albertella, M.R.; Jones, H.; Thomson, W. [Oxford Univ. (United Kingdom)] [and others


    A wide range of autoimmune and other diseases are known to be associated with the major histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility antigens in the class I and class II regions, but some appear to be more strongly associated with genes in the central 1100-kb class III region, making it important to characterize this region fully for the presence of novel genes. An {approximately}220-kb segment of DNA in the class III region separating the Hsp70 (HSPA1L) and BAT1 (D6S8IE) genes, which was previously known to contain 14 genes. Genomic DNA fragments spanning the gaps between the known genes were used as probes to isolate cDNAs corresponding to five new genes within this region. Evidence from Northern blot analysis and exon trapping experiments that suggested the presence of at least two more new genes was also obtained. Partial cDNA and complete exonic genomic sequencing of one of the new genes has identified it as the casein kinase II{beta} subunit (CSNK2B). Two of the other novel genes lie within a region syntenic to that implicated in susceptibility to experimental allergic orchitis in the mouse, an autoimmune disease of the testis, and represent additional candidates for the Orch-1 locus associated with this disease. In addition, characterization of the 13-kb intergenic gap separating the RD (D6545) and G11 (D6S60E) genes has revealed the presence of a gene encoding a 1246-amino-acid polypeptide that shows significant sequence similarity to the yeast anti-viral Ski2p gene product. 49 refs., 8 figs.

  17. An unexpected ethyl transfer reaction between Et2Zn anddo(t-butyl)glyoxaldiimine (t-BuDAB).Studies of thepersistent [EtZn(t-BuDAB)] radical which is in equilibrium with its C-C coupled dimer

    Koten, G. van; Jastrzebski, J.T.B.H.; Klerks, J.M.; Vrieze, K.


    Whereas p-Tol{2}Zn reacts with t-BuN@?CHCH@?N-t-Bu (t-BuDAB) to give a stable 11 complex [p-Tol{2}Zn(t-BuDAB)], Et{2}Zn gives EtZnN(Et)(t-Bu)CH@?CHN-(t-Bu) via intramolecular ethyl transfer in the unstable Et{2}Zn(t-BuDAB) complex. In solution the stable persistent organozinc radical EtZn(t-BuDAB),

  18. Hydrothermal Synthesis and Crystal Structure of Zinc(Ⅱ) Dinicotinate Complex [Zn(nic)2(H2O)4](nic=nicotinic acid):A Three-dimensional Hydrogen-bond Network

    MAO Hong-yan; ZHANG Zong-pei; ZHANG Hong-yun; XU Chen; WANG En-bo; WU Qing-an; ZHU Yu


    @@ Introduction Nicotinic acid and its transition-metal comple-xes have become increasingly important due to their potential applications as cosmetics or medicines with antitumor, antibacterial and antifungal activities, and the activity in the maintenance of normal glucose metabolism[1-3], etc. A major research effort has been made to generate such materials and to study their biological activity[4-9]. But few of the previous works have directed towards the structure investigation of these metal complexes[6-9]. So, in this report we aim at testing the effect of hydrothermal synthesis on the formation of the crystal structures of crystalline [Zn(nic)2(H2O)4 ](nic=nicotinic acid).

  19. Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

    M. Padma Latha


    Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

  20. FT-IR, micro-Raman and UV-vis spectroscopic and quantum chemical investigations of free 2,2'-dithiodipyridine and its metal (Co, Cu and Zn) halide complexes.

    Gökce, Halil; Bahçeli, Semiha


    In this study the elemental analysis results, molecular geometries, vibrational and electronic absorption spectra of free 2,2'-dithiodipyridine(C10H8N2S2), (or DTDP) (with synonym, 2,2'-dipyridyl disulfide) and M(C10H8N2S2)Cl2 (M=Co, Cu and Zn) complexes have been reported. Vibrational wavenumbers of free DTDP and its metal halide complexes have been calculated by using DFT/B3LYP calculation method with 6-31++G(d,p) and Lanl2DZ basis sets, respectively, in the ground state, for the first time. The calculated fundamental vibrational frequencies are in a good agreement with experimental data. The HOMO, LUMO and MEP analyses of all compounds are performed by DFT method.

  1. An atypical human induced pluripotent stem cell line with a complex, stable, and balanced genomic rearrangement including a large de novo 1q uniparental disomy.

    Steichen, Clara; Maluenda, Jérôme; Tosca, Lucie; Luce, Eléanor; Pineau, Dominique; Dianat, Noushin; Hannoun, Zara; Tachdjian, Gérard; Melki, Judith; Dubart-Kupperschmitt, Anne


    Human induced pluripotent stem cells (hiPSCs) hold great promise for cell therapy through their use as vital tools for regenerative and personalized medicine. However, the genomic integrity of hiPSCs still raises some concern and is one of the barriers limiting their use in clinical applications. Numerous articles have reported the occurrence of aneuploidies, copy number variations, or single point mutations in hiPSCs, and nonintegrative reprogramming strategies have been developed to minimize the impact of the reprogramming process on the hiPSC genome. Here, we report the characterization of an hiPSC line generated by daily transfections of modified messenger RNAs, displaying several genomic abnormalities. Karyotype analysis showed a complex genomic rearrangement, which remained stable during long-term culture. Fluorescent in situ hybridization analyses were performed on the hiPSC line showing that this karyotype is balanced. Interestingly, single-nucleotide polymorphism analysis revealed the presence of a large 1q region of uniparental disomy (UPD), demonstrating for the first time that UPD can occur in a noncompensatory context during nonintegrative reprogramming of normal fibroblasts.

  2. The Mouse-colored Tyrannulet (Phaeomyias murina) is a species complex that includes the Cocos Flycatcher (Nesotriccus ridgwayi), an island form that underwent a population bottleneck.

    Zucker, Marc R; Harvey, Michael G; Oswald, Jessica A; Cuervo, Andrés; Derryberry, Elizabeth; Brumfield, Robb T


    Simultaneous examination of evolutionary history in island forms and closely related mainland relatives can provide reciprocal insight into the evolution of island and mainland faunas. The Cocos Flycatcher (Nesotriccus ridgwayi) is a small tyrant flycatcher (Tyrannidae) endemic to Cocos Island, an oceanic island in the eastern Pacific Ocean. We first established its close relationship to the mainland species Mouse-colored Tyrannulet (Phaeomyias murina) using a phylogeny from genome-wide ultraconserved elements and exons. We then used mitochondrial DNA to explore the relationships between Nesotriccus and Phaeomyias populations from across its distribution in Central and South America. We found that Nesotriccus is nested within the Phaeomyias evolutionary tree, and that Phaeomyias represents a complex of at least four evolutionarily distinct species that differ in plumage, voice, and habitat association. Nesotriccus underwent a population bottleneck subsequent to its divergence from Central American and northern South American Phaeomyias populations in the middle Pleistocene. The 46 UCE loci containing alleles that are fixed between the two species are widely distributed across the genome, which suggests that selective or neutral processes responsible for divergence have occurred genome-wide. Overall, our simultaneous examination of Phaeomyias and Nesotriccus revealed divergent levels of genetic diversity and evolutionary histories between island and mainland forms.

  3. DNA barcode identification of lichen-forming fungal species in the Rhizoplaca melanophthalma species-complex (Lecanorales, Lecanoraceae, including five new species

    Steven Leavitt


    Full Text Available Recent studies using sequence data from multiple loci and coalescent-based species delimitation have revealed several species-level lineages within the phenotypically circumscribed taxon Rhizoplaca melanophthalma sensu lato. Here, we formally describe five new species within this group, R. occulta, R. parilis, R. polymorpha, R. porterii, and R. shushanii, using support from the coalescent-based species delimitation method implemented in the program Bayesian Phylogenetics and Phylogeography (BPP as the diagnostic feature distinguishing new species. We provide a reference DNA sequence database using the ITS marker as a DNA barcode for identifying species within this complex. We also assessed intraspecific genetic distances within the six R. melanophthalma sensu lato species. While intraspecific genetic distances within the five new species were less than or equal to the lowest interspecific pairwise comparison values, an overlap in genetic distances within the R. melanophthalma sensu stricto clade suggests the potential for additional phenotypically cryptic lineages within this broadly distributed lineage. Overall, our results demonstrate the potential for accurately identifying species within the R. melanophthalma group by using molecular-based identification methods.

  4. 低温配位-沉淀法合成疏水ZnO及提高泡沫稳定性的应用%Hydrophobic ZnO: Low Temperature Complex-Precipitate Synthesis and Application in Improving Foam Stability

    顾少楠; 李文军; 罗文利; 常志东; 周花蕾



  5. A long-term, complex, unitary appraisal regarding neurorestorative, including neurorehabilitative, outcomes in patients treated with Cerebrolysin®, following traumatic brain injury

    Daia CO


    Full Text Available Cristina O Daia,1,2 Monica Haras,1,2 Tiberiu Spircu,1 Aurelian Anghelescu,1,2 Liliana Onose,3 Alexandru Vlad Ciurea,1,2 Anca Sanda Mihaescu,2 Gelu Onose1,21Carol Davila University of Medicine and Pharmacy, Bucharest, Romania; 2Bagdasar-Arseni Teaching Emergency Hospital, Bucharest, Romania; 3Metrorex – The Medical Service, Bucharest, RomaniaBackground: Neuroprotection is a modern therapeutic concept that has some useful outcomes discussed in the literature, including for traumatic brain injury (TBI.Scope and study design: This was a retrospective case-control study that was approved by the bioethics commission of the Bagdasar-Arseni Teaching Emergency Hospital, Bucharest, Romania. The aim of the study was to comparatively assess neurorestorative, including neurorehabilitative, outcomes obtained with or without Cerebrolysin®.Materials and methods: Nineteen cases treated with Cerebrolysin versus 28 who did not receive this drug were included in this study. All cases had a subacute or post-acute status after TBI and were hospitalized (only at their first admission between January 2005 and December 2010 in the hospital's NeuroRehabilitation Clinic Division. Epidemiological, clinical, paraclinical, and functional parameters were evaluated, using the: Functional Independence Measure (FIMTM, Glasgow Outcome Score (GOS, and Modified Rankin Scale.Results: Patients in the Cerebrolysin group had, on average, higher (although not statistically significant FIM evolution values (36.53 than the control group (29.64 (P=0.174, 95% confidence interval: -8.0 to 21.8. The effect size assessed on the GOS was 2.1%. Additionally, the mean FIM value at admission of the Cerebrolysin group (45.79 was lower than that of controls (61.50; P=0.076.Discussion and conclusion: The clinical/functional evolution, comparatively evaluated in the studied inpatients, and taking into account the small sample and effect sizes – including for GOS – suggest that Cerebrolysin

  6. Green emission in carbon doped ZnO films

    L. T. Tseng


    Full Text Available The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60–100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR and low temperature photoluminescence (PL measurement.

  7. Green emission in carbon doped ZnO films

    Tseng, L. T.; Yi, J. B., E-mail:; Zhang, X. Y.; Xing, G. Z.; Luo, X.; Li, S. [School of Materials Science and Engineering, University of New South Wales, Kensington, NSW, 2052 (Australia); Fan, H. M. [School of Chemical Engineering, Northwest University, Xi' an 710069 (China); Herng, T. S.; Ding, J. [Department of Materials Science and Engineering, National University of Singapore, 119260 (Singapore); Ionescu, M. [Australian Nuclear Science and Technology Organization, (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234 (Australia)


    The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60–100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.

  8. Mn(II), Co(II), Zn(II), Fe(III) and U (VI) complexes of 2-acetylpyridine 4N-(2-pyridyl) thiosemicarbazone (HAPT); structural, spectroscopic and biological studies

    El-Ayaan, Usama; Youssef, Magdy M.; Al-Shihry, Shar


    The present work carried out a study on transition metal ion complexes which have been synthesized from 2-acetylpyridine 4N-(2-pyridyl) thiosemicarbazone (HAPT) 1. These complexes namely [Zn(HAPT)Cl 2] 2, [Mn (HAPT)Cl 2] 3, [Co (HAPT)Cl 2] 4, [Fe(APT)Cl 2(H 2O)] 5 and [UO 2(HAPT)(OAc) 2] 6, were characterized by elemental analysis, spectral (IR, 1H NMR and UV-vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E, A, Δ H, Δ S and Δ G) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. The biochemical studies showed that, complexes 3 and 6 have powerful and complete degradation effect on the both DNA and protein. The SOD-like activity exhibited that complex 3 has a strong antioxidative properties. The antibacterial screening demonstrated that, the free ligand (HAPT), complexes 2, 3 and 6 have the maximum and broad activities against Gram-positive and Gram-negative bacterial strains.

  9. Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: antimicrobial evaluation and anticancer studies.

    Dhahagani, K; Mathan Kumar, S; Chakkaravarthi, G; Anitha, K; Rajesh, J; Ramu, A; Rajagopal, G


    Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by (1)H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M=Cu(II), Co(II)), Zn(II), or VO(IV); MPMP=2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X=Cl, (L1H), X=Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

  10. Room-temperature violet luminescence and ultraviolet photodetection of Sb-doped ZnO/Al-doped ZnO homojunction array

    Chen, Wei-Jen; Wu, Jen-Kai; Lin, Jheng-Cyuan; Lo, Shun-Tsung; Lin, Huang-De; Hang, Da-Ren; Shih, Ming Feng; Liang, Chi-Te; Chang, Yuan Huei


    A Sb-doped ZnO microrod array was fabricated on an Al-doped ZnO thin film by electrodeposition. Strong violet luminescence, originated from free electron-to-acceptor level transitions, was identified by temperature-dependent photoluminescence measurements. This acceptor-related transition was attributed to substitution of Sb dopants for Zn sites, instead of O sites, to form a complex with two Zn vacancies (VZn), the SbZn-2VZn complex. This SbZn-2VZn complex has a lower formation energy and ac...

  11. 配合物锌-2,5-噻吩二羧酸-邻菲啰啉的合成及其与DNA作用的研究%Synthesis of a Zn(Ⅱ) Complex[Zn(thca)(phen)(H_2O)] and Its DNA Binding

    徐进; 姜美平; 武光磊; 高恩军


    合成锌混合配体配合物[Zn(thca)(phen)(H2O)](其中thca:2,5-噻吩二羧酸,phen:邻菲啰啉).Bruker smart 1000 CCD-X射线单晶衍射仪确定了配合物的晶体结构.用紫外可见光谱、荧光光谱研究该配合物与HC-DNA(Hela细胞DNA)的作用规律,用凝胶电泳法研究该配合物对pBR322-DNA的切割作用,从插入方式角度讨论配合物与DNA相互作用机理,并进行HeLa细胞凋亡实验.%A new complex[Zn(thca)(phen)(H2O)](thca=2,5-thiophenedicarboxylic acid,phen=1,10-Phenanthroline monohydrate) has been successfully synthesized.Bruker smart 1000 CCD-X-ray single crystal diffraction determined by the complexes crystal unit structure.The binding of the complex with HC-DNA(DNA of HeLa cells was extracted) was investigated by UV and fluorescence spectrum,and gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 DNA,the interaction mechanism between complex and DNA discussed from the perspective of insert mode and HeLa cell apoptosis experiment.

  12. Electrodeposition of nanostructured Sn-Zn coatings

    Salhi, Y.; Cherrouf, S.; Cherkaoui, M.; Abdelouahdi, K.


    The electrodeposition of Sn-Zn coating at ambient temperature was investigated. The bath consists of metal salts SnCl2·2H2O and ZnSO4·7H2O and sodium citrate (NaC6H5Na3O7·2H2O) as complexing agent. To prevent precipitation, the pH is fixed at 5. Reducing tin and zinc through Sncit2- and ZnHcit- complex respectively is confirmed by the presence of two cathodic peaks on the voltammogram. The kinetic of tin (II) reduction process is limited by the SnCit2- dissociation. The SEM and TEM observations have showed that the coating consists of a uniform Sn-Zn layer composed of fine grains on which tin aggregates grow up. XRD revealed peaks corresponding to the hexagonal Zn phase and the tetragonal β-Sn phase.

  13. Fabrication of ZnO and ZnO:Sb Nanoparticles for Gas Sensor Applications

    A.B. Kashyout; Soliman,H. M. A.; H. Shokry Hassan; Abousehly, A. M.


    ZnO and Sb-doped ZnO nanoparticles were successfully prepared using sol-gel technique. Different concentrations of triethanolamine (TEA) were utilized as the preparation procedure to act as complexing agent that enhances the doping probability of the formed Sb-doped ZnO nanopowder. Thick films of the prepared nanopowders were fabricated with spinner coating. Morphological characteristics, phase structure, chemical composition, thermal stability, and optical properties of the prepared nanopowd...

  14. Characterization of the corrosion products of electrodeposited Zn, Zn-Co and Zn-Mn alloys coatings

    Ortiz, Z.I.; Diaz-Arista, P.; Meas, Y.; Ortega-Borges, R. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76703 Queretaro (Mexico); Trejo, G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica (CIDETEQ), Parque Tecnologico Sanfandila, Pedro Escobedo, Queretaro, A.P. 064, C.P. 76703 Queretaro (Mexico)], E-mail:


    The morphology, composition, phase composition and corrosion products of coatings of pure Zn (obtained from two types of electrolytic bath: an acidic bath (Zn{sub acid}) and a cyanide-free alkaline bath (Zn{sub alkaline})) and of Zn-Mn and Zn-Co alloys on steel substrates were studied. To achieve this, diverse techniques were used, including polarization curves, atomic force microscopy (AFM), scanning electron microscopy (SEM), glow discharge spectroscopy (GDS), X-ray diffraction (XRD), and the salt spray test. In the salt spray test, the exposure time required for the coatings to exhibit red corrosion (associated with the oxidation of steel) decreased in the following order: Zn-Mn{sub (432h)} > Zn-Co{sub (429h)} > Zn{sub alkaline(298h)} > Zn{sub acid(216h)}. The shorter exposure times required for corrosion of the pure Zn coatings are related to the coating composition and the crystallographic structure. Analysis of the corrosion products disclosed that Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O was a corrosion product of all of the coatings tested. However, the formation of oxides of manganese (MnO, Mn{sub 0.98}O{sub 2}, Mn{sub 5}O{sub 8}) in the Zn-Mn coating, and the formation of the hydroxide Zn{sub 2}Co{sub 3}(OH){sub 10}.2H{sub 2}O in the Zn-Co coating, produced more compact and stable passive layers, with lower dissolution rates.

  15. Some new nano-sized Fe(II), Cd(II) and Zn(II) Schiff base complexes as precursor for metal oxides: Sonochemical synthesis, characterization, DNA interaction, in vitro antimicrobial and anticancer activities.

    Abdel-Rahman, Laila H; Abu-Dief, Ahmed M; El-Khatib, Rafat M; Abdel-Fatah, Shimaa Mahdy


    The complexes of Fe(II), Cd(II) and Zn(II) with Schiff base derived from 2-amino-3-hydroxypyridine and 3-methoxysalicylaldehyde have been prepared. Melting points, decomposition temperatures, Elemental analyses, TGA, conductance measurements, infrared (IR) and UV-Visible spectrophotometric studies were utilized in characterizing the compounds. The UV-Visible spectrophotometric analysis revealed 1:1 (metal-ligand) stoichiometry for the three complexes. In addition to, the prepared complexes have been used as precursors for preparing their corresponding metal oxides nanoparticles via thermal decomposition. The structures of the nano-sized complexes and their metal oxides were characterized by X-ray powder diffraction and transmittance electron microscopy. Moreover, the prepared Schiff base ligand, its complexes and their corresponding nano-sized metal oxides have been screened in vitro for their antibacterial activity against three bacteria, gram-positive (Microccus luteus) and gram-negative (Escherichia coli, Serratia marcescence) and three strains of fungus. The metal chelates were shown to possess more antimicrobial activity than the free Schiff-base chelate and their nano-sized metal oxides have the highest activity. The binding behaviors of the complexes to calf thymus DNA have been investigated by absorption spectra, viscosity mensuration and gel electrophoresis. The DNA binding constants reveal that all these complexes interact with DNA through intercalative binding mode. Furthermore, the cytotoxic activity of the prepared Schiff base complexes on human colon carcinoma cells, (HCT-116 cell line) and hepatic cellular carcinoma cells, (HepG-2) showed potent cytotoxicity effect against growth of carcinoma cells compared to the clinically used Vinblastine standard. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Integrative taxonomy of the Plain-backed Thrush (Zoothera mollissima) complex (Aves, Turdidae) reveals cr yptic species, including a new species

    Per Alström; Fumin Lei; Urban Olsson; Pamela C. Rasmussen; Chao Zhao; Jingzi Xu; Shashank Dalvi; Tianlong Cai; Yuyan Guan; Ruiying Zhang; Mikhail V. Kalyakin


    Background: The Plain-backed Thrush Zoothera mol issima breeds in the Himalayas and mountains of central China. It was long considered conspeciifc with the Long-tailed Thrush Zoothera dixoni, until these were shown to be broadly sympatric. Methods: We revise the Z. mollissima–Z. dixoni complex by integrating morphological, acoustic, genetic (two mito-chondrial and two nuclear markers), ecological and distributional datasets. Results: In earlier ifeld observations, we noted two very different song types of“Plain-backed”Thrush segregated by breeding habitat and elevation. Further integrative analyses congruently identify three groups:an alpine breeder in the Himalayas and Sichuan, China (“Alpine Thrush”);a forest breeder in the eastern Himalayas and northwest Yunnan (at least), China (“Himalayan Forest Thrush”);and a forest breeder in central Sichuan (“Sichuan Forest Thrush”). Alpine and Himalayan Forest Thrushes are broadly sympatric, but segregated by habitat and altitude, and the same is prob-ably true also for Alpine and Sichuan Forest Thrushes. These three groups differ markedly in morphology and songs. In addition, DNA sequence data from three non-breeding specimens from Yunnan indicate that yet another lineage exists (“Yunnan Thrush”). However, we ifnd no consistent morphological differences from Alpine Thrush, and its breed-ing range is unknown. Molecular phylogenetic analyses suggest that all four groups diverged at least a few million years ago, and identify Alpine Thrush and the putative“Yunnan Thrush”as sisters, and the two forest taxa as sisters. Cytochrome b divergences among the four Z. mollissima sensu lato (s.l.) clades are similar to those between any of them and Z. dixoni, and exceed that between the two congeneric outgroup species. We lectotypify the name Oreocin-cla rostrata Hodgson, 1845 with the Z. mollissima sensu stricto (s.s.) specimen long considered its type. No available name unambiguously pertains to the

  17. Integrative taxonomy of the Plain-backed Thrush(Zoothera mollissima) complex(Aves, Turdidae) reveals cryptic species, including a new species

    Per Alstr?m; Pamela C.Rasmussen; Chao Zhao; Jingzi Xu; Shashank Dalvi; Tianlong Cai; Yuyan Guan; Ruiying Zhang; Mikhail V.Kalyakin; Fumin Lei; Urban Olsson


    Background: The Plain-backed Thrush Zoothera mollissima breeds in the Himalayas and mountains of central China. It was long considered conspecific with the Long-tailed Thrush Zoothera dixoni, until these were shown to be broadly sympatric.Methods: We revise the Z. mollissima–Z. dixoni complex by integrating morphological, acoustic, genetic(two mitochondrial and two nuclear markers), ecological and distributional datasets.Results: In earlier field observations, we noted two very different song types of "Plain-backed" Thrush segregated by breeding habitat and elevation. Further integrative analyses congruently identify three groups: an alpine breeder in the Himalayas and Sichuan, China("Alpine Thrush"); a forest breeder in the eastern Himalayas and northwest Yunnan(at least), China("Himalayan Forest Thrush"); and a forest breeder in central Sichuan("Sichuan Forest Thrush"). Alpine and Himalayan Forest Thrushes are broadly sympatric, but segregated by habitat and altitude, and the same is probably true also for Alpine and Sichuan Forest Thrushes. These three groups differ markedly in morphology and songs. In addition, DNA sequence data from three non-breeding specimens from Yunnan indicate that yet another lineage exists("Yunnan Thrush"). However, we find no consistent morphological differences from Alpine Thrush, and its breeding range is unknown. Molecular phylogenetic analyses suggest that all four groups diverged at least a few million years ago, and identify Alpine Thrush and the putative "Yunnan Thrush" as sisters, and the two forest taxa as sisters. Cytochrome b divergences among the four Z. mollissima sensu lato(s.l.) clades are similar to those between any of them and Z. dixoni, and exceed that between the two congeneric outgroup species. We lectotypify the name Oreocincla rostrata Hodgson, 1845 with the Z. mollissima sensu stricto(s.s.) specimen long considered its type. No available name unambiguously pertains to the Himalayan Forest Thrush

  18. Properties of Square-Pyramidal Alkyl-Thiolate FeIII-Complexes, Including an Analogue of the Unmodified Form of Nitrile Hydratase

    Lugo-Mas, Priscilla; Taylor, Wendy; Schweitzer, Dirk; Theisen, Roslyn M.; Xu, Liang; Shearer, Jason; Swartz, Rodney D.; Gleaves, Morgan C.; DiPasquale, Antonio; Kaminsky, Werner; Kovacs, Julie A.


    The syntheses and structures of three new coordinatively unsaturated, monomeric, square pyramidal thiolate-ligated Fe(III) complexes are described, [FeIII((tame—N3)S2Me2)]+ (1), [FeIII(Et—N2S2Me2)(py)]1- (3), and [FeIII((tame—N2S)S2Me2)]2- (15). The anionic bis-carboxamide, tris-thiolate N2S3 coordination sphere of 15 is potentially similar to that of the yet-to-be characterized unmodified form of NHase. Comparison of the magnetic and reactivity properties of these reveals how anionic charge build-up (from cationic 1 to anionic 3 and dianionic 15) and spin-state influence apical ligand affinity. For all of the ligand-field combinations examined, an intermediate S= 3/2 spin-state was shown to be favored by a strong N2S2 basal plane ligand-field, and this was found to reduce the affinity for apical ligands, even when they are built-in. This is in contrast to the post-translationaly modified NHase active site, which is low-spin, and displays a higher affinity for apical ligands. Cationic 1 and its reduced FeII precursor are shown to bind NO and CO, respectively, to afford [FeIII((tame-N3)S2Me(NO)]+ (18, νNO= 1865 cm-1), an analogue of NO-inactivated NHase, and [FeII((tame-N3)S2Me)(CO)] (16; νCO stretch (1895 cm-1). Anions (N3-, CN-) are shown to be unreactive towards 1, 3 and 15, and neutral ligands unreactive towards 3 and 15, even when present in 100-fold excess, and at low—temperatures. The curtailed reactivity of 15, an analogue of the unmodified form of NHase, and its apical-oxygenated S= 3/2 derivative [FeIII((tame—N2SO2)S2Me2)]2- (20) suggests that regioselective post—translational oxygenation of the basal plane NHase cysteinate sulfurs plays an important role in promoting substrate binding. This is supported by previously reported theoretical (DFT) calculations.1 PMID:18989922

  19. Integrative taxonomy resolves the cryptic and pseudo-cryptic Radula buccinifera complex (Porellales, Jungermanniopsida, including two reinstated and five new species

    Matt Renner


    Full Text Available Molecular data from three chloroplast markers resolve individuals attributable to Radula buccinifera in six lineages belonging to two subgenera, indicating the species is polyphyletic as currently circumscribed. All lineages are morphologically diagnosable, but one pair exhibits such morphological overlap that they can be considered cryptic. Molecular and morphological data justify the re-instatement of a broadly circumscribed ecologically variable R. strangulata, of R. mittenii, and the description of five new species. Two species Radula mittenii Steph. and R. notabilis sp. nov. are endemic to the Wet Tropics Bioregion of north-east Queensland, suggesting high diversity and high endemism might characterise the bryoflora of this relatively isolated wet-tropical region. Radula demissa sp. nov. is endemic to southern temperate Australasia, and like R. strangulata occurs on both sides of the Tasman Sea. Radula imposita sp. nov. is a twig and leaf epiphyte found in association with waterways in New South Wales and Queensland. Another species, R. pugioniformis sp. nov., has been confused with Radula buccinifera but was not included in the molecular phylogeny. Morphological data suggest it may belong to subg. Odontoradula. Radula buccinifera is endemic to Australia including Western Australia and Tasmania, and to date is known from south of the Clarence River on the north coast of New South Wales. Nested within R. buccinifera is a morphologically distinct plant from Norfolk Island described as R. anisotoma sp. nov. Radula australiana is resolved as monophyletic, sister to a species occurring in east coast Australian rainforests, and nesting among the R.buccinifera lineages with strong support. The molecular phylogeny suggests several long-distance dispersal events may have occurred. These include two east-west dispersal events from New Zealand to Tasmania and south-east Australia in R. strangulata, one east-west dispersal event from Tasmania to

  20. Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine

    Mohamed, Gehad G.; El-Gamel, Nadia E. A.


    The ternary piroxicam (Pir; 4-hydroxy-2-methyl- N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA cheletes were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

  1. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II, Cu(II, Ni(II, and Zn(II Complexes with Amino Acid-Derived Compounds

    Zahid H. Chohan


    Full Text Available A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II, copper(II, nickel(II, and zinc(II metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L1–(L5 were derived by condensation of β-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc via the azomethine-N and deprotonated-O of the respective amino acid. The stoichiometric reaction between the metal(II ion and synthesized ligands in molar ratio of M: L (1: 1 resulted in the formation of the metal complexes of type [M(L(H2O4]Cl (where M = Co(II, Cu(II, and Zn(II and of M: L (1: 2 of type [M(L2(H2O2] (where M = Co(II, Cu(II, Ni(II, and Zn(II. The magnetic moment data suggested for the complexes to have an octahedral geometry around the central metal atom. The electronic spectral data also supported the same octahedral geometry of the complexes. Elemental analyses and NMR spectral data of the ligands and their metal(II complexes agree with their proposed structures. The synthesized ligands, along with their metal(II complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa, and Salmonella typhi and two Gram-positive (Bacillus subtilis and Staphylococcus aureus bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glaberata. The results of these studies show the metal(II complexes to be more antibacterial/antifungal against one or more species as compared to the uncomplexed ligands. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Five compounds, (3, (7, (10, (11, and (22, displayed potent cytotoxic

  2. Synthesis, spectral studies, thermal behavior, and antibacterial activity of Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

    Mohammad Azarkish; Tahereh Sedaghat


    Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-1,3-diphenylpropen- 1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry.The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.

  3. batman Interacts with polycomb and trithorax group genes and encodes a BTB/POZ protein that is included in a complex containing GAGA factor.

    Faucheux, M; Roignant, J-Y; Netter, S; Charollais, J; Antoniewski, C; Théodore, L


    Polycomb and trithorax group genes maintain the appropriate repressed or activated state of homeotic gene expression throughout Drosophila melanogaster development. We have previously identified the batman gene as a Polycomb group candidate since its function is necessary for the repression of Sex combs reduced. However, our present genetic analysis indicates functions of batman in both activation and repression of homeotic genes. The 127-amino-acid Batman protein is almost reduced to a BTB/POZ domain, an evolutionary conserved protein-protein interaction domain found in a large protein family. We show that this domain is involved in the interaction between Batman and the DNA binding GAGA factor encoded by the Trithorax-like gene. The GAGA factor and Batman codistribute on polytene chromosomes, coimmunoprecipitate from nuclear embryonic and larval extracts, and interact in the yeast two-hybrid assay. Batman, together with the GAGA factor, binds to MHS-70, a 70-bp fragment of the bithoraxoid Polycomb response element. This binding, like that of the GAGA factor, requires the presence of d(GA)n sequences. Together, our results suggest that batman belongs to a subset of the Polycomb/trithorax group of genes that includes Trithorax-like, whose products are involved in both activation and repression of homeotic genes.

  4. Synthesis and characterization of two novel bimetallic macrocyclic complexes generated from 1,2,4-triazole-containing semi-rigid ligands and M(NO3)2 units (M = Ni and Zn).

    Wu, Xiang Wen; Yin, Shi; Wu, Wan Fu; Ma, Jian Ping


    Bimetallic macrocyclic complexes have attracted the attention of chemists and various organic ligands have been used as molecular building blocks, but supramolecular complexes based on semi-rigid organic ligands containing 1,2,4-triazole have remained rare until recently. It is easier to obtain novel topologies by making use of asymmetric semi-rigid ligands in the self-assembly process than by making use of rigid ligands. A new semi-rigid ligand, 3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine (L), has been synthesized and used to generate two novel bimetallic macrocycle complexes, namely bis{μ-3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine}bis[(methanol-κO)(nitrato-κ(2)O,O')nickel(II)] dinitrate, [Ni2(NO3)2(C17H14N6S)2(CH3OH)2](NO3)2, (I), and bis{μ-3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine}bis[(methanol-κO)(nitrato-κ(2)O,O')zinc(II)] dinitrate, [Zn2(NO3)2(C17H14N6S)2(CH3OH)2](NO3)2, (II), by solution reactions with the inorganic salts M(NO3)2 (M = Ni and Zn, respectively) in mixed solvents. In (I), two Ni(II) cations with the same coordination environment are linked by L ligands through Ni-N bonds to form a bimetallic ring. Compound (I) is extended into a two-dimensional network in the crystallographic ac plane via N-H...O, O-H...N and O-H...O hydrogen bonds, and neighbouring two-dimensional planes are parallel and form a three-dimensional structure via π-π stacking. Compound (II) contains two bimetallic rings with the same coordination environment of the Zn(II) cations. The Zn(II) cations are bridged by L ligands through Zn-N bonds to form the bimetallic rings. One type of bimetallic ring constructs a one-dimensional nanotube via O-H...O and N-H...O hydrogen bonds along the crystallographic a direction, and the other constructs zero-dimensional molecular cages via O-H...O and N-H...O hydrogen bonds. They are interlinked into a two-dimensional network in the ac

  5. Hydrothermal Synthesis and Crystal Structure of a New Zero-dimensional Complex: [Zn(H2BPTC)(phen)2]n·3nH2O


    A new metal-organic coordination complex [Zn(H2BPTC)(phen)2]n·3nH2O (BPTC =3,3',4,4'-benzophenone tetracarboxylate, phen = 1,10-phenanthroline) 1 has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. In compound 1, the zinc cation is hexa-coordinated with two carboxylate oxygen atoms from one H2BPTC ligand and four nitrogen atoms from two different phen ligands, showing a slightly distorted octahedral geometry. Crystal data: C41H30N4O12Zn, Mr = 836.06, monoclinic,P21/c, a = 14.2714(9), b = 16.9386(10), c = 15.0151(9) (A),β = 101.3420(10)°, V= 3558.8(4) (A)3, Dc= 1.560 g/cm3,μ(MoKα) = 0.766 mm-1, F(000) = 1720, Z = 4, R = 0.0439 and wR = 0.1157 for 4123observed reflections with I > 2σ(I).

  6. Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

    Muslih, E. Y.; Kim, K. H.


    Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

  7. Synthesis and Structural Characterization of a Novel 2D Supramolecular Complex {[Dy2Zn(dinic)4(H2O)8]·H2O}n (H2dinic=2,5-Pyridinedicaboxylic Acid)

    HU De-Xin; XUE Lin; CHE Yun-Xia


    A new dysprosium-zinc coordination polymer {[Dy2Zn(dinic)4(H2O)8]·H2O}n 1(H2dinic = 2,5-pyridinedicaboxylic acid) has been synthesized and structurally characterized by X-ray analysis. The complex (C28H30Dy2N4O25Zn, Mr = 1212.94) crystallizes in triclinic, space group P-1 with a = 7.8911(16), b = 9.3177(19), c = 13.029(3)(A), α = 75.29(3), β = 75.04(3), γ =79.00(3)°, V = 887.1(3)(A)3, Z = 1, Dc=2.236 g/cm3,μ(MoKα) = 4.947 mm-1, F(000) = 570, the final R = 0.0345 and wR = 0.0903 for 3644 observed reflections with I> 2σ(I). A two-dimensional supramolecular structure is formed in 1, which was characterized by elemental analysis, IR, TG analysis, and single-crystal X-ray diffraction.

  8. Synthesis, spectroscopic, molecular structure, antioxidant, antimicrobial and antitumor behavior of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of O2N type tridentate chromone-2-carboxaldehyde Schiff's base ligand

    Ammar, Reda A.; Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Al-Bedair, Lamia A.


    Tridentate Schiff's base (HL) ligand was synthesized via condensation of salicylaldehyde and 3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR), magnetic moment, EPR, and thermal measurements. The IR spectra showed that HL was coordinated to the metal ions in tridentate manner with O2N donor sites of the azomethine N, deprotonated phenolic-OH and carbonyl-O. The activation of thermodynamic parameters are calculated using Coast-Redfern and Horowitz-Metzger (HM). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations, UV-Vis and magnetic moment measurements, ESR and ligand field parameters. Antioxidant activities have also been performed for all the compounds. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all inspected compounds were evaluated towards human liver Carcinoma (HepG2) cell line.

  9. Preparation and Spectral Properties of Mixed-Ligand Complexes of VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II with Dimethylglyoxime and N-acetylglycine

    Shayma A. Shaker


    Full Text Available A number of mixed-ligand complexes of the general formula [M(D(G] where D=dimethylglyoximato monoanion, G=N-acetylglycinato and M=VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II were prepared. Each complex was characterized by elemental analysis, determination of metal, infrared spectra, electronic spectra, (1H and 13C NMR spectra, conductivity and magnetic moments. All these complexes were not soluble in some of the organic solvent but highly soluble in dimethylformamide. The conductivity data showed the non-electrolytic nature of the complexes. The electronic spectra exhibited absorption bands in the visible region caused by the d-d electronic transition such as VO(IV, Ni(II and Pd(II. The IR and (1H, 13C NMR spectra which have indicate that the dimethylglyoxime was coordinated with the metal ions through the N and O atoms of the oxime group and N-acetylglycine was coordinated with metal ions through the N atom and terminal carboxyl oxygen atom.

  10. Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD.

    Bóka, Beáta; Myari, Alexandra; Sóvágó, Imre; Hadjiliadis, Nick


    Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD were studied by potentiometric and spectroscopic (UV-Vis, CD and EPR) techniques. The results reveal that both ligands have effective metal binding sites, but the tripeptide is a much stronger complexing agent than the tetrapeptide. The formation of a macrochelate via the coordination of the imidazolyl residues is suggested in the copper(II)-Ac-HisValHis-NH2 system in the acidic pH range, while a 4N complex predominates at physiological pH. The interaction of Ac-HisValHis-NH2 with zinc(II) results in the formation of a precipitate indicating polynuclear complex formation. Both copper(II)-Ac-HisValHis-NH2 and copper(II)-HisValHis systems exhibit catalytic activity toward the dismutation of superoxide anion at physiological pH, but the saturated coordination sphere of the metal ions in both systems results in low reactivity as compared to the native enzyme.

  11. ZnO nanostructures and their applications

    Xiaowei, Sun


    This book focuses on the various functional properties and potential applications of one-dimensional ZnO nanostructures, from basic principles to our most recent discoveries. It comprises experimental analysis of various properties of ZnO nanostructures, preparation techniques, research methods, and some promising applications. The areas of focus include ZnO-based gas/biochemical sensing devices, field emitters, solar cells, light-emitting diodes, e-papers, and single-nanowire-based transistors.

  12. Determination of 67Zn distribution in navy bean (Phaseolus vulgaris L.) after foliar application of 67Zn-lignosulfonates using isotope pattern deconvolution.

    Benedicto, Ana; Hernández-Apaolaza, Lourdes; Rivas, Inmaculada; Lucena, Juan J


    The improvement of Zn fertilizers requires new techniques to evaluate their efficacy. In this paper, the (67)Zn stable isotope was used as tracer of several Zn-lignosulfonate complexes to study the foliar-applied Zn uptake and distribution behavior in the plant, compared with ZnEDTA. Navy bean plants ( Phaseolus vulgaris L.) were grown hydroponically in a Zn-free nutrient solution, and six modified lignosulfonates and EDTA complexed with (67)Zn were used in foliar application in the young leaves as Zn sources. Zinc isotopes in roots, stems, and sprayed and unsprayed leaves were determined by ICP-MS, and signal interferences caused by the compounds of the digested vegetal samples were corrected. The mathematical procedure of isotope pattern deconvolution allowed the minimization of the uncertainty in the measured molar fractions of Zn from fertilizer or from natural sources. Significant differences in Zn use and distribution were observed among the fertilizers when the calculated concentrations of Zn from the fertilizer were compared, whereas they were unnoticeable attending to the total Zn in plant tissues, usually determined at the conventional studies. By foliar spray, higher Zn uptake and mobilization to leaves and stems were achieved with (67)ZnEDTA than with (67)Zn-LS complexes. The ultrafiltered LS and phenolated LS showed slightly better ability to provide Zn to the bean plants than the other LS. The foliar-applied Zn use and distribution in the plant were related with the stability of the Zn-lignosulfonates complexes. Those presenting the lower stability versus pH, but the highest complexing capacity, were slightly more suitable to supply foliar-applied Zn to navy beans.

  13. Dynamics of Zn in an urban wetland soil-plant system: Coupling isotopic and EXAFS approaches

    Aucour, Anne-Marie; Bedell, Jean-Philippe; Queyron, Marine; Magnin, Valérie; Testemale, Denis; Sarret, Géraldine


    Plants play a key role in the stabilization of metals in contaminated environments. Studies have been performed on Zn uptake and storage mechanisms, mainly for Zn hyperaccumulating plants, though less is known about Zn stabilization in the rhizosphere of non-accumulating plants. This study was focused on the dynamics of Zn in a whole soil-litter-plant system and the processes controlling Zn mobilization and stabilization. The site studied was an infiltration basin receiving urban stormwater, in which Phalaris arundinacea (reed canary grass) developed spontaneously. A combination of chemical extractions (CaCl2, DTPA), EXAFS spectroscopy and Zn stable isotope measurements was applied for the water inlet, soil, plant organs and decaying biomass. Zn speciation changed from the water inlet to the soil. In the soil, Zn was present as Zn-layered double hydroxide (Zn-LDH), tetrahedral and octahedral sorbed Zn species. The formation of Zn-LDH participates in Zn stabilization. Tetrahedral Zn species, which were partly DTPA exchangeable, were enriched in heavy isotopes, whereas octahedral Zn (Zn-LDH and sorbed species) were enriched in light isotopes. Based on a linear model between δ66Zn and Zn speciation, δ66Zn for pure tetrahedral and octahedral end-members were estimated at ca. 0.33‰ and 0.04‰, respectively. In the plant, a mixture of octahedral Zn (attributed to aqueous Zn-organic acid complexes present in the symplasm), and tetrahedral Zn (attributed to apoplasmic Zn-cell wall complexes) was observed in all organs. Large enrichment in light isotopes from the soil to the plant Δ66Zn (of ca. -0.6‰) was observed. The stem was enriched in light isotopes versus roots and, to a lesser extent, versus leaves. The results suggest that Zn was taken up via a low-affinity transport system and that Zn was sequestrated in the stem symplasm after transit through leaves. Finally, intense Zn exchanges were observed between the decaying biomass and the soil, with the sorption of

  14. Simple inorganic complexes but intricate hydrogen bonding networks: Synthesis and crystal structures of [MII(opda)2(NO3)2] (M = Zn and Cd; opda = orthophenylenediamine)

    Sabbani Supriya


    The compounds [ZnII{C6H4(NH2)2}2(NO3)2], (1) and [CdII{C6H4(NH2)2}2(NO3)2] (2) have been prepared (C6H4(NH2)2 = orthophenylenediammine = opda) and characterized by routine spectroscopic methods and single crystal X-ray diffraction analysis. Compound 1 crystallizes in orthorhombic space group , where as compound 2 crystallizes in monoclinic space 21/. In the crystal structure of 1 an extended hydrogen bonding network is formed involving zinc coordinated amines and nitrato ligands. The compound 2 consists of molecules in which the cadmium ion is eight coordinated, with two bidentate nitrate groups and two bidentate opda ligands. The geometry around the cadmium described as a distorted dodecahedron. The crystal structure of 2 shows an intricate hydrogen bonding network, formed by amine and nitro groups coordinated to cadmium.

  15. Cr(III,Mn(II,Fe(III,Co(II,Ni(II,Cu(II and Zn(II Complexes with Diisobutyldithiocarbamato Ligand

    Mohammad Tarique


    Full Text Available The synthesis of sulphur and nitrogen containing dithiocarbamato ligand derived from diisobutylamine as well as its coordination compounds with 3d series transition metals is presented. These synthesized compounds were characterized on the basis of elemental analysis, conductometric measurements and IR spectral studies. The analytical data showed the stoichiometry 1:2 and 1:3 for the compounds of the types ML2 {M=Mn(II, Co(II, Ni(II, Cu(II and Zn(II} and M'L3{M'=Cr(III and Fe(III} respectively. The conductometric measurements proved the non-electrolytic behaviour of all the compounds. The bidentate nature of dithiocarbamato moiety was confirmed on the basis of IR spectral data.

  16. In vitro DNA binding, pBR322 plasmid cleavage and molecular modeling study of chiral benzothiazole Schiff-base-valine Cu(II) and Zn(II) complexes to evaluate their enantiomeric biological disposition for molecular target DNA.

    Alizadeh, Rahman; Afzal, Mohd; Arjmand, Farukh


    Bicyclic heterocyclic compounds viz. benzothiazoles are key components of deoxyribonucleic acid (DNA) molecules and participate directly in the encoding of genetic information. Benzothiazoles, therefore, represent a potent and selective class of antitumor compounds. The design and synthesis of chiral antitumor chemotherapeutic agents of Cu(II) and Zn(II), L- and -D benzothiazole Schiff base-valine complexes 1a &b and 2a &b, respectively were carried out and thoroughly characterized by spectroscopic and analytical techniques. Interaction of 1a and b and 2a and b with CT DNA by employing UV-vis, florescence, circular dichroic methods and cleavage studies of 1a with pBR322 plasmid, molecular docking were done in order to demonstrate their enantiomeric disposition toward the molecular drug target DNA. Interestingly, these studies unambiguously demonstrated the greater potency of L-enantiomer in comparison to D-enantiomer.

  17. A DFT/TD DFT study of the structure and spectroscopic properties of 5-methyl-2-(8-quinolinyl)benzoxazole and its complexes with Zn(II) ion.

    Guzow, Katarzyna; Milewska, Magda; Czaplewski, Cezary; Wiczk, Wiesław


    The structure and spectroscopic properties of 5-methyl-2-(8-quinolinyl)benzoxazole and its complexes with Zn(II) ion were studied using a DFT and TD DFT methods with def2-TZVP basis set. It was shown that the type of functional used (B3-LYP or pbe0) implemented in TURBOMOLE package does not have essential influence on the geometry (small differences in bond length, valence and dihedral angles) of studied compounds in both ground and excited states. However, significant differences were obtained for the position of vertical absorption and emission transition but not for the oscillator strength of transition. Application of pbe0 functional seems to reproduce better the experimental spectrum.

  18. In vitro DNA binding, pBR322 plasmid cleavage and molecular modeling study of chiral benzothiazole Schiff-base-valine Cu(II) and Zn(II) complexes to evaluate their enantiomeric biological disposition for molecular target DNA

    Alizadeh, Rahman; Afzal, Mohd; Arjmand, Farukh


    Bicyclic heterocyclic compounds viz. benzothiazoles are key components of deoxyribonucleic acid (DNA) molecules and participate directly in the encoding of genetic information. Benzothiazoles, therefore, represent a potent and selective class of antitumor compounds. The design and synthesis of chiral antitumor chemotherapeutic agents of Cu(II) and Zn(II), L- and -D benzothiazole Schiff base-valine complexes 1a &b and 2a &b, respectively were carried out and thoroughly characterized by spectroscopic and analytical techniques. Interaction of 1a and b and 2a and b with CT DNA by employing UV-vis, florescence, circular dichroic methods and cleavage studies of 1a with pBR322 plasmid, molecular docking were done in order to demonstrate their enantiomeric disposition toward the molecular drug target DNA. Interestingly, these studies unambiguously demonstrated the greater potency of L-enantiomer in comparison to D-enantiomer.

  19. Metal Atom Effect on the Photophysical Properties of Mg(II, Zn(II, Cd(II, and Pd(II Tetraphenylporphyrin Complexes Proposed as Possible Drugs in Photodynamic Therapy

    Bruna Clara De Simone


    Full Text Available The effects of Mg, Zn, Cd, and Pd dications on the photophysical properties of the tetraphenylporphyrin ligand have been explored, considering the corresponding complexes and by using the density functional theory and its time-dependent extension. Results show that absorption wavelengths do not change significantly when the metal ion changes contrary to what happens to the singlet–triplet energy gaps (ΔES−T and the spin-orbit matrix elements ΨSnHsoΨTm. The most probable intersystem spin crossing (ISC pathways for the population of the lowest triplet states have been explored. Our findings can contribute to rationalize the available experimental data and promote the potential therapeutic use of these compounds as photosensitizers in photodynamic therapy (PDT.

  20. Spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV/VIS), thermogravimetric and antimicrobial studies of Ca(II), Mn(II), Cu(II), Zn(II) and Cd(II) complexes of ferulic acid

    Kalinowska, M.; Piekut, J.; Bruss, A.; Follet, C.; Sienkiewicz-Gromiuk, J.; Świsłocka, R.; Rzączyńska, Z.; Lewandowski, W.


    The molecular structure of Mn(II), Cu(II), Zn(II), Cd(II) and Ca(II) ferulates (4-hydroxy-3-methoxycinnamates) was studied. The selected metal ferulates were synthesized. Their composition was established by means of elementary and thermogravimetric analysis. The following spectroscopic methods were used: infrared (FT-IR), Raman (FT-Raman), nuclear magnetic resonance (13C, 1H NMR) and ultraviolet-visible (UV/VIS). On the basis of obtained results the electronic charge distribution in studied metal complexes in comparison with ferulic acid molecule was discussed. The microbiological study of ferulic acid and ferulates toward Escherichia coli, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus and Proteus vulgaris was done.

  1. Direct atomic-level observation and chemical analysis of ZnSe synthesized by in situ high-throughput reactive fiber drawing.

    Hou, Chong; Jia, Xiaoting; Wei, Lei; Stolyarov, Alexander M; Shapira, Ofer; Joannopoulos, John D; Fink, Yoel


    We demonstrate a high-throughput method for synthesizing zinc selenide (ZnSe) in situ during fiber drawing. Central to this method is a thermally activated chemical reaction occurring across multiple interfaces between alternately layered elemental zinc- (Zn-) and selenium- (Se-) rich films embedded in a preform and drawn into meters of fiber at a temperature well below the melting temperature of either Zn or ZnSe. By depositing 50 nm thick layers of Zn interleaved between 1 μm thick Se layers, a controlled breakup of the Zn sheet is achieved, thereby enabling a complete and controlled chemical reaction. The thermodynamics and kinetics of this synthesis process are studied using thermogravimetric analysis and differential scanning calorimetry, and the in-fiber compound is analyzed by a multiplicity of materials characterization tools, including transmission electron microscopy, Raman microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, all resulting in unambiguous identification of ZnSe as the compound produced from the reactive fiber draw. Furthermore, we characterize the in-fiber ZnSe/Se97S3 heterojunction to demonstrate the prospect of ZnSe-based fiber optoelectronic devices. The ability to synthesize new compounds during fiber drawing at nanometer scale precision and to characterize them at the atomic-level extends the architecture and materials selection compatible with multimaterial fiber drawing, thus paving the way toward more complex and sophisticated functionality.

  2. 静电纺丝法制备锌镍复合纳米线及[Zn-NiO/(PVDF+BT)]复合材料介电性能研究%Preparation of Zn-Ni complex nanowire by Electrospinning and their dielectric constant of composites of multiple phase (Zn-NiO/(PVDF+BT))

    朱丽新; 王志文; 袁艳林; 关晓辉; 鲁敏


    采用静电纺丝法制备了锌镍复合纳米线,用TG、SEM、TEMM和XRD等对其进行了分析和表征.利用锌镍复合纳米线、聚偏氟乙烯(PVDF)和钛酸钡(BT)制备[Zn-NiO/(BT+PVDF)]复合材料,并对其介电性能进行了研究.结果表明,锌镍复合纳米线前躯体直径约500 nm;通过焙烧得到直径约为250nm的纳米线氧化物;[Zn-NiO/(BT+PVDF)]复合材料的介电性能均优于三相NiO/(BT+PVDF)和两相NiO/PVDF的介电性能.

  3. Studies on Synthesis, DNA Binding Action and Bio-Toxicity of Zn(Ⅱ)-Trp-Phen Complex%锌(Ⅱ)-色氨酸-邻菲咯啉配合物的合成及其与DNA的作用和生物毒性研究

    刘向伟; 袁永安; 张前前; 李苓; 牛淑妍


    合成了一种新的锌(Ⅱ)—色氨酸—邻菲咯啉配合物[Zn(Trp) (phen)2]Cl·7H2O(Ⅰ)(Trp为L-色氨酸离子,phen为邻菲咯啉).通过元素分析、红外光谱及热重—差热分析对其进行了结构表征,采用电子吸收光谱法、荧光光谱法及琼脂糖凝胶电泳法考察了其与DNA的作用,研究了配合物对斑马鱼胚胎的生物毒性,并与2种已知结构的锌—邻菲咯啉配合物[Zn(phen)2] Cl2·5H2O(Ⅱ)和[Zn(phen)]Cl2(Ⅲ)进行了比较.结果表明,配合物与鲑鱼精DNA作用大小顺序为配合物Ⅰ>配合物Ⅱ>配合物Ⅲ,但作用方式不同;在抗坏血酸存在下,配合物Ⅰ对pBR322 DNA的切割作用最强;配合物对斑马鱼胚胎毒性作用大小顺序为配合物Ⅱ>配合物Ⅰ>配合物Ⅲ.%A novel complex of [Zn(Trp) (phen)2] Cl·7H2O (Ⅰ) (Trp = ion of L-tryptophan, phen = phenanthroline) was synthesized and characterized by elemental analysis,IR spectroscopy and TG-DTA. The interaction of the complex with DNA was investigated by electric absorption spectroscopy,ethidium bromide(EB) fluorescence spectroscopy and agarose gel electrophoresis. The bio-toxicity of the complex on zebrafish embryos was determined. Two known complexes [Zn(phen)2] Cl2·5H2O( Ⅱ ) and [Zn(phen)Cl2](Ⅲ ) were chosen to study as comparison reference. The results indicated that the three complexes bond to sperm DNA by different modes,and clove pBR322 DNA in the presence of vitamin C as a reducing regent with the order of the binding ability and cleavage activity:complex Ⅰ >complex Ⅱ > complex Ⅲ. The bio-toxicity of the complexes on ze brafish embryos increased in the order;complex Ⅱ >complex Ⅰ >complex Ⅲ.

  4. Schiff base ligand derived from (±trans-1,2-cyclohexanediamine and its Cu(II, Co(II, Zn(II and Mn(II complexes: Synthesis, characterization, styrene oxidation and hydrolysis study of the imine bond in Cu(II Schiff base complex

    Sarkheil Marzieh


    Full Text Available A Schiff base ligand (H2L derived from 2´-hydroxypropiophenone and (±trans-1,2-cyclohexanediamine was synthesized. The reactions of MCl2.xH2O (M =Cu(II, Co(II, Zn(II and Mn(IIwith the di-Schiff base ligand (H2L were studied. This ligand when stirred with 1 equivalent of CuCl2.2H2O in the solution of ethanol and chloroform undergoes partial hydrolysis of the imino bond and the resultant tridentate ligand (HL′immediately forms complex[CuL´Cl]∙3/2CHCl3(1with N2O coordination sphere. Under the same condition, the reaction of H2L with MCl2.xH2O (M = Co(II (3, Zn(II (4 and Mn(II (5 gave complexes[ML]•1/2CHCl3∙3/2H2O (3-5with N2O2 coordination sphere and no hydrolytic cleavage was occurred. Also, the reaction of H2L with CuCl2.2H2O in THF gave the complex CuL (2with N2O2 coordination sphere. The ligand and complexes were characterized by FTIR, UV-Vis, 1H NMRand elemental analysis. The homogeneous catalytic activity of the complexes1, 3 and 5wasevaluated for the oxidation of styrene using tert-butyl hydroperoxide (TBHP as oxidant. Finally, the copper(II complex(1encapsulated in the nanopores of zeolite-Y by flexible ligand method (CuL´-Yand its encapsulation was ensured by different studies. The catalytic performance of heterogeneous catalyst in the styrene oxidation with TBHP was investigated. The catalytic tests showed that the homogenous and heterogeneous catalysts were active in the oxidation of styrene.

  5. Enhanced Acetone Sensing Characteristics of ZnO/Graphene Composites.

    Zhang, Hao; Cen, Yuan; Du, Yu; Ruan, Shuangchen


    ZnO/graphene (ZnO-G) hybrid composites are prepared via hydrothermal synthesis with graphite, N-methyl-pyrrolidone (NMP), and Zn(NO₃)₂·6H₂O as the precursors. The characterizations, including X-ray diffraction (XRD), thermogravimetric analyses (TGA), Raman spectroscopy, and transmission electron microscopy (TEM) indicate the formation of ZnO-G. Gas sensors were fabricated with ZnO-G composites and ZnO as sensing material, indicating that the response of the ZnO towards acetone was significantly enhanced by graphene doping. It was found that the ZnO-G sensor exhibits remarkably enhanced response of 13.3 at the optimal operating temperature of 280 °C to 100 ppm acetone, an improvement from 7.7 with pure ZnO.

  6. Control of Zn uptake in Arabidopsis halleri: a balance between Zn and Fe

    Varanavasiappan eShanmugam


    Full Text Available Zinc (Zn is an essential plant micronutrient but is toxic in excess. To cope with excess Zn, plant species possess a strict metal homeostasis mechanism. The Zn hyperaccumulator Arabidopsis halleri has developed various adaptive mechanisms involving uptake, chelation, translocation and sequestration of Zn. In this mini review, we broadly discuss the different Zn tolerance mechanisms and then focus on controlled Zn uptake in A. halleri. Members of the ZRT/IRT-like protein (ZIP family of metal transporters are mainly regulated by Zn and are involved in Zn uptake. A few members of the ZIP family, such as IRT1 and IRT2, are regulated by iron (Fe and can transport multi-metals, including Zn, Fe, manganese (Mn, cadmiun (Cd and cobalt (Co. This mini-review also discusses the differential expression of multiple metal ZIP transporters in A. halleri and A. thaliana, a non-hyperaccumulater, with Zn exposure as well as Fe deficiency and their role in controlled Zn uptake and tolerance.

  7. Designer ligands. Part 14. Novel Mn(lI), Ni(II) and Zn(II) complexes of benzamide- and biphenyl-derived ligands

    Wellington, Kevin W


    Full Text Available and, in earlier papers, we have described the development of biomimetic complexes designed to mimic the active site of tyrosinase,1 an enzyme capable of ortho-hydroxylating phenols (phenolase activity) and oxidising catechols to ortho... tyrosinase. This was investigated because manganese is a redox metal and capable of binding oxygen - as can be seen in the formation of the complexes 3c and 4. In order to evaluate the ‘phenolase’ and ‘catecholase’ activity of the complexes, 3,5-di...

  8. Enhanced luminescence of rare-earth complexes Tb 1- xEu x( m-NBA) 3Phen in ZnS

    Lv, Yuguang; Zhang, Jingchang; Cao, Weiliang; Song, Lin; Xu, Zheng


    Rare-earth ternary complexes Tb 1- xEu x( m-NBA) 3Phen ( X = 1, 0.25, 0.5, 0.75, 1.0) were synthesized and characterized by IR, DTA-TG, UV, fluorescent spectra and elemental analysis. It was found that luminescence of Eu 3+ complex was enhanced by doped with Tb 3+. It is proved by TG curve that the complexes are stable, ranging from ambient temperature to 360 °C in air. The organic-inorganic combined structural device was fabricated, and the electroluminescence intensity of the combined structural device was improved compared with the device of the purely organic components.

  9. Enhanced luminescence of rare-earth complexes Tb(1-x)Eu(x)(m-NBA)3Phen in ZnS.

    Lv, Yuguang; Zhang, Jingchang; Cao, Weiliang; Song, Lin; Xu, Zheng


    Rare-earth ternary complexes Tb(1-x)Eu(x)(m-NBA)(3)Phen (X=1, 0.25, 0.5, 0.75, 1.0) were synthesized and characterized by IR, DTA-TG, UV, fluorescent spectra and elemental analysis. It was found that luminescence of Eu(3+) complex was enhanced by doped with Tb(3+). It is proved by TG curve that the complexes are stable, ranging from ambient temperature to 360 degrees C in air. The organic-inorganic combined structural device was fabricated, and the electroluminescence intensity of the combined structural device was improved compared with the device of the purely organic components.

  10. Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

    Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan


    A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

  11. Phenoxide bridged tetranuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes: Electrochemical, magnetic and antimicrobial studies

    Kamath, Anupama; Kulkarni, Naveen V.; Netalkar, Priya P.; Revankar, Vidyanand K.


    Phenoxide bridged later first row transition metal(II) complexes have been prepared by the interaction of later 3d transition metal(II) chlorides with tetranucleating compartmental Schiff base ligand system derived from 2,6-diformyl-4-methylphenol, p-phenylenediamine and 2-hydrazinobenzothiazole. Ligand and complexes were characterized by analytical, spectral (IR, UV-visible, ESR, FAB-mass and fluorescence), magnetic and thermal studies. All complexes are found to have octahedral geometry. The mutual influence of metal centres in terms of cooperative effect on the electronic, magnetic, electrochemical and structural properties was investigated. The Schiff base and its complexes have been screened for their antibacterial (against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa) and antifungal activities (against Aspergillus niger, and Candida albicans).

  12. In Vitro Antibacterial Studies of Ciprofloxacin-imines and Their Complexes with Cu(II),Ni(II),Co(II), and Zn(II)

    Imran, Muhammad; IQBAL, Javed; Iqbal, Shahid; IJAZ, Nazia


    Some new transition metal complexes of ciprofloxacin-imines derived from ciprofloxacin and p-substituted anilines were synthesized and characterized on the basis of physical properties, conductance measurements, elemental analysis, UV/Vis., infrared and nuclear magnetic resonance spectroscopy. These ligands as well as their metal complexes were also evaluated for their antibacterial activity against several bacterial strains, such as Staphylococcus aureus, Bacillus subtilus, Salmonella typhae...

  13. Kinetic control on Zn isotope signatures recorded in marine diatoms

    Köbberich, Michael; Vance, Derek


    Marine diatoms dominate the oceanic cycle of the essential micronutrient zinc (Zn). The stable isotopes of zinc and other metals are increasingly used to understand trace metal micronutrient cycling in the oceans. One clear feature of the early isotope data is the heavy Zn isotope signature of the average oceanic dissolved pool relative to the inputs, potentially driven by uptake of light isotopes into phytoplankton cells and export to sediments. However, despite the fact that diatoms strip Zn from surface waters across the Antarctic polar front in the Southern Ocean, the local upper ocean is not isotopically heavy. Here we use culturing experiments to quantify the extent of Zn isotope fractionation by diatoms and to elucidate the mechanisms driving it. We have cultured two different open-ocean diatom species (T. oceanica and Chaetoceros sp.) in a series of experiments at constant medium Zn concentration but at bioavailable medium Fe ranging from limiting to replete. We find that T. oceanica can maintain high growth rates and Zn uptake rates over the full range of bioavailable iron (Fe) investigated, and that the Zn taken up has a δ66Zn that is unfractionated relative to that of the bioavailable free Zn in the medium. The studied representative of the genus Chaetoceros, on the other hand, shows more significantly reduced Zn uptake rates at low Fe and records more variable biomass δ66Zn signatures, of up to 0.85‰ heavier than the medium. We interpret the preferential uptake of heavy isotopes at extremely low Zn uptake rates as potentially due to either of the following two mechanisms. First, the release of extracellular polymeric substances (EPS), at low Fe levels, may preferentially scavenge heavy Zn isotopes. Second, the Zn uptake rate may be slow enough to establish pseudo-equilibrium conditions at the transporter site, with heavy Zn isotopes forming more stable surface complexes. Thus we find that, in our experiments, Fe-limitation exerts a key control that

  14. StudyonTwo-stagesPressureLeachingofZn,CuandFeFromCu-Pb-ZnComplexPolymetallicOre%从铜铅锌复杂多金属精矿中两段加压浸出锌铜铁试验研究

    刘述平; 李博; 王昌良; 唐湘平


    T he experimental sample is a Cu-Pb-Zn complex polymetallic ore .Leaching of Zn ,Cu and Fe from the ore by a two-stages pressure leaching process was researched .Using the solution in which H2 SO4 initial concentration is 105 g/L ,Fe concentration is 15 g/L ,Zn concentration is 55 g/L as leaching agent ,the first-stage leaching was conducted under the conditions of leching temperature of 120 ℃ ,leaching time of 2 h ,the ratio between liquid and solid of 4 mL/g ,total pressure of 1 .9 MPa , stirring speed of 600 r/min ,additive usage of 0 .3% ,the leaching rate of Zn was about 72% ,while Cu wasn’t leached ,the removal rate of Fe was 95% .The second-stage leaching of the first-stage leaching residue was conducted under the conditions of H2SO4 initial concentration of 140 g/L ,the ratio between liquid and solid of 4 mL/g ,total pressure of 1 .9 MPa ,stirring speed of 600 r/min ,leaching temperature of 160 ℃ ,leaching time of 3 h ,additive usage of 0 .3% ,leaching rate of Zn ,Cu and Fe were 85 .91% ,77 .76% and 58 .84% ,respectively .The second-stage leaching solution was used to prepare the leaching agent for the first-stage leaching .The first-stage leaching solution with lower concentation of H2 SO4 and Fe is easy to be purified in subsequent ,the purified solution meets with the requirement of zinc electrodepositing .%针对某地铜铅锌复杂多金属精矿,研究了采用两段加压浸出法浸出锌、铜、铁。试验结果表明:以H2 SO4初始质量浓度105 g/L、Fe质量浓度约15 g/L、Zn质量浓度约55 g/L的溶液为浸出剂,在温度120℃、浸出时间2 h、液固体积质量比4 mL/g、总压力1.9 M Pa、搅拌转速600 r/min、添加剂加入量为矿石质量的0.3%条件下进行一次浸出,锌浸出率为72%左右,铜基本不被浸出,溶液中铁去除率为95%;对一次浸出渣,在硫酸初始质量浓度140 g/L、液固体积质量比4 mL/g、总压力1.9 M Pa、搅拌转速600 r/min、温度160

  15. Supramolecular Complexes Formed by the Self-assembly of Hydrophobic Bis(Zn(2+)-cyclen) Complexes, Copper, and Di- or Triimide Units for the Hydrolysis of Phosphate Mono- and Diesters in Two-Phase Solvent Systems (Cyclen=1,4,7,10-Tetraazacyclododecane).

    Hisamatsu, Yosuke; Miyazawa, Yuya; Yoneda, Kakeru; Miyauchi, Miki; Zulkefeli, Mohd; Aoki, Shin


    We previously reported on supramolecular complexes 4 and 5, formed by the 4 : 4 : 4 or 2 : 2 : 2 assembly of a dimeric zinc(II) complex (Zn2L(1)) having 2,2'-bipyridyl linker, dianion of cyanuric acid (CA) or 5,5-diethylbarbituric acid (Bar), and copper(II) ion (Cu(2+)) in an aqueous solution. The supermolecule 4 possesses Cu2(μ-OH)2 centers and catalyzes hydrolysis of phosphate monoester dianion, mono(4-nitrophenyl)phosphate (MNP), at neutral pH. In this manuscript, we report on design and synthesis of hydrophobic supermolecules 9 and 10 by 4 : 4 : 4 and 2 : 2 : 2 self-assembly of hydrophobic Zn2L(2) and Zn2L(3) containing long alkyl chains, CA or Bar, and Cu(2+) and their phosphatase activity for the hydrolysis of MNP and bis(4-nitrophenyl)phosphate (BNP) in two-phase solvent systems. We assumed that the Cu2(μ-OH)2 active sites of 9 and 10 would be more stable in organic solvent than in aqueous solution and that product inhibition of the supermolecules might be avoided by the release of HPO4(2-) into the aqueous layer. The findings indicate that 9 and 10 exhibit phosphatase activity in the two-phase solvent system, although catalytic turnover was not observed. Furthermore, the hydrolysis of BNP catalyzed by the hydrophobic 2 : 2 : 2 supermolecules in the two-phase solvent system is described.

  16. Labile Zn ions on octacalcium phosphate-derived Zn-containing hydroxyapatite surfaces

    Honda, Yoshitomo; Anada, Takahisa; Morimoto, Shinji [Division of Craniofacial Function Engineering (CFE), Tohoku University Graduate School of Dentistry, Sendai (Japan); Suzuki, Osamu, E-mail: [Division of Craniofacial Function Engineering (CFE), Tohoku University Graduate School of Dentistry, Sendai (Japan)


    We previously synthesized and characterized zinc-containing octacalcium phosphate (OCP) and its hydrolyzed Ca-deficient hydroxyapatite (HA). In the present report, we attempted to define the state of Zn in the OCP-derived Zn-calcium phosphates (CaPs) in relation to the presence of specific amino acids. Zn-containing OCPs were prepared in solutions that included Zn ions up to a concentration of 3.5 mM, and their hydrolyzates [hydrolyzed (hy)-Zn-CaP] were obtained in hot water. The materials were characterized by x-ray diffraction and scanning electron microscopy. The concentration of Ca and Zn ions at room temperature was determined by analyzing the supernatant after incubating the materials in α-minimal essential medium (α-MEM) and HEPES buffer including cysteine, histidine, lysine, aspartic acid, and glutamic acid. Zn ions were more dissolved in α-MEM than HEPES buffer in the absence of amino acids. The inclusion of the amino acids enhanced Zn dissolution by several hundred fold, even in HEPES buffer. Among the amino acids, both cysteine and histidine enhanced the release of Zn. The effect was particularly remarkable with cysteine even in the presence of the other amino acids tested. These results indicate that Zn ions are present as a surface labile pool, which tends to be preferentially desorbed by cysteine, a ubiquitous molecule present in serum.

  17. Labile Zn ions on octacalcium phosphate-derived Zn-containing hydroxyapatite surfaces

    Honda, Yoshitomo; Anada, Takahisa; Morimoto, Shinji; Suzuki, Osamu


    We previously synthesized and characterized zinc-containing octacalcium phosphate (OCP) and its hydrolyzed Ca-deficient hydroxyapatite (HA). In the present report, we attempted to define the state of Zn in the OCP-derived Zn-calcium phosphates (CaPs) in relation to the presence of specific amino acids. Zn-containing OCPs were prepared in solutions that included Zn ions up to a concentration of 3.5 mM, and their hydrolyzates [hydrolyzed (hy)-Zn-CaP] were obtained in hot water. The materials were characterized by x-ray diffraction and scanning electron microscopy. The concentration of Ca and Zn ions at room temperature was determined by analyzing the supernatant after incubating the materials in α-minimal essential medium (α-MEM) and HEPES buffer including cysteine, histidine, lysine, aspartic acid, and glutamic acid. Zn ions were more dissolved in α-MEM than HEPES buffer in the absence of amino acids. The inclusion of the amino acids enhanced Zn dissolution by several hundred fold, even in HEPES buffer. Among the amino acids, both cysteine and histidine enhanced the release of Zn. The effect was particularly remarkable with cysteine even in the presence of the other amino acids tested. These results indicate that Zn ions are present as a surface labile pool, which tends to be preferentially desorbed by cysteine, a ubiquitous molecule present in serum.

  18. Amending the anisotropy barrier and luminescence behavior of heterometallic trinuclear linear [M(II) -Ln(III) -M(II) ] (Ln(III) =Gd, Tb, Dy; M(II) =Mg/Zn) complexes by change from divalent paramagnetic to diamagnetic metal ions.

    Das, Sourav; Bejoymohandas, K S; Dey, Atanu; Biswas, Sourav; Reddy, M L P; Morales, Roser; Ruiz, Eliseo; Titos-Padilla, Silvia; Colacio, Enrique; Chandrasekhar, Vadapalli


    The sequential reaction of a multisite coordinating compartmental ligand [2-(2-hydroxy-3-(hydroxymethyl)-5-methylbenzylideneamino)-2-methylpropane-1,3-diol] (LH4 ) with appropriate lanthanide salts followed by the addition of [Mg(NO3 )2 ]⋅6 H2 O or [Zn(NO3 )2 ]⋅6 H2 O in a 4:1:2 stoichiometric ratio in the presence of triethylamine affords a series of isostructural heterometallic trinuclear complexes containing [Mg2 Ln](3+) (Ln=Dy, Gd, and Tb) and [Zn2 Ln](3+) (Ln=Dy, Gd, and Tb) cores. The formation of these complexes is demonstrated by X-ray crystallography as well as ESI-MS spectra. All complexes are isostructural possessing a linear trimetallic core with a central lanthanide ion. The comprehensive studies discussed involve the synthesis, structure, magnetism, and photophysical properties on this family of trinuclear [Mg2 Ln](3+) and [Zn2 Ln](3+) heterometallic complexes. [Mg2 Dy](3+) and [Zn2 Dy](3+) show slow relaxation of the magnetization below 12 K under zero applied direct current (dc) field, but without reaching a neat maximum, which is due to the overlapping with a faster quantum tunneling relaxation mediated through dipole-dipole and hyperfine interactions. Under a small applied dc field of 1000 Oe, the quantum tunneling is almost suppressed and temperature and frequency dependent peaks are observed, thus confirming the single-molecule magnet behavior of complexes [Mg2 Dy](3+) and [Zn2 Dy](3+) .

  19. 香豆素杯[4]芳烃的合成及其锌(Ⅱ)配合物的光谱%Synthesis of Coumarin- Calix[ 4 ] arene Derivative and Spectral Properties of Its Zn(Ⅱ) Complex

    王飞; 张晓梅; 徐国财


    为探寻对过渡金属离子具有配合作用的新型超分子配体,将杯[4]芳烃经醚化、氨解得到的中间体3与香豆素-3-甲酰氯反应,合成了新的合香豆素片段的杯[4]芳烃配体H2L,用1 HNMR、13CNMR、IR、MS( Maldi - Tof)表征其结构.H2L与醋酸锌反应,获得了相应锌(Ⅱ)配合物(LZn),元素分析及MS( ESI)分析结果表明,LZn的化学组成为L(ZnAc)2·2H2O.研究了锌(Ⅱ)配合物的UV和IR吸收光谱性质,还测定了它的荧光强度.结果表明,与H2L相比,锌(Ⅱ)配合物分子中共轭体系增大且平面刚性增加.%In order to seek a new supramolecular ligand with the capacity for coordination to transition metal I-ons, a new calix[4]arene derivative H2L with coumarin sections was synthesized by the reaction of coumarin -3 -formyl chloride with intermediater 3 prepared by etherification firstly and then ammonolysis of calix[4]arene, and its structure was characterized by 1HNMR, 13C NMR, IR and MS (Maldi -Tof). Reacting H2L with zinc acetate could produce a Zn(II) complex (LZn) , and the chemical composition of LZn was L(ZnAc)2 · 2H2O determined by elementary analysis and MS (ESI). Using IR and UV, the absorption spectra of LZn were studied, and the fluorescence intensity was examined also. Results showed that conjugation system in LZn was enlarged and plane rigidity increased by comparison with those in H2L.

  20. Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate ONO donor Schiff base ligand: Synthesis, characterization, thermal, non-isothermal kinetics and DFT calculations

    Kusmariya, Brajendra S.; Mishra, A. P.


    We report here four mononuclear Co(II), Ni(II), Cu(II) and Zn(II) coordination compounds of general formula [M(L)2] {L = dcp; M = CoII, CuII & ZnII} and [M(L)(H2O)]·H2O {L = dcp; M = NiII} derived from tridentate 2,4-dichloro-6-{[(3-chloro-2-hydroxy-5-nitrophenyl)imino]methyl}phenol (dcp) ligand. These compounds were synthesized and characterized by elemental analysis, FT-IR, uv-vis, 1H NMR, molar conductance, magnetic moment, thermal, PXRD and SEM-EDX. The Powder X-ray Diffraction patterns and SEM analyses showed the crystalline nature of synthesized compounds. The peak broadening was explained in terms of crystallite size and the lattice strain using Scherrer and Williamson-Hall method. Thermogravimetric analysis was performed to determine the thermal stability of synthesized compounds under nitrogen atmosphere up to 820 K at 10 Kmin-1 heating rate. The kinetic and thermodynamic parameters of thermal decomposition were calculated using Coats-Redfern (C-R), Piloyan-Novikova (P-N) and Horowitz-Metzger (H-M) methods assuming first order degradation. The calculated optical band gap values of complexes were found to be in semiconducting range. To support the experimental findings, and derive some fruitful information viz. frequency calculations, HOMO-LUMO, energy gap (ΔE), molecular electrostatic potential (MEP), spin density, absorption spectra etc.; theoretical calculations by means of DFT and TD-DFT at B3LYP level were incorporated.

  1. Solution Studies on Co(II, Ni(II, Cu(II, and Zn(II Complexes of Hexamethylenetetramine in Aqueous and Non-Aqueous Solvents

    Awawou G. Paboudam


    Full Text Available Potentiometric studies in aqueous medium and spectrophotometric study in non-aqueous medium were used to understand the behavior of hexamethylenetetramine (HMTA complexes. The protometric studies of HMTA enabled us to confirm that only one basic site of this ligand is protonated in acidic medium and this ligand is decomposed in acidic medium. In aqueous medium, only hexa-aqua complexes in which HMTA is present in the second coordination sphere forming H-bonds with hydrogen atoms of coordinated and uncoordinated water molecules are obtained. In non-aqueous solvents, HMTA coordinates to metal ions displaying diversity in the structures of the resulting complexes in which HMTA can either be monodentate, bridged bidentate, tridentate, or tetradentate.

  2. Synthesis, characterization and antimicrobial activity of Fe(II), Zn(II), Cd(II) and Hg(II) complexes with 2,6-bis(benzimidazol-2-yl) pyridine ligand.

    Aghatabay, Naz M; Neshat, A; Karabiyik, T; Somer, M; Haciu, D; Dülger, B


    2,6-Bis(benzimidazol-2-yl)pyridine (L) ligand and complexes [M(L)Cl(2)] and [Fe(L)(2)](ClO(4))(2) (M=Zn, Cd, Hg) have been synthesized. The geometries of the [M(L)Cl(2)] complexes were derived from theoretical calculation in DGauss/DFT level (DZVP basis set) on CACHE. The central M(II) ion is penta-coordinated and surrounded by N(3)Cl(2) environment, adopting a distorted trigonal bipyramidal geometry. The ligand is tridentate, via three nitrogen atoms to metal centre and two chloride ions lie on each side of the distorted benzimidazole ring. In the [Fe(L)(2)](ClO(4))(2) complex, the central Fe(II) ion is surrounded by two (3N) units, adopting a octahedral geometry. The elemental analysis, molecular conductivity, FT-Raman, FT-IR (mid-, far-IR), (1)H, and (13)C NMR were reported. The antimicrobial activities of the free ligand, its hydrochloride salt, and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against 10 bacteria and the results compared with that for gentamycin. Antifungal activities were reported for Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, Hanseniaspora guilliermondii, and the results were referenced against nystatin, ketaconazole, and clotrimazole antifungal agents. In most cases, the compounds tested showed broad-spectrum (Gram positive and Gram negative bacteria) activities that were either more effective than or as potent as the references. The binding of two most biologically effective compounds of zinc and mercury to calf thymus DNA has also been investigated by absorption spectra.

  3. Effects of polyphosphates and orthophosphate on the dissolution and transformation of ZnO nanoparticles.

    Wan, Biao; Yan, Yupeng; Tang, Yuanzhi; Bai, Yuge; Liu, Fan; Tan, Wenfeng; Huang, Qiaoyun; Feng, Xionghan


    The fate and toxicity of zinc oxide nanoparticles (ZnO NPs) in nature are affected by solution chemistry such as pH, anions, and natural organic matter (NOM). Inorganic polyphosphates are environmentally ubiquitous phosphorus (P) species that may change the speciation and environmental fate of ZnO NPs. In this study, the interactions of polyphosphates with ZnO NPs and the impacts on ZnO NP dissolution and transformation were investigated and compared with orthophosphate (P1). The results revealed that pyrophosphate (P2), tripolyphosphate (P3), and hexametaphosphate (P6) enhanced whereas P1 inhibited the dissolution of ZnO NPs. In addition, P1, P2, and P3 promoted the transformation of ZnO NPs into zinc phosphate (Zn-P) precipitates via interactions with dissolved Zn(2+). However, P6-promoted ZnO NP dissolution was through the formation of soluble Zn-P complexes due to the strong capability of P6 to chelate with Zn(2+). The transformation of ZnO NPs in the presence of P3 was affected by reaction time, pH, and P/Zn molar ratio. P3 first formed inner-sphere surface complexes on ZnO NPs, which gradually transformed into crystalline Zn2HP3O10(H2O)6 precipitates. This study provided a new perspective for understanding the reactivity of various forms of inorganic phosphate species with ZnO NPs in the natural environment.

  4. Complexes of myo-Inositol-Hexakisphosphate (IP6) with Zinc or Lanthanum for the Decorporation of Radiocesium.

    Ogawa, Kazuma; Aoki, Miho; Fukuda, Tadahisa; Kadono, Sumi; Kiwada, Tatsuto; Odani, Akira


    Radioactive nuclides leak into the surrounding environment after nuclear power plant disasters, such as the Chernobyl accident and the Fukushima Daiichi Nuclear Power Plant disaster. Cesium-137 ((137)Cs) (t1/2=30.1 year), a water-soluble radionuclide with a long physical half-life, contaminates aquatic ecosystems and food products. In humans, (137)Cs concentrates in muscle tissue and has a long biological half-life, indicating it may be harmful. myo-Inositol-hexakisphosphate (IP6) is a compound found in grain, beans, and oil seeds. IP6 has the ability to form insoluble complexes with metals, including lanthanum (La) and zinc (Zn). We hypothesized that La-IP6 and Zn-IP6 may promote the elimination of (137)Cs from the body through the adsorption of La-IP6 and Zn-IP6 to (137)Cs in the gastrointestinal tract. Therefore, in this study, we evaluated the adsorptive capacity of La-IP6 and Zn-IP6 complexes with (137)Cs in vitro and in vivo. La-IP6 and Zn-IP6 complexes were stable in acidic solution (pH 1.2) at 37°C. In vitro binding assays indicated that La-IP6 and Zn-IP6 complexes adsorbed (137)Cs, with the adsorption capacity of Zn-IP6 to (137)Cs greater than that of La-IP6. To evaluate the usefulness of La-IP6 and Zn-IP6 in vivo, La-IP6 or Zn-IP6 was administrated to mice after intravenous injection of (137)Cs. However, the biodistribution of (137)Cs in the La-IP6 treated group and the Zn-IP6 treated group was nearly identical to the non-treated control group, indicating that La-IP6 and Zn-IP6 were not effective at promoting the elimination of (137)Cs in vivo.




    Full Text Available The new adducts and complexes obtained have discrete or dimeric structures; in these structures the diamine behaves as a monodentate and hydrogen bonds involved or bidentate ligand. In one rare earth halide adduct the high coordination number (7 proposed is common for this family. When extra intermolecular hydrogen bonds are taken into account, supramolecular architectures may be obtained.

  6. Extracellular polymeric substances for Zn (II) binding during its sorption process onto aerobic granular sludge.

    Wei, Dong; Li, Mengting; Wang, Xiaodong; Han, Fei; Li, Lusheng; Guo, Jie; Ai, Lijie; Fang, Lulu; Liu, Ling; Du, Bin; Wei, Qin


    The aim of this study was to evaluate the interaction between extracellular polymeric substances (EPS) and Zn (II) during the sorption process of Zn (II) onto aerobic granular sludge. Batch results showed that the adsorption rate of Zn (II) onto aerobic granular sludge was better fitted with pseudo-second order kinetics model, and the adsorption isotherm data agreed well with Freundlich equation. Extracellular polymeric substances (EPS) for Zn (II) binding during sorption process was investigated by using a combination of three-dimensional excitation-emission matrix (3D-EEM), synchronous fluorescence spectra, two-dimensional correlation spectroscopy (2D-COS) and Fourier transform infrared spectroscopy (FTIR). Results implied that the main composes of EPS, including polysaccharide (PS) and protein (PN), decreased from 5.92±0.13 and 23.55±0.76 mg/g SS to 4.11±0.09 and 9.55±0.68 mg/g SS after the addition of different doses of Zn (II). 3D-EEM showed that the intensities of PN-like substances and humic-like substances were obviously decreased during the sorption process. According to synchronous fluorescence spectra, the quenching mechanism between PN-like substances and Zn (II) was mainly caused by a static quenching process. Additionally, 2D-COS indicated that PN-like substances were more susceptible to Zn (II) binding than humic-like substances. It was also found that the main functional groups for complexation of Zn (II) and EPS were OH groups, N-H groups and C=O stretching vibration. The findings of this study are significant to reveal the fate of heavy metal during its sorption process onto aerobic granular sludge through EPS binding, and provide useful information on the interaction between EPS and heavy metal.

  7. [Effects of ZnO Nanoparticles, ZnSO₄ and Arbuscular Mycorrhizal Fungus on the Growth of Maize].

    Li, Shuai; Liu, Xue-qin; Wang, Fa-yuan; Miao, Yan-fang


    As one of the most widely used metal-based nanoparticles (NPs), ZnO NPs have been shown to be toxic to organisms. Arbuscular mycorrhizal (AM) fungi can improve mineral nutrition and increase the resistance of host plants. However, little is known on the interaction between ZnO NPs and other Zn pollutants, as well as the effect of AM fungi on their biological effects. The present greenhouse pot culture experiment studied the effects of inoculation with or without AM fungus Funneliformis mosseae BEG 167 on the growth of maize in soil supplemented with ZnO NPs and ZnSO₄ (500 mg · kg⁻¹) seperately or in combination. The results showed that ZnO NPs inhibited mycorrhizal colonization and the growth of maize plants, showing similar phytotoxicity and effects to ZnSO₄at the same concentration (500 mg · kg⁻¹). Compared with the nonmycorrhizal controls, AM fungal inoculation decreased Zn concentrations or uptake in maize plants, and showed a better growth-promoting effect in the combination treatment. Our results showed for the first time that there was a complex interaction in their biological toxicity between ZnO NPs and ZnSO₄, while AM fungal inoculation exhibited a protective effect under combined pollution of ZnO NPs and ZnSO₄.

  8. Growth of vertically aligned ZnO nanorods using textured ZnO films

    Meléndrez Manuel


    Full Text Available Abstract A hydrothermal method to grow vertical-aligned ZnO nanorod arrays on ZnO films obtained by atomic layer deposition (ALD is presented. The growth of ZnO nanorods is studied as function of the crystallographic orientation of the ZnO films deposited on silicon (100 substrates. Different thicknesses of ZnO films around 40 to 180 nm were obtained and characterized before carrying out the growth process by hydrothermal methods. A textured ZnO layer with preferential direction in the normal c-axes is formed on substrates by the decomposition of diethylzinc to provide nucleation sites for vertical nanorod growth. Crystallographic orientation of the ZnO nanorods and ZnO-ALD films was determined by X-ray diffraction analysis. Composition, morphologies, length, size, and diameter of the nanorods were studied using a scanning electron microscope and energy dispersed x-ray spectroscopy analyses. In this work, it is demonstrated that crystallinity of the ZnO-ALD films plays an important role in the vertical-aligned ZnO nanorod growth. The nanorod arrays synthesized in solution had a diameter, length, density, and orientation desirable for a potential application as photosensitive materials in the manufacture of semiconductor-polymer solar cells. PACS 61.46.Hk, Nanocrystals; 61.46.Km, Structure of nanowires and nanorods; 81.07.Gf, Nanowires; 81.15.Gh, Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.

  9. Surfactant-thermal method to synthesize a new Zn(II)-trimesic MOF with confined Ru(bpy){sub 3}{sup 2+} complex

    Xu, Hui [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China); Gao, Junkuo, E-mail: [The Key laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Wang, Jiangpeng; Qian, Xuefeng [The Key laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Song, Ruijing; Cui, Yuanjing; Yang, Yu [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China); Qian, Guodong, E-mail: [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China)


    A surfactant-thermal method was used to prepare a new zinc-1,3,5-benzentricarboxylate-based metal-organic framework (ZJU-100) with confined Ru(bpy){sub 3}{sup 2+} (RuBpy) complex by using surfactant PEG 400 as reaction medium. The RuBpy molecules were encapsulated between the 2-D sheets in ZJU-100. ZJU-100 showed bathochromic shift in the steady-state emission spectrum and increased emission lifetimes relative to RuBpy molecules. The extended lifetime is attributed to the reduced nonradiative decay rate due to the stabilization of RuBpy within the rigid MOF framework. These results represent the first example of MOF with confined complex synthesized by surfactant, indicating that the surfactant-thermal method could offer exciting opportunities for preparing new MOFs host/guest materials with novel structures and interesting luminescent properties. - Graphical abstract: A surfactant-thermal method was used to prepare a new zinc-1,3,5-benzentricarboxylate-based metal-organic framework (ZJU-100) with confined Ru(bpy){sub 3}{sup 2+} (RuBpy) complex by using surfactant PEG 400 as reaction medium. - Highlights: • Surfactant-thermal synthesis of crystalline metal-organic framework host/guest materials. • RuBpy molecules were encapsulated between the 2-D sheets of MOFs. • Extended lifetime is observed due to the stabilization of RuBpy within the rigid MOF framework.

  10. A fluorescent bis(benzoxazole) ligand: toward binuclear Zn(II)-Zn(II) assembly.

    Chu, Qinghui; Medvetz, Doug A; Panzner, Matthew J; Pang, Yi


    A bis(benzoxazole) ligand (HL) has been synthesized, and its reaction with Zn(OAc)(2) has led to fluorescent complexes via formation of binuclear Zn(II)-Zn(II) cores. The ligand-to-metal ratio of the complexes varies from 1 : 1 to 2 : 1, depending on the reaction conditions. A large binding constant K = 8.3 x 10(20) [M(-3)] has been determined for the reaction L + Zn(2+)-->L(2):Zn(2)(2+). The result indicates that the bis(benzoxazole) ligand is a useful building block to construct a binuclear core. On the basis of X-ray analysis, the binuclear Zn(II)-Zn(II) distance in the complexes is determined to be approximately 3.22 A, which is quite comparable to that found in the enzymes (3.3 A). Absorption and fluorescence study shows that a subtle chemical environmental change within the binuclear core can induce a large optical response.

  11. Influence of terminal acryloyl arms on the coordination chemistry of a ditopic pyrimidine-hydrazone ligand: comparison of Pb(II), Zn(II), Cu(II), and Ag(I) complexes.

    Hutchinson, Daniel J; Hanton, Lyall R; Moratti, Stephen C


    A new ditopic pyrimidine-hydrazone ligand, 6-hydroxymethylacryloyl-2-pyridinecarboxaldehyde, 2,2'-[2,2'-(2-methyl-4,6-pyrimidinediyl)bis(1-methylhydrazone)] (L2), was synthesized with terminal acryloyl functional groups to allow incorporation into copolymer gel actuators. NMR spectroscopy was used to show that L2 adopted a horseshoe shape with transoid-transoid pym-hyz-py linkages. Metal complexation studies were performed with L2 and salts of Pb(II), Zn(II), Cu(II), and Ag(I) ions in CH3CN in a variety of metal to ligand ratios. Reacting L2 with an excess amount of any of the metal ions resulted in linear complexes where the pym-hyz-py linkages were rotated to a cisoid-cisoid conformation. NMR spectroscopy showed that the acryloyl arms of L2 did not interact with the bound metal ions in solution. Seven of the linear complexes (1-7) were crystallized and analyzed by X-ray diffraction. Most of these complexes (4-7) also showed no coordination between the acryloyl arms and the metal ions; however, complexes 1-3 showed some interactions. Both of the acryloyl arms were coordinated to Pb(II) ions in [Pb2L2(SO3CF3)4] (1), one through the carbonyl oxygen donor and the other through the alkoxy oxygen donor. One of the acryloyl arms of [Cu2L2(CH3CN)3](SO3CF3)4 (2) was coordinated to one of the Cu(II) ions through the carbonyl oxygen donor. There appeared to be a weak association between the alkoxy donors of the acryloyl arms and the Pb(II) ions of [Pb2L2(ClO4)4]·CH3CN (3). Reaction of excess AgSO3CF3 with L2 was repeated in CD3NO2, resulting in crystals of {[Ag7(L2)2(SO3CF3)6(H2O)2] SO3CF3}∞ (8), the polymeric structure of which resulted from coordination between the carbonyl donors of the acryloyl arms and the Ag(I) ions. In all cases the coordination and steric effects of the acryloyl arms did not inhibit isomerization of the pym-hyz bonds of L2 or the core shape of the linear complexes.

  12. Fractionation of Cu and Zn isotopes during adsorption onto amorphous Fe(III) oxyhydroxide: Experimental mixing of acid rock drainage and ambient river water

    Balistrieri, Laurie S.; Borrok, David M.; Wanty, Richard B.; Ridley, W. Ian


    Fractionation of Cu and Zn isotopes during adsorption onto amorphous ferric oxyhydroxide is examined in experimental mixtures of metal-rich acid rock drainage and relatively pure river water and during batch adsorption experiments using synthetic ferrihydrite. A diverse set of Cu- and Zn-bearing solutions was examined, including natural waters, complex synthetic acid rock drainage, and simple NaNO3 electrolyte. Metal adsorption data are combined with isotopic measurements of dissolved Cu (65Cu/63Cu) and Zn (66Zn/64Zn) in each of the experiments. Fractionation of Cu and Zn isotopes occurs during adsorption of the metal onto amorphous ferric oxyhydroxide. The adsorption data are modeled successfully using the diffuse double layer model in PHREEQC. The isotopic data are best described by a closed system, equilibrium exchange model. The fractionation factors (αsoln-solid) are 0.99927 ± 0.00008 for Cu and 0.99948 ± 0.00004 for Zn or, alternately, the separation factors (Δsoln-solid) are -0.73 ± 0.08‰ for Cu and -0.52 ± 0.04‰ for Zn. These factors indicate that the heavier isotope preferentially adsorbs onto the oxyhydroxide surface, which is consistent with shorter metal-oxygen bonds and lower coordination number for the metal at the surface relative to the aqueous ion. Fractionation of Cu isotopes also is greater than that for Zn isotopes. Limited isotopic data for adsorption of Cu, Fe(II), and Zn onto amorphous ferric oxyhydroxide suggest that isotopic fractionation is related to the intrinsic equilibrium constants that define aqueous metal interactions with oxyhydroxide surface sites. Greater isotopic fractionation occurs with stronger metal binding by the oxyhydroxide with Cu > Zn > Fe(II).

  13. Fractionation of Cu and Zn isotopes during adsorption onto amorphous Fe(III) oxyhydroxide: Experimental mixing of acid rock drainage and ambient river water

    Balistrieri, L.S.; Borrok, D.M.; Wanty, R.B.; Ridley, W.I.


    Fractionation of Cu and Zn isotopes during adsorption onto amorphous ferric oxyhydroxide is examined in experimental mixtures of metal-rich acid rock drainage and relatively pure river water and during batch adsorption experiments using synthetic ferrihydrite. A diverse set of Cu- and Zn-bearing solutions was examined, including natural waters, complex synthetic acid rock drainage, and simple NaNO3 electrolyte. Metal adsorption data are combined with isotopic measurements of dissolved Cu (65Cu/63Cu) and Zn (66Zn/64Zn) in each of the experiments. Fractionation of Cu and Zn isotopes occurs during adsorption of the metal onto amorphous ferric oxyhydroxide. The adsorption data are modeled successfully using the diffuse double layer model in PHREEQC. The isotopic data are best described by a closed system, equilibrium exchange model. The fractionation factors (??soln-solid) are 0.99927 ?? 0.00008 for Cu and 0.99948 ?? 0.00004 for Zn or, alternately, the separation factors (??soln-solid) are -0.73 ?? 0.08??? for Cu and -0.52 ?? 0.04??? for Zn. These factors indicate that the heavier isotope preferentially adsorbs onto the oxyhydroxide surface, which is consistent with shorter metal-oxygen bonds and lower coordination number for the metal at the surface relative to the aqueous ion. Fractionation of Cu isotopes also is greater than that for Zn isotopes. Limited isotopic data for adsorption of Cu, Fe(II), and Zn onto amorphous ferric oxyhydroxide suggest that isotopic fractionation is related to the intrinsic equilibrium constants that define aqueous metal interactions with oxyhydroxide surface sites. Greater isotopic fractionation occurs with stronger metal binding by the oxyhydroxide with Cu > Zn > Fe(II).

  14. Modified Sandwich-graft Technique Employing Aorfix and Viabahn Stent-grafts to Preserve Hypogastric Flow in Cases of Complex Aortoiliac and Isolated Common Iliac Artery Aneurysms Including the Internal Iliac Artery Ostium.

    Lim, C S; Naji, Y; Hussain, S T; Pleban, E; Wiszniewski, A; Onida, S; Mosquera Arochena, N J; Szopinski, P


    The aim was to assess the early and mid-term safety and clinical outcomes of a modified sandwich-graft technique (MSGT) that employed the Aorfix and Viabahn stent-grafts to preserve hypogastric flow in cases of complex aortoiliac and isolated common iliac artery (CIA) aneurysms including internal iliac artery (IIA) ostium who were not suitable for an iliac branch device (IBD). A review of prospective collected data of all consecutive cases of treatment of complex aortoiliac or isolated CIA aneurysms including IIA ostium using the MSGT to preserve the hypogastric flow in three European centres between April 1, 2010, and December 31, 2013, was performed. All patients included were unfit for open repair and not suitable for an IBD. During the study period, 21 patients met the study criteria and had 25 MSGTs. The mean follow-up duration was 17.2 months. The technical success rate was 100%, with no perioperative mortality and stent-graft or MSGT-treated IIA occlusions. There were two cases with Type Ib endoleaks and one Type III endoleaks intraoperatively that were successfully managed. There was also no reported early and late pelvic ischaemia. The primary patency rate was 90.5%, and two cases of MGST treated IIA occlusions with no reported symptoms of pelvic ischaemia during follow-up. MSGT was a safe and feasible strategy to preserve hypogastric flow in cases of complex aortoiliac and isolated CIA aneurysms including IIA ostium and who were not suitable for IBD, with encouraging early and mid-term outcomes. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  15. Corrosion Inhibition by Sodium Gluconate-Zn2+-DTPMP System

    P. Manjula


    Full Text Available The inhibition efficiency of a phosphonic acid, Diethylene Triamine Pentamethylene Phosphonic acid (DTPMP in controlling corrosion of carbon steel immersed in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight loss method in the absence and presence of Zn2+. The formulation consisting of DTPMP and Zn2+ has excellent inhibition efficiency (IE. A synergistic effect is noticed between Zn2+ and DTPMP. Addition of sodium gluconate (SG enhances the IE of Zn2+ and DTPMP system. The DTPMP-Zn2+-SG system function as a mixed inhibitor as revealed by polarization study. AC impedance spectrum, optical and atomic force micrographs reveal the formation of a protective film on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+-DTPMP complex, Fe2+-SG complex and Zn(OH2.

  16. Metathesis synthesis and characterization of complex metal fluoride, KMF3 (M = Mg, Zn, Mn, Ni, Cu and Co) using mechanochemical activation

    V Manivannan; P Parhi; Jonathan W Kramer


    Metathesis synthesis of complex metal fluorides using mechanochemical activation has been reported. The high lattice energy of the byproduct KCl helps the reaction towards product formation in under 20 min. The proposed process, in contrast to the available methods of synthesis, is very rapid, economical and results in products with controlled morphology. The structural, optical and chemical properties of synthesized powders are determined by powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, magnetization measurements and diffused reflectance spectra in the UV–VIS range.

  17. Experimental and theoretical study of the decomposition of [Zn(NO3)3]-

    Hester, Thomas H.; Goebbert, Daniel J.


    Zinc nitrate anion complexes, [Zn(NO3)3]- and [ZnO(NO3)2]-, were generated by electrospray ionization and studied by tandem mass spectrometry. Dissociation of [Zn(NO3)3]- yields two direct fragments, [ZnO(NO3)2]- and NO3-. In contrast, the [ZnO(NO3)2]- complex produces several zinc-containing fragments. Three direct elimination products from [ZnO(NO3)2]- are identified as [Zn(NO2)(NO3)]-, [ZnO2(NO3)]-, and [ZnO(NO3)]-. The [ZnO2(NO3)]- product undergoes further elimination of O2 to yield either [ZnO(NO2)]- or [Zn(NO3)]-. Theory predicts a mixture of the product isomers, [ZnO(NO2)]- and [Zn(NO3)]-, is formed due to similar energetics. The increased reactivity of [ZnO(NO3)2]- is attributed to radical anion character on the unique oxygen atom.

  18. Direct evidence for As as a Zn-site impurity in ZnO

    Wahl, Ulrich; Correia, J G; Lourenço-Santana-Marques, Ana Claudia; Alves, E; Carvalho-Soares, José


    Arsenic has been reported in the literature as one of the few p-type dopants in the technologically promising II-VI semiconductor ZnO. However, there is an ongoing debate whether the p-type character is due to As simply replacing O atoms or to the formation of more complicated defect complexes, possibly involving As on Zn sites. We have determined the lattice location of implanted As in ZnO by means of conversion electron emission channeling from radioactive $^{73}$As. In contrast to what one might expect from its nature as a group V element, we find that As does not occupy substitutional O sites but in its large majority substitutional Zn sites. Arsenic in ZnO (and probably also in GaN) is thus an interesting example for an impurity in a semiconductor where the major impurity lattice site is determined by atomic size and electronegativity rather than its position in the periodic system.

  19. Non-bonding interactions and non-covalent delocalization effects play a critical role in the relative stability of group 12 complexes arising from interaction of diethanoldithiocarbamate with the cations of transition metals Zn(II), Cd(II), and Hg(II): a theoretical study.

    Bahrami, Homayoon; Farhadi, Saeed; Siadatnasab, Firouzeh


    The chelating properties of diethanoldithiocarbamate (DEDC) and π-electron flow from the nitrogen atom to the sulfur atom via a plane-delocalized π-orbital system (quasi ring) was studied using a density functional theory method. The molecular structure of DEDC and its complexes with Zn(II), Cd(II), and Hg(II) were also considered. First, the geometries of this ligand and DEDC-Zn(II), DEDC-Cd(II), and DEDC-Hg(II) were optimized, and the formation energies of these complexes were then calculated based on the electronic energy, or sum of electronic energies, with the zero point energy of each species. Formation energies indicated the DEDC-Zn(II) complex as the most stable complex, and DEDC-Cd(II) as the least stable. Structural data showed that the N1-C2 π-bond was localized in the complexes rather than the ligand, and a delocalized π-bond over S7-C2-S8 was also present. The stability of DEDC-Zn(II), DEDC-Cd(II), and DEDC-Hg(II) complexes increased in the presence of the non-specific effects of the solvent (PCM model), and their relative stability did not change. There was π-electron flow or resonance along N1-C2-S7 and along S7-C2-S8 in the ligand. The π-electron flow or resonance along N1-C2-S7 was abolished when the metal interacted with sulfur atoms. Energy belonging to van der Waals interactions and non-covalent delocalization effects between the metal and sulfur atoms of the ligand was calculated for each complex. The results of nucleus-independent chemical shift (NICS) indicated a decreasing trend as Zn(II) < Cd(II) < Hg(II) for the aromaticity of the quasi-rings. Finally, by ignoring van der Waals interactions and non-covalent delocalization effects between the metal and sulfur atoms of the ligand, the relative stability of the complexes was changed as follows:[Formula: see text] Graphical Abstract Huge electronic cloud localized on Hg(II) in the Hg(II)-DEDC complex.

  20. Revisiting the geometry of nd10 (n+1)s0 [M(H2O)]p+ complexes using four-component relativistic DFT calculations and scalar relativistic correlated CSOV energy decompositions (M(p+) = Cu+, Zn2+, Ag+, Cd2+, Au+, Hg2+).

    Gourlaouen, Christophe; Piquemal, Jean-Philip; Saue, Trond; Parisel, Olivier


    Hartree-Fock and DFT (B3LYP) nonrelativistic (scalar relativistic pseudopotentials for the metallic cation) and relativistic (molecular four-component approach coupled to an all-electron basis set) calculations are performed on a series of six nd10 (n+1)s0 [M(H2O)]p+ complexes to investigate their geometry, either planar C2v or nonplanar C(s). These complexes are, formally, entities originating from the complexation of a water molecule to a metallic cation: in the present study, no internal reorganization has been found, which ensures that the complexes can be regarded as a water molecule interacting with a metallic cation. For [Au(H2O)]+ and [Hg(H2O)]2+, it is observed that both electronic correlation and relativistic effects are required to recover the C(s) structures predicted by the four-component relativistic all-electron DFT calculations. However, including the zero-point energy corrections makes these shallow C(s) minima vanish and the systems become floppy. In all other systems, namely [Cu(H2O)]+, [Zn(H2O)]2+, [Ag(H2O)]+, and [Cd(H2O)]2+, all calculations predict a C2v geometry arising from especially flat potential energy surfaces related to the out-of-plane wagging vibration mode. In all cases, our computations point to the quasi-perfect transferability of the atomic pseudopotentials considered toward the molecular species investigated. A rationalization of the shape of the wagging potential energy surfaces (i.e., single well vs. double well) is proposed based on the Constrained Space Orbital Variation decompositions of the complexation energies. Any way of stabilizing the lowest unoccupied orbital of the metallic cation is expected to favor charge-transfer (from the highest occupied orbital(s) of the water ligand), covalence, and, consequently, C(s) structures. The CSOV complexation energy decompositions unambiguously reveal that such stabilizations are achieved by means of relativistic effects for [Au(H2O)]+, and, to a lesser extent, for [Hg(H2O)]2

  1. The structure of ? precipitates in Mg-Zn-Y alloys

    Singh, Alok; Rosalie, Julian M.; Somekawa, Hidetoshi; Mukai, Toshiji


    It is shown here by high-resolution electron microscopy that the structure of rod-like ? precipitates perpendicular to the basal planes of the magnesium matrix in Mg-Zn-Y alloys consist of complex domains at nanoscale. These domains can be recognized to be those of monoclinic Mg4Zn7 phase and hexagonal Laves phase MgZn2 with axial orientations ? . Due to disorder, often complete unit cells of the Mg4Zn7 structure cannot be recognized. Inside a domain of Mg4Zn7, the structure may locally transform to that of MgZn2. The structure of both the phases are composed of similar units of icosahedral coordinations. Maintaining the above axial orientation, the Mg4Zn7 can exhibit two orientation relationships with the matrix, ? or ? . The hexagonal MgZn2 forms in the monoclinic Mg4Zn7 in two different orientations, related to rhombic units (with angle ∼72°) in the Mg4Zn7 unit cell. With the common axial relationship given above, these two orientation relationships can be given as ? or ? . One of these two variants forms a known orientation relationship ? , ? with the matrix. The structure of the MgZn2 was found to be modified by the ordering of zinc layers perpendicular to the hexagonal axis.

  2. Biodegradable coordination polymer: Polycondensation of glutaraldehyde and starch in complex formation with transition metals Mn(II, Co(II, Ni(II, Cu(II and Zn(II

    Nahid Nishat


    Full Text Available Starch a biopolymer, possesses many unique characteristics features accompanied with some shortcoming simultaneously. Some synthetic compounds are of great help to these demerits of starch and so by an addition of all these alternatively may acquire the tailor made features of starch-based compounds. By combining the individual advantages of starch and some other compounds and elements, starch-based biodegradable polymers were prepared for potential applications in biomedical and environmental fields. In this research, the structural analysis and characterization studies of starch glutaraldehyde polycondensed polymer were undertaken, and then the formation of polymer metal complexes with transition metal in coordinated form are carried out. FT-IR spectroscopy and 1H NMR and 13C NMR spectroscopy were used to analyze the functionality of the synthesized compound. CHN of the synthesized compound was supported by FT-IR and NMR which again proved helpful for structural analysis. Electronic spectroscopy confirmed the geometry of the synthesized compounds. Thermal studies were carried out by thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. Besides this the biodegradable studies were carried out by ASTM standards of biodegradable materials by CO2 evolution in respirometric titration method. All the polymers showed good thermal strength and reduced biodegradation on attachment of transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II.

  3. Oxoaporphine Metal Complexes (CoII, NiII, ZnII) with High Antitumor Activity by Inducing Mitochondria-Mediated Apoptosis and S-phase Arrest in HepG2

    Qin, Jiao-Lan; Shen, Wen-Ying; Chen, Zhen-Feng; Zhao, Li-Fang; Qin, Qi-Pin; Yu, Yan-Cheng; Liang, Hong


    Three new oxoaporphine Co(II), Ni(II) and Zn(II) complexes 1–3 have been synthesized and fully characterized. 1–3 have similar mononuclear structures with the metal and ligand ratio of 1:2. 1–3 exhibited higher cytotoxicity than the OD ligand and cisplatin against HepG2, T-24, BEL-7404, MGC80–3 and SK-OV-3/DDP cells, with IC50 value of 0.23−4.31 μM. Interestingly, 0.5 μM 1–3 significantly caused HepG2 arrest at S-phase, which was associated with the up-regulation of p53, p21, p27, Chk1 and Chk2 proteins, and decrease in cyclin A, CDK2, Cdc25A, PCNA proteins. In addition, 1–3 induced HepG2 apoptosis via a caspase-dependent mitochondrion pathway as evidenced by p53 activation, ROS production, Bax up-regulation and Bcl-2 down-regulation, mitochondrial dysfunction, cytochrome c release, caspase activation and PARP cleavage. Furthermore, 3 inhibited tumor growth in HepG2 xenograft model, and displayed more safety profile in vivo than cisplatin. PMID:28436418

  4. 锌铋复杂氧化物Bi2Zn5O8的合成及其晶体生长特性%Synthesis and Crystal Growth Characteristic of Zinc Bismuth Complex Oxide Bi2Zn5O8



    The zinc bismuth complex oxides were prepared from zinc sulfate, bismuth nitrate and sodium hydroxide under ultrasonic irradiation.The effects of feed order and feed molar ratio on the final product were studied.The properties of the product were characterized by TG-DTA, SEM and TEM.The chemical composition was defined by means of X-ray fluorescence and continuous titration.The TEM and SEM images showed the dendrite crystal was formed.%利用硫酸锌、硝酸铋、氢氧化钠为原料在超声体系中反应合成锌铋复杂氧化物,考察了反应物料比和加料顺序对产物组成的影响.经X射线荧光及化学滴定确定了产物的分子式为Bi2Zn5O8,并由TEM、SEM和TG-DTA等方法对所得产物进行表征.TEM和SEM结果显示晶体呈枝蔓晶生长.

  5. On Cu diffusion in ZnO

    Herklotz, F.; Lavrov, E.V.; Weber, J. [Technische Universitaet Dresden (Germany)


    Copper in ZnO is of special interest since recent theoretical and experimental studies found ferromagnetic behavior of ZnO:Cu at room temperature. In addition, Cu is a deep acceptor in ZnO and one of the causes of the green emission band. Experimental studies of Cu diffusion in bulk ZnO single crystals were carried out in the temperature range 1030 to 1180 C. Concentration profiles of substitutional Cu were determined via IR absorption at 5817 cm{sup -1}. Our findings reveal that the diffusion coefficient of Cu is 7.6 x 10{sup 7} exp(-4.56 eV/k{sub B}T) cm{sup 2}s{sup -1}. This is about a factor of 25 higher than reported in the earlier studies, which probed the total Cu concentration. The discrepancy is explained by the formation of Cu complexes, which occurs at high concentrations. Diffusion mechanisms are discussed.

  6. Low-temperature synthesis of ZnO nanonails

    Song, Xubo; Zhang, Yaohua; Zheng, Jie; Li, Xingguo


    Wurtzite ZnO nanonails on silicon substrate were successfully synthesized by thermal vapor transport and condensation method at a low temperature without a metal catalyst. Pure Zn powders were used as raw material and O2/Ar powders as source gas. The products were characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results show that the deposited nanostructures include aligned ZnO nanonails. The ZnO nanonails, with crystalline cap and small-diameter shafts, grow along the c-axis. The optical properties have been revealed by photoluminescence spectra. We considered that the ZnO nanonails growth is a vapor solid process.

  7. Room-temperature violet luminescence and ultraviolet photodetection of Sb-doped ZnO/Al-doped ZnO homojunction array.

    Chen, Wei-Jen; Wu, Jen-Kai; Lin, Jheng-Cyuan; Lo, Shun-Tsung; Lin, Huang-De; Hang, Da-Ren; Shih, Ming Feng; Liang, Chi-Te; Chang, Yuan Huei


    A Sb-doped ZnO microrod array was fabricated on an Al-doped ZnO thin film by electrodeposition. Strong violet luminescence, originated from free electron-to-acceptor level transitions, was identified by temperature-dependent photoluminescence measurements. This acceptor-related transition was attributed to substitution of Sb dopants for Zn sites, instead of O sites, to form a complex with two Zn vacancies (VZn), the SbZn-2VZn complex. This SbZn-2VZn complex has a lower formation energy and acts as a shallow acceptor which can induce the observed strong violet luminescence. The photoresponsivity of our ZnO p-n homojunction device under a negative bias demonstrated a nearly 40-fold current gain, illustrating that our device is potentially an excellent candidate for photodetector applications in the ultraviolet wavelength region.

  8. Internal Zn allocation influences Zn deficiency tolerance and grain Zn loading in rice (Oryza sativa L.

    Impa Muthappa Somayanda


    Full Text Available One of the important factors that influences Zn deficiency tolerance and grain Zn loading in crops is the within-plant allocation of Zn. Three independent experiments were carried out to understand the internal Zn distribution patterns in rice genotypes grown in Zn-sufficient and Zn-deficient agar nutrient solution (ANS. In one of the experiments, two rice genotypes (IR55179 and KP contrasting in Zn deficiency tolerance were leaf-labeled with 65Zn. In the other two experiments, two Zn biofortification breeding lines (IR69428 and SWHOO were either root- or leaf-labeled with 65Zn. Rice genotype IR55179 showed significantly higher Zn deficiency tolerance than KP at 21 and 42 days after planting. When KP was Zn-deficient, it failed to translocate 65Zn from the labeled leaf to newly emerging leaves. Similarly, the root-to-shoot translocation of unlabeled Zn was lower in KP than in IR55179. These results suggest that some Zn-efficient rice genotypes have greater ability to translocate Zn from older to actively growing tissues than genotypes sensitive to Zn deficiency. Among the two Zn biofortication breeding lines that were leaf-labeled with 65Zn at 10 days before panicle initiation stage, 65Zn distribution in the grains at maturity was similar between both genotypes in Zn-sufficient conditions. However, under Zn-deficient conditions, SWHOO accumulated significantly higher 65Zn in grains than IR69428, indicating that SWHOO is a better remobilizer than IR69428. When the roots of these two Zn biofortication breeding lines were exposed to 65Zn solution at 10 days after flowering, IR69428 showed higher root uptake of 65Zn than SWHOO in Zn-sufficient conditions, but 65Zn allocation in the aerial parts of the plant was similar between both genotypes.

  9. Structure and corrosion resistance of Zn-Ni alloy coatings electrodeposited from alkaline binary complexes bath%二元配合物中电镀锌镍合金的结构与抗腐蚀性

    张秀; 龙晋明; 裴和中; 由劲博; 黄攀


    为深入了解碱性锌酸盐体系的工艺参数对锌镍合金镀层结构和耐蚀性的影响,在以四乙烯五胺( TEPA)为镍离子主络合剂、三乙醇胺( TEA)为辅助络合剂的碱性镀液中电沉积制备了锌镍合金镀层,利用电子能谱、X射线衍射、极化曲线和电化学阻抗谱等方法表征镀层的组成结构和在氯化钠溶液中的耐腐蚀性.结果表明:镀层含镍原子数分数11.54%~20.12%,为γ-Ni2 Zn11+纯Zn两相结构(低含镍原子数分数时)或单一γ相结构(较高含镍原子数分数时),γ相晶粒在(600)方向上具有不同程度的择优取向性;随着镀液中镍原子数分数的提高,镀层的腐蚀电位正移,阻抗增加,耐蚀性提高;当电流密度为2 A/dm2时,镀层的腐蚀电位和电荷传递电阻最高,耐蚀性最好.%To know how the technological parameters affect the structure and anti⁃corrosion property of Zinc⁃nickel alloy plating in alkaline zincate system, the synthesis of the zinc⁃nickel alloy plating is made by the electrochemical deposition method. The alkaline solution is a mixture of Tetraethylenepentamine ( TEPA) and Triethanolamine ( TEA ) , and the prior part is the main complexing agent for nickel ions. The energy dispersive spectrometer ( EDS ) , X⁃ray diffraction ( XRD ) associated with polarization curves and electrochemical impedance spectroscopy ( EIS ) were used to characterize the structure and anti⁃corrosion property respectively. The result shows that the particles inγ⁃phase preferred (600) orientation with respect to the atom percentage of nickel varies between 11.54% and 20.12%, 11.54% corresponds to aγ⁃Ni2 Zn11 and Zn two⁃phase area and 20.12% corresponds to a single γ⁃phase. With an increasing atom percentage of nickel in the bath, the corrosion potential of plating becomes more positive, which results in an increasing impedance and a better anti

  10. Zinc-Dependent Lysosomal Enlargement in TRPML1-Deficient Cells Involves MTF-1 Transcription Factor and ZnT4 (Slc30a4) Transporter


    Zn is critical for a multitude of cellular processes, including gene expression, secretion and enzymatic activities. Cellular Zn is controlled by Zn-chelating proteins and by Zn transporters. The recent identification of Zn permeability of the lysosomal ion channel TRPML1, and the evidence of abnormal Zn levels in cells deficient in TRPML1, suggested a role for TRPML1 in Zn transport. Here we provide new evidence for such a role and identify additional cellular components responsible for it. ...

  11. Controllable synthesis of branched ZnO/Si nanowire arrays with hierarchical structure.

    Huang, Shengli; Yang, Qianqian; Yu, Binbin; Li, Dingguo; Zhao, Ruisheng; Li, Shuping; Kang, Junyong


    A rational approach for creating branched ZnO/Si nanowire arrays with hierarchical structure was developed based on a combination of three simple and cost-effective synthesis pathways. The crucial procedure included growth of crystalline Si nanowire arrays as backbones by chemical etching of Si substrates, deposition of ZnO thin film as a seed layer by magnetron sputtering, and fabrication of ZnO nanowire arrays as branches by hydrothermal growth. The successful synthesis of ZnO/Si heterogeneous nanostructures was confirmed by morphologic, structural, and optical characterizations. The roles of key experimental parameters, such as the etchant solution, the substrate direction, and the seed layer on the hierarchical nanostructure formation, were systematically investigated. It was demonstrated that an etchant solution with an appropriate redox potential of the oxidant was crucial for a moderate etching speed to achieve a well-aligned Si nanowire array with solid and round surface. Meanwhile, the presence of gravity gradient was a key issue for the growth of branched ZnO nanowire arrays. The substrate should be placed vertically or facedown in contrast to the solution surface during the hydrothermal growth. Otherwise, only the condensation of the ZnO nanoparticles took place in a form of film on the substrate surface. The seed layer played another important role in the growth of ZnO nanowire arrays, as it provided nucleation sites and determined the growing direction and density of the nanowire arrays for reducing the thermodynamic barrier. The results of this study might provide insight on the synthesis of hierarchical three-dimensional nanostructure materials and offer an approach for the development of complex devices and advanced applications.

  12. Zn-Al-La hydrotalcite-like compounds as heating stabilizer in PVC resin

    WEN Runjuan; YANG Zhanhong; CHEN Hongyan; HU Youwang; DUAN Ji'an


    ZnAlLa-CO3 layered double hydroxides (LDHs) with different Zn/Al/La molar ratios were prepared by the constant pH coprecipitation method.The synthetic materials were characterized by X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),scanning electron microscopy (SEM),Brtmauer-Emmett-Teller method (BET) and particle analysis.The results showed that the hydrotalcite-like materials had a layered structure.The ZnAlLa-CO3-LDHs as stabilizers were mixed with PVC resin.The tests of thermal aging,mass loss test and Congo red for the PVC composites were carried out at 180±1 ℃,respectively.The results showed that ZnAlLa-CO3- LDHs used as single thermal stabilizers could enhance both the long-term thermal stability and initial thermal stability of PVC,and 2.4 phr (parts per hundred PVC resin) ZnAlLa-CO3-LDHs with Zn/Al/La (molar ratio)=20/8/2 had a better stabilizing effect on PVC than others.Compared with single thermal stabilizers,the composite thermal stabilizers including 0.3 phr calcium stearate (CaSt2),0.4 phr β-diketone and 2.4 phr ZnAlLa-CO3-LDHs significantly enhanced the thermal stability of PVC sample.And rare earth ion could optimize the conformation of PVC and refrain the initiation of the thermal stability and the thermal stable time was over 220 min.The main reason could be concluded to the special structure of rare earth ion,which had longer atom radius and more coordination numbers.So the rare earth ion (REδ+) could react with the labile chlorine atoms (Cl-) to form a stable coordinate complex.

  13. Effects of Complex Heavy Metals Pb/Zn on the Physiological Characteristics of Paulowniu fortunel (seem) Hems.%复合重金属Pb /Zn对香樟生理特征的影响

    王锦文; 白秀; 陈锦峰; 王江; 张崇邦


    [目的]阐明重金属Pb /Zn复合污染对香樟生理的影响,为利用香樟进行尾矿恢复提供技术支持.[方法]以香樟为试验材料,采用土培盆栽方法,研究不同复合重金属Pb/Zn浓度(0、200、400和800 mg/kg)对樟树叶和根中的叶绿素含量、抗氧化酶(SOD、POD和CAT)活性、丙二醛(MDA)和脯氨酸(Pro)含量的影响.[结果]随着复合重金属处理浓度的增加,叶绿素全量、叶绿素a含量和叶绿素b含量呈现明显的下降趋势,但是叶绿素a/ b比值只在复合重金属浓度为800 mg/kg时明显下降.复合重金属对樟树幼苗抗氧化酶活性有着不同的影响作用,对POD呈现明显的抑制作用,对SOD则表现出促进的作用,而对CAT则是呈明显的低促高抑现象.随着重金属处理浓度的升高,叶和根中的MDA和Pro呈现明显增加的趋势.[结论]重金属胁迫对香樟的光合作用产生了抑制作用,对抗氧化酶活性表现出不同的影响作用.%[Objective]The study aimed to study the effects of complex heavy metals (Pb/Zn) on physiological reponses of P. fortunel, and provide theoretical guidance for re-vegetating mine tailing with P. fortunel. [Method]A pot experiment was performed to investigate the effects of different concentration (0, 200, 400 and 800 mg/kg) of complex heavy metals on chlorophyll contents, antioxidant enzyme activities (SOD, POD and CAT), MDA and proline contents. [Result]Along with the increase concentration of complex heavy metals, chlorophyll a, chlorophyll b and total chlorophyll contents significantly decreased, but the chlorophyll a/b ration only significantly decreased at 800 mg/kg. Complex heavy metals had different effects on specific antioxidant enzyme. Complex heavy metals had significant restrain effects on POD, significant promoting effects on SOD, and promoting effects on CAT at low concentration but restrain effects on CAT at high concentration. Moreover, the contents of MDA and proline significantly

  14. Molecular Modeling on the Recognition of Wobble DNA