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Sample records for znii metal complexes

  1. A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency

    Science.gov (United States)

    Richardson, Christopher E. R.; Cunden, Lisa S.; Butty, Vincent L.; Nolan, Elizabeth M.; Lippard, Stephen J.; Shoulders, Matthew D.

    2018-01-01

    We describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the “A12-resin,” that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids, including human serum. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293 cells cultured in medium depleted of Zn(II) using S100A12. The resulting data provide insight into how cells respond to acute Zn(II) deficiency. We expect that the A12-resin will facilitate interrogation of disrupted Zn(II) homeostasis in biological settings, uncovering novel roles for Zn(II) in biology. PMID:29334734

  2. Solar photocatalytic removal of Cu(II), Ni(II), Zn(II) and Pb(II): Speciation modeling of metal-citric acid complexes

    International Nuclear Information System (INIS)

    Kabra, Kavita; Chaudhary, Rubina; Sawhney, R.L.

    2008-01-01

    The present study is targeted on solar photocatalytic removal of metal ions from wastewater. Photoreductive deposition and dark adsorption of metal ions Cu(II), Ni(II), Pb(II) and Zn(II), using solar energy irradiated TiO 2 , has been investigated. Citric acid has been used as a hole scavenger. Modeling of metal species has been performed and speciation is used as a tool for discussing the photodeposition trends. Ninety-seven percent reductive deposition was obtained for copper. The deposition values of other metals were significantly low [nickel (36.4%), zinc (22.2%) and lead (41.4%)], indicating that the photocatalytic treatment process, using solar energy, was more suitable for wastewater containing Cu(II) ions. In absence of citric acid, the decreasing order deposition was Cu(II) > Ni(II) > Pb(II) > Zn(II), which proves the theoretical thermodynamic predictions about the metals

  3. Micellar effect on metal-ligand complexes of Co(II, Ni(II, Cu(II and Zn(II with citric acid

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    Nageswara Rao Gollapalli

    2009-12-01

    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.

  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

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    Nahid Nishat

    2016-09-01

    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, 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

    OpenAIRE

    Nahid Nishat; Ashraf Malik

    2016-01-01

    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, wh...

  6. 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))

    Science.gov (United States)

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

    2015-12-01

    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.

  7. Thermal, spectral, magnetic and biological studies of thiosemicarbazones complexes with metal ions: Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO2(VI)

    International Nuclear Information System (INIS)

    Mashaly, M.M.; Seleem, H.S.; El-Behairy, M.A.; Habib, H.A.

    2004-01-01

    Thiosemicarbazones ligands, isatin-3-thiosemicarbazone(HIT) and N-acetylisatin-3-thiosemicarbazone (HAIT), which have tridentate ONN coordinating sites were prepared. The complexes of both ligands with Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO 2 (VI) ions were isolated. The ligands and their metal complexes were characterized by elemental analysis, IR, UV-Vis and mass spectra, also by conductance, magnetic moment and TG-DSC measurements. All the transition metal complexes have octahedral configurations, except Cu-complexes which have planar geometry and the UO 2 (VI) complexes which have coordination number 8 and may acquire the distorted dodecahedral geometry. Thermal studies explored the possibility of obtaining new complexes. Inversion from octahedral to square-planar configuration occurred upon heating the parent Ni-HIAT complex to form the corresponding pyrolytic product. The antifungal activity against the tested organisms showed that some metal complexes enhanced the activity with respect to the parent ligands. (author)

  8. Recognition of thymine in DNA bulges by a Zn(II) macrocyclic complex.

    Science.gov (United States)

    del Mundo, Imee Marie A; Fountain, Matthew A; Morrow, Janet R

    2011-08-14

    A Zn(II) macrocyclic complex with appended quinoline is a bifunctional recognition agent that uses both the Zn(II) center and the pendent aromatic group to bind to thymine in bulges with good selectivity over DNA containing G, C or A bulges. Spectroscopic studies show that the stem containing the bulge stays largely intact in a DNA hairpin with the Zn(II) complex bound to the thymine bulge. This journal is © The Royal Society of Chemistry 2011

  9. Cu(II AND Zn(II COMPLEX COMPOUNDS WITH BIGUANIDES AROMATIC DERIVATIVES. SYNTHESIS, CHARACTERIZATION, BIOLOGICAL ACTIVITY

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    Ticuţa Negreanu-Pîrjol

    2011-05-01

    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.

  10. Neuroprotective Effects and Mechanisms of Curcumin-Cu(II) and -Zn(II) Complexes Systems and Their Pharmacological Implications.

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    Yan, Fa-Shun; Sun, Jian-Long; Xie, Wen-Hai; Shen, Liang; Ji, Hong-Fang

    2017-12-28

    Alzheimer's disease (AD) is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa , is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II) or Zn(II) on hydrogen peroxide (H₂O₂)-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12) cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin-Cu(II) complexes systems possessed enhanced O₂ ·- -scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin-Cu(II) complexes systems were stronger than curcumin-Zn(II) system. Curcumin-Cu(II) or -Zn(II) complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin-Cu(II) complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin-Cu(II) or -Zn(II) complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB) pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin-Cu(II) or -Zn(II) complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ricciardi, Loredana, E-mail: loredana.ricciardi@unical.it [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)

    2014-07-01

    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.

  12. Metal based pharmacologically active complexes of Cu(II), Ni(II) and Zn(II): synthesis, spectral, XRD, antimicrobial screening, DNA interaction and cleavage investigation.

    Science.gov (United States)

    Raman, Natarajan; Mahalakshmi, Rajkumar; Arun, T; Packianathan, S; Rajkumar, R

    2014-09-05

    The present contribution reports a thorough characterization of newly obtained metallointercalators incorporating Schiff bases, formed by the condensation of N-acetoacetyl-o-toluidine with 1-amino-4-nitrobenzene (L(1))/1-amino-4-chlorobenzene (L(2)) as main ligand and 1,10-phenanthroline as co-ligand respectively. The characterization of newly formed metallointercalators has been done by (1)H NMR, UV-Vis, IR, EPR spectroscopy and molar conductivity studies. X-ray powder diffraction illustrates that they are crystalline nature. Binding interaction of these complexes with calf thymus (CT-DNA) has been investigated by emission, absorption, viscosity, cyclic voltammetry and differential pulse voltammetry. DNA binding experiments results reveal that the synthesized complexes interact with DNA through intercalative mode. The in vitro antibacterial and antifungal assay indicate that these complexes are good antimicrobial agents against various pathogens. The DNA cleavage exhibits that they act as efficient cleaving agents. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Intercalation of a Zn(II) complex containing ciprofloxacin drug between DNA base pairs.

    Science.gov (United States)

    Shahabadi, Nahid; Asadian, Ali Ashraf; Mahdavi, Mryam

    2017-11-02

    In this study, an attempt has been made to study the interaction of a Zn(II) complex containing an antibiotic drug, ciprofloxacin, with calf thymus DNA using spectroscopic methods. It was found that Zn(II) complex could bind with DNA via intercalation mode as evidenced by: hyperchromism in UV-Vis spectrum; these spectral characteristics suggest that the Zn(II) complex interacts with DNA most likely through a mode that involves a stacking interaction between the aromatic chromophore and the base pairs of DNA. DNA binding constant (K b = 1.4 × 10 4 M -1 ) from spectrophotometric studies of the interaction of Zn(II) complex with DNA is comparable to those of some DNA intercalative polypyridyl Ru(II) complexes 1.0 -4.8 × 10 4 M -1 . CD study showed stabilization of the right-handed B form of DNA in the presence of Zn(II) complex as observed for the classical intercalator methylene blue. Thermodynamic parameters (ΔH DNA-MB, indicating that it binds to DNA in strong competition with MB for the intercalation.

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

    Science.gov (United States)

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

    2014-09-11

    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.

  15. Metallic complexes with glyphosate: a review

    OpenAIRE

    Coutinho, Cláudia F. B.; Mazo, Luiz Henrique

    2005-01-01

    We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature.

  16. Metallic complexes with glyphosate: a review

    International Nuclear Information System (INIS)

    Coutinho, Claudia F.B.; Mazo, Luiz Henrique

    2005-01-01

    We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature. (author)

  17. Polymerization of Methyl Methacrylate Catalyzed by Co(II), Cu(II), and Zn(II) Complexes Bearing N-Methyl-N-((pyridin-2-yl)methyl) cyclohexanamine

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seoung Hyun; Lee, Hyosun [Kyungpook National University, Daegu (Korea, Republic of); Shin, Jongwon [POSTECH, Pohang (Korea, Republic of); Nayab, Saira [Shaheed Benazir Bhutto University, Sheringal (Pakistan)

    2016-05-15

    We demonstrated the synthesis and characterization of Co(II), Cu(II), and Zn(II) complexes ligated to N-methyl-N-((pyridin-2-yl)methyl)cyclohexanamine. The complex [Co(nmpc)Cl{sub 2}] in the presence of MMAO showed the highest catalytic activity for MMA polymerization at 60 °C compared with its Zn(II) and Cu(II) analogs. The metal center showed an obvious influence on the catalytic activity, although this appeared to have no effect on the stereo-regularity of the resultant PMMA. X-ray diffraction analysis revealed that [Co(nmpc)Cl{sub 2}] and [Zn(nmpc)Cl{sub 2}] crystallized in the monoclinic system with space group P2{sub 1}/c and existed as monomeric and solvent-free complexes.

  18. Structural basis of Zn(II induced metal detoxification and antibiotic resistance by histidine kinase CzcS in Pseudomonas aeruginosa.

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    Dan Wang

    2017-07-01

    Full Text Available Pseudomonas aeruginosa (P. aeruginosa is a major opportunistic human pathogen, causing serious nosocomial infections among immunocompromised patients by multi-determinant virulence and high antibiotic resistance. The CzcR-CzcS signal transduction system in P. aeruginosa is primarily involved in metal detoxification and antibiotic resistance through co-regulating cross-resistance between Zn(II and carbapenem antibiotics. Although the intracellular regulatory pathway is well-established, the mechanism by which extracellular sensor domain of histidine kinase (HK CzcS responds to Zn(II stimulus to trigger downstream signal transduction remains unclear. Here we determined the crystal structure of the CzcS sensor domain (CzcS SD in complex with Zn(II at 1.7 Å resolution. This is the first three-dimensional structural view of Zn(II-sensor domain of the two-component system (TCS. The CzcS SD is of α/β-fold in nature, and it senses the Zn(II stimulus at micromole level in a tetrahedral geometry through its symmetry-related residues (His55 and Asp60 on the dimer interface. Though the CzcS SD resembles the PhoQ-DcuS-CitA (PDC superfamily member, it interacts with the effector in a novel domain with the N-terminal α-helices rather than the conserved β-sheets pocket. The dimerization of the N-terminal H1 and H1' α-helices is of primary importance for the activity of HK CzcS. This study provides preliminary insight into the molecular mechanism of Zn(II sensing and signaling transduction by the HK CzcS, which will be beneficial to understand how the pathogen P. aeruginosa resists to high levels of heavy metals and antimicrobial agents.

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

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    C. SPÎNU

    2008-04-01

    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.

  20. Synthesis, characterization and crystal structure determination of a new Zn(II Schiff base complex derived from condensation of a new asymmetrical tripodal amine, 3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol and 2-hydroxy-3-methoxybenzaldehyde

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    Majid Rezaeivala

    2017-05-01

    Full Text Available A new tripodal amine, 3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol (HL has been prepared. This has been used to synthesize a new Schiff base complex by template condensation with 2-hydroxy-3-methoxybenzaldehyde in the presence of Zn(II metal ion in methanol. The complex has been characterized using spectroscopic methods and the crystal structure of [ZnL]BF4, L:3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol was confirmed by single crystal X-ray diffraction studies. Single crystal X-ray structure analysis showed that in the mononuclear Zn(II complex, [ZnL]BF4 the Zn(II ion is in a distorted square pyramidal environment.

  1. 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.

    Science.gov (United States)

    Bahrami, Homayoon; Farhadi, Saeed; Siadatnasab, Firouzeh

    2016-07-01

    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) 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.

  2. Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

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    Chih-Chieh Wang

    2017-11-01

    Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

  3. Anti-inflammatory drugs interacting with Zn(II), Cd(II) and Pt(II) metal ions.

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    Dendrinou-Samara, C; Tsotsou, G; Ekateriniadou, L V; Kortsaris, A H; Raptopoulou, C P; Terzis, A; Kyriakidis, D A; Kessissoglou, D P

    1998-09-01

    Complexes of Zn(II), Cd(II) and Pt(II) metal ions with the anti-inflammatory drugs, 1-methyl-5-(p-toluoyl)-1H-pyrrole-2-acetic acid (Tolmetin), alpha-methyl-4-(2-methylpropyl)benzeneacetic acid (Ibuprofen), 6-methoxy-alpha-methylnaphthalene-2-acetic acid (Naproxen) and 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid (indomethacin) have been synthesized and characterized. In the structurally characterized Cd(naproxen)2 complex the anti-inflammatory drugs acts as bidentate chelate ligand coordinatively bound to metal ions through the deprotonated carboxylate group. Crystal data for 1: [C32H26O8Cd], orthorhombic, space group P22(1)2(1), a = 5.693(2) (A), b = 8.760(3) (A), c = 30.74(1) (A), V = 1533(1) A3, Z = 2. Antibacterial and growth inhibitory activity is higher than that of the parent ligands or the platinum(II) diamine compounds.

  4. Lutetium-177 complexation of DOTA and DTPA in the presence of competing metals

    International Nuclear Information System (INIS)

    Watanabe, Satoshi; Ishioka, Noriko S.; Hashimoto, Kazuyuki

    2013-01-01

    177 Lu complexation of DOTA and DTPA is investigated by the addition of Ca(II), Fe(II) and Zn(II). The 177 Lu complexation yield of DTPA was higher than that of DOTA in the presence of Ca(II), Fe(II) and Zn(II). Therefore, it was found that the 177 Lu complexation of DTPA was more advantageous compared with DOTA in the presence of competing metals, Ca, Fe and Zn. (author)

  5. 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

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

    2016-09-23

    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.

  6. Synthesis and Characterization of Some New Cu(II, Ni(II and Zn(II Complexes with Salicylidene Thiosemicarbazones: Antibacterial, Antifungal and in Vitro Antileukemia Activity

    Directory of Open Access Journals (Sweden)

    Tudor Rosu

    2013-07-01

    Full Text Available Thirty two new Cu(II, Ni(II and Zn(II complexes (1–32 with salicylidene thiosemicarbazones (H2L1–H2L10 were synthesized. Salicylidene thiosemicarbazones, of general formula (XN-NH-C(S-NH(Y, were prepared through the condensation reaction of 2-hydroxybenzaldehyde and its derivatives (X with thiosemicarbazide or 4-phenylthiosemicarbazide (Y = H, C6H5. The characterization of the new formed compounds was done by 1H-NMR, 13C-NMR, IR spectroscopy, elemental analysis, magnetochemical, thermoanalytical and molar conductance measurements. In addition, the structure of the complex 5 has been determined by X-ray diffraction method. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60 cells growth and antibacterial and antifungal activities.

  7. Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Saeednia, S., E-mail: sami_saeednia@yahoo.com [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Iranmanesh, P. [Department of physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Ardakani, M. Hatefi; Mohammadi, M.; Norouzi, Gh. [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of)

    2016-06-15

    Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.

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

    Science.gov (United States)

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

    2017-04-01

    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).

  9. and Zn(II) Complexes with the Schiff base N-salicylidene-4-chlor

    African Journals Online (AJOL)

    2017-12-13

    Dec 13, 2017 ... 2010) Schiff bases are used as intermediate for the ... Infrared spectral analysis .... Table 6: Percentage Composition of the Metal in the complexes using Gravimetric Method .... Internal journal of pharmacy & Technology.

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

    Directory of Open Access Journals (Sweden)

    MUHAMMED BASHEER UMMATHUR

    2009-03-01

    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.

  11. Antibacterial Co(II, Ni(II, Cu(II and Zn(II complexes with biacetyl-derived Schiff bases

    Directory of Open Access Journals (Sweden)

    MUHAMMAD IMRAN

    2010-08-01

    Full Text Available The condensation reactions of biacetyl with ortho-hydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2(H2O2] where M = Co(II, Ni(II, Cu(II and Zn(II and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR, 13C-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141–160 °C. These compounds were also screened for their in vitro antibacterial activity against four bacterial species, namely: Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtilis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

  12. Synthesis, structural studies and antituberculosis evaluation of new hydrazone derivatives of quinoline and their Zn(II complexes

    Directory of Open Access Journals (Sweden)

    Mustapha C. Mandewale

    2018-02-01

    Full Text Available The quinoline hydrazone ligands were synthesized through multi-step reactions. The 2-hydroxy-3-formylquinoline derivatives (1a–1c were prepared from acetanilide derivatives as starting materials using Vilsmeier–Haack reaction. Then the condensation of 2-hydroxy-3-formylquinoline derivatives with hydrazide derivatives (2a–2c yielded quinoline hydrazone ligands (3a–3i. The synthesis of a new series of Zn(II complexes carried out by refluxing with these quinoline hydrazone ligands (3a–3i is reported. The molecular structures of the ligands (3a–3i and the Zn complexes were characterized by elemental analysis and spectral studies like FT-IR, 1H and 13C NMR, MS, UV–Visible and fluorescence. The preliminary results of antituberculosis study showed that most of the Zn(II complexes 4a–4i demonstrated very good antituberculosis activity while the ligands 3a–3i showed moderate activity. Among the tested compounds 4e and 4g were found to be most active with minimum inhibitory concentration (MIC of 8.00μM and 7.42 μM respectively against Mycobacterium tuberculosis (H37 RV strain ATCC No-27294 which is comparable to “first and second line” drugs used to treat tuberculosis.

  13. Study of the competitive reaction ability of harmine and harmaline during complex formation with transition metals

    International Nuclear Information System (INIS)

    Chepulsky, S.A.; Kadirova, Z.Ch.; Parpiev, N.A.

    2006-01-01

    New coordination compounds of d-metals (Zn(II), Co(II), Mn(II), Mo(VI), Cr(VI)) β-carboline alkaloids were synthesized. The structure of obtained substances was established by IR, PMR spectroscopy. The quantum-chemical assessment of the harmine and harmaline reactivity in complexation reactions with d-metals was carried out. (author)

  14. The synthesis and characterization of 1,2-dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene nonane and its complexes with Ni(II), Cu(II), Zn(II) and Cd(II)

    International Nuclear Information System (INIS)

    Canpolat, E.; Kaya, M.; Gorgulu, A.O.

    2002-01-01

    1,2-dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene nonane (H 2 L) was synthesized starting from 1,2-O-iso-butylidene-4-aza-6-amino hexane (RNH 2 ) and antichloroglyoxime. Ni(II) and Cu(II) complexes of H 2 L have a metal:ligand ratio 1:2 and the ligand coordinates through two N atoms, as do most of the vic-dioximes. However, Zn(II) and Cd(II) complexes of H 2 L have a metal: ligand ratio 1:1 and one chloride ion and one water molecule are also coordinated to the metal ion. Structures of the ligand and its transition-metal complexes are proposed, according to elemental analysis, IR, 13 C and 1 H NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA). (author)

  15. Adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II), and As(V) on bacterially produced metal sulfides.

    Science.gov (United States)

    Jong, Tony; Parry, David L

    2004-07-01

    The adsorption of Pb(II), Cu(II), Cd(II), Zn(II), Ni(II), Fe(II) and As(V) onto bacterially produced metal sulfide (BPMS) material was investigated using a batch equilibrium method. It was found that the sulfide material had adsorptive properties comparable with those of other adsorbents with respect to the specific uptake of a range of metals and, the levels to which dissolved metal concentrations in solution can be reduced. The percentage of adsorption increased with increasing pH and adsorbent dose, but decreased with increasing initial dissolved metal concentration. The pH of the solution was the most important parameter controlling adsorption of Cd(II), Cu(II), Fe(II), Ni(II), Pb(II), Zn(II), and As(V) by BPMS. The adsorption data were successfully modeled using the Langmuir adsorption isotherm. Desorption experiments showed that the reversibility of adsorption was low, suggesting high-affinity adsorption governed by chemisorption. The mechanism of adsorption for the divalent metals was thought to be the formation of strong, inner-sphere complexes involving surface hydroxyl groups. However, the mechanism for the adsorption of As(V) by BPMS appears to be distinct from that of surface hydroxyl exchange. These results have important implications to the management of metal sulfide sludge produced by bacterial sulfate reduction.

  16. Preparation of Schiff s base complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) and their spectroscopic, magnetic, thermal, and antifungal studies

    International Nuclear Information System (INIS)

    Parekh, H.M.; Patel, M.N.

    2006-01-01

    The potassium salt of salicylidene-DL-alanine (KHL), bis(benzylidene)ethylenediamine (A 1 ), thiophene-o-carboxaldene-p-toluidine (A 2 ), and its metal complexes of the formula [(M II (L)(A)(H 2 O)] (M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II); A = A 1 or A 2 ) are prepared. They are characterized by elemental analysis, magnetic susceptibility measurements, thermogravimetric analysis, and infrared and electronic spectral studies. The electronic spectral and magnetic moment data suggest an octahedral geometry for the complexes. All of these complexes, metal nitrates, fungicides (bavistin and emcarb), and ligands are screened for their antifungal activity against Aspergillus niger, Fusarium oxysporum, and Aspergillus flavus using a plate poison technique. The complexes show higher activity than those of the free ligands, metal nitrate, and the control (DMSO) and moderate activity against bavistin and emcarb [ru

  17. Synthesis, characterization and biological studies of 2-(4-nitrophenylamino-carbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

    International Nuclear Information System (INIS)

    Imran, M; Nazir, S.; Latif, S.; Mahmood, Z.

    2010-01-01

    Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2-(4-Nitrophenyl aminocarbonyl)benzoic acid were synthesized and characterized on the basis of physical, analytical and spectroscopic data. The ligands, as well as its metal complexes were checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis, Escherichia coli, Pseudomonas aeuroginosa, and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. Disc diffusion method and Tube diffusion test were used for antibacterial and antifungal activities, respectively. The synthesized complexes only show significant antifungal activity but inactive for antibacterial, however, in general, the metal complexes were found to be more active against antimicrobial activities as compared to their un complexed ligand. (author)

  18. Synthesis, characterization and biological studies of 2-(4-nitro phenylaminocarbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

    International Nuclear Information System (INIS)

    Aqeel Ashraf, M.; Jamil Maah, M.; Yusuf, I.

    2012-01-01

    Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) salts of 2-(4-nitro phenylaminocarbonyl)benzoic acid were characterized by physical, analytical and spectroscopic studies and checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis (Gram +ve), Escherichia coli (Gram -ve), Pseudomonas aeuroginosa (Gram -ve) and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. The antimicrobial activities of the metal complexes - were found to be greater than those of 2-(4-nitro phenylaminocarbonyl)benzoic acid alone.

  19. Metallic complexes with glyphosate: a review; Complexos metalicos com o herbicida glifosato: revisao

    Energy Technology Data Exchange (ETDEWEB)

    Coutinho, Claudia F.B.; Mazo, Luiz Henrique [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: claudiabreda@iqsc.usp.br

    2005-11-15

    We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature. (author)

  20. Conducting metal dithiolate complexes

    DEFF Research Database (Denmark)

    Underhill, A. E.; Ahmad, M. M.; Turner, D. J.

    1985-01-01

    Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound......Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound...

  1. New heteroleptic Zn(II) complexes of thiosemicarbazone and diimine Co-Ligands: Structural analysis and their biological impacts

    Science.gov (United States)

    Mathan Kumar, Shanmugaiah; Kesavan, Mookkandi Palsamy; Vinoth Kumar, Gujuluva Gangatharan; Sankarganesh, Murugesan; Chakkaravarthi, Ganesan; Rajagopal, Gurusamy; Rajesh, Jegathalaprathaban

    2018-02-01

    A thiosemicarbazone ligand HL appended new Zn(II) complexes [Zn(L)(bpy)] (1) and [Zn(L)(phen)] (2) (where, HL = {2-(3-bromo-5-chloro-2-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide}, bpy = 2, 2‧-bipyridine and phen = 1, 10-phenanthroline) have been synthesized and well characterized using conventional spectroscopic techniques viz.,1H NMR, FTIR and UV-Vis spectra. The crystal structures of complexes 1 and 2 have been determined by single crystal X-ray diffraction studies. Both the complex 1 (τ = 0.5) and 2 (τ = 0.37) possesses square based pyramidally distorted trigonal bipyramidal geometry. The ground state electronic structures of complexes 1 and 2 were investigated by DFT/B3LYP theoretical analysis using 6-311G (d,p) and LANL2DZ basis set level. The superior DNA binding ability of complex 2 has been evaluated using absorption and fluorescence spectral titration studies. Antimicrobial evaluation reveals that complex 2 endowed better screening than HL and complex 1 against both bacterial as well as fungal species. Consequently, complex 2 possesses highest antibacterial screening against Staphylococcus aureus (MIC = 3.0 ± 0.23 mM) and antifungal screening against Candida albicans (MIC = 6.0 ± 0.11 mM). Furthermore, the anticancer activity of the ligand HL, complexes 1 and 2 have been examined against the MCF-7 cell line (Human breast cancer cell line) using MTT assay. It is remarkable that complex 2 (12 ± 0.67 μM) show highest anticancer activity than HL (25.0 ± 0.91 μM) and complex 1 (15 ± 0.88 μM) due to the presence of phen ligand moiety.

  2. Complexation of 1,3-dimorpholinopropane with Hg(II) and Zn(II) salts: Synthese, crystal structures and antibacterial studies

    Czech Academy of Sciences Publication Activity Database

    Goudarziafshar, H.; Yousefi, S.; Abbasityula, Y.; Dušek, Michal; Eigner, Václav; Rezaeivala, M.; Özbek, N.

    2015-01-01

    Roč. 31, č. 6 (2015), s. 1076-1084 ISSN 1001-4861 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : crystal structure * 1,3-dimorpholinopropane * antibacterial activity * Hg(II) complex * Zn(II) complex Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.488, year: 2015

  3. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  4. Synthesis, molecular structure, biological properties and molecular docking studies on Mn(II), Co(II) and Zn(II) complexes containing bipyridine-azide ligands.

    Science.gov (United States)

    Thamilarasan, Vijayan; Jayamani, Arumugam; Sengottuvelan, Nallathambi

    2015-01-07

    Metal complexes of the type Mn(bpy)2(N3)2 (1), Co(bpy)2(N3)2·3H2O (2) and Zn2(bpy)2(N3)4 (3) (Where bpy = 2,2-bipyridine) have been synthesized and characterized by elemental analysis and spectral (FT-IR, UV-vis) studies. The structure of complexes (1-3) have been determined by single crystal X-ray diffraction studies and the configuration of ligand-coordinated metal(II) ion was well described as distorted octahedral coordination geometry for Mn(II), Co(II) and distorted square pyramidal geometry for Zn(II) complexes. DNA binding interaction of these complexes (1-3) were investigated by UV-vis absorption, fluorescence circular dichroism spectral and molecular docking studies. The intrinsic binding constants Kb of complexes 1, 2 and 3 with CT-DNA obtained from UV-vis absorption studies were 8.37 × 10(4), 2.23 × 10(5) and 5.52 × 10(4) M(-1) respectively. The results indicated that the three complexes are able to bind to DNA with different binding affinity, in the order 2 > 1 > 3. Complexes (1-3) exhibit a good binding propensity to bovine serum albumin (BSA) proteins having relatively high binding constant values. Gel electrophoresis assay demonstrated the ability of the complexes 1-3 promote the cleavage ability of the pBR322 plasmid DNA in the presence of the reducing agent 3-mercaptopropionic acid (MPA) but with different cleavage mechanisms: the complex 3 cleaves DNA via hydrolytic pathway (T4 DNA ligase assay), while the DNA cleavage by complexes 1 and 2 follows oxidative pathway. The chemical nuclease activity follows the order: 2 > 1 > 3. The effects of various activators were also investigated and the nuclease activity efficacy followed the order MPA > GSH > H2O2 > Asc. The cytotoxicity studies of complexes 1-3 were tested in vitro on breast cancer cell line (MCF-7) and they found to be active. Copyright © 2014. Published by Elsevier Masson SAS.

  5. Interaction of Cr (III), Ni (II), Pb (II) with DTPA complexes of essential metal ions

    International Nuclear Information System (INIS)

    Gulzar, S.; Zahida; Maqsood, T.; Naqvi, R.R.

    2002-01-01

    With the increase of anthropogenic activities in the environment, heavy metal toxicity (Chromium, Nickel and Lead) is more common now. DTPA (diethylene triamine pentaacetic acid) a polyamino carboxylic acid is widely used to form hydrophilic and stable complexes with most of the metal ions. In this spectrophotometric study, concentration of Cr(III), Ni(II) and Pb(II) (toxic metal ions) exchanged with Fe(III), Zn(II) and Ca(II) from their DTPA complexes were estimated at pH 4,7 and 9. Concentration of added metal was varied from 1-4 times to that of complexed metal. (author)

  6. 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

    Science.gov (United States)

    Onwudiwe, Damian C.; Strydom, Christien A.

    2015-01-01

    Bipyridine adducts of N-phenyldithiocarbamato complexes, [ML12L2] (M = Cd(II), Zn(II); L1 = N-phenyldithiocarbamate, L2 = 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.

  7. Synthesis and characterization of heterobimetallic complexes of the type [Cu(pn2][MCl4] where M = Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II

    Directory of Open Access Journals (Sweden)

    Seema Yadav

    2016-11-01

    Full Text Available A series of new bimetallic transition metal complexes of the type [Cu(pn2] [MCl4] have been synthesized (where M = Co(II, Ni(II, Cu(II, Zn(II, Cd(II and Hg(II, pn = 1,3-diaminopropane and characterized by elemental analysis, molar conductance, TGA, IR and electronic spectra. All the compounds are 1:1 electrolyte in DMF. The Cu(II ion is square-planar while metal ions in the anionic moiety acquire their usual tetrahedral arrangement. On the basis of these studies it is concluded that anionic moiety is electrically stabilized by its cationic counterpart.

  8. Structural and thermal characterization of ternary complexes of piroxicam and alanine with transition metals: Uranyl binary and ternary complexes of piroxicam. Spectroscopic characterization and properties of metal complexes

    Science.gov (United States)

    Mohamed, Gehad G.

    2005-12-01

    Ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO 2(II) complexes with piroxicam (Pir) drug (H 2L 1) and dl-alanine (Ala) (HL 2) and also the binary UO 2(II) complex with Pir were studied. The structures of the complexes were elucidated using elemental, IR, molar conductance, magnetic moment, diffused reflectance and thermal analyses. The UO 2(II) binary complex was isolated in 1:2 ratio with the formula [UO 2(H 2L) 2](NO 3) 2. The ternary complexes were isolated in 1:1:1 (M:H 2L 1:L 2) ratios. The solid complexes were isolated in the general formulae [M(H 2L)(L 2)(Cl) n(H 2O) m]· yH 2O (M = Fe(III) ( n = 2, m = 0, y = 1), Co(II) ( n = 1, m = 1, y = 2) and Ni(II) ( n = 1, m = 1, y = 0)); [M(H 2L)(L 2)](X) z· yH 2O (M = Cu(II) (X = AcO, z = 1, y = 0), Zn(II) (X = AcO, z = 1, y = 3) and UO 2(II) (X = NO 3, z = 1, y = 2)). Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine-N and carbonyl-O groups, while Ala behaves as a uninegatively bidentate ligand coordinated to the metal ions via the deprotonated carboxylate-O and amino-N. The magnetic and reflectance spectral data show that the complexes have octahedral geometry except Cu(II) and Zn(II) complexes have tetrahedral structures. The thermal decomposition of the complexes was discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated.

  9. Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Mohd F., E-mail: faisalt@petronas.com.my; Shaharun, Maizatul S. [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia); Shuib, Anis Suhaila, E-mail: anisuha@petronas.com.my; Borhan, Azry [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia)

    2014-10-24

    An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m{sup 2}/g and 0.17 cm{sup 2}/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution were carried out at a fixed initial concentration of metal ion (150 ppm) with variation amount of adsorbent (rice husk-based activated carbon) as a function of varied contact time at room temperature. The concentration of each metal ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Isotherm and kinetic model analyses suggested that the experimental data of adsorption studies fitted well with Langmuir, Freundlich and second-order kinetic models.

  10. Synthesis and characterization of mixed ligand complexes of Zn(II ...

    Indian Academy of Sciences (India)

    Unknown

    the total % weight loss is 60⋅73%, and the weight loss at 891°C was 54⋅24%, which corresponds to a weight loss of molecular weight of 179 units. The. TGA curve of 3 complex showed sudden weight loss at 300°C, indicating the absence of water molecules in the coordination sphere of the complex. The total weight loss ...

  11. 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

    Directory of Open Access Journals (Sweden)

    Morteza Montazerozohori

    2013-01-01

    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.

  12. 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

    Directory of Open Access Journals (Sweden)

    Shayma A. Shaker

    2010-01-01

    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.

  13. A new photoactive Ru(II)tris(2,2'-bipyridine) templated Zn(II) benzene-1,4-dicarboxylate metal organic framework: structure and photophysical properties.

    Science.gov (United States)

    Whittington, Christi L; Wojtas, Lukasz; Gao, Wen-Yang; Ma, Shengqian; Larsen, Randy W

    2015-03-28

    It has now been demonstrated that Ru(ii)tris(2,2'-bipyridine) (RuBpy) can be utilized to template the formation of new metal organic framework (MOF) materials containing crystallographically resolved RuBpy clusters with unique photophysical properties. Two such materials, RWLC-1 and RWLC-2, have now been reported from our laboratory and are composed of RuBpy encapsulated in MOFs composed of Zn(ii) ions and 1,3,5-tris(4-carboxyphenyl)benzene ligands (C. L. Whittington, L. Wojtas and R. W. Larsen, Inorg. Chem., 2014, 53, 160-166). Here, a third RuBpy templated photoactive MOF is described (RWLC-3) that is derived from the reaction between Zn(ii) ions and 1,4-dicarboxybenzene in the presence of RuBpy. Single Crystal X-ray diffraction studies determined the position of RuBpy cations within the crystal lattice. The RWLC-3 structure is described as a 2-fold interpenetrated pillared honeycomb network (bnb) containing crystallographically resolved RuBpy clusters. The two bnb networks are weakly interconnected. The encapsulated RuBpy exhibits two emission decay lifetimes (τ-fast = 120 ns, τ-slow = 453 ns) and a bathochromic shift in the steady state emission spectrum relative to RuBpy in ethanol.

  14. Selenophene transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    White, Carter James [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η5- and the η1(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The 77Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η1(S)-bound thiophenes, η1(S)-benzothiophene and η1(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η1(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh3)Re(2-benzothioenylcarbene)]O3SCF3 was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η1(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

  15. Synthesis, physico-chemical characterization and biological activity of 2-aminobenzimidazole complexes with different metal ions

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2004-01-01

    Full Text Available Complexes of 2-aminobenzimidazole (L with nitrates of cobalt(II nickel(II, copper (II, zinc(II and silver(I were synthesized. The molar ratio metal:ligand in the reaction of the complex formation was 1:2. It should be noticed, that the reaction of all the metal salts yielded bis(ligand complexes of the general formula M(L2(NO32 × nH2O (M=Co, Ni Cu, Zn or Ag; n=0, 1, 2 or 6. The complexes were characterized by elemental analysis of the metal, molar conductivity, magnetic susceptibility measurements and IR spectra. Co(II, Ni(II and Cu(II complexes behave as non-electrolytes, whilst Zn(II and Ag(I are 1:1 electrolytes. Cu(II complex has a square-planar stereochemistry, Ag(I complex is linear, whilst the Co(II, Ni(II and Zn(II complexes have a tetrahedral configuration. In all the complexes ligand is coordinated by participation of the pyridine nitrogen of the benzimidazole ring. The antimicrobial activity of the ligand and its complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus and Saccharomyces cerevisiae was investigated. The effect of metal on the ligand antimicrobial activity is discussed.

  16. Cd(II) and Zn(II) Complexes Containing N,N'-Bidentate N-(Pyridin-2-ylmethylene)cyclopentanamine: Synthesis, Characterisation and Methyl Methacrylate Polymerisation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu Jin; Lee, Ha Jun; Lee, Hyo Sun [Kyungpook National University, Daeju (Korea, Republic of)

    2014-09-15

    The reaction between [CdBr{sub 2}·4H{sub 2}O] and anhydrous [ZnCl{sub 2}] with N,N'-bidentate N-(pyridin-2-ylmethylene)- cyclopentanamine (impy) in ethanol yields dimeric [(impy)Cd(μ-Br)Br]2 and monomeric [(impy)ZnCl{sub 2}] complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in [(impy)Cd(μ-Br)Br]2 and zinc in [(impy)ZnCl{sub 2}] formed a distorted trigonal–bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

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

    International Nuclear Information System (INIS)

    Koo, Bon Kweon

    2013-01-01

    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) 2 - 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

  18. Synthesis, Characterization, and Biological Activity of Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II Complexes of N-Thiophenoyl-N′-Phenylthiocarbohydrazide

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2013-01-01

    Full Text Available Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II complex of N-thiophenoyl -N′-phenylthiocarbohydrazide (H2 TPTH have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, infrared, NMR, electronic, and ESR spectral studies. The complexes were found to have compositions [Mn(H TPTH2], [Co(TPTH (H2O2], [Ni(TPTH (H2O2], [Cu(TPTH], [Zn(H TPTH], [Cd(H TPTH2], and [Fe(H TPTH2(EtOH]. The magnetic and electronic spectral studies suggest square planar geometry for [Cu(TPTH], tetrahedral geometry for [Zn(TPTH] and [Cd(H TPTH2], and octahedral geometry for rest of the complexes. The infrared spectral studies of the 1 : 1 deprotonated complexes suggest bonding through enolic oxygen, thiolato sulfur, and both the hydrazinic nitrogens. Thus, H2TPTH acts as a binegative tetradentate ligand. H2 TPTH and its metal complexes have been screened against several bacteria and fungi.

  19. Cr(III,Mn(II,Fe(III,Co(II,Ni(II,Cu(II and Zn(II Complexes with Diisobutyldithiocarbamato Ligand

    Directory of Open Access Journals (Sweden)

    Mohammad Tarique

    2011-01-01

    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.

  20. Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes

    Science.gov (United States)

    Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M. Arif

    2016-05-01

    We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.

  1. Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes.

    Science.gov (United States)

    Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M Arif

    2016-05-15

    We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. New octahedral ZnII and CdII complexes based on azo derivatives and azomethines of pyrazole-5-thione

    International Nuclear Information System (INIS)

    Uraev, A.I.; Vasil'chenko, I.S.; Borodkin, G.S.; Borodkina, I.G.; Vlasenko, V.G.; Burlov, A.S.; Divaeva, L.N.; Garnovskij, A.D.; Lysenko, K.A.; Antipin, M.Yu.

    2005-01-01

    New metal chelates of Zn II and Cd II (ML 2 ) based on (4Z)-3-methyl-1-phenyl-5-thioxo- 1,5-dihydro-4H-pyrazol-4-one quinolin-8-ylhydrazone (HL 1 ) and (4Z)-5-methyl-2-phenyl- 4-[(quinolin-8-ylimino)methyl]-2,4-dihydro-3H-pyrazole-3-thione (HL 2 ) were synthesized. The structures of the metal chelates were studied by EXAFS and NMR ( 1 H, 13 C, and 111 Cd) spectroscopy. The structure of the Cd(L 1 ) 2 complex was established by X-ray diffraction analysis. The complexes have pseudo octahedral structures with the N 4 S 2 ligand environment [ru

  3. Preparation and characterisation of some transition metal complexes of niacinamide (vitamin b3)

    International Nuclear Information System (INIS)

    Hasan, M.M.; Hossain, M.E.; Halim, M.E.

    2015-01-01

    Niacinamide forms metal complexes of general formula (M(C/sub 6/H/sub 6/N/sub 2/O)2)Cl/sub 2/; where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) in the aqueous medium. The complexes were formulated by comparing the experimental and calculated data for C, H, N and metal. The prepared complexes were characterized by different physicochemical methods. The UV-vis, FTIR spectral analysis and thermo gravimetric analysis (TGA). TGA of these complexes have been discussed. Magnetic susceptibility values indicate that all complexes except Zn complex are paramagnetic in nature. The redox properties of the metal ions in the Mn, Cu and Zn complexes have been discussed from the cyclic voltammetric studies. In all cases the systems are quasi reversible. (author)

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

    Science.gov (United States)

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

    2015-01-01

    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.

  5. 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.

    Science.gov (United States)

    Onwudiwe, Damian C; Strydom, Christien A

    2015-01-25

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Magnetic interactions as a stabilizing factor of semiquinone species of lawsone by metal complexation

    International Nuclear Information System (INIS)

    Valle-Bourrouet, Grettel; Ugalde-Saldivar, Victor M.; Gomez, Martin; Ortiz-Frade, Luis A.; Gonzalez, Ignacio; Frontana, Carlos

    2010-01-01

    Changes in electrochemical reactivity for lawsone anions (lawsone, 2-hydroxy-1,4-naphthoquinone, HLw) being coordinated to a series of metallic ions in dimethylsulfoxide solution were evaluated. Upon performing cyclic voltammetry experiments for metal complexes of this quinone with pyridine (Py) - structural formula M(II)(Lw - ) 2 (Py) 2 ; M: Co(II), Ni(II), Zn(II) - it was found that the reduction of coordinated Lw - units occurs during the first and second electron uptake in the analyzed compounds. The stability of the electrogenerated intermediates for each complex depends on the d electron configuration in each metal center and is determined by magnetic interactions with the available spins considering an octahedral conformation for all the compounds. This was evidenced by in situ spectroelectrochemical-ESR measurements in the Zn(II) complex in which due to the lack of magnetic interaction owing to its electron configuration, the structure of the coordinated anion radical species was determined. Successive reduction of the associated Lw - units leads to partial dissociation of the complex, determined by the identification of free radical dianion structures in solution. These results show some insights on how metal-lawsone complexation can modify the solution reactivity and stability of the electrogenerated radical species.

  7. Magnetic interactions as a stabilizing factor of semiquinone species of lawsone by metal complexation

    Energy Technology Data Exchange (ETDEWEB)

    Valle-Bourrouet, Grettel [Universidad de Costa Rica, Escuela de Quimica, San Jose (Costa Rica); Ugalde-Saldivar, Victor M. [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, C.P. 04510, Mexico, D.F. (Mexico); Gomez, Martin [Departamento de Sistemas Biologicos, Universidad Autonoma Metropolitana-Xochimilco, C.P. 04960, Mexico, D.F. (Mexico); Ortiz-Frade, Luis A. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro, Sanfandila, 76703, Pedro Escobedo, Queretaro (Mexico); Gonzalez, Ignacio [Universidad Autonoma Metropolitana - Iztapalapa, Departamento de Quimica, Area de Electroquimica, Apartado postal 55-534, 09340, Mexico, D.F. (Mexico); Frontana, Carlos, E-mail: ultrabuho@yahoo.com.m [Departamento de Quimica, Centro de Investigacion y Estudios Avanzados, Av. Instituto Politecnico Nacional No. 2508 Col. San Pedro Zacatenco, C.P. 07360, Mexico, D.F. (Mexico)

    2010-12-01

    Changes in electrochemical reactivity for lawsone anions (lawsone, 2-hydroxy-1,4-naphthoquinone, HLw) being coordinated to a series of metallic ions in dimethylsulfoxide solution were evaluated. Upon performing cyclic voltammetry experiments for metal complexes of this quinone with pyridine (Py) - structural formula M(II)(Lw{sup -}){sub 2}(Py){sub 2}; M: Co(II), Ni(II), Zn(II) - it was found that the reduction of coordinated Lw{sup -} units occurs during the first and second electron uptake in the analyzed compounds. The stability of the electrogenerated intermediates for each complex depends on the d electron configuration in each metal center and is determined by magnetic interactions with the available spins considering an octahedral conformation for all the compounds. This was evidenced by in situ spectroelectrochemical-ESR measurements in the Zn(II) complex in which due to the lack of magnetic interaction owing to its electron configuration, the structure of the coordinated anion radical species was determined. Successive reduction of the associated Lw{sup -} units leads to partial dissociation of the complex, determined by the identification of free radical dianion structures in solution. These results show some insights on how metal-lawsone complexation can modify the solution reactivity and stability of the electrogenerated radical species.

  8. 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

    Science.gov (United States)

    Mohamed, Gehad G.; El-Gamel, Nadia E. A.

    2004-11-01

    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.

  9. Zn(II)- and Cu(II)-induced non-fibrillar aggregates of amyloid-beta (1-42) peptide are transformed to amyloid fibrils, both spontaneously and under the influence of metal chelators.

    Science.gov (United States)

    Tõugu, Vello; Karafin, Ann; Zovo, Kairit; Chung, Roger S; Howells, Claire; West, Adrian K; Palumaa, Peep

    2009-09-01

    Aggregation of amyloid-beta (Abeta) peptides is a central phenomenon in Alzheimer's disease. Zn(II) and Cu(II) have profound effects on Abeta aggregation; however, their impact on amyloidogenesis is unclear. Here we show that Zn(II) and Cu(II) inhibit Abeta(42) fibrillization and initiate formation of non-fibrillar Abeta(42) aggregates, and that the inhibitory effect of Zn(II) (IC(50) = 1.8 micromol/L) is three times stronger than that of Cu(II). Medium and high-affinity metal chelators including metallothioneins prevented metal-induced Abeta(42) aggregation. Moreover, their addition to preformed aggregates initiated fast Abeta(42) fibrillization. Upon prolonged incubation the metal-induced aggregates also transformed spontaneously into fibrils, that appear to represent the most stable state of Abeta(42). H13A and H14A mutations in Abeta(42) reduced the inhibitory effect of metal ions, whereas an H6A mutation had no significant impact. We suggest that metal binding by H13 and H14 prevents the formation of a cross-beta core structure within region 10-23 of the amyloid fibril. Cu(II)-Abeta(42) aggregates were neurotoxic to neurons in vitro only in the presence of ascorbate, whereas monomers and Zn(II)-Abeta(42) aggregates were non-toxic. Disturbed metal homeostasis in the vicinity of zinc-enriched neurons might pre-dispose formation of metal-induced Abeta aggregates, subsequent fibrillization of which can lead to amyloid formation. The molecular background underlying metal-chelating therapies for Alzheimer's disease is discussed in this light.

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

    International Nuclear Information System (INIS)

    Zhang, Zhongyu; Bi, Caifeng; Fan, Yuhua; Zhang, Xia; Zhang, Nan; Yan, Xingchen; Zuo, Jian

    2014-01-01

    A novel complex [Zn(phen)(o-AB) 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 3 , Z = 4, F(000) = 1064, S = 1.058, Dc = 1.520 g·cm -3 , R 1 = 0.0412, wR 2 = 0.0948, μ = 1.128 mm -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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tabassum, Sartaj [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)

    2012-11-15

    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.

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

    International Nuclear Information System (INIS)

    Tabassum, Sartaj; Al–Asbahy, Waddhaah M.; Afzal, Mohd.; Shamsi, Manal; Arjmand, Farukh

    2012-01-01

    A new water soluble complex [Zn(glygly)(ssz)(H 2 O)]·6H 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′-TMP and 5′-GMP were carried out by UV–vis titration which was validated by 1 H and 31 P NMR with 5′-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 2 O)]·6H 2 O (1) containing glycyl glycine and sulfasalazine ligand. Complex 1 recognize minor groove of DNA and show hydrolytic DNA cleavage. Highlights: ► Novel Zn(II) complex 1 bearing bioactive glycyl glycine and sulfasalazine ligand scaffold. ► Cleavage activity of 1 was enhanced in presence of activators: H 2 O 2 >MPA>GSH>Asc. ► Complex 1 recognize minor groove as depicted in the cleavage pattern and molecular docking. ► Complex 1 cleaves pBR322 DNA via hydrolytic mechanism and validated by T4 DNA ligase experiments.

  13. Synthesis, spectroscopic and DNA binding ability of CoII, NiII, CuII and ZnII 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.

    Science.gov (United States)

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

    2017-06-01

    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 ]·l2H 2 O, [Ni(L)Cl·(H 2 O) 2 ].5H 2 O, [Cu(L)Cl] and [Zn(L)(CH 3 COO)]. 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 (K b ). Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Complex metal hydrides

    DEFF Research Database (Denmark)

    Ley, Morten Brix

    2014-01-01

    og batterier de to mest lovende energibærere til mobile applikationer. Komplekse metalhydrider er blevet undersøgt i vid udstrækning over de sidste tyve år, siden de gravimetrisk og volumetrisk kan indeholde store mængder brint. Derfor er metal borhydrider velegnet til faststofopbevaring af brint...

  15. Cu(II) AND Zn(II)

    African Journals Online (AJOL)

    Preferred Customer

    SYNTHESIS OF 2,2-DIMETHYL-4-PHENYL-[1,3]-DIOXOLANE USING ZEOLITE. ENCAPSULATED Co(II), Cu(II) AND Zn(II) COMPLEXES. B.P. Nethravathi1, K. Rama Krishna Reddy2 and K.N. Mahendra1*. 1Department of Chemistry, Bangalore University, Bangalore-560001, India. 2Department of Chemistry, Government ...

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

    Science.gov (United States)

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

    2017-04-01

    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.

  17. Structural and biological evaluation of some metal complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone

    Science.gov (United States)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2013-12-01

    The synthesis and characterization of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O2 complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone (H2PVT) are reported. Theoretical calculations have been performed to obtain IR spectra of ligand and its complexes using AM1, Zindo/1, MM+ and PM3, methods. The Schiff base and its metal complexes have been screened for antibacterial Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus saprophyticus. H2VPT shows no apparent digestion effect on the egg albumin while Mn(II), Hg(II) and Cu(II) complexes exhibited a considerable digestion effect following the order Cu(II) > Mn(II) > Hg(II). Moreover, Ni(II) and Co(II) complexes revealed strong digestion effect. Fe(II), Mn(II), Cu(II), Zn(II) and Ni(II) acted as metal co- SOD enzyme factors, which are located in different compartments of the cell.

  18. Structural, theoretical and corrosion inhibition studies on some transition metal complexes derived from heterocyclic system

    Science.gov (United States)

    Gupta, Shraddha Rani; Mourya, Punita; Singh, M. M.; Singh, Vinod P.

    2017-06-01

    A Schiff base, (E)-N‧-((1H-indol-3-yl)methylene)-2-aminobenzohydrazide (Iabh) and its Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. These compounds have been characterized by different physico-chemical and spectroscopic tools (UV-Vis, IR, NMR and ESI-Mass). The molecular structure of Iabh is determined by single crystal X-ray diffraction technique. The ligand Iabh displays E-configuration about the >Cdbnd N- bond. The structure of ligand is stabilized by intra-molecular H-bonding. In all the metal complexes the ligand coordinates through azomethine-N and carbonyl-O resulting a distorted octahedral geometry for Mn(II), Co(II) and Cu(II) complexes in which chloride ions occupy axial positions. Ni(II) and Zn(II) complexes, however, form 4-coordinate distorted square planer and tetrahedral geometry around metal ion, respectively. The structures of the complexes have been satisfactorily modeled by calculations based on density functional theory (DFT) and time dependent-DFT (TD-DFT). The corrosion inhibition study of the compounds have been performed against mild steel in 0.5 M H2SO4 solution at 298 K by using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). They show appreciable corrosion inhibition property.

  19. benzimidazole metal complexes

    Indian Academy of Sciences (India)

    aUnité de Recherche de Chimie de l'Environnement et Moléculaire Structurale, Université des Frères. Mentouri .... determine the quantum chemical parameters for the title ..... retical study of benzazole thioether and its zinc complex.

  20. Model studies of the Cu(B) site of cytochrome c oxidase utilizing a Zn(II) complex containing an imidazole-phenol cross-linked ligand.

    Science.gov (United States)

    Pesavento, Russell P; Pratt, Derek A; Jeffers, Jerry; van der Donk, Wilfred A

    2006-07-21

    Cytochrome c oxidase, the enzyme complex responsible for the four-electron reduction of O2 to H2O, contains an unusual histidine-tyrosine cross-link in its bimetallic heme a3-CuB active site. We have synthesised an unhindered, tripodal chelating ligand, BPAIP, containing the unusual ortho-imidazole-phenol linkage, which mimics the coordination environment of the CuB center. The ligand was used to investigate the physicochemical (pKa, oxidation potential) and coordination properties of the imidazole-phenol linkage when bound to a dication. Zn(II) coordination lowers the pKa of the phenol by 0.6 log units, and increases the potential of the phenolate/phenoxyl radical couple by approximately 50 mV. These results are consistent with inductive withdrawal of electron density from the phenolic ring. Spectroscopic data and theoretical calculations (DFT) were used to establish that the cationic complex [Zn(BPAIP)Br]+ has an axially distorted trigonal bipyramidal structure, with three coordinating nitrogen ligands (two pyridine and one imidazole) occupying the equatorial plane and the bromide and the tertiary amine nitrogen of the tripod in the axial positions. Interestingly, the Zn-Namine bonding interaction is weak or absent in [Zn(BPAIP)Br]+ and the complex gains stability in basic solutions, as indicated by 1H NMR spectroscopy. These observations are supported by theoretical calculations (DFT), which suggest that the electron-donating capacity of the equatorial imidazole ligand can be varied by modulation of the protonation and/or redox state of the cross-linked phenol. Deprotonation of the phenol makes the equatorial imidazole a stronger sigma-donor, resulting in an increased Zn-Nimd interaction and thereby leading to distortion of the axial ligand axis toward a more tetrahedral geometry.

  1. Transition Metal Complexes and Catalysis

    Indian Academy of Sciences (India)

    approaches towards the study of bonding in transition metal complexes. Despite .... industrial scale reactions for the production of organic compounds using transition ..... It has found several applications as an engineering thermoplastic. .... and processes of interest to the company, that is, applied research. It is this very ...

  2. Spectral, optical and cytotoxicity studies on 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide(H3L) and some of its metal complexes

    Science.gov (United States)

    Hosny, Nasser M.; Hassan, Nader Y.; Mahmoud, Heba M.; Abdel-Rhman, Mohamed H.

    2018-03-01

    The ligand 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide (H3L) and its metal complexes with Co(II), Ni(II), Cu(II) and Zn(II) acetates have been synthesized. The isolated compounds have been characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR, ESR, mass, electronic spectra, electrical conductivity, effective magnetic moments and thermal analyses. The free organic ligand exists in the keto form, but in the metal complexes, it coordinates in the enol form. Four coordinated species were suggested for all the isolated metal complexes. The measured optical band gap values confirmed the presence of direct electronic transition and the semi-conductivity of the compounds. The ligand and its Zn(II) complex were examined as cytotoxic agent against HCT-116 and HePG-2. The ligand showed very strong cytotoxic effect against HePG-2, but moderate cytotoxicity against HCT-116. Zn(II) complex showed weak cytotoxicity against the two cell lines.

  3. Metal complexes with 5-aminotetrazole

    International Nuclear Information System (INIS)

    Lavrenova, L.G.; Larionov, S.V.; Grankina, Z.A.; Ikorskij, V.N.

    1983-01-01

    Nitrate and chloride complexes of Co(2), Ni(2), Cu(2), Cd(2), Hg(2), Pb(2) with 5 aminotetrazole (ATE) and compoUnds Zn(ATE') 2 and Cd(ATEE') 2 , where ATE' is a 5 aminotetrazole ano /nion. On the base of spectroscopic data (spectrophotometry, IR- spectra, EPR and magnetic measurements assumptions on M(2) coordination in complexes are made. Most probably ATE is a bridge ligand which is joined by two nitrogen atoms to various M(2) ions. In Co(2), Ni(2) and Cu(ATE) 3 -Cl 2 compounds the metal has a distorted actahedral coordination and forms MN 6 unit, which suggests the interaction of metal ions with ATE nitrogen atoms along the Z-axis. In the Cu(ATE) 2 (NO 3 ) 2 octahedral complex the CuN 4 O 2 coordination unit is realized at the expense of participation of nitratogroups in coordination

  4. Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand

    Science.gov (United States)

    Bakale, Raghavendra P.; Naik, Ganesh N.; Machakanur, Shrinath S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.; Gudasi, Kalagouda B.

    2018-02-01

    A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV-Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.

  5. Adsorption of enrofloxacin in presence of Zn(II) on a calcareous soil.

    Science.gov (United States)

    Graouer-Bacart, Mareen; Sayen, Stéphanie; Guillon, Emmanuel

    2015-12-01

    As a result of their consumption, excretion, disposal and persistence, antibiotics enter the soil environment and may be transported to surface and ground waters. During their transfer through soils, retention processes play a key role in their mobility. Antibiotics often coexist with heavy metals in soils due to agricultural practices and other sources of inputs. In this context, this study deals with the co-adsorption of Zn(II) and enrofloxacin (ENR), a widely-used veterinary antibiotic, on a calcareous soil using batch retention experiments and X-ray Absorption Near Edge Structure (XANES) spectroscopy. To improve our understanding of the interaction of this emerging organic contaminant with metal cations at the water-soil interface, the ternary system containing ENR, Zn(II) and a selected calcareous soil was investigated over a pH range between 7 and 10, at different solid-solution contact times and ENR concentrations. The presence of Zn(II) slightly influenced the retention of the antibiotic, leading to an increase of the adsorbed ENR amounts. The distribution coefficient Kd value increased from 0.66 Lg(-1) for single ENR adsorption to 1.04 Lg(-1) in presence of Zn(II) at a 1/2 ENR/Zn(II) ratio. The combination of adsorption isotherm data, solution speciation diagrams and XANES spectra evidenced a small proportion of Zn(II)-ENR complexes at soil pH leading to the slight increase of ENR adsorption in presence of zinc. These results suggest that it is necessary to consider the interaction between ENR and metal cations when assessing the mobility of ENR in soils. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Co-sequestration of Zn(II) and phosphate by γ-Al{sub 2}O{sub 3}: From macroscopic to microscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    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: xkwang@ipp.ac.cn [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)

    2015-10-30

    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.

  7. Effect of substituents on polarizability and hyperpolarizability values of benzimidazole metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, P. A.; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli - 620 024, Tamilnadu (India)

    2016-05-23

    In this report, the polarizability and first and second order hyperpolarizability values of bis benzimidazole Zn(II)-2R and bis benzimidazole Cd(II)-2R complexes, with different electron donating moieties R (R= Cl, Br, I, Acetate) were calculated using time dependent Hartree-Fock (TDHF) formalism embedded in MOPAC2012 package. Further the role of substituents on polarizability and hyperpolarizability values is investigated for the first time by analyzing the frontier molecular orbitals of the complexes with respect to the electronegativity of the substituents. It is found that the increase in electronegativity of the substituents correspondingly increases the energy gap of the molecules, which in turn reduces the polarizability values of both Zn and Cd benzimidazole complexes. Similarly, increase in electronegativity reduces the electric quadrupole moments of both the metal complexes, which in turn reduces the hyperpolarizability values.

  8. Supramolecularly assembled water layers stabilized by sebacic anions in complexes of Zn(II) and Co(II)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two three-dimensional supramolecular water architectures,[Zn(phen)3]2 ·[Zn(C10H16O4)·(H2O)3]·(C10H16O4)2·20H2O(1) and [Co(phen)3]2 ·[Co(H2O)6]·(C10H16O4)3·30H2O(2)[phen=1,10-Phenanthroline,C10H16O4=sebacic dianion],have been synthesized and characterized by IR,elemental analysis,thermogravimetric analysis,and single-crystal X-ray diffractions.The two structures both contain extensive hydrogen bonding between water molecules as well as between water molecules and sebacic anions.The water molecules and sebacic acid O atoms assembled 2D supramolecular corrugated sheets with different morphology in the two complexes.

  9. Synthesis and Spectral Characterization of Antifungal Sensitive Schiff Base Transition Metal Complexes

    Science.gov (United States)

    Sakthivel, A.; Rajasekaran, K.

    2007-01-01

    New N2O2 donor type Schiff base has been designed and synthesized by condensing acetoacetanilido-4-aminoantipyrine with 2-aminobenzoic acid in ethanol. Solid metal complexes of the Schiff base with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) metal ions were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conduction, fast atom bombardment (FAB) mass, IR, UV-Vis, and 1H NMR spectral studies. The data show that the complexes have the composition of ML type. The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Candida albicans, Rhizoctonia bataicola and Trichoderma harizanum. All the metal complexes showed stronger antifungal activities than the free ligand. The minimum inhibitory concentrations (MIC) of the metal complexes were found in the range of 10~31 µg/ml. PMID:24015086

  10. Synthesis and characterization of some metal complexes of a Schiff base derived from ninhydrin and α,L-alanine

    Directory of Open Access Journals (Sweden)

    Mehabaw Getahun Derebe

    2002-06-01

    Full Text Available Complexes of Mn(II, Fe(III, Co(II, Ni(II and Zn(II with an intermediate Schiff base derived from ninhydrin and α,L-alanine (indane-1,3-dione-2-imine-N-2-propionate, IDIP were successfully synthesized. All complexes were distinctly colored and were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The ligand (Schiff base was shown to behave as a monobasic tridentate ONO donor. The Mn(II and Fe(III complexes contain only one ligand molecule plus water and chloride(s per metal ion, while all the others contain two ligand molecules per metal ion. An octahedral geometry is proposed for the metal complexes.

  11. Synthesis, Characterization and Biological Evaluation of Transition Metal Complexes Derived from N, S Bidentate Ligands

    Directory of Open Access Journals (Sweden)

    Enis Nadia Md Yusof

    2015-05-01

    Full Text Available Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC with 2-methoxybenzaldehyde (2MB and 3-methoxybenzaldehyde (3MB. The ligands were reacted separately with acetates of Cu(II, Ni(II and Zn(II yielding 1:2 (metal:ligand complexes. The metal complexes formed were expected to have a general formula of [M(NS2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1 and S2M3MBH (2 were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7 and estrogen receptor-negative (MDA-MB-231 breast cancer cell lines. Only the Cu(II complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II complexes have a strong DNA binding affinity.

  12. Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

    Science.gov (United States)

    Sakthi, Marimuthu; Ramu, Andy

    2017-12-01

    A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV-vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

  13. Template synthesis, characterization and antimicrobial activity of the complex combinations of some transitional metals with isonicotinoylhydrazone -2,4,6- trimethylbenzaldehyde

    International Nuclear Information System (INIS)

    Mitu, L.ITU; Imran, M.

    2011-01-01

    The complexes of Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) with isonicotinoyl-hydrazone -2,4,6-trimethylbenzaldehyde (INHTB) are reported. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility, thermal analysis and for the Cu(II) complex the ESR spectrum has been recorded. The anti-bacterial activity of these complexes were investigated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Shigella flexneri bacteria. The INHTB ligand is coordinated at the metallic ions by oxygen amide (O=C) and the azomethine nitrogen. (author)

  14. Fixation of metallic sulfosalicylate complexes on an anionic exchange resin

    International Nuclear Information System (INIS)

    Cahuzac, S.

    1969-06-01

    Since sulfosalicylate ions have acid-base properties, sulfosalicylate complexes have an apparent stability which varies with the ph. As a result, the fixation of sulfo-salicylates on an anionic exchange resin depends on the ph of the solution in equilibrium with the resin. This research has been aimed at studying the influence of the ph on the fixation on an anionic exchange resin (Dowex 1 x 4) of sulfosalicylate anions on the one hand, and of metallic sulfosalicylate complexes on the other hand. In the first part of this work, a determination has been made, by frontal analysis of the distribution of sulfosalicylate ions in the resin according to the total sulfosalicylate I concentration in the aqueous solution in equilibrium with the resin. The exchange constants of these ions between the resin and the solution have been calculated. In the second part, a study has been made of the fixation of anionic sulfosalicylate complexes of Fe(III), Al(III), Cr(III), Cu(II), Ni(II), Co(II), Zn(II), Mn(II), Cd(II), Fe(II) and UO 2 2+ . By measuring the partition coefficients of these different elements between the resin and the solution it has been possible to give interpretation for the modes of fixation of the metallic ions, and to calculate their exchange constant between the resin and the solution. The relationship has been established for each metallic element studied, between its partition coefficient, the ph and the total concentration of the complexing agent in solution. Such a relationship makes it possible to predict, for given conditions, the nature of the species in solution and in the resin, as well as the partition coefficient of a metallic, element. Finally, in the third part of the work, use has been made of results obtained previously, to carry out some separations (Ni 2+ - Co 2+ ; Ni 2+ - Co 2+ - Cu 2+ ; UO 2 2+ - Fe 3+ ; UO 2 2+ - Cr 3+ ; UO 2 2+ - Cu 2+ ; UO 2 2+ - Ni 2+ ; UO 2 2+ - Co 2+ ; UO 2 2+ - Mn 2+ and UO 2 2+ - Cd 2+ ), as well as the purification

  15. Thermal Studies of Zn(II, Cd(II and Hg(II Complexes of Some N-Alkyl-N-Phenyl-Dithiocarbamates

    Directory of Open Access Journals (Sweden)

    Peter A. Ajibade

    2012-07-01

    Full Text Available The thermal decomposition of Zn(II, Cd(II and Hg(II complexes of N-ethyl-N-phenyl and N-butyl-N-phenyl dithiocarbamates have been studied using thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The products of the decomposition, at two different temperatures, were further characterized by scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDX. The results show that while the zinc and cadmium complexes undergo decomposition to form metal sulphides, and further undergo oxidation forming metal oxides as final products, the mercury complexes gave unstable volatiles as the final product.

  16. 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

    Directory of Open Access Journals (Sweden)

    M. Padma Latha

    2007-04-01

    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.

  17. Synthesis and Structural Studies on Transition Metal Complexes Derived from 4-Hydroxy-4-methyl–2-pentanone-1H-benzimidazol-2-yl-hydrazone

    Directory of Open Access Journals (Sweden)

    M. Neelamma

    2011-01-01

    Full Text Available Transition metal complexes of Cr(III, Fe(III, Mn(II, Co(II, Ni(II, Cu(II and Zn(II with a tridentate ligand, 4-hydroxy-4-methyl-2-pentanone-1H-benzimidazole-2yl-hydrazone (H-HPBH derived from the condensation of 2-hydrazinobenzimidazole and diacetone alcohol was synthesized. Characterization has been done on the basis of analytical, conductance, thermal and magnetic data, infrared, 1H NMR, electronic, mass and ESR spectral data. From analytical and thermal data, the stoichiometry of the complexes has been found to be 1:1 (metal: ligand. Divalent complexes have the general formula [M(HPBHCl(H2O2] in octahedral geometry, [M(HPBHCl] in tetrahedral and square planar stereochemistries and trivalent complexes [M(HPBHCl2(H2O] in octahedral disposition. Infrared spectral data suggest that the ligand HPBH behaves as a monobasic tridentate ligand with N: N: O donor sequence towards the metal ions. On the basis of the above physicochemical data, octahedral, tetrahedral and square planar geometries were assigned for the complexes. The ligand and metal complexes were screened for their physiological activities against E. coli and S. aureus. The order of physiological activity has been found to be Cu(II > Ni(II > Zn(II > Co(II > Cr(III > Mn(II > Fe (III > ligand against E.coli and Ni(II > Cu(II > Zn(II > Mn(II > Cr(III > Fe(III > Co(II > ligand against S. aureus.

  18. Synthesis, spectral characterisation, morphology, biological activity and DNA cleavage studies of metal complexes with chromone Schiff base

    Directory of Open Access Journals (Sweden)

    P. Kavitha

    2016-07-01

    Full Text Available Cu(II, Co(II, Ni(II and Zn(II complexes have been synthesized using 3-((pyridine-2-yliminomethyl-4H-chromen-4-one as a ligand derived from 3-formyl chromone and 2-amino pyridine. All the complexes were characterised by analytical, conductivity, IR, electronic, magnetic, ESR, thermal, powder XRD and SEM studies. The analytical data revealed that the metal to ligand molar ratio is 1:2 in all the complexes. Molar conductivity data indicates that all the complexes are neutral in nature. On the basis of magnetic and electronic spectral data, octahedral geometry is proposed for all the complexes. Thermal behaviour of the synthesized complexes indicates the coordinated and lattice water molecules are present in the complexes. The X-ray diffraction data suggest a triclinic system for all compounds. Different surface morphologies were identified from SEM micrographs. All metal complexes exhibit fluorescence. The antimicrobial and nematicidal activity data show that metal complexes are more potent than the parent ligand. The DNA cleavage activity of the ligand and its metal complexes were observed in the presence of H2O2.

  19. Computer augumented modelling studies of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid in 1,2-propanediol–water mixtures

    Directory of Open Access Journals (Sweden)

    MAHESWARA RAO VEGI

    2008-12-01

    Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid was studied at 303 K in 0–60 vol. % 1,2-propanediol–water mixtures, whereby the ionic strength was maintained at 0.16 mol dm-3. The active forms of the ligand are LH3+, LH2 and LH–. The predominant detected species were ML, ML2, MLH, ML2H and ML2H2. The trend of the variation in the stability constants with changing dielectric constant of the medium is explained based on the cation stabilizing nature of the co-solvents, specific solvent–water interactions, charge dispersion and specific interactions of the co-solvent with the solute. The effect of systematic errors in the concentrations of the substances on the stability constants is in the order alkali > > acid > ligand > metal. The bioavailability and transportation of metals are explained based on distribution diagrams and stability constants.

  20. Development of luminescent sensors based on transition metal complexes for the detection of nitroexplosives.

    Science.gov (United States)

    Sathish, Veerasamy; Ramdass, Arumugam; Velayudham, Murugesan; Lu, Kuang-Lieh; Thanasekaran, Pounraj; Rajagopal, Seenivasan

    2017-12-12

    The detection of chemical explosives is a major area of research interest and is essential for the military as well as homeland security to counter the catastrophic effects of global terrorism. In recent years, tremendous effort has been devoted to the development of luminescent materials for the detection of explosives in the vapor, solution, and solid states with a high degree of selectivity and sensitivity and a rapid response time. Apart from the wide range of organic fluorescent chemosensors, transition metal complexes play a prominent role in the sensing of nitroaromatic explosives owing to their rich photophysical characteristics. This review briefly summarizes the salient features of the design and preparation of transition metal (Zn(ii), Ir(iii), Pd(ii), Pt(ii), Re(i) and Ru(ii)) complexes/metallacycles/metallosupramolecules with emphasis on their photophysical properties, sensing behavior, mechanism of action, and the driving forces for detecting explosives and future prospects and challenges. Most of the probes that have been reported to date act as "turn-off" luminescent sensors because their emission (intensity, lifetime, and quantum yield) is eventually quenched upon sensing with nitroaromatic compounds (NACs) through photo-induced electron or energy transfer. These unique properties of transition metal complexes in response to explosives open up new vistas for the development of real world applications such as on-site detection, in-field security, forensic research, etc.

  1. Complexes of natural carbohydrates with metal cations

    International Nuclear Information System (INIS)

    Alekseev, Yurii E; Garnovskii, Alexander D; Zhdanov, Yu A

    1998-01-01

    Data on the interaction of natural carbohydrates (mono-, oligo-, and poly-saccharides, amino sugars, and natural organic acids of carbohydrate origin) with metal cations are surveyed and described systematically. The structural diversity of carbohydrate metal complexes, caused by some specific features of carbohydrates as ligands, is demonstrated. The influence of complex formation on the chemical properties of carbohydrates is discussed. It is shown that the formation of metal complexes plays an important role in the configurational and conformational analysis of carbohydrates. The practical significance of the coordination interaction in the series of carbohydrate ligands is demonstrated. The bibliography includes 571 references.

  2. New 14-membered octaazamacrocyclic complexes of divalent transition metal ions with their antimicrobial and spectral studies

    Science.gov (United States)

    Singh, D. P.; Kumar, Krishan; Sharma, Chetan

    2010-01-01

    A novel series of macrocyclic complexes of the type [M(C 18H 14N 10S 2)X 2]; where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); X = Cl -, NO 3-, CH 3COO - has been synthesized by [2+2] condensation of thiocarbohydrazide and isatin in the presence of divalent metal salts in methanolic medium. The complexes have been characterized with the help of elemental analyses, conductance measurements, magnetic measurements, electronic, NMR and infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. On the basis of various studies a distorted octahedral geometry may be proposed for all of these complexes. These metal complexes were also tested for their in vitro antimicrobial activities against some Gram-positive bacteria viz. Staphylococcus aureus, Bacillus subtilis, and some Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa and some fungal strains Aspergillus niger, Aspergillus flavus (molds), Candida albicans, Saccharomyces cerevisiae (yeasts). The results obtained were compared with standard antibiotic: Ciprofloxacin and the standard antifungal drug: Amphotericin-B.

  3. Stability Constants of Mixed Ligand Complexes of Transition Metal(II Ions with Salicylidene-4-methoxyaniline as Primary Ligand and 5-Bromosalicylidene-4-nitroaniline as Secondary Ligand

    Directory of Open Access Journals (Sweden)

    N. G. Nadkarni

    2011-01-01

    Full Text Available Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II, Ni(II, Cu(II and Zn(II; X = salicylidene-4-methoxyaniline and Y=5-bromosalicylidene-4-nitroaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ= 0.1 M (KCl in 75 : 25(v/v 1,4-dioxne-water medium. The stability constants for binary (M-Y and ternary (M-X-Y systems were calculated. The relative stability (Δ log KT values of the ternary complexes with corresponding binary complexes for all the metal(II ions in the present study found to be negative indicating that ternary 1:1:1 (M-X-Y complexes are less stable than binary 1:1 (M-Y complexes. In the ternary system studied, the order of stability constants of mixed ligand complexes with respect to the metal ions was found to be Cu(II > NI(II > Mn(II > Zn(II; which is same as in the corresponding binary (M-Y systems.

  4. New fluorescent azo-Schiff base Cu(II) and Zn(II) metal chelates; spectral, structural, electrochemical, photoluminescence and computational studies

    Science.gov (United States)

    Purtas, Fatih; Sayin, Koray; Ceyhan, Gokhan; Kose, Muhammet; Kurtoglu, Mukerrem

    2017-06-01

    A new Schiff base containing azo chromophore group obtained by condensation of 2-hydroxy-4-[(E)-phenyldiazenyl]benzaldehyde with 3,4-dimethylaniline (HL) are used for the syntheses of new copper(II) and zinc(II) chelates, [Cu(L)2], and [Zn(L)2], and characterized by physico-chemical and spectroscopic methods such as 1H and 13C NMR, IR, UV.-Vis. and elemental analyses. The solid state structure of the ligand was characterized by single crystal X-ray diffraction study. X-ray diffraction data was then used to calculate the harmonic oscillator model of aromaticity (HOMA) indexes for the rings so as to investigate of enol-imine and keto-amine tautomeric forms in the solid state. The phenol ring C10-C15 shows a considerable deviation from the aromaticity with HOMA value of 0.837 suggesting the shift towards the keto-amine tautomeric form in the solid state. The analytical data show that the metal to ligand ratio in the chelates was found to be 1:2. Theoretical calculations of the possible isomers of the ligand and two metal complexes are performed by using B3LYP method. Electrochemical and photoluminescence properties of the synthesized azo-Schiff bases were also investigated.

  5. Pharmacologically significant tetraaza macrocyclic metal complexes ...

    Indian Academy of Sciences (India)

    MOHAMMAD SHAKIR

    2017-11-22

    Nov 22, 2017 ... structural biological models.6 Hence, biological prop- erties of ... poor water solubility, exhibits intrinsic resistance and ..... pdb). The metal complex files were drawn using. ChemDraw (MM2) and their energies were minimized.

  6. Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

    Science.gov (United States)

    Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

    2014-10-15

    Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Template synthesis and characterization of biologically active transition metal complexes comprising 14-membered tetraazamacrocyclic ligand

    Directory of Open Access Journals (Sweden)

    DHARMPAL SINGH

    2010-02-01

    Full Text Available A novel series of complexes of the type [M(C28H24N4X2], whereM = Co(II, Ni(II, Cu(II, Zn(II and Cd(II, X = Cl–, NO3–, CH3COO– and (C28H24N4 corresponds to the tetradentate macrocyclic ligand, were synthe¬sized by template condensation of 1,8-diaminonaphthalene and diacetyl in the presence of divalent metal salts in methanolic medium. The complexes were characterized by elemental analyses, conductance and magnetic measurements, as well as by UV/Vis, NMR, IR and MS spectroscopy. The low values of the molar conductance indicate non-electrolyte type of complexes. Based on these spectral data, a distorted octahedral geometry may be proposed for all of these complexes. All the synthesized macrocyclic complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, viz Bacillus cereus, Salmonella typhi, Escherichia coli and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains were compared with the MIC shown by the standard antibiotics linezolid and cefaclor.

  8. Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

    International Nuclear Information System (INIS)

    Reddy, K. R. K; Mahendra, K.N.

    2008-01-01

    The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

  9. Quinonoid metal complexes: toward molecular switches.

    Science.gov (United States)

    Dei, Andrea; Gatteschi, Dante; Sangregorio, Claudio; Sorace, Lorenzo

    2004-11-01

    The peculiar redox-active character of quinonoid metal complexes makes them extremely appealing to design materials of potential technological interest. We show here how the tuning of the properties of these systems can be pursued by using appropriate molecular synthetic techniques. In particular, we focus our attention on metal polyoxolene complexes exhibiting intramolecular electron transfer processes involving either the ligand and the metal ion or the two dioxolene moieties of a properly designed ligand thus inducing electronic bistability. The transition between the two metastable electronic states can be induced by different external stimuli such as temperature, pressure, light, or pH suggesting the use of these systems for molecular switches.

  10. Studies on chelation properties of ampicillin with trace metal ions and comparison with penicillin complexes

    International Nuclear Information System (INIS)

    Rehmani, F.S.; Hameed, W.

    2003-01-01

    The penicillin is highly effective antibiotic with extremely wide margin of safety. Ampicillin e is the penicillin group of antibiotic in which side chain is phenyl group i.e. D-amino benzyl penicillin. The side chain determines many of anti bacterial and pharmacological characteristics. They inhibit the protein synthesis in bacterial cell wall. The chelating properties of the antibiotic may be used in the metal transport across the membrane. The present investigations are helpful in drug metabolism and their effects on minerals contents of the body. The complex formation between Ampicillin and penicillin with trace metal ions such as Fe(III), Cr(III), Al(III), Mn(II), Ni(II), Co(II), Ca(II), Mg(II), Cu(III) and Zn(II) were studied by potentiometric titrations and spectrophotometric methods. Stoichiometry of these complexes were studied by mole ratio method. It was found that the Fe(III) and Cu(II) ions form most stable complexes near physiological pH and the mole ratio was 1:1. (author)

  11. Studies on complexation of a tridentate ONS Schiff base with lighter and heavier metals ions, and investigation into their biological properties

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Ali, A.M.; Juan, W.D.; Crouse, K.A.; Silong, S.

    1999-05-01

    Several new complexes of a tridentate ONS Schiff base derived from the condensation of S-benzyldithiocarbazate with salicylaldehyde have been characterised by elemental analyses, molar conductivity measurements, infrared, and electronic spectral studies. The tridentate Schiff base (HONSH) behaves as a dinegatively charged ligand coordinating through the thiolo sulphur, the azomethine nitrogen atom and the hydroxyl oxygen atom. It forms mono-ligand complexes of the general formula, [M(ONS)X], [M = Ni(II), Cu(II), Cr(III), Sb(III), Zn(II), Zr(IV) or U(VI) and X = H 2 O, Cl]. The ligand produced bis-chelated complex with Th(IV) of composition, [Th(ONS) 2 ]. Square-planar structures were proposed for the Ni(II) and Cu(II) complexes. Antimicrobial tests indicated that the Schiff base and five of the metal complexes of Cu(II), Ni(II), U(VI), Zn(II) and Sb(III) were found to be strongly active against bacteria. Ni(II) and Sb(III) complexes were the most effective against Pseudomonas aeruginosa (gram negative) while the Cu(II) complex proved to be the best against Bacillus cereus (gram positive bacteria). Antifungal activities were also noted with the Schiff base and the U(VI) complex. These compounds have shown results against Candida albicans fungi. But none of these compounds were effective against Aspergillus ochraceous fungi. (author)

  12. Acid-base-controlled stereoselective metalation of overhanging carboxylic acid porphyrins: consequences for the formation of heterobimetallic complexes.

    Science.gov (United States)

    Le Gac, Stéphane; Najjari, Btissam; Dorcet, Vincent; Roisnel, Thierry; Fusaro, Luca; Luhmer, Michel; Furet, Eric; Halet, Jean-François; Boitrel, Bernard

    2013-08-12

    Overhanging carboxylic acid porphyrins have revealed promising ditopic ligands offering a new entry in the field of supramolecular coordination chemistry of porphyrinoids. Notably, the adjunction of a so-called hanging-atop (HAT) Pb(II) cation to regular Pb(II) porphyrin complexes allowed a stereoselective incorporation of the N-core bound cation, and an allosterically controlled Newton's cradle-like motion of the two Pb(II) ions also emerged from such bimetallic complexes. In this contribution, we have extended this work to other ligands and metal ions, aiming at understanding the parameters that control the HAT Pb(II) coordination. The nature of the N-core bound metal ion (Zn(II), Cd(II)), the influence of the deprotonation state of the overhanging COOH group and the presence of a neutral ligand on the opposite side (exogenous or intramolecular), have been examined through (1)H NMR spectroscopic experiments with the help of radiocrystallographic structures and DFT calculations. Single and bis-strap ligands have been considered. They all incorporate a COOH group hung over the N-core on one side. For the bis-strap ligands, either an ester or an amide group has been introduced on the other side. In the presence of a base, the mononuclear Zn(II) or Cd(II) complexes incorporate the carbonyl of the overhanging carboxylate as apical ligand, decreasing its availability for the binding of a HAT Pb(II). An allosteric effector (e.g., 4-dimethylaminopyridine (DMAP), in the case of a single-strap ligand) or an intramolecular ligand (e.g., an amide group), strong enough to compete with the carbonyl of the hung COO(-), is required to switch the N-core bound cation to the opposite side with concomitant release of the COO(-), thereby allowing HAT Pb(II) complexation. In the absence of a base, Zn(II) or Cd(II) binds preferentially the carbonyl of the intramolecular ester or amide groups in apical position rather than that of the COOH. This better preorganization, with the

  13. Coordination structure of adsorbed Zn(II) at Water-TiO2 interfaces

    Energy Technology Data Exchange (ETDEWEB)

    He, G.; Pan, G.; Zhang, M.; Waychunas, G.A.

    2011-01-15

    The local structure of aqueous metal ions on solid surfaces is central to understanding many chemical and biological processes in soil and aquatic environments. Here, the local coordination structure of hydrated Zn(II) at water-TiO{sub 2} interfaces was identified by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations. A nonintegral coordination number of average {approx}4.5 O atoms around a central Zn atom was obtained by EXAFS analysis. DFT calculations indicated that this coordination structure was consistent with the mixture of 4-coordinated bidentate binuclear (BB) and 5-coordinated bidentate mononuclear (BM) metastable equilibrium adsorption (MEA) states. The BB complex has 4-coordinated Zn, while the monodentate mononuclear (MM) complex has 6-coordinated Zn, and a 5-coordinated adsorbed Zn was found in the BM adsorption mode. DFT calculated energies showed that the lower-coordinated BB and BM modes were thermodynamically more favorable than the higher-coordinated MM MEA state. The experimentally observed XANES fingerprinting provided additional direct spectral evidence of 4- and 5-coordinated Zn-O modes. The overall spectral and computational evidence indicated that Zn(II) can occur in 4-, 5-, and 6-oxygen coordinated sites in different MEA states due to steric hindrance effects, and the coexistence of different MEA states formed the multiple coordination environments.

  14. Intracellular Zn(II) Intoxication Leads to Dysregulation of the PerR Regulon Resulting in Heme Toxicity in Bacillus subtilis

    Science.gov (United States)

    2016-01-01

    Transition metal ions (Zn(II), Cu(II)/(I), Fe(III)/(II), Mn(II)) are essential for life and participate in a wide range of biological functions. Cellular Zn(II) levels must be high enough to ensure that it can perform its essential roles. Yet, since Zn(II) binds to ligands with high avidity, excess Zn(II) can lead to protein mismetallation. The major targets of mismetallation, and the underlying causes of Zn(II) intoxication, are not well understood. Here, we use a forward genetic selection to identify targets of Zn(II) toxicity. In wild-type cells, in which Zn(II) efflux prevents intoxication of the cytoplasm, extracellular Zn(II) inhibits the electron transport chain due to the inactivation of the major aerobic cytochrome oxidase. This toxicity can be ameliorated by depression of an alternate oxidase or by mutations that restrict access of Zn(II) to the cell surface. Conversely, efflux deficient cells are sensitive to low levels of Zn(II) that do not inhibit the respiratory chain. Under these conditions, intracellular Zn(II) accumulates and leads to heme toxicity. Heme accumulation results from dysregulation of the regulon controlled by PerR, a metal-dependent repressor of peroxide stress genes. When metallated with Fe(II) or Mn(II), PerR represses both heme biosynthesis (hemAXCDBL operon) and the abundant heme protein catalase (katA). Metallation of PerR with Zn(II) disrupts this coordination, resulting in depression of heme biosynthesis but continued repression of catalase. Our results support a model in which excess heme partitions to the membrane and undergoes redox cycling catalyzed by reduced menaquinone thereby resulting in oxidative stress. PMID:27935957

  15. Synthesis, spectroscopic characterization, electrochemistry and biological evaluation of some metal (II) complexes with ONO donor ligand containing benzo[b]thiophene and coumarin moieties

    Science.gov (United States)

    Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

    2014-09-01

    Schiff base ligand 3-chloro-N‧-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzo[b]thiophene-2-carbohydrazide and its Cu(II), Co(II), Ni(II) and Zn(II) complexes were synthesized, characterized by elemental analysis and various physico-chemical techniques like, IR, 1H NMR, ESI-mass, UV-Visible, thermogravimetry - differential thermal analysis, magnetic measurements and molar conductance. Spectral analysis indicates octahedral geometry for all the complexes. Cu(II) complex have 1:1 stoichiometry of the type [M(L)(Cl)(H2O)2], whereas Co(II), Ni(II) and Zn(II) complexes have 1:2 stoichiometric ratio of the type [M(L)2]. The bonding sites are the oxygen atom of amide carbonyl, nitrogen of azomethine function and phenolic oxygen of the Schiff base ligand via deprotonation. The thermogravimetry - differential thermal analysis studies gave evidence for the presence of coordinated water molecules in the composition of Cu(II) complex which was further supported by IR measurements. All the complexes were investigated for their electrochemical activity, but only the Cu(II) complex showed the redox property. In order to evaluate the effect of antimicrobial potency of metal ions upon chelation, ligand and its metal complexes along with their respective metal chlorides were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The results showed that the metal complexes were found to be more active than free ligand. Ligand and its complexes were screened for free radical scavenging activity by DPPH method and DNA cleavage activity using Calf-thymus DNA (Cat. No-105850).

  16. Synthesis, spectral characterization, theoretical, antimicrobial, DNA interaction and in vitro anticancer studies of Cu(II and Zn(II complexes with pyrimidine-morpholine based Schiff base ligand

    Directory of Open Access Journals (Sweden)

    M. Sankarganesh

    2018-05-01

    Full Text Available Novel Cu(II (1 and Zn(II (2 complexes with 4-(1-(4-morpholinophenylethylideneaminopyrimidine-5-carbonitrile (L have been synthesized and characterized by various spectroscopic and analytical techniques. DFT (density functional theory studies result confirms that, LMCT mechanism have been done between L and M(II ions. The antimicrobial studies indicate that the ligand L and complexes 1 & 2 exhibit higher activity against the E. coli bacteria and C. albicans fungi. The groove binding mode of ligand L and complexes 1 & 2 with CT-DNA have been confirmed by electronic absorption, competitive binding, viscometric and cyclic voltammetric studies. The electronic absorption titration of ligand L and complexes 1 & 2 with DNA have been carried out in different buffer solutions (pH 4.0, 7.0 & 10.0. The Kb values of ligand L and complexes 1 & 2 are higher in acidic buffer at pH 4.0 (Kb = 2.42 × 105, L; 2.8 × 105, 1; 2.65 × 105, 2 and the results revealed that, the interaction of synthesized compounds with DNA were higher in the acidic medium than basic and neutral medium. Furthermore, CT-DNA cleavage studies of ligand L and complexes 1 & 2 have been studied. The in vitro anticancer activities results show that complexes 1 & 2 have moderate cytotoxicity against cancer cell lines and low toxicity on normal cell line than ligand L. Keywords: Pyrimidine, Morpholine, DFT, Antimicrobial, DNA binding, Anticancer studies

  17. Effect on the Inhibitory Activity of Potential Microbes on the Complexation of Methyl Anthranilate Derived Hydrazide with Cu, Ni and Zn (II) Metal Ions

    International Nuclear Information System (INIS)

    Ikram, M.; Rehman, S.; Khan, K.

    2013-01-01

    The hydrazide ligand 2-amino-(N-aminobezoyl)benzohydrazide (ABH) have been synthesized and characterized by 1H-NMR, 13C-NMR, ES+-MS, elemental analyses and infrared studies. The ligand was complexed with Ni(II), Cu(II) and Zn(II) metal ions and were characterized by analytical and spectroscopic methods including elemental analyses, ES+-MS, conductance, infrared, UV-Visible and magnetic susceptibilities studies. Infrared spectra show that the ligand form complexes through -NH2 and carbonyl moieties, the elemental studies suggested the M(ABH)X2 composition of the coordination compounds. The synthesized complexes were studied for their biological activities against gram negative bacteria including Escherichia coli, Salmonella typhi, Enterobacter aerogenes, Proteus vulgaris, Pseudomonas aeruginosa, Gram positive bacterial strains like Staphylococcus aureus and fungus like Candida albican. These activities show that the metal complexes are more active to the tested microbes as compared to neat ligand. (author)

  18. Alkane Soluble Transition Metal Complexes.

    Science.gov (United States)

    1983-10-01

    lCam ludoalNm’s W S. has aA F. . Hadley. uppokli *mvahs Capm amAe Hall. 1~i. 6. 08 o.. ILDuataA ulpmr. Cai. 1d. CAM 4. 111aII. lop C Themm. - hftupvtm of...phoahines.3 descrbed previously.’ In this analyuis a series of assumption . isre onadc Our reasons for doing this were twofold. in order to enable a lhoea...nalytical method to be used. It sii be w-me First, pfmospftane complexes have been widely used as be. apparent that the assumptions that must be made

  19. Self-organization in metal complexes

    International Nuclear Information System (INIS)

    Radecka-Paryzek, W.

    1999-01-01

    Inorganic self-organization involves the spontaneous generation of well-defined supramolecular architectures from metal ions and organic ligands. The basic concept of supramolecular chemistry is a molecular recognition. When the substrate are metal ions, recognition is expressed in the stability and selectivity of metal ion complexation by organic ligands and depends on the geometry of the ligand and on their binding sites that it contains. The combination of the geometric features of the ligand units and the coordination geometries of the metal ions provides very efficient tool for the synthesis of novel, intriguing and highly sophisticated species such as catenanes, box structures, double and triple helicates with a variety of interesting properties. The article will focus on the examples of inorganic self-organization involving the templating as a first step for the assembly of supramolecular structures of high complexity. (author)

  20. On monosubstituted cyanurate complexes of transition metals

    International Nuclear Information System (INIS)

    Sejfer, G.B.; Tarasova, Z.A.

    1995-01-01

    Complex monosubstituted cyanurates of transition metals K 2 [Eh(H 2 C 3 N 3 O 3 ) 4 ]x4H 2 ) where Eh = Mn, Co, Ni, Cu, Zn, Cd are synthesized and investigated by means of IR - spectroscopy and thermal analysis methods. It is shown that only thermal decomposition of a manganese complex leads to the production of this metal oxide. All other derivatives decompose with the production of a free metal, because decomposition of these substances in argon atmosphere occurs through an intermediate production of their nitrides. An assumption is made that nitroduction of yttrium or rare earth element salts (instead of transition or alkali metal derivatives) as accelerating additions will facilitate increase of polyisocyanurate resin thermal stability. 25 refs.; 2 figs.; 3 tabs

  1. Reaction mechanisms of metal complexes

    CERN Document Server

    Hay, R W

    2000-01-01

    This text provides a general background as a course module in the area of inorganic reaction mechanisms, suitable for advanced undergraduate and postgraduate study and/or research. The topic has important research applications in the metallurgical industry and is of interest in the science of biochemistry, biology, organic, inorganic and bioinorganic chemistry. In addition to coverage of substitution reactions in four-, five- and six-coordinate complexes, the book contains further chapters devoted to isomerization and racemization reactions, to the general field of redox reactions, and to the reactions of coordinated ligands. It is relevant in other fields such as organic, bioinorganic and biological chemistry, providing a bridge to organic reaction mechanisms. The book also contains a chapter on the kinetic background to the subject with many illustrative examples which should prove useful to those beginning research. Provides a general background as a course module in the area of inorganic reaction mechanis...

  2. Synthesis of high-surface-area γ-Al2O3 from aluminum scrap and its use for the adsorption of metals: Pb(II), Cd(II) and Zn(II)

    International Nuclear Information System (INIS)

    Asencios, Yvan J.O.; Sun-Kou, María R.

    2012-01-01

    Highlights: ► Aluminum hydroxide obtained from aluminum scrap led to the formation of gamma alumina. ► Acidic pH of precipitation favored the formation of small particles of high surface areas. ► Higher aging temperature favored the formation of large structures of large pore sizes. ► Higher aging temperature generated symmetrical solids of regular hexagonal prism forms. ► Aluminas of large pores adsorbed metals as following: Pb (1.75 Å) > Cd (1.54 Å) > Zn (1.38 Å). - Abstract: Several types of alumina were synthesized from sodium aluminate (NaAlO 2 ) by precipitation with sulfuric acid (H 2 SO 4 ) and subsequently calcination at 500 °C to obtain γ-Al 2 O 3 . The precursor aluminate was derived from aluminum scrap. The various γ-Al 2 O 3 synthesized were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), adsorption–desorption of N 2 (S BET ) and scanning electron microscopy (SEM). XRD revealed that distinct phases of Al 2 O 3 were formed during thermal treatment. Moreover, it was observed that conditions of synthesis (pH, aging time and temperature) strongly affect the physicochemical properties of the alumina. A high-surface-area alumina (371 m 2 g −1 ) was synthesized under mild conditions, from inexpensive raw materials. These aluminas were tested for the adsorption of Cd(II), Zn(II) and Pb(II) from aqueous solution at toxic metal concentrations, and isotherms were determined.

  3. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  4. Heavy metal / polyacid interaction : an electrochemical study of the binding of Cd(II), Pb(II) and Zn(II) to polycarboxylic and humic acids

    NARCIS (Netherlands)

    Cleven, R.F.M.J.

    1984-01-01

    Polyelectrolyte effects in the interaction of heavy metal ions with model polycarboxylic acids have been described, in order to establish the relevance of these effects in the interaction of heavy metal ions with naturally occurring humic and fulvic acids. The model systems consisted of Cd(II),

  5. EDTA excess Zn(II) back-titration in the presence of 4-(2-pyridylazo)-resorcinol indicator and naphthol green {beta} as inert dye for determining Cr(III) as Cr(III)/EDTA complex: Application of the method to a leather industry wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Venezia, M.; Alonzo, G. [Dipartimento di Ingegneria e Tecnologie Agro Forestali, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Palmisano, L. [Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy)], E-mail: palmisano@dicpm.unipa.it

    2008-03-01

    The colour changes of 4-(2-pyridylazo)-resorcinol and naphthol green {beta} as new screening metallochromic indicator in back-titration of EDTA excess with Zn(II) to determine Cr(III)/EDTA complex was investigated with the help of tristimulus colorimetry. Specific colour discrimination (SCD) and L*, a*, b* 1976 parameters were successfully applied to evaluate the quality of colour transition at the end-point in non-alkaline media and in the presence of Zn(II) and Ca(II) which resulted in non-interfering species at 1 x 10{sup -3} M and 2 x 10{sup -3} M, respectively. The above concentrations are comparable with those used for Cr(III). Validation of the fast and accurate reported method was performed by atomic absorption spectroscopy. Moreover, the method was applied for determining Cr as Cr(III) in a wastewater effluent deriving from a leather industry.

  6. EDTA excess Zn(II) back-titration in the presence of 4-(2-pyridylazo)-resorcinol indicator and naphthol green β as inert dye for determining Cr(III) as Cr(III)/EDTA complex: Application of the method to a leather industry wastewater

    International Nuclear Information System (INIS)

    Venezia, M.; Alonzo, G.; Palmisano, L.

    2008-01-01

    The colour changes of 4-(2-pyridylazo)-resorcinol and naphthol green β as new screening metallochromic indicator in back-titration of EDTA excess with Zn(II) to determine Cr(III)/EDTA complex was investigated with the help of tristimulus colorimetry. Specific colour discrimination (SCD) and L*, a*, b* 1976 parameters were successfully applied to evaluate the quality of colour transition at the end-point in non-alkaline media and in the presence of Zn(II) and Ca(II) which resulted in non-interfering species at 1 x 10 -3 M and 2 x 10 -3 M, respectively. The above concentrations are comparable with those used for Cr(III). Validation of the fast and accurate reported method was performed by atomic absorption spectroscopy. Moreover, the method was applied for determining Cr as Cr(III) in a wastewater effluent deriving from a leather industry

  7. Biosorption of Zn(II) by chemically modified biomass of corncob

    International Nuclear Information System (INIS)

    Zafar, H.; Nadeem, R.; Iqbal, T.; Ansari, T.M.

    2011-01-01

    In conducted research corncob powder was pretreated with inorganic acids and bases. The consequence of different parameters such as initial metal concentration, pH and contact time on Zn(II) bio sorption from aqueous solution was deliberated. The order of maximum Zn(II) uptake q/sub max/ (mgg/sup -1/) for different pretreated and raw corncob powder was Ba(OH)/sub 2/ (128.9)> H/sub 3/PO/sub 4/ (124.07)> NaOH (118.737)> H/sub 2/SO/sub 4/ (114.8)> HCl (93.41)> Al(OH)/sup 3/ (87.9)> Native (86.74). The percentage of Zn(II) removed on corncob biomass increased with increase in pH reaching a maximum at pH 5.5. Kinetics of Zn(II) bio sorption described that Zn(II) sorption rate was high in first 15-30 minutes and equilibrium was established after 120 minutes. The maximum adsorption data of native and pretreated biomass was investigated using Langmuir, Freundlich equilibrium and Pseudo first and second order kinetic models. It was accomplished that structural modifications onto corncob powder lead to the formation of novel bio masses with increased sorption efficiency and environmental stability for the abatement of Zn(II). Thus, optimization of bio sorption parameters, chemical pretreatments of bio sorbents and study of mechanisms are the main keys to transfer the bio sorption process from Lab to Industry. (author)

  8. Studies of the polynuclear complexes of labile ligands of vitamin B1 and Zn(II), Cd(II) and Hg(II) with Fe(III)

    International Nuclear Information System (INIS)

    Ojo, J.O.

    2003-01-01

    The ligands (complex salts) of vitamin B/sub 1/ (H Vit.) and the chlorides of Zn, Cd and Hg with the general formula, [H Vit]/sup +2/ [MCl/sub 4/]/sup -2/ were prepared and their interactions with iron (III) investigated. It was found that the complex salts of Zn and Cd produced the dinuclear complexes and that of mercury produced a complex without the thiamine moiety. The possible reason for the absence of a Hg complex similar to those of Zn and Cd may be that large size of mercury ion. The complexes were characterized by elementary analyses, infrared and visible spectra, magnetic moment and conductivity measurements.(author)

  9. Anharmonic Vibrational Spectroscopy on Metal Transition Complexes

    Science.gov (United States)

    Latouche, Camille; Bloino, Julien; Barone, Vincenzo

    2014-06-01

    Advances in hardware performance and the availability of efficient and reliable computational models have made possible the application of computational spectroscopy to ever larger molecular systems. The systematic interpretation of experimental data and the full characterization of complex molecules can then be facilitated. Focusing on vibrational spectroscopy, several approaches have been proposed to simulate spectra beyond the double harmonic approximation, so that more details become available. However, a routine use of such tools requires the preliminary definition of a valid protocol with the most appropriate combination of electronic structure and nuclear calculation models. Several benchmark of anharmonic calculations frequency have been realized on organic molecules. Nevertheless, benchmarks of organometallics or inorganic metal complexes at this level are strongly lacking despite the interest of these systems due to their strong emission and vibrational properties. Herein we report the benchmark study realized with anharmonic calculations on simple metal complexes, along with some pilot applications on systems of direct technological or biological interest.

  10. A fluorescent chemosensor for Zn(II). Exciplex formation in solution and the solid state.

    Science.gov (United States)

    Bencini, Andrea; Berni, Emanuela; Bianchi, Antonio; Fornasari, Patrizia; Giorgi, Claudia; Lima, Joao C; Lodeiro, Carlos; Melo, Maria J; de Melo, J Seixas; Parola, Antonio Jorge; Pina, Fernando; Pina, Joao; Valtancoli, Barbara

    2004-07-21

    The macrocyclic phenanthrolinophane 2,9-[2,5,8-triaza-5-(N-anthracene-9-methylamino)ethyl]-[9]-1,10-phenanthrolinophane (L) bearing a pendant arm containing a coordinating amine and an anthracene group forms stable complexes with Zn(II), Cd(II) and Hg(II) in solution. Stability constants of these complexes were determined in 0.10 mol dm(-3) NMe(4)Cl H(2)O-MeCN (1:1, v/v) solution at 298.1 +/- 0.1 K by means of potentiometric (pH metric) titration. The fluorescence emission properties of these complexes were studied in this solvent. For the Zn(II) complex, steady-state and time-resolved fluorescence studies were performed in ethanol solution and in the solid state. In solution, intramolecular pi-stacking interaction between phenanthroline and anthracene in the ground state and exciplex emission in the excited state were observed. From the temperature dependence of the photostationary ratio (I(Exc)/I(M)), the activation energy for the exciplex formation (E(a)) and the binding energy of the exciplex (-DeltaH) were determined. The crystal structure of the [ZnLBr](ClO(4)).H(2)O compound was resolved, showing that in the solid state both intra- and inter-molecular pi-stacking interactions are present. Such interactions were also evidenced by UV-vis absorption and emission spectra in the solid state. The absorption spectrum of a thin film of the solid complex is red-shifted compared with the solution spectra, whereas its emission spectrum reveals the unique featureless exciplex band, blue shifted compared with the solution. In conjunction with X-ray data the solid-state data was interpreted as being due to a new exciplex where no pi-stacking (full overlap of the pi-electron cloud of the two chromophores - anthracene and phenanthroline) is observed. L is a fluorescent chemosensor able to signal Zn(II) in presence of Cd(II) and Hg(II), since the last two metal ions do not give rise either to the formation of pi-stacking complexes or to exciplex emission in solution.

  11. Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions

    International Nuclear Information System (INIS)

    Ghandour, M.A.; Azab, H.A.; Hassan, A.; Ali, A.M.

    1992-01-01

    The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO 2 (II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25±0.1 deg C and μ=0.1 moll -1 (NaNO 3 ). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO 2 (II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors)

  12. Adsorption of aqueous Zn(II) species on synthetic zeolites

    International Nuclear Information System (INIS)

    Badillo-Almaraz, Veronica; Trocellier, Patrick; Davila-Rangel, Ignacio

    2003-01-01

    To supply a good quality drinkable water tends to become a strategic task in both developed and under development countries in the world due to the number of potential contamination sources. One of the major problems is derived from the presence of heavy toxic metals like zinc or lead resulting from industrial activities. Zeolites are known as very efficient mineral substrates for fixing aqueous ionic species through their wide range of channels present in the crystalline structure and due to their strong surface reactivity. MicroPIXE coupled with microRBS (3.05 MeV 4 He + ions) have been used to quantify the incorporation of zinc within two commercial zeolites containing alkali elements (zeolite X and clinoptilolite) in the concentration range of: 0.0002-0.05 M at neutral pH. At the beginning of the interaction between zeolite and Zn(II) solution, the adsorption process exhibits a direct proportionality between the content of zinc fixed on the mineral substrate and the aqueous concentration up to 0.01 M. Beyond this point a saturation effect seems to occur, indicating the strong decrease of available adsorption sites. Sodium or potassium ions are probably exchanged with Zn(II) ions during this process. The compared behaviour of the two zeolites is then discussed in terms of kinetic effects based on ionic radius values. A co-adsorption test carried on with a 50-50% Zn(II) 0.001 M-Pb(II) 0.001 M solution shows that lead does not occupy the same sites as zinc because the content of zinc fixed on the zeolite sample exactly corresponds to the result obtained with a pure 0.001 M Zn(II) solution. All these data clearly showed that zeolite surface reactivity is greatly influenced by the mineral cage-like structure and particularly the presence of pockets, spaces and channels

  13. Synthesis, spectroscopic properties, molecular docking, anti-colon cancer and anti-microbial studies of some novel metal complexes for 2-amino-4-phenylthiazole derivative

    Science.gov (United States)

    Al-Harbi, Sami A.; Bashandy, Mahmoud S.; Al-Saidi, Hammed M.; Emara, Adel A. A.; Mousa, Tarek A. A.

    2015-06-01

    This article describes the synthesis of novel bidentate Schiff base (H2L) from condensation of 2-amino-4-phenylthiazole (APT) with 4,6-diacetylresorcinol (DAR) in the molar ratio 2:1. We studied interaction of ligand (H2L) with transition metal ions such as Cr(III), Fe(III), Cu(II), Zn(II) and Cd(II). The ligand (H2L) has two bidentate sets of (N-O) units which can coordinate with two metal ions to afford novel binuclear metal complexes. The directions of coordinate bonds are from nitrogen atoms of azomethine groups and oxygen atoms of the phenolic groups. Structures of the newly synthesized complexes were confirmed by elemental analysis, IR, UV, 1H NMR, ESR, TGA and mass spectral data. All of the newly synthesized complexes were evaluated for their antibacterial and anti-fungal activities. They were also evaluated for their in vitro anticancer activity against human colon carcinoma cells (HCT-116) and mammalian cells of African green monkey kidney (VERO). The Cu(II) complex with selectivity index (S.I.) = 21.26 exhibited better activity than methotrexate (MTX) as a reference drug with S.I. value = 13.30, while Zn(II) complex with S.I. value = 10.24 was found to be nearly as active as MTX. Molecular docking studies further helped in understanding the mode of action of the compounds through their various interactions with active sites of dihydrofolate reductase (DHFR) enzyme. The observed activity of Fe(III) and Cu(II) complexes gave rise to the conclusion that they might exert their action through inhibition of the DHFR enzyme.

  14. Biosorption of Cd(II) and Zn(II) by nostoc commune: isotherm and kinetics studies

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, Fatthy M. [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Hassan, Sedky H.A. [Department of Biological Environment, Kangwon National University, Kangwon-do (Korea, Republic of); Koutb, Mostafa [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Umm Al-Qura University, Faculty of Applied Science, Biology Department, Mecca (Saudi Arabia)

    2011-07-15

    In this study, Nostoc commune (cyanobacterium) was used as an inexpensive and efficient biosorbent for Cd(II) and Zn(II) removal from aqueous solutions. The effect of various physicochemical factors on Cd(II) and Zn(II) biosorption such as pH 2.0-7.0, initial metal concentration 0.0-300 mg/L and contact time 0-120 min were studied. Optimum pH for removal of Cd(II) and Zn(II) was 6.0, while the contact time was 30 min at room temperature. The nature of biosorbent and metal ion interaction was evaluated by infrared (IR) technique. IR analysis of bacterial biomass revealed the presence of amino, carboxyl, hydroxyl, and carbonyl groups, which are responsible for biosorption of Cd(II) and Zn (II). The maximum biosorption capacities for Cd(II) and Zn(II) biosorption by N. commune calculated from Langmuir biosorption isotherm were 126.32 and 115.41 mg/g, respectively. The biosorption isotherm for two biosorbents fitted well with Freundlich isotherm than Langmuir model with correlation coefficient (r{sup 2} < 0.99). The biosorption kinetic data were fitted well with the pseudo-second-order kinetic model. Thus, this study indicated that the N. commune is an efficient biosorbent for the removal of Cd(II) and Zn(II) from aqueous solutions. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. 4,4′-Bipyridine-aided synthesis and characterization of Zn(II) and Cd(II) 2-sulfoterephthalate complexes

    International Nuclear Information System (INIS)

    Xiao, Shan-Shan; Li, Xin-Xin; Zheng, Xiang-Jun; Jia, Tian-Jing; Jin, Lin-Pei

    2013-01-01

    Six d 10 complexes, [Zn 1.5 (stp)(bpy) 0.5 (H 2 O) 2 ]·0.5H 2 O (1), Cd 1.5 (stp)(bpy) 0.5 (H 2 O) 2 (2), [Cd 1.5 (stp)(bpy)(H 2 O)]·H 2 O (3), [Zn 0.5 (bpy) 0.5 (H 2 O) 2 ][Zn(stp)(bpy)(H 2 O)]·0.5H 2 O (4), Cd 3 (stp) 2 (bpy) 3 (H 2 O) 3 (5), Hbpy·[Zn 0.5 (bpy)(H 2 O) 2 ][Zn 0.5 (stp)(H 2 O)]·H 2 O (6) based on 2-sulfoterephthalate (stp 3− ) and 4,4′-bipyridine (bpy) have been synthesized under hydro/solvo-thermal conditions and structurally characterized. Complex 1 exhibits a three-fold interpenetrated 3D porous architecture. Complexes 2 and 3 possess helices with different chirality arranging alternately. 4 and 6 are addition compounds, which compose of complex cation and complex anion. Complex 5 features a 3D layer-pillar framework in which a (4, 4) grid layer is constructed by stp 3− ligands and Cd(II) ions, and the layers are further connected by bpy pillars. The solid-state luminescent properties of the coordination polymers have also been investigated. - Graphical abstract: Display Omitted - Highlights: • Complexes 1–3 possess helices with different chirality arranging alternately. • The structural diversity can be attributed to various coordination modes of ligands. • The formation of helical structure is related to the adjacent carboxyl and sulfonate groups. • Bpy exhibits three roles: bridge, hydrogen bonding acceptor, and template

  16. TDPAC studies on metal-complex ferrimagnets

    Energy Technology Data Exchange (ETDEWEB)

    Ohkubo, Yoshitaka [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Abe, Shizuko; Okada, Takuya [and others

    1997-03-01

    TDPAC spectra of {sup 117}In (left-arrow {sup 117}Cd) and {sup 111}Cd (left-arrow {sup 111m}Cd) in the mixed metal complex N(C{sub 4}H{sub 9}){sub 4}(M(II)Fe(III)(C{sub 2}O{sub 4}){sub 3})(M=Fe,Ni), the related substraces and LiNbO{sub 3} have been studied. In this paper, pure potassium iron (III) oxalate was prepared and mixed metal complexes were synthesized by changing amount of reagents and the order added, then observed by TDPAC. 2 mol%Cd was dispersed throughout potassium iron oxalate and potassium nickel oxalate, formulating M(II){sub 0.98}Cd(II){sub 0.02}C{sub 2}O{sub 4}{center_dot}2H{sub 2}O (M=Fe, Ni) with the same crystal structure. The formation reaction of mixed metal complex-Fe(II) was faster than that of iron oxalate. Its mixed metal complex-Ni(II) was slower than that of iron oxalate. The rate of quadrupole oscillation was obtained by {omega}{sub Q}({sup 117}In)=67.3 Mrad/s and {omega}{sub Q}({sup 111}Cd)=29.7 Mrad/s of which values were determined by TDPAC spectra of {sup 117}In and {sup 111}Cd in LiNbO{sub 3} at 4K. The value showed pure ion bond of oxygen coordinated with {sup 117}In and {sup 111}Cd. 0.08 {eta} was determined by TDPAC spectrum of {sup 111}Cd(left-arrow {sup 111m}Cd). The rate of {omega}{sub Q} of mixed metal oxalate complex was larger than 2.3, indicating 5s and 5p orbital electron took part in bond of oxygen of oxalic acid or approaching oxygen ion to In nucleus depend on the structual relaxation in decaying of {sup 117}In(left-arrow {sup 117}Cd). (S.Y.)

  17. Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II and Zn(II complexes

    Directory of Open Access Journals (Sweden)

    NATARAJAN RAMAN

    2010-06-01

    Full Text Available Several mixed ligand Cu(II/Zn(II complexes using 3-(phenyl-imino-1,3-dihydro-2H-indol-2-one (obtained by the condensation of isatin and aniline as the primary ligand and 1,10-phenanthroline (phen/2,2’-bipyridine (bpy as an additional ligand were synthesized and characterized analytically and spectroscopically by elemental analyses, magnetic susceptibility and molar conductance measurements, as well as by UV–Vis, IR, NMR and FAB mass spectroscopy. The interaction of the complexes with calf thymus (CT DNA was studied using absorption spectra, cyclic voltammetric and viscosity measurements. They exhibit absorption hypochromicity, and the specific viscosity increased during the binding of the complexes to calf thymus DNA. The shifts in the oxidation–reduction potential and changes in peak current on addition of DNA were shown by CV measurements. The Cu(II/Zn(II complexes were found to promote cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and linear form III. The complexes show enhanced antifungal and antibacterial activities compared with the free ligand.

  18. Effect of the pillar ligand on preventing agglomeration of ZnO nanoparticles prepared from Zn(II metal-organic frameworks

    Directory of Open Access Journals (Sweden)

    Maryam Moeinian

    2016-01-01

    Full Text Available Metal-Organic Frameworks (MOFs represent a new class of highly porous materials. On this regard,  two nano porous metal-organic frameworks of [Zn2(1,4-bdc2(H2O2∙(DMF2]n (1 and [Zn2(1,4-bdc2(dabco]·4DMF·1⁄2H2O (2, (1,4-bdc = benzene-1,4-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane and DMF = N,N-dimethylformamide were synthesized and characterized. They were used for preparation of ZnO nanomaterials. With calcination of 1, agglomerated ZnO nanoparticles could be fabricated, but by the same process on 2, the tendency of ZnO nanoparticles to agglomeration was decreased. In addition, the ZnO nanoparticles prepared from compound 2 had smaller diameter than those obtained from compound 1. In fact, the role of organic dabco ligands in 2 is similar to the role of polymeric stabilizers in formation of nanoparticles. Finally, considering the various applications of ZnO nanomaterials such as light-emitting diodes, photodetectors, photodiodes, gas sensors and dye-sensitized solar cells (DSSCs, it seems that preparation of ZnO nanomaterials from their MOFs could be one of the simple and effective methods which may be applied for preparation of them.

  19. Synthesis, spectroscopic characterization, biological studies and DFT calculations on some transition metal complexes of NO donor ligand

    Science.gov (United States)

    Zordok, W. A.; Sadeek, S. A.

    2018-04-01

    Seven new complexes of2-oxo-4,6-diphenyl-1,2-dihyropyridine-3-carbonitrile (L) with Fe(III), Co(II), Cu(II), Zn(II), Y(III), Zr(IV) and La(III) were synthesized. The isolated solid compounds were elucidated from micro analytical, IR, electronic, mass, 1H NMR, magnetic susceptibility measurements and TG/DTG, DTA analyses. The intensity of ν(Ctbnd N) was changed to strong and shifted to around 2200 cm-1. Also, the ν(Cdbnd O) was shifted to higher frequency value (1644 cm-1). The spectra of the complexes indicate that the free ligand is coordinated to the metal ions via nitrogen of carbonitrile group and oxygen of keto group. From DFT calculations the Cu(II) and Fe(III) complexes behave as regular octahedral, while other complexes are distorted octahedral. The value of energy gap of the free ligand (ΔE = 0.3343 eV) is greater than all new complexes, so they are more reactive than free ligand, also the Fe(III) complex (ΔE = 0.0985 eV) is the most reactive complex, while Cu(II) complex (ΔE = 0.3219 eV) is the least reactive complex. The LMCT in case of Zr(IV) complex was resulted from transitions from HOMO-2 (62%), HOMO-1 (16%)and HOMO (25%), while the d-d transition in Fe(III) complex was resulted from HOMO-1(30%), HOMO-2(62%) and HOMO(30%). Also, the metal complexes exhibit antibacterial activity for Gram-positive and Gram-negative and antifungal activity. The Y(III) and Cu(II) complexes are highly significant for Escherichia coli and salmonella typhimurium.

  20. 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

    International Nuclear Information System (INIS)

    Bagatin, Izilda A.; Legnani, Cristiano; Cremona, Marco

    2009-01-01

    A comparison between [Al·1] 3+ and [Zn·1] 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 p and electron affinity E a parameters for the [Al·1] 3+ (I p = 5.82eV, E a = 2.80eV) and [Zn·1] 2+ (I p = 5.67eV, E a = 2.32eV) evidenced that the [Al·1] 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·1] 3+ systems expected from the energy level diagrams

  1. Synthesis, characterization and screening of biological activity of Zn(II), Fe(II) and Mn(II) complexes with trithiocyanuric acid

    Czech Academy of Sciences Publication Activity Database

    Kopel, P.; Doležal, Karel; Machala, L.; Langer, V.

    2007-01-01

    Roč. 26, č. 8 (2007), s. 1583-1589 ISSN 0277-5387 Institutional research plan: CEZ:AV0Z50380511 Keywords : Complexes * Trithiocyanuric acid * Cytotoxicity Subject RIV: CA - Inorganic Chemistry Impact factor: 1.756, year: 2007

  2. Biological activities of some Fluoroquinolones-metal complexes

    African Journals Online (AJOL)

    McRoy

    DNA cleavage studies of some synthesized metal complexes of fluoroquinolone ... Although the FQs are generally characterized by a broad antimicrobial spectrum ..... six Coordinate 3rd metal complexes with N- (5 –Phenyl-3,4- thiadiazol-2-yl).

  3. Synthesis, crystal structures and luminescence properties of new multi-component co-crystals of isostructural Co(II) and Zn(II) complexes

    Science.gov (United States)

    Tella, Adedibu C.; Owalude, Samson O.; Omotoso, Mary F.; Olatunji, Sunday J.; Ogunlaja, Adeniyi S.; Alimi, Lukman O.; Popoola, Olugbenga K.; Bourne, Susan A.

    2018-04-01

    Two novel isostructural compounds containing multi-component co-crystals [M(C6H4NO2)2(H2O)2](C9H6O6)2 (M = Co (1), Zn (2), C6H4NO2 = Picolinic acid, C9H6O6 = Trimesic acid) have been synthesized. The compounds were characterized by elemental analysis, FT-IR, UV-Visible and 1H NMR spectroscopies as well as thermal and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that 1 and 2 are isostructural. Compound 1 crystallizes in triclinic space group (P-1, with a = 5.154 (10) Å, b = 11.125 (2) Å, c = 14.113 (3) Å, α = 91.01 (3)°, β = 100.54 (3)°, and γ = 102.71 (3)°). In a similar fashion, compound 2 crystallizes in triclinic space group (P-1, with a = 5.1735 (3) Å, b = 11.0930 (10) Å, c = 14.1554 (8) Å, α = 91.70 (3)°, β = 100.26 (3)°, γ = 102.90 (3)°). The metal (II) cation presents distorted MN2O4 octahedral geometry with H2O molecules coordinated to the metal in equatorial position while the picolinic acid molecules are axially coordinated through the pyridine N atom. The two trimesic acid molecules are not part of the first coordination sphere. Compounds 1 and 2 constitute an example of a class of coordination compound of multicomponent crystals having trimesic acid outside the coordination sphere where it is neither protonated or deprotonated. The two compounds were investigated for luminiscence properties.

  4. The DNA binding site specificity and antiproliferative property of ternary Pt(II) and Zn(II) complexes of phenanthroline and N,N'-ethylenediaminediacetic acid.

    Science.gov (United States)

    Nakamura, Yusuke; Taruno, Yoko; Sugimoto, Masashi; Kitamura, Yusuke; Seng, Hoi Ling; Kong, Siew Ming; Ng, Chew Hee; Chikira, Makoto

    2013-03-14

    The binding site specificity of the ternary complexes, [M(II)(phen)(edda)] (M(II) = Pt(2+) and Zn(2+); phen = 1,10-phenanthroline; edda = N,N'-ethylenediaminediacetic acid), for the self-complementary oligonucleotides (ODNs), ds(C(1)G(2)C(3)G(4)A(5)A(6)T(7)T(8)C(9)G(10)C(11)G(12))(2) (ODN1) and ds(C(1)G(2)C(3)G(4)T(5)A(6)T(7)A(8)C(9)G(10)C(11)G(12))(2) (ODN2), was studied by NMR measurements. The results indicated that [Pt(ii)(phen)(edda)] was partially intercalated between C(3)/G(10) and G(4)/C(9) base pairs of ODN1 and ODN2 in the major grooves, whereas [Zn(II)(phen)(edda)] was bound specifically to the TATA region of ODN2 in the minor groove and to the terminal G(2)/C(11) base pair of ODN1 in the major groove. The preference for the TATA sequence over the AATT sequence in the binding of [Zn(phen)(edda)] was attributed to the wider minor groove width of the TATA sequence. The bindings of the complexes to ct-DNA were also studied by UV, CD, and fluorescence spectroscopy. Additionally, the antiproliferative property of [Pt(II)(phen)(edda)] towards MCF7 breast cancer cells and normal MCF10-A cells was compared with that of [Zn(II)(phen)(edda)].

  5. Ligand-based photooxidations of dithiomaltolato complexes of Ru(II) and Zn(II): photolytic CH activation and evidence of singlet oxygen generation and quenching.

    Science.gov (United States)

    Bruner, Britain; Walker, Malin Backlund; Ghimire, Mukunda M; Zhang, Dong; Selke, Matthias; Klausmeyer, Kevin K; Omary, Mohammad A; Farmer, Patrick J

    2014-08-14

    The complex [Ru(bpy)2(ttma)](+) (bpy = 2,2'-bipyridine; ttma = 3-hydroxy-2-methyl-thiopyran-4-thionate, 1, has previously been shown to undergo an unusual C-H activation of the dithiomaltolato ligand upon outer-sphere oxidation. The reaction generated alcohol and aldehyde products 2 and 3 from C-H oxidation of the pendant methyl group. In this report, we demonstrate that the same products are formed upon photolysis of 1 in presence of mild oxidants such as methyl viologen, [Ru(NH3)6](3+) and [Co(NH3)5Cl](2+), which do not oxidize 1 in the dark. This reactivity is engendered only upon excitation into an absorption band attributed to the ttma ligand. Analogous experiments with the homoleptic Zn(ttma)2, 4, also result in reduction of electron acceptors upon excitation of the ttma absorption band. Complexes 1 and 4 exhibit short-lived visible fluorescence and long-lived near-infrared phosphorescence bands. Singlet oxygen is both generated and quenched during aerobic excitation of 1 or 4, but is not involved in the C-H activation process.

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

    Directory of Open Access Journals (Sweden)

    Dehestani Maryam

    2015-01-01

    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.

  7. Metal ammine complexes for hydrogen storage

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Sørensen, Rasmus Zink; Johannessen, Tue

    2005-01-01

    The hopes of using hydrogen as an energy carrier are severely dampened by the fact that there is still no safe, high-density method available for storing hydrogen. We investigate the possibility of using metal ammine complexes as a solid form of hydrogen storage. Using Mg(NH3)(6)Cl-2 as the example......, we show that it can store 9.1% hydrogen by weight in the form of ammonia. The storage is completely reversible, and by combining it with an ammonia decomposition catalyst, hydrogen can be delivered at temperatures below 620 K....

  8. Evaluation of heavy metal complex phytotoxicity

    Directory of Open Access Journals (Sweden)

    Vita Vasilyevna Datsenko

    2016-07-01

    Full Text Available The experimental data dealing with the effect of heavy metals contained in the technogenic contaminated soils on plant objects under controlled conditions was discussed. The aim of this work is to define the quantitative indicators of copper and zinc potential phytotoxicity, namely germination energy, simultaneous germination and duration of the test plants. It was found that the activity of the test plant growth is linked with copper and zinc complex action. Joint effect of copper and zinc is manifested both in inhibition of lettuce growth and determined, above all, by the nature contamination, soil properties and biological specificity of the test plants.

  9. Complexes in polyvalent metal - Alkali halide melts

    International Nuclear Information System (INIS)

    Akdeniz, Z.; Tosi, M.P.

    1991-03-01

    Experimental evidence is available in the literature on the local coordination of divalent and trivalent metal ions by halogens in some 140 liquid mixtures of their halides with alkali halides. After brief reference to classification criteria for main types of local coordination, we focus on statistical mechanical models that we are developing for Al-alkali halide mixtures. Specifically, we discuss theoretically the equilibrium between (AlF 6 ) 3- and (AlF 4 ) - complexes in mixtures of AlF 3 and NaF as a function of composition in the NaF-rich region, the effect of the alkali counterion on this equilibrium, the possible role of (AlF 5 ) 2- as an intermediate species in molten cryolite, and the origin of the different complexing behaviours of Al-alkali fluorides and chlorides. We also present a theoretical scenario for processes of structure breaking and electron localization in molten cryolite under addition of sodium metal. (author). 26 refs, 2 tabs

  10. Modelling Zn(II) sorption onto clayey sediments using a multi-site ion-exchange model

    International Nuclear Information System (INIS)

    Tertre, E.; Beaucaire, C.; Coreau, N.; Juery, A.

    2009-01-01

    In environmental studies, it is necessary to be able to predict the behaviour of contaminants in more or less complex physico-chemical contexts. The improvement of this prediction partly depends on establishing thermodynamic models that can describe the behaviour of these contaminants and, in particular, the sorption reactions on mineral surfaces. In this way, based on the mass action law, it is possible to use surface complexation models and ion exchange models. Therefore, the aim of this study is (i) to develop an ion-exchange model able to describe the sorption of transition metal onto pure clay minerals and (ii) to test the ability of this approach to predict the sorption of these elements onto natural materials containing clay minerals (i.e. soils/sediments) under various chemical conditions. This study is focused on the behaviour of Zn(II) in the presence of clayey sediments. Considering that clay minerals are cation exchangers containing multiple sorption sites, it is possible to interpret the sorption of Zn(II), as well as competitor cations, by ion-exchange equilibria with the clay minerals. This approach is applied with success to interpret the experimental data obtained previously in the Zn(II)-H + -Na + -montmorillonite system. The authors' research team has already studied the behaviour of Na + , K + , Ca 2+ and Mg 2+ versus pH in terms of ion exchange onto pure montmorillonite, leading to the development of a thermodynamic database including the exchange site concentrations associated with montmorillonite and the selectivity coefficients of Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ versus H + . In the present study, experimental isotherms of Zn(II) on two different sediments in batch reactors at different pH and ionic strengths, using NaCl and CaSO 4 as electrolytes are reported. Assuming clay minerals are the main ion-exchanging phases, it is possible to predict Zn(II) sorption onto sediments under different experimental conditions, using the previously

  11. Solid state and solution photoluminescence properties of a novel meso–meso-linked porphyrin dimer Schiff base ligand and its metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    Tümer, Mehmet, E-mail: mtumer@ksu.edu.tr; Ali Güngör, S.; Raşit Çiftaslan, A.

    2016-02-15

    We prepared novel meso-meso linked 4-bromo-2,6-bis[5-(4-iminophenyl)-10,15,20-triphenylporphyrin]phenol (HL) and its Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II) transition metal complexes. Structural characterizations of the ligand (HL) and its metal complexes were done by the spectroscopic and analytical methods. The electronic absorption and photoluminescence spectra of the ligand, its metal complexes and the metal salts used for preparing of the complexes were investigated in the solid and solution state. The emission and excitation data of the CuCl{sub 2}·2H{sub 2}O in both solid and the solution state were obsrved in the longest wavelenght. On the other hand, the emission value of the ZnCl{sub 2} salt was shown at the shortest wavelenght. The emission values of the [LCu{sub 4}Cl{sub 3}(H{sub 2}O){sub 2}]H{sub 2}O and LPt{sub 4}Cl{sub 3} complexes in the solid state are bigger than the other metal salts. The ligand and its metal complexes show the very interesting absorption spectral properties in the solid state. Metal complexes have less number Q bands in the solid state. The electrochemical properties of the ligand and its metal complexes were investigated and found that they show the reversible or irreversible redox processes at the different scan rates. Thermal properties of the compopunds were investigated in the 20–900 °C temperature range.

  12. Synthesis, structure, luminescent, and magnetic properties of carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2] (Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato).

    Science.gov (United States)

    Ehama, Kiyomi; Ohmichi, Yusuke; Sakamoto, Soichiro; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Tsuchimoto, Masanobu; Re, Nazzareno

    2013-11-04

    Carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2]·solvent were synthesized through atmospheric CO2 fixation reaction of [Zn(II)L(n)(H2O)2]·xH2O, Ln(III)(NO3)3·6H2O, and triethylamine, where Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato. Each Zn(II)2Ln(III)2 structure possessing an inversion center can be described as two di-μ-phenoxo-bridged {Zn(II)L(n)Ln(III)(NO3)} binuclear units bridged by two carbonato CO3(2-) ions. The Zn(II) ion has square pyramidal coordination geometry with N2O2 donor atoms of L(n) and one oxygen atom of a bridging carbonato ion at the axial site. Ln(III) ion is coordinated by nine oxygen atoms consisting of four from the deprotonated Schiff-base L(n), two from a chelating nitrate, and three from two carbonate groups. The temperature-dependent magnetic susceptibilities in the range 1.9-300 K, field-dependent magnetization from 0 to 5 T at 1.9 K, and alternating current magnetic susceptibilities under the direct current bias fields of 0 and 1000 Oe were measured. The magnetic properties of the Zn(II)2Ln(III)2 complexes are analyzed on the basis of the dicarbonato-bridged binuclear Ln(III)-Ln(III) structure, as the Zn(II) ion with d(10) electronic configuration is diamagnetic. ZnGd1 (L(1)) and ZnGd2 (L(2)) show a ferromagnetic Gd(III)-Gd(III) interaction with J(Gd-Gd) = +0.042 and +0.028 cm(-1), respectively, on the basis of the Hamiltonian H = -2J(Gd-Gd)ŜGd1·ŜGd2. The magnetic data of the Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) were analyzed by a spin Hamiltonian including the crystal field effect on the Ln(III) ions and the Ln(III)-Ln(III) magnetic interaction. The Stark splitting of the ground state was so evaluated, and the energy pattern indicates a strong easy axis (Ising type) anisotropy. Luminescence spectra of Zn(II)2Tb(III)2 complexes were observed, while those

  13. Two new Zn(II) and Cd(II) coordinastion polymers based on amino-tetrazole and phenylcarboxylate: Syntheses, topological structures and photoluminescent properties

    International Nuclear Information System (INIS)

    Liu, Dong-Sheng; Sui, Yan; Chen, Weng-Tong; Huang, Jian-Gen; Chen, Jian-Zhong; Huang, Chang-Cang

    2012-01-01

    Two Zn(II) and Cd(II) compounds with the in-situ generated ligand of 5-amino-tetrazolate (atz − ) were prepared from the hydrothermal reactions of the corresponding Cd or Zn(II) salts with phenylcarboxylate, and characterized by elemental analysis, IR spectroscopy, and TGA. The results of X-ray crystallographic analysis reveal that compound [Zn 2 (BZA)(atz) 2 (OH)] n (1) (BZA=benzoic acid) presents a two-dimensional (2D) “hcb” topological network constructed from the ZnN 2 O 2 tetrahedra. In compound [Cd 6 (atz) 6 (PTA) 3 ] n (2) (PTA=terephthalic acid), the identical [Cd 3 (atz) 3 )] 3+ n clusters are connected by atz ligands to generate a 2D cationic layer, and the neighboring cationic layers are pillared by PTA giving birth to 3D network. After simplifying, the complicated 3D network of 2 can be presented as an unprecedented (4, 4, 10)-connected trinodal topology. The formations of the structures show a good example that using the combination of the in-situ generated ligand and other coligand synthetic strategy can construct interesting topological structures. The thermal stabilities and fluorescent properties of the complexes have also been studied. - Graphical abstract: Two d 10 metal complexes have been synthesized by employing mixed-ligand synthetic approach. Complex 1 presents a 2D “hcb” topological network. Complex 2 shows an unprecedented (4, 4, 10)-connected trinodal topology. Highlights: ► Coligand synthetic strategy was applied to obtain new MOFs with useful properties. ► Two new Zn(II) and Cd(II) complexes were constructed from the mixed-ligand. ► Topologically, compound 2 presented an unprecedented (4, 4, 10)-connected trinodal topology. ► The two compounds may be excellent candidates for potential photoactive material.

  14. Structural, spectral and biological studies of binuclear tetradentate metal complexes of N 3O Schiff base ligand synthesized from 4,6-diacetylresorcinol and diethylenetriamine

    Science.gov (United States)

    Emara, Adel A. A.

    2010-09-01

    The binuclear Schiff base, H 2L, ligand was synthesized by reaction of 4,6-diacetylresorcinol with diethylenetriamine in the molar ratio 1:2. The coordination behavior of the H 2L towards Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cr(III), VO(IV) and UO 2(VI) ions has been investigated. The elemental analyses, magnetic moments, thermal studies and IR, electronic, 1H NMR, ESR and mass spectra were used to characterize the isolated ligand and its metal complexes. The ligand acts as dibasic with two N 3O-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The bonding sites are the nitrogen atoms of the azomethine and amine groups and the oxygen atoms of the phenolic groups. The metal complexes exhibit either square planar, tetrahedral, square pyramid or octahedral structures. The Schiff base ligand and its metal complexes were tested against four pathogenic bacteria ( Staphylococcus aureus and Streptococcus pyogenes) as Gram-positive bacteria, and ( Pseudomonas fluorescens and Pseudomonas phaseolicola) as Gram-negative bacteria and two pathogenic fungi ( Fusarium oxysporum and Aspergillus fumigatus) to assess their antimicrobial properties. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  15. pH-dependence of the specific binding of Cu(II) and Zn(II) ions to the amyloid-β peptide

    International Nuclear Information System (INIS)

    Ghalebani, Leila; Wahlström, Anna; Danielsson, Jens; Wärmländer, Sebastian K.T.S.; Gräslund, Astrid

    2012-01-01

    Highlights: ► Cu(II) and Zn(II) display pH-dependent binding to the Aβ(1–40) peptide. ► At pH 7.4 both metal ions display residue-specific binding to the Aβ peptide. ► At pH 5.5 the binding specificity is lost for Zn(II). ► Differential Cu(II) and Zn(II) binding may help explain metal-induced AD toxicity. -- Abstract: Metal ions like Cu(II) and Zn(II) are accumulated in Alzheimer’s disease amyloid plaques. The amyloid-β (Aβ) peptide involved in the disease interacts with these metal ions at neutral pH via ligands provided by the N-terminal histidines and the N-terminus. The present study uses high-resolution NMR spectroscopy to monitor the residue-specific interactions of Cu(II) and Zn(II) with 15 N- and 13 C, 15 N-labeled Aβ(1–40) peptides at varying pH levels. At pH 7.4 both ions bind to the specific ligands, competing with one another. At pH 5.5 Cu(II) retains its specific histidine ligands, while Zn(II) seems to lack residue-specific interactions. The low pH mimics acidosis which is linked to inflammatory processes in vivo. The results suggest that the cell toxic effects of redox active Cu(II) binding to Aβ may be reversed by the protective activity of non-redox active Zn(II) binding to the same major binding site under non-acidic conditions. Under acidic conditions, the protective effect of Zn(II) may be decreased or changed, since Zn(II) is less able to compete with Cu(II) for the specific binding site on the Aβ peptide under these conditions.

  16. Copper(II) and zinc(II) as metal-carboxylate coordination complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: Synthesis, crystal structure, spectroscopy, DFT calculations and antioxidant activity

    Science.gov (United States)

    Benhassine, Anfel; Boulebd, Houssem; Anak, Barkahem; Bouraiou, Abdelmalek; Bouacida, Sofiane; Bencharif, Mustapha; Belfaitah, Ali

    2018-05-01

    This work presents a combined experimental and theoretical study of two new metal-carboxylate coordination compounds. These complexes were prepared from (1-methyl-1H-benzimidazol-2-yl)methanol under mild conditions. The structures of the prepared compounds were characterized by single-crystal X-ray analysis, FTIR and UV-Vis spectroscopy. In the Cupper complex, the Cu(II) ion is coordinated by two ligands, which act as bidentate chelator through the non-substituted N and O atoms, and two carboxylicg oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in the Zinc complex the ligand is ligated to the Zn(II) ion in monodentate fashion through the N atom, and the metal ion is also bonded to carboxylic oxygen atoms. The tetra-coordinated compound displays a distorted tetrahedral shape. The density functional theory calculations are carried out for the determination of the optimized structures. The electronic transitions and fundamental vibrational wave numbers are calculated and are in good agreement with experimental. In addition, the ligand and its Cu(II) and Zn(II) complexes were screened and evaluated for their potential as DPPH radical scavenger.

  17. Novel Metals and Metal Complexes as Platforms for Cancer Therapy

    OpenAIRE

    Frezza, Michael; Hindo, Sarmad; Chen, Di; Davenport, Andrew; Schmitt, Sara; Tomco, Dajena; Dou, Q. Ping

    2010-01-01

    Metals are essential cellular components selected by nature to function in several indispensable biochemical processes for living organisms. Metals are endowed with unique characteristics that include redox activity, variable coordination modes, and reactivity towards organic substrates. Due to their reactivity, metals are tightly regulated under normal conditions and aberrant metal ion concentrations are associated with various pathological disorders, including cancer. For these reasons, coo...

  18. Extraction of fluoride metal complexes by octanols

    International Nuclear Information System (INIS)

    Baklanova, I.V.; Nikolaev, A.I.; Il'in, E.G.; Majorov, V.G.

    2005-01-01

    The extraction of niobium(V) and tantalum(V) by octanols, including 1-octanol, 2-octanol, and iso-octanol (2-ethylhexanol), was studied. The composition of the octanols and their solubility in various aqueous solutions were evaluated. The capacity of the octanols for tantalum(V) and niobium(V), the extraction properties of the octanols, the viscosity of extracts under conditions of metal fluoride extraction, and the temperature dependence of the viscosity of the octanols were studied. The composition of the extracted complexes was studied by IR and NMR spectroscopy and chemical analysis, and the hydration-solvation mechanism of the extraction of tantalum(V) and niobium(V) was supported [ru

  19. A treatise on benzimidazole based Schiff base metal(II) complexes accentuating their biological efficacy: Spectroscopic evaluation of DNA interactions, DNA cleavage and antimicrobial screening

    Energy Technology Data Exchange (ETDEWEB)

    Kumaravel, Ganesan; Raman, Natarajan, E-mail: ramchem1964@gmail.com

    2017-01-01

    Two novel imidazole derived Schiff bases, (Z)-1-(1H-benzo[d]imidazol-2-yl)-N-benzylidenemethanamine (L{sup 1}) and 1-(1H-benzo[d]imidazol-2-yl)-N-(4-nitrobenzylidene) methanamine, and a series of their transition metal complexes of the types [M(L{sup 1}){sub 2}]Cl{sub 2} and [M(L{sup 2}){sub 2}]Cl{sub 2} where, M = Cu(II), Ni(II), Co(II) and Zn(II) have been designed and synthesized. These compounds were characterized by various spectral and physicochemical data. UV–Vis, magnetic susceptibility and molar conductivity data indicate that all the complexes adopt square planar geometry. The EPR spectral data of the Cu(II) complexes have provided supportive evidence to the conclusion derived on the basis of electronic absorption and magnetic moment values. Moreover, the interaction of complexes with DNA via intercalation has been explored by absorption, fluorescence spectroscopy, cyclic voltammetry, viscosity and circular dichroism. Agarose gel electrophoresis technique reveals that the complexes are good metallonucleases. All the compounds have relatively high antibacterial and antifungal potencies. Among the metal complexes, Cu(II) complexes exhibit higher efficacy against all the pathogens. - Highlights: • Synthesis of new and efficient benzimidazole based DNA targeting complexes • Synthesis of efficient metallointercalators • Excellent DNA exploiting ability of Cu(II) complexes • Efficient antimicrobial agents against various pathogens.

  20. Metal ion site engineering indicates a global toggle switch model for seven-transmembrane receptor activation

    DEFF Research Database (Denmark)

    Elling, Christian E; Frimurer, Thomas M; Gerlach, Lars-Ole

    2006-01-01

    for monoamine binding in TM-III, was used as the starting point to engineer activating metal ion sites between the extracellular segments of the beta2-adrenergic receptor. Cu(II) and Zn(II) alone and in complex with aromatic chelators acted as potent (EC50 decreased to 0.5 microm) and efficacious agonists...

  1. Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity

    Science.gov (United States)

    Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin

    2018-02-01

    Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (LG, LP) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by 1H NMR, 13C NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of LG and LP. The LG, LP and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi.

  2. METAL COMPLEXES OF SALICYLHYDROXAMIC ACID AND 1,10 ...

    African Journals Online (AJOL)

    Preferred Customer

    Metal complexes which are formed in biological systems between a ligand and a metal ion are in dynamic ... In a continuation of our research work oriented towards studying the .... Antimicrobial activity techniques. Preparation of test samples.

  3. Theoretical studies of transition metal complexes with nitriles and isocyanides

    International Nuclear Information System (INIS)

    Kuznetsov, Maksim L

    2002-01-01

    Theoretical studies of transition metal complexes with nitriles and isocyanides are reviewed. The electronic structures and the nature of coordination bonds in these complexes are discussed. The correlation between the electronic structures of transition metal complexes with nitriles and isocyanides and their structural properties, spectroscopic characteristics, and reactivities are considered. The bibliography includes 121 references.

  4. Metal complexation capacity of Antarctic lacustrine sediments.

    Science.gov (United States)

    Alberti, Giancarla; Mussi, Matteo; Quattrini, Federico; Pesavento, Maria; Biesuz, Raffaela

    2018-04-01

    The purpose of this study is to implement a work that is a part of a project funded by the Italian National Antarctic Research Program (PNRA, Piano Nazionale di Ricerche in Antartide) within the main thematic focus "Chemical Contamination-Global Change". This research was devoted to detect and characterize micro and nano components with strong complexing capability towards metal ions at trace level in sea water, lakes and lacustrine sediments, sampled during the XXII expedition of PNRA. In particular, in the present work, the sorption complexation capacity of an Antarctic lacustrine sediments toward Cu(II) and Pb(II) is described. The characterization of the sorption was undertaken, studying kinetics and isotherm profiles. The lake here considered is Tarn Flat in the area of Terra Nova Bay. The sorption equilibria of Cu(II) and Pb(II) on the lacustrine sediments were reached in about 10 h, and they were best modelled by the Langmuir equation. Preliminary, to establish if the data here obtained were consistent with those reported for the same area in other expeditions, a common multivariate techniques, namely the principal component analysis (PCA), was applied and finally the consistency of the data has been confirmed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Complex metal hydrides for hydrogen, thermal and electrochemical energy storage

    DEFF Research Database (Denmark)

    Møller, Kasper T.; Sheppard, Drew; Ravnsbæk, Dorthe B.

    2017-01-01

    field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...... how complex metal hydrides may act in an integrated setup with a fuel cell. This review focuses on the unique properties of light element complex metal hydrides mainly based on boron, nitrogen and aluminum, e.g., metal borohydrides and metal alanates. Our hope is that this review can provide new...

  6. Cationic rare-earth metal SALEN complexes.

    Science.gov (United States)

    Liu, Qiancai; Meermann, Christian; Görlitzer, Hans W; Runte, Oliver; Herdtweck, Eberhardt; Sirsch, Peter; Törnroos, Karl W; Anwander, Reiner

    2008-11-28

    Complexes (Salpren(tBu,tBu))Y[N(SiHMe2)2](thf) and (SALEN(tBu,tBu))La[N(SiHMe2)2](thf) (SALEN(tBu,tBu) = Salcyc(tBu,tBu) and Salpren(tBu,tBu)) were prepared from Ln[N(SiHMe2)2]3(thf)2 and H2SALEN(tBu,tBu). The yttrium complex was characterized by X-ray crystallography revealing intrinsic solid-state structural features: the metal centre is displaced by 1.05 angstroms from the [N2O2] least squares plane of a highly bent Salpren(tBu,tBu) ligand (angle(Ph,Ph) dihedral angle of 80.4(1) degrees ) and is coordinated asymmetrically by the silylamide ligand exhibiting one significant Y---(HSi) beta-agostic interaction (Y-N1-Si1, 106.90(9) degrees; Y---Si1, 3.2317(6) angstroms). Complexes (SALEN(tBu,tBu))Ln[N(SiHMe2)2](thf)n (n = 1, Sc; n = 2, Y, La) react with ammonium tetraphenylborate to form the ion pairs [(SALEN(tBu,tBu))Ln(thf)n][BPh4]. The cationisation was proven by X-ray crystal structure analyses of [(Salpren(tBu,tBu))Sc(thf)2][B(C6H5)4].2(thf) and [(Salpren(tBu,tBu))Ln(thf)3][B(C6H5)4].4(thf) (Ln = Y, La), showing an octahedral and pentagonal-bipyramidal coordination geometry, respectively.

  7. Mn(II), Zn(II) and VO(II) Schiff

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3. 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. Inorganic Volume 113 Issue 3 June 2001 pp 183-189 ...

  8. Metal oxalate complexes as novel inorganic dopants: Studies on ...

    Indian Academy of Sciences (India)

    Unknown

    UV-visible and IR spectral features not only confirmed the polyaniline doping by complex anions but also substantiated ... MoS3 dopant. Although inorganic metal complexes bear- ... distilled water and then with methanol and acetone until.

  9. Lability of Nanoparticulate Metal Complexes at a Macroscopic Metal Responsive (Bio)interface

    NARCIS (Netherlands)

    Duval, Jérôme F.L.; Town, Raewyn M.; Leeuwen, Van Herman P.

    2018-01-01

    The lability of metal complexes expresses the extent of the dissociative contribution of the complex species to the flux of metal ions toward a macroscopic metal-responsive (bio)interface, for example, an electrodic sensor or an organism. While the case of molecular ligands is well-established, it

  10. Ionophoretic method in the study of mixed ligand ternary chelates of UO2(II), Ni(II) and Zn(II) involving nitrilotriacetate and cytosine as ligands

    International Nuclear Information System (INIS)

    Mishra, A.P.; Mishra, S.K.; Yadava, K.L.

    1987-01-01

    A novel electrophoretic technique is described for the assessment of the equilibria in mixed-ligand complex system in solution. It is based on the movement of spot of the metal ion under an electric field with the complexants added in the background electrolyte at fixed pH. The concentration of primary ligand nitrilotriacetate was constant while that of secondary ligand (cytosine) was varied. The plot of log (cytosine) against mobility was used to obtain information on the formation of the mixed complexes and to calculate its stability constants. Experimentally obtained logK values are as 5.62, 4.55 and 4.42 for mixed complexes of UO 2 (II), Ni(II) and Zn(II) respectively at μ=0.1 and temp.=35 +- 01.degC. (author). 10 refs

  11. Plasmon hybridization in complex metallic nanostructures

    Science.gov (United States)

    Hao, Feng

    With Plasmon Hybridization (PH) and Finite-Difference Time-Domain (FDTD) method, we theoretically investigated the optical properties of some complex metallic nanostructures (coupled nanoparticle/wire, nanostars, nanorings and combined ring/disk nanocavity systems). We applied the analytical formulism of PH studying the plasmonic coupling of a spherical metallic nanoparticle and an infinite long cylindrical nanowire. The plasmon resonance of the coupled system is shown shifted in frequency, which highly depends on the polarization of incident light relative to the geometry of the structure. We also showed the nanoparticle serves as an efficient antenna coupling the electromagnetic radiation into the low-energy propagating wire plasmons. We performed an experimental and theoretical analysis of the optical properties of gold nanorings with different sizes and cross sections. For light polarized parallel to the ring, the optical spectrum sensitively depends on the incident angle. When light incidence is normal to the ring, two dipolar resonance is observed. As the incident light is titled, some previously dark mulipolar plasmon resonances will be excited as a consequence of the retardation. The concept of plasmon hybridization is combined with the power of brute-force numerical methods to understand the plasmonic properties of some very complicated nanostructures. We showed the plasmons of a gold nanostar are a result of hybridization of the plasmons of the core and the tips of the particle. The core serves as a nanoantenna, dramatically enhanced the optical spectrum and the field enhancement of the nanostar. We also applied this method analyzing the plasmonic modes of a nanocavity structure composed of a nanodisk with a surrounding minoring. For the concentric combination, we showed the nature of the plasmon modes can be understood as the plasmon hybrization of an individual ring and disk. The interation results in a blueshifted and broadened superradiant antibonding

  12. Cell complexes of transition metals in biochemistry and medicine

    International Nuclear Information System (INIS)

    Voloshin, Ya.Z.; Varzatskij, O.A.; Bubnov, Yu.N.

    2007-01-01

    Basic directions and prospects of use of cell complexes of transition metals in medicine and biochemistry are considered: incapsulation of radioactive metal ions for radiotherapy and diagnostics; preparation of contrast compounds for magnetic resonance tomography, antidotes and pharmaceutical preparation of prolonged effect, preparations for boron-neutron-capture therapy of neoplasms, antioxidants; membrane transport of metal ions; study of interaction of cell metal complexes with nucleic acids; possibility of use of self-assembly of cell complexes for imitation of ligases and use of clathrochelates as linkers; design of inhibitors of viruses for AIDS therapy [ru

  13. 40 CFR 721.4596 - Diazo substituted carbomonocyclic metal complex.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Diazo substituted carbomonocyclic... Specific Chemical Substances § 721.4596 Diazo substituted carbomonocyclic metal complex. (a) Chemical... as a diazo substituted carbomonocyclic metal complex (PMN P-94-1039) is subject to reporting under...

  14. Tris-diamine-derived transition metal complexes of flurbiprofen as ...

    African Journals Online (AJOL)

    admin

    butyrylcholinesterase (BChE) inhibitory activities. Method: Tris-diamine-derived transition metal complexes of Co(II), Ni(II), and Mn(II) were synthesized and characterized ... Conductance measurements indicated that diamine-derived metal complexes of ..... contributes to enhanced biological activity, and provides novel ...

  15. Mixed Metal Complexes of Isoniazid and Ascorbic Acid: Chelation ...

    African Journals Online (AJOL)

    HP

    these ligands and their metal complexes have revealed the bi-dentate coordination of isoniazid ligand to ... of the drugs on coordination with a metal is enhanced ..... James, O.O., Nwinyi, C.O. and. Allensela, M.A. (2008). Cobalt(II) complexes of mixed antibiotics: Synthesis,. Characterization, antimicrobial potential and their.

  16. Spectral studies, thermal investigation and biological activity of some metal complexes derived from (E)-N‧-(1-(4-aminophenyl)ethylidene)morpholine-4-carbothiohydrazide

    Science.gov (United States)

    El-Samanody, El-Sayed A.; Polis, Magdy W.; Emara, Esam M.

    2017-09-01

    A new series of biologically active Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes derived from the novel thiosemicarbazone ligand; (E)-N‧-(1-(4-aminophenyl)ethylidene)morpholine-4-carbothiohydrazide (HL) were synthesized. The mode of bonding of the ligand and the geometrical structures of its metal complexes were achieved by different analytical and spectral methods. The ligand coordinated with metal ions in a neutral bidentate fashion through the thione sulfur and azomethine nitrogen atoms. All metal complexes adopted octahedral geometry, except Cu(II) complexes (3, 6, 7) which have a square planar structure. The general thermal decomposition pathways of the ligand along with its metal complexes were explained. The thermal stability of the complexes is controlled by the number of outer and inner sphere water molecules, ionic radii and the steric hindrance. The activation thermodynamic parameters; (activation energy (E*), enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*)) along with order of reaction (n) were estimated from DTG curves. The ESR spectra of Cu(II) complexes indicated that (dx2-y2)1 is the ground state with covalence character of metal-ligand bonds. The molluscicidal and biochemical effects of the ligand and its Ni(II); Cu(II) complexes (2; 3, 5, 7) along with their combinations with metaldehyde were screened in vitro on the mucous gland of Eobania vermiculata. The tested compounds exhibited a significant toxicity against the tested animals and have almost the same toxic effect of metaldehyde which increases the mucous secretion of the snails and leads to death.

  17. Synthesis, structural characterization, in vitro antimicrobial and anticancer activity studies of ternary metal complexes containing glycine amino acid and the anti-inflammatory drug lornoxicam

    Science.gov (United States)

    Mahmoud, Walaa H.; Mohamed, Gehad G.; El-Dessouky, Maher M. I.

    2015-02-01

    Mixed ligand complexes were synthesized using lornoxicam (LOR) as the primary ligand and glycine amino acid (HGly) as the secondary ligand. They were characterized by FT-IR, UV-Vis, mass, 1H NMR, ESR spectral studies, TG-DTG, X-ray powder diffraction and physical analytical studies. From the molar conductance, magnetic moment and electronic spectral data of the synthesized complexes, general formulae of [M(LOR)2(Gly)]·Xn·yH2O where M = Cr(III) (X = Cl, n = 2, y = 3), Mn(II) (X = Cl, n = 1, y = 1), Co(II) (X = BF4, n = 1, y = 0), Ni(II) (X = Cl, n = 1, y = 0), Cu(II) (X = BF4, n = 1, y = 2) and Zn(II) (X = BF4, n = 1, y = 2) and (M = Fe(II) (X = BF4, n = 1, y = 1) and Fe(III) (X = Cl, n = 2, y = 1) with an octahedral structure were proposed. Thermal analyses show that the complexes lose water molecules of hydration initially and subsequently expel anionic parts and organic ligands in continuous steps. The kinetic parameters namely E, ΔH∗, ΔS∗ and ΔG∗ illustrate the spontaneous association of the metal and ligands in the formation of the complexes. The antimicrobial efficiency of the LOR and HGly ligands and the ternary complexes were examined by in vitro method against various pathogenic bacterial and fungal strains. The metal complexes were found to possess efficient antimicrobial properties compared to lornoxicam and most of these complexes could turn out to be excellent models for the design of effective antibiotic drug substances. Also, the two ligands, in comparison to ternary metal complexes are screened for their anticancer activity against breastic cancer cell line. The results showed that the metal complexes be more active than the parent LOR and glycine free ligands except Cr(III) ternary complex which was found to be inactive.

  18. Simultaneous spectrophotometric determination of heavy metal ions Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) with Br-PADPA in primary reactor coolant system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Hyeong; Yun, Jong-Il [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    The performance with integrity of nuclear power plants is highly influenced by the presence of the corrosion products. The deposition of corrosion products in the steam generator is the one of the main concerns of power plants. The quantification of corrosion products is considered of importance. In this study, we applied the spectrophotometric method to detect metal ions such as iron, cobalt, nickel, copper, and zinc, which are major elements of structural material of the plant. In particular, the chemical complexation of those divalent metal ions with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) provides high molar absorptivity. For the simultaneous determination of metal ions, a partial least square (PLS) regression method was applied. In the present work, the complexation of Br-PADAP with divalent metal ions (iron, cobalt, nickel, copper and zinc) was studied. The PLS regression method was successfully applied for simultaneous elemental detection in multi-element systems. These results suggests that the method is very ample to detect corrosion products in nuclear power plants.

  19. Metallacyclopentadienes: structural features and coordination in transition metal complexes

    International Nuclear Information System (INIS)

    Dolgushin, Fedor M; Yanovsky, Aleksandr I; Antipin, Mikhail Yu

    2004-01-01

    Results of structural studies of polynuclear transition metal complexes containing the metallacyclopentadiene fragment are overviewed. The structural features of the complexes in relation to the nature of the substituents in the organic moiety of the metallacycles, the nature of the transition metals and their ligand environment are analysed. The main structural characteristics corresponding to different modes of coordination of metallacyclopentadienes to one or two additional metal centres are revealed.

  20. Cu(II), Zn(II)

    African Journals Online (AJOL)

    the kinetic parameters as order of decomposition reaction, activation energy and ..... Cu as anode material, K - alpha [Å] = 1.54060 and the generator settings 30 .... Calculated quantum chemical parameters for ligand and its metal complexes.

  1. A novel polymer probe for Zn(II) detection with ratiometric fluorescence signal

    Science.gov (United States)

    Diao, Haipeng; Guo, Lixia; Liu, Wen; Feng, Liheng

    2018-05-01

    A conjugated polymer probe comprised of fluorene, quinolone and benzothiazole units was designed and synthesized by the Suzuki coupling reaction. Through the studies of photophysical and thermal properties, the polymer displays blue-emitting feature and good thermal stability. A ratiometric fluorescence signal of the probe for Zn(II) was observed in ethanol with a new emission peak at 555 nm. The probe possesses a high selectivity and sensitivity for Zn(II) during familiar metal ions in ethanol. The detection limit of the probe for Zn (II) is up to 10-8 mol/L. The electron distributions of the polymer before and after bonding with Zn (II) were investigated by the Gaussian 09 software, which agreed with the experimental results. Noticeably, based on the color property of the probe with Zn(II), a series of color test paper were developed for visual detecting Zn(II) ions. This work helps to provide a platform or pattern for the development of polymer fluorescence probe in the chemosensor field.

  2. Synthesis and description of complexes of Cu(I), Mn(II) and Zn(II) using the linking N,N'-bis(2-sulphide benzil)-3,3'-diamine N'-methyldipropylamine of sodium

    International Nuclear Information System (INIS)

    Amador Godoy, Ginnette

    2000-01-01

    This work optimized the synthesis's procedure of the linking called N,N ' -bis(2-sulphide benzil)-3,3 ' -diamino - N ' -methyldipropylamine of sodium. It described the synthesis's intermediate products of the linking by 1 H-NMR. It synthesized complexes utilizing the linking mentioned previously and the metal salts of cooper and manganese. The description of the complexes was realized by electrochemical, magnetic and spectroscopic methods. To the (I) cooper's complex, it was gotten an effective magnetic moment of 0.62 M.B. and the molecular formula proposed is: C 2 1H 2 9N 3 S 2 Cu.CH 3 OH. It determined that the oxide-reduction process is quasi reversible. The (II) manganese's complex has an effective magnetic moment of 5.2 M.B. that corresponds to a configuration d 5 of tall porcupine. It proposes the molecular formula C 2 1H 2 9N 3 S 2 Mn and the metal/nitrogen relation is 3/1. The oxide-reduction process is quasi reversible. It described the zinc's complex in dissolution by 1 H-NMR and 1 3C-NMR to different temperatures, it observed an increase of the separation and definition of the signals when the temperature increased until to get an spectro 1 H-NMR to 130 centigrade with the standard signals of the different shapes that can adopt the molecule, besides it got an spectro of 1 3C-NMR to 100 centigrade [es

  3. Mononuclear late first row transition metal complexes of ONO donor hydrazone ligand: Synthesis, characterization, crystallographic insight, in vivo and in vitro anti-inflammatory activity

    Science.gov (United States)

    Kendur, Umashri; Chimmalagi, Geeta H.; Patil, Sunil M.; Gudasi, Kalagouda B.; Frampton, Christopher S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.

    2018-02-01

    Air and moisture stable coordination compounds of late first row transition metal ions, viz., Co(II), Ni(II), Cu(II) and Zn(II) with a newly designed ligand, (E)-2-amino-N'-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl)ethylidene)benzohydrazide (H2L) were prepared and extensively characterized using various spectro-analytical techniques. The ligand acts both in mono as well as doubly deprotonated manner. The ligand to metal stoichiometry was found to be 1:2 in case of complexes using chloride salts, whereas 1:1 in case of copper (II) complex using its acetate salt. The molecular structures of H2L, nickel and copper complexes were unambiguously determined by single-crystal X-ray diffraction studies reveal that H2L exists in a zwitterionic form while copper complex has copper centre in a distorted square planar environment. On the other hand, cobalt, nickel and zinc complexes display distorted octahedral coordination around the metal ion. In case of [Ni(HL)2].H2O, intramolecular Csbnd H⋯π stacking interaction were observed between the centroid of five membered chelate ring and phenyl proton C5sbnd H5 and intermolecular Csbnd H⋯π stacking interaction between the centroid of phenyl ring, dehydroacetic acid (DHA) ring and phenyl protons. The [Cu(L)DMF] complex is stabilized by intramolecular hydrogen bonding N1H⋯N2 and by intermolecular hydrogen bonding N1H⋯O4. Intermolecular interactions were investigated by Hirshfeld surfaces. Further, H2L and its metal complexes were screened for their in vivo and in vitro anti-inflammatory activities. The activity of the ligand has enhanced on coordination with transition metals. The tested compounds have shown excellent activity, which is almost equipotent to the standard used in the study.

  4. Ternary complexes of Zn(II) and Cu(II) with 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide in the presence of heterocyclic bases as auxiliary ligands: Synthesis, spectroscopic and structural characterization and antibacterial activity

    Science.gov (United States)

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

    2018-03-01

    The new ternary complexes, ZnLL‧ [L = 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide and L‧ = imidazole (1), 2, 2‧-bipyridine (2) and 2-methyimidazole (3)], Zn2L2L‧ [L‧ = 4, 4‧-bipy (4)] and CuLL‧ [L‧ = 2, 2‧-bipy (5)] have been synthesized by the reaction of a metal(II) acetate salt with the thiosemicarbazone and in presence of heterocyclic bases as auxiliary ligands. The synthesized compounds were investigated by elemental analysis and IR, 1H NMR, and 13C NMR spectroscopy and complex 5 was structurally characterized by X-ray crystallography. The results indicate the thiosemicarbazone doubly deprotonated and coordinates to metal through the thiolate sulfur, imine nitrogen and phenolic oxygen atoms. The nitrogen atom(s) of the auxiliary ligand complete the coordination sphere. Complex 4 is binuclear with 4, 4‧-bipy acting as a bridging ligand. The structure of 5 is a distorted square pyramid with one of the bipyridine nitrogen atoms in the apical position. This compound creates an inversion dimer in solid state by intermolecular hydrogen bonds of Nsbnd H⋯S type. The in vitro antibacterial activity of the synthesized compounds were evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (P. aeruginosa) bacteria and is compared to that of standard antibacterial drugs. All complexes exhibit good inhibitory effects and are significantly more effective than the parent ligand.

  5. Bioassay studies of metal(II complexes of 2,2'-(ethane-1,2-diyldiiminodiacetic acid

    Directory of Open Access Journals (Sweden)

    Saeed-ur-Rehman

    2011-08-01

    Full Text Available Ni(II, Cu(II and Zn(II coordination compounds with modified diammine 2,2'-(ethane-1,2-diyldiiminodiacetic acid (EDDA were prepared and characterized. Coordination complexes of the EDDA were characterized by physical measurements including elemental analysis, IR, UV-Visible, magnetic susceptibilities and conductance measurements. The complexes were screened against four pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus and their concentrations for maximum inhibition zones were obtained.

  6. Improving the SMM and luminescence properties of lanthanide complexes with LnO9 cores in the presence of ZnII: an emissive Zn2Dy single ion magnet.

    Science.gov (United States)

    Fondo, Matilde; Corredoira-Vázquez, Julio; Herrera-Lanzós, Antía; García-Deibe, Ana M; Sanmartín-Matalobos, Jesús; Herrera, Juan Manuel; Colacio, Enrique; Nuñez, Cristina

    2017-12-12

    Mononuclear complexes of stoichiometry [Ln(H 3 L)(H 2 O)(NO 3 )](NO 3 ) 2 (Ln = Tb, 1; Dy, 2, Er, 3), which crystallise with different solvates, and the heterotrinuclear compound [Zn 2 Dy(L)(NO 3 ) 3 (OH)] (4) can be obtained with the same H 3 L compartmental ligand. The single X-ray crystal structure of the mononuclear complexes shows a LnO 9 core with a muffin-like disposition while the geometry of the DyO 9 core in 4 seems to be closer to spherical capped square antiprism. The analysis of the magnetic properties of all the complexes demonstrates that the mononuclear lanthanide compounds do not show slow relaxation of the magnetization, even when the samples are diluted with a diamagnetic matrix and subjected to a dc applied field of 1000 Oe. Nevertheless, the heterotrinuclear dysprosium complex 4·3H 2 O is a field-induced single ion magnet, with an estimated U eff barrier of 59 K. The luminescence characterisation of all the metal complexes in methanol solution at 298 K also shows a notable increase in the fluorescence emission of the heterotrinuclear complex with respect to the mononuclear ones, in such a way that 4 can be defined as a fluorescent single ion magnet.

  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.

    Science.gov (United States)

    Yamgar, B A; Sawant, V A; Bharate, B G; Chavan, S S

    2011-01-01

    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. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Adsorption of Zn(II) on the kaolinite(001) surfaces in aqueous environment: A combined DFT and molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiang; Kong, Xiang-Ping; Zhang, Bao-Hua; Wang, Juan, E-mail: juaner80@163.com

    2017-08-31

    Highlights: • Zn(II) adsorption on two types of neutral kaolinite(001) surfaces is investigated. • Surface “Ou” is found the preferred site for mono- and bi-dentate complexes. • Both Zn(II) and surface oxygen accept electrons from aqua oxygens. • Coupling of O 2p with Zn sp{sup 3}d{sup 2} (or sp{sup 3}) hybridization states is the bonding nature. - Abstract: Adsorption of Zn(II) on two types of neutral (001) surfaces of kaolinite, tetrahedral Si(t) and octahedral Al(o), was studied by means of DFT calculations and classical molecular dynamics simulations. The position and structure for both outer-sphere and mono-/bi-dentate inner-sphere complexes of Zn(II) in aqueous environment were examined, with binding energy and radial distribution function calculated. Outer-sphere complex on the Si(t) surface, monodentate inner-sphere complex of “O{sub u}” (surface oxygen with “upright” hydrogen) site and bidentate complex of “O{sub u}-O{sub u}” site of neighboring Al centers on the Al(o) surface are considered to be the dominant adsorption species. The outer-sphere complex is found six-coordinated with distorted octahedral geometry, while both the inner-sphere complexes exhibit the tetrahedral structure with coordination number of four. Hydrogen bonding interactions between oxygen or hydrogen of the kaolinite(001) surfaces and the aqua ligands of Zn(II) act as the key role for the structure and stability of adsorption complexes. Upon the Mulliken population analysis and partial density of states, both Zn(II) and surface oxygen accept electrons from aqua oxygens, and coupling of O 2p with the sp{sup 3}d{sup 2} or sp{sup 3} hybridization states of Zn(II) is the primary bonding nature of Zn(II) with oxygen in outer- and inner-sphere complexes, respectively.

  9. Reactivity of monoolefin ligand in transition metal complexes

    International Nuclear Information System (INIS)

    Rybinskaya, M.I.

    1978-01-01

    The main tendencies in the coordinated olefin ligand property changes are discussed in the transition metal complexes in comparison with free olefins. The review includes the papers published from 1951 up to 1976. It has been shown that in complexes with transition metal cations olefin π-base acquires the ability to react with nucleophylic reagents. Olefin π-acids in complexes with zero valent metals are easily subjected to electrophylic reagent action. At coordination with transition metal cations the olefin properties are generally preserved, while in the zero-valent metal complexes the nonsaturated ligand acquires the properties of a saturated compounds. The ability of transition metal cations in complexes to intensify reactions of nucleophylic bimolecular substitution of vinyl halogen is clearly detected in contrast to the zero valent metal complexes. It has been shown that investigations of the coordinated olefin ligand reactivity give large possibilities in the further development of the organic synthesis. Some reactions are taken as the basis of important industrial processes

  10. N-acyl thioureas - selective ligands for complexing of heavy metals and noble metals

    International Nuclear Information System (INIS)

    Schuster, M.

    1992-01-01

    Acyl thioureas are complexing agents for heavy metals that are easily produced and very stable. Their favourable toxicological data make them particularly suitable for industrial applications, e.g. detoxification of metallic process solutions or solvent extraction of metals. (orig.) [de

  11. Alkylation and arylation of alkenes by transition metal complexes

    International Nuclear Information System (INIS)

    Volkova, L.G.; Levitin, I.Ya.; Vol'pin, M.E.

    1975-01-01

    In this paper are reviewed methods of alkylation and irylation of unsaturated compounds with complexes of transition metals (Rh, Pd). Analysis of alkylation and arylation of olefines with organic derivatives of transition metals, obtained as a result of exchange reactions between organic compounds of transition metals and salts of metals of the 8th group of the periodic system, allows a conclusion as to the wide possibilities of these reactions in the synthesis of various derivatives of unsaturated compounds. In all the reactions under consideration, intermediate formation of sigma-complexes is assumed. Also considered are alkylation and arylation of olefines with organic derivatives of halogens in the presence of compounds of metals of the 8th group of the periodic system, as well as arylation of olefines with aromatic compounds in the presence of salts of transition metals

  12. Kinetics of the reactions of hydrated electrons with metal complexes

    International Nuclear Information System (INIS)

    Korsse, J.

    1983-01-01

    The reactivity of the hydrated electron towards metal complexes is considered. Experiments are described involving metal EDTA and similar complexes. The metal ions studied are mainly Ni 2+ , Co 2+ and Cu 2+ . Rates of the reactions of the complexes with e - (aq) were measured using the pulse radiolysis technique. It is shown that the reactions of e - (aq) with the copper complexes display unusually small kinetic salt effects. The results suggest long-range electron transfer by tunneling. A tunneling model is presented and the experimental results are discussed in terms of this model. Results of approximate molecular orbital calculations of some redox potentials are given, for EDTA chelates as well as for series of hexacyano and hexaquo complexes. Finally, equilibrium constants for the formation of ternary complexes are reported. (Auth./G.J.P.)

  13. Crystal structures and thermodynamics/kinetics of Zn(II) coordination polymers with helical chains

    Energy Technology Data Exchange (ETDEWEB)

    He, Tian [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Yue, Ke-Fen, E-mail: ykflyy@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Zhao, Yi-xing; Chen, San-Ping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Zhou, Chun-sheng, E-mail: slzhoucs@126.com.cn [Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources, College of Chemical Engineering and Modern Materials, Shangluo University, Shangluo 726000 (China); Yan, Ni [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China)

    2016-07-15

    curve. The structural stability could be illustrated from the point of thermodynamics and kinetics. - Graphical abstract: Four new zinc coordination architectures constructed from the primary ligand bib, transition metal ions Zn(II) and four V-shaped carboxylate coligands. The different structural evolutions of complexes 1–4 have systematically illustrated that the carboxylate coligands play a critical role in the assemblies of the CPs. Their thermal decompositions properties of 1–4 were investigated by simultaneous TG/DTG–DSC technique. The apparent activation energy E and the pre-exponential factor (A) of skeleton collapse for the complexes 1−4 are calculated by the integral Kissinger’s method and Ozawa–Doyle’s method. The structural stability could be illustrated from the point of thermodynamics and kinetics. Display Omitted.

  14. Equilibrium and NMR studies on GdIII, YIII, CuII and ZnII complexes of various DTPA-N,N''-bis(amide) ligands. Kinetic stabilities of the gadolinium(III) complexes.

    Science.gov (United States)

    Jászberényi, Zoltán; Bányai, István; Brücher, Ernö; Király, Róbert; Hideg, Kálmán; Kálai, Tamás

    2006-02-28

    Three DTPA-derivative ligands, the non-substituted DTPA-bis(amide) (L(0)), the mono-substituted DTPA-bis(n-butylamide) (L(1)) and the di-substituted DTPA-bis[bis(n-butylamide)] (L(2)) were synthesized. The stability constants of their Gd3+ complexes (GdL) have been determined by pH-potentiometry with the use of EDTA or DTPA as competing ligands. The endogenous Cu2+ and Zn2+ ions form ML, MHL and M(2)L species. For the complexes CuL(0) and CuL(1) the dissociation of the amide hydrogens (CuLH(-1)) has also been detected. The stability constants of complexes formed with Gd3+, Cu2+ and Zn2+ increase with an increase in the number of butyl substituents in the order ML(0) DTPA)2-, while the complex GdL2 possesses a much higher kinetic stability.

  15. Thiosemicarbazone complexes of the platinum metals. A story of ...

    Indian Academy of Sciences (India)

    Unknown

    Thiosemicarbazone complexes; platinum metals; variable coordination; ... carbonylic carbon via one or two intervening atoms, D,N,S tricoordination usually takes .... modelling studies show that in this coordination mode, the phenyl ring of the.

  16. 3d-METAL COMPLEXES WITH BARBITURIC ACID DERIVATIVES

    Directory of Open Access Journals (Sweden)

    T. V. Koksharova

    2015-04-01

    Full Text Available The various aspects of the 3d-metal complexes with barbiturates and uric acid chemistry such as composition, structure, physicochemical properties, possible fields of application – have been illustrated in this review

  17. Structural systematics of some metal complexes with 4,5 ...

    Indian Academy of Sciences (India)

    study reveals that each metal(II) centre in the four complexes adopts distorted octahedral geometry with MN6 ... potassium permanganate (E Merck, India), potassium. 717 ... The final reaction solu- ..... ble in water, methanol, acetonitrile, etc.

  18. Sub-chronic toxicological studies of transition metal complexes of ...

    African Journals Online (AJOL)

    Md. Sharif Hasan

    2017-01-18

    Jan 18, 2017 ... naproxen showed more side effects than metal complexes which ..... Fosslein E. Adverse effects of nonsteroidal anti-inflammatory drugs on the ... association increases the anti-inflammatory and analgesic activity of ibuprofen.

  19. Synthesis and characterization of some metal complexes of a Schiff ...

    African Journals Online (AJOL)

    KEY WORDS: Metal complexes, Schiff base, Ninhydrin, α,L-Alanine, .... Buck Scientific Infrared Spectrophotometer Model 500 in the range of 4000 .... Assignments based on Nakamoto [35], ν - stretching vibration, δ - bending or deformation.

  20. Bovine Serum Albumin Metal Complexes for Mimic of SOD

    Indian Academy of Sciences (India)

    Key Lab. Eco-Environment-Related Polymer Materials of Ministry of Education, Key Lab. ... scaffold and the metal complex functioned as the catalytic active center. ... small molecule.22 It is found that the antioxidative ... and absence, respectively, of the measured compound. ... monitor the interaction of metal ions with BSA.

  1. Inkjet Printing of 3D Metallic Silver Complex Microstructures

    NARCIS (Netherlands)

    Wits, Wessel Willems; Sridhar, Ashok; Dimitrov, D.

    2010-01-01

    To broaden the scope of inkjet printing, this paper focuses on printing of an organic silver complex ink on glass substrates towards the fabrication of metallic 3D microstructures. The droplet formation sequence of the inkjet printer is optimised to print continuous layers of metal. A brief

  2. Revisited: the conception of lability of metal complexes

    NARCIS (Netherlands)

    Leeuwen, van H.P.

    2001-01-01

    Starting from the original reaction layer concept, the voltammetric properties of electroinactive metal complexes are critically reviewed in terms of their finite rates of dissociation into electroactive free metal ions. The limiting conditions for the reaction layer-based flux expressions are made

  3. Compartmentation and complexation of metals in hyperaccumulator plants

    Directory of Open Access Journals (Sweden)

    Barbara eLeitenmaier

    2013-09-01

    Full Text Available Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their strange behaviour in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defence against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e. detoxified by binding to strong ligands such as metallothioneins.

  4. Removal of Zn(II) and Hg(II) from aqueous solution on a carbonaceous sorbent chemically prepared from rice husk

    International Nuclear Information System (INIS)

    El-Shafey, E.I.

    2010-01-01

    A carbonaceous sorbent was prepared from rice husk via sulfuric acid treatment. Sorption of Zn(II) and Hg(II) from aqueous solution was studied varying time, pH, metal concentration, temperature and sorbent status (wet and dry). Zn(II) sorption was found fast reaching equilibrium within ∼2 h while Hg(II) sorption was slow reaching equilibrium within ∼120 h with better performance for the wet sorbent than for the dry. Kinetics data for both metals were found to follow pseudo-second order model. Sorption rate of both metals was enhanced with temperature rise. Activation energy, E a , for Zn(II) sorption, was ∼13.0 kJ/mol indicating a diffusion-controlled process ion exchange process, however, for Hg(II) sorption, E a was ∼54 kJ/mol indicating a chemically controlled process. Sorption of both metals was low at low pH and increased with pH increase. Sorption was much higher for Hg(II) than for Zn(II) with higher uptake for both metals by rising the temperature. Hg(II) was reduced to Hg(I) on the sorbent surface. This was confirmed from the identification of Hg 2 Cl 2 deposits on the sorbent surface by scanning electron microscopy and X-ray diffraction. However, no redox processes were observed in Zn(II) sorption. Sorption mechanism is discussed.

  5. Synthesis, characterization and biological profile of metal and azo-metal complexes of embelin

    Directory of Open Access Journals (Sweden)

    R. Aravindhan

    2014-12-01

    Full Text Available The present study emphasizes synthesis and bioprofiling of embelin, embelin-metal (EM and embelin-azo-metal (EAM complexes in detail. EM complexes were prepared using pure embelin and d-block transition elements, namely Mn, Fe, Co, Ni, Cu, and Zn. Similarly, EAM complexes were synthesized using phenyl azo-embelin with the said transition metals. Embelin, EM, and EAM complexes were subjected to ultra violet visible spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance, electrospray ionization mass spectrometry, thermogravimetric analysis, carbon hydrogen nitrogen sulfur analysis. With regard to bioprofiling, the test complexes were studied for the antioxidant and antimicrobial activities. Results revealed that the prepared EM and EAM complexes form octahedral complexes with embelin with the yield in the range of 45–75%. All the instrumental analyses authenticate the interaction of metals with bidentate embelin through its enolic and quinonic oxygen atoms as [M(Emb2(H2O2]H2O and [M(Emb-Azo2(H2O2]. The antioxidant profile studies suggested that upon complexation with metals, the free radical scavenging activity of embelin reduced significantly. But, with regard to antimicrobial activity, cobalt and nickel embelin complexes displayed>80% growth inhibition in comparison with embelin alone. The hemolytic activity studies suggested that both embelin and the metal complexes are non-hemolytic. The reason for the reduction in antioxidant and an increase in antimicrobial activities were discussed in detail.

  6. Lability of nanoparticulate metal complexes in electrochemical speciation analysis

    DEFF Research Database (Denmark)

    van Leeuwen, Herman P.; Town, Raewyn M.

    2016-01-01

    Lability concepts are elaborated for metal complexes with soft (3D) and hard (2D) aqueous nanoparticles. In the presence of a non-equilibrium sensor, e.g. a voltammetric electrode, the notion of lability for nanoparticulate metal complexes, M-NP, reflects the ability of the M-NP to maintain...... equilibrium with the reduced concentration of the electroactive free M2+ in its diffusion layer. Since the metal ion binding sites are confined to the NP body, the conventional reaction layer in the form of a layer adjacent to the electrode surface is immaterial. Instead an intraparticulate reaction zone may...... of the electrochemical technique is crucial in the lability towards the electrode surface. In contrast, for nanoparticulate complexes it is the dynamics of the exchange of the electroactive metal ion with the surrounding medium that governs the effective lability towards the electrode surface....

  7. Metal plasmon enhanced europium complex luminescence

    International Nuclear Information System (INIS)

    Liu Feng; Aldea, Gabriela; Nunzi, Jean-Michel

    2010-01-01

    The plasmon enhanced luminescence of a rare-earth complex Tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato) europium (Eu(fod) 3 ) was investigated. A polyvinyl alcohol (PVA) thin film was successfully adopted as a spacer to separate the Eu complex from the silver island film (SIF), and five-fold enhancement of the radiative decay rate of the Eu complex on SIF was demonstrated based on the luminescence intensity and lifetime measurement. Investigation of the distance dependent luminescence indicates that 7 nm is an optimal distance for SIF enhanced Eu luminescence. Plasmon enhanced rare-earth luminescence based on an organic film spacer would find potential applications in plasmon enhanced organic light emitting diode (OLED) devices.

  8. Mixed metal complexes of isoniazid and ascorbic acid: chelation ...

    African Journals Online (AJOL)

    Novel mixed complexes of isoniazid and ascorbic acid have been synthesized and characterized using infrared, electronic absorption data, elemental analysis, molar conductivity, melting point, thin layer chromatography and solubility. The metal ions involved in the complex formation are Cu2+, Zn2+ and Cd2+. The melting ...

  9. Metal complex catalysis in the synthesis of organoaluminium compounds

    International Nuclear Information System (INIS)

    Dzhemilev, Usein M; Ibragimov, Askhat G

    2000-01-01

    The published data on the synthesis of organoaluminium compounds involving metal complex catalysts are generalised and systematised. Hydro-, carbo- and cycloalumination reactions of alkenes, conjugated dienes and alkynes catalysed by Ti and Zr complexes are considered in detail. The use of organoaluminium reagents in organic synthesis and novel reactions involving these compounds are discussed. The bibliography includes 240 references.

  10. An Experiment on Isomerism in Metal-Amino Acid Complexes.

    Science.gov (United States)

    Harrison, R. Graeme; Nolan, Kevin B.

    1982-01-01

    Background information, laboratory procedures, and discussion of results are provided for syntheses of cobalt (III) complexes, I-III, illustrating three possible bonding modes of glycine to a metal ion (the complex cations II and III being linkage/geometric isomers). Includes spectrophotometric and potentiometric methods to distinguish among the…

  11. Syntheses, spectroscopic and thermal analyses of cyanide bridged heteronuclear polymeric complexes: [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine or N-ethylethylenediamine; Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II))

    Science.gov (United States)

    Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla

    2016-02-01

    Polymeric tetracyanonickelate(II) complexes of the type [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine (men) or N-ethylethylenediamine (neen); Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal and elemental analysis techniques. Additionally, FT-IR and Raman spectral analyses of men and neen have experimentally and theoretically investigated in the range of 4000-250 cm-1. The corresponding vibration assignments of men and neen are performed by using B3LYP density functional theory (DFT) method together with 6-31 G(d) basis set. The spectral features of the complexes suggest that the coordination environment of the M(II) ions are surrounded by the two symmetry related men and neen ligands and the two symmetry related N atom of cyanide groups, whereas the Ni(II) atoms are coordinated with a square-planar to four C atoms of the cyanide groups. Polymeric structures of the complexes consist of one dimensional alternative chains of [M(L)2]2+ and [Ni(CN)4]2- moieties. The thermal decompositions in the temperature range 30-700 °C of the complexes were investigated in the static air atmosphere.

  12. DFT study on metal-mediated uracil base pair complexes

    Directory of Open Access Journals (Sweden)

    Ayhan Üngördü

    2017-11-01

    Full Text Available The most stable of metal-mediated uracil base pair complexes were determined. Method was used density functional theory, B3LYP. The calculations of systems containing C, H, N, O were described by 6-311++G(d,p and cc-PVTZ basis sets and LANL2DZ and SDD basis sets was used for transition metals. Then Egap values of complexes were calculated and the electrical conductivity of the complexes for single nanowires was studied by band theory. Metal-mediated uracil base pair complexes which will be used as conductive wires in nanotechnology were predicted. In nanoworld, this study is expected to show a way for practical applications.

  13. Preparation and Characterization of Double Metal Cyanide Complex Catalysts

    Directory of Open Access Journals (Sweden)

    Weilin Guo

    2003-01-01

    Full Text Available A series of double metal cyanide (DMC complex catalysts were prepared in two different methods by using ß-cyclodextrin, PEG-1000 and Tween-60 as an additional complex ligands respectively. It was showed that a mixture of crystalline and amorphous DMC was synthesized by using traditional method in which the additional complex ligand was added after the precipitation of DMC. Amorphous and dispersed DMC with higher activity could be obtained when the additional complex ligand was added in the reactant solution before reaction. The effect of additional complex ligand and preparation method on the crystalline state and catalytic property of DMC were also investigated.

  14. Metal Complexes for Organic Optoelectronic Applications

    Science.gov (United States)

    Huang, Liang

    Organic optoelectronic devices have drawn extensive attention by over the past two decades. Two major applications for Organic optoelectronic devices are efficient organic photovoltaic devices(OPV) and organic light emitting diodes (OLED). Organic Solar cell has been proven to be compatible with the low cost, large area bulk processing technology and processed high absorption efficiencies compared to inorganic solar cells. Organic light emitting diodes are a promising approach for display and solid state lighting applications. To improve the efficiency, stability, and materials variety for organic optoelectronic devices, several emissive materials, absorber-type materials, and charge transporting materials were developed and employed in various device settings. Optical, electrical, and photophysical studies of the organic materials and their corresponding devices were thoroughly carried out. In this thesis, Chapter 1 provides an introduction to the background knowledge of OPV and OLED research fields presented. Chapter 2 discusses new porphyrin derivatives- azatetrabenzylporphyrins for OPV and near infrared OLED applications. A modified synthetic method is utilized to increase the reaction yield of the azatetrabenzylporphyrin materials and their photophysical properties, electrochemical properties are studied. OPV devices are also fabricated using Zinc azatetrabenzylporphyrin as donor materials. Pt(II) azatetrabenzylporphyrin were also synthesized and used in near infra-red OLED to achieve an emission over 800 nm with reasonable external quantum efficiencies. Chapter 3, discusses the synthesis, characterization, and device evaluation of a series of tetradentate platinum and palladium complexesfor single doped white OLED applications and RGB white OLED applications. Devices employing some of the developed emitters demonstrated impressively high external quantum efficiencies within the range of 22%-27% for various emitter concentrations. And the palladium complex, i

  15. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II ...

    Indian Academy of Sciences (India)

    Unknown

    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 and A KULANDAISAMY. Department of Chemistry, VHNSN College, Virudhunagar 626 001, India e-mail: ra_man@123india.com.

  16. Homogeneous Catalysis with Metal Complexes Fundamentals and Applications

    CERN Document Server

    Duca, Gheorghe

    2012-01-01

    The book about homogeneous catalysis with metal complexes deals with the description of the reductive-oxidative, metal complexes  in a liquid phase (in polar solvents, mainly in water, and less in nonpolar solvents). The exceptional importance of the redox processes in chemical systems, in the reactions occuring in living organisms, the environmental processes, atmosphere, water, soil, and in industrial technologies (especially in food-processing industries) is discussed. The detailed practical aspects of the established regularities are explained for solving the specific practical tasks in various fields of industrial chemistry, biochemistry, medicine, analytical chemistry and ecological chemistry. The main scope of the book is the survey and systematization of the latest advances in homogeneous catalysis with metal complexes. It gives an overview of the research results and practical experience accumulated by the author during the last decade.

  17. Complexation-induced supramolecular assembly drives metal-ion extraction.

    Science.gov (United States)

    Ellis, Ross J; Meridiano, Yannick; Muller, Julie; Berthon, Laurence; Guilbaud, Philippe; Zorz, Nicole; Antonio, Mark R; Demars, Thomas; Zemb, Thomas

    2014-09-26

    Combining experiment with theory reveals the role of self-assembly and complexation in metal-ion transfer through the water-oil interface. The coordinating metal salt Eu(NO3)3 was extracted from water into oil by a lipophilic neutral amphiphile. Molecular dynamics simulations were coupled to experimental spectroscopic and X-ray scattering techniques to investigate how local coordination interactions between the metal ion and ligands in the organic phase combine with long-range interactions to produce spontaneous changes in the solvent microstructure. Extraction of the Eu(3+)-3(NO3(-)) ion pairs involves incorporation of the "hard" metal complex into the core of "soft" aggregates. This seeds the formation of reverse micelles that draw the water and "free" amphiphile into nanoscale hydrophilic domains. The reverse micelles interact through attractive van der Waals interactions and coalesce into rod-shaped polynuclear Eu(III) -containing aggregates with metal centers bridged by nitrate. These preorganized hydrophilic domains, containing high densities of O-donor ligands and anions, provide improved Eu(III) solvation environments that help drive interfacial transfer, as is reflected by the increasing Eu(III) partitioning ratios (oil/aqueous) despite the organic phase approaching saturation. For the first time, this multiscale approach links metal-ion coordination with nanoscale structure to reveal the free-energy balance that drives the phase transfer of neutral metal salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Synthesis, spectroscopic and biological activities studies of acyclic and macrocyclic mono and binuclear metal complexes containing a hard-soft Schiff base.

    Science.gov (United States)

    Abou-Hussein, Azza A A; Linert, Wolfgang

    2012-09-01

    Mono- and bi-nuclear acyclic and macrocyclic complexes with hard-soft Schiff base, H(2)L, ligand derived from the reaction of 4,6-diacetylresorcinol and thiocabohydrazide, in the molar ratio 1:2 have been prepared. The H(2)L ligand reacts with Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and UO(2)(VI) nitrates, VO(IV) sulfate and Ru(III) chloride to get acyclic binuclear complexes except for VO(IV) and Ru(III) which gave acyclic mono-nuclear complexes. Reaction of the acyclic mono-nuclear VO(IV) and Ru(III) complexes with 4,6-diacetylresorcinol afforded the corresponding macrocyclic mono-nuclear VO(IV) and Ru(IIII) complexes. Template reactions of the 4,6-diacetylresorcinol and thiocarbohydrazide with either VO(IV) or Ru(III) salts afforded the macrocyclic binuclear VO(IV) and Ru(III) complexes. The Schiff base, H(2)L, ligand acts as dibasic with two NSO-tridentate sites and can coordinate with two metal ions to form binuclear complexes after the deprotonation of the hydrogen atoms of the phenolic groups in all the complexes, except in the case of the acyclic mononuclear Ru(III) and VO(IV) complexes, where the Schiff base behaves as neutral tetradentate chelate with N(2)S(2) donor atoms. The ligands and the metal complexes were characterized by elemental analysis, IR, UV-vis (1)H-NMR, thermal gravimetric analysis (TGA) and ESR, as well as the measurements of conductivity and magnetic moments at room temperature. Electronic spectra and magnetic moments of the complexes indicate the geometries of the metal centers are either tetrahedral, square planar or octahedral. Kinetic and thermodynamic parameters were calculated using Coats-Redfern equation, for the different thermal decomposition steps of the complexes. The ligands and the metal complexes were screened for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria, and Pseudomonas fluorescens as Gram-negative bacteria in addition to Fusarium oxysporum fungus. Most of the complexes exhibit

  19. Physicochemical and biological properties of new steroid metal complexes

    International Nuclear Information System (INIS)

    Huber, R.

    1980-04-01

    The aim of this investigation was to prepare stable steroid metal chelates by chemical conversion of the natural steroid hormones testerone, 5α-dihydrotestosterone (5α-DHT) and estradiol and to characterize these by means of their spectroscopic and other physico-chemical properties. In addition, various measuring techniques for the qualitative and quantitative study of complex stabilities and hydrolytic properties were employed. The distribution of some tritiated steroid metal complexes in the tissues of rats was tested using whole animal autoradiography, mainly with a view to identifying whether selective concentration occurs in certain organs. (orig.) [de

  20. Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage

    DEFF Research Database (Denmark)

    Moller, Kasper T.; Sheppard, Drew; Ravnsbaek, Dorthe B.

    2017-01-01

    Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds, which have fascinating structures, compositions and properties. Complex metal hydrides are a rapidly expanding class of materials, approaching multi-functionality, in particular within the energy storage...... inspiration to solve the great challenge of our time: efficient conversion and large-scale storage of renewable energy....... field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...

  1. THE THEORY OF DEVELOPMENT OF SUPPORTED METAL-COMPLEX CATALYSTS

    Directory of Open Access Journals (Sweden)

    T. L. Rakitskaya

    2015-06-01

    Full Text Available Some results of the investigations for the purpose of development of supported metal-complex catalysts for phosphine and carbon monoxide oxidation as well as for ozone decomposition are summarized. The activity of such catalysts has been found to depend not only on a nature of a central atom and ligands but also on a nature of supports. The theoretical model explaining mechanisms of surface complex formation taking into account the influence of physicochemical and structural-adsorption properties of the supports (SiO2, Al2O3, carbon materials, zeolites, dispersed silicas, lamellar aluminosilicates, etc. has been proposed. For quantitative description of the support effect, such a thermodynamic parameter as the adsorbed water activity assignable with the help of water vapor adsorption isotherms has been introduced. Successive stability constants of the surface metal complexes have been calculated by the kinetic method and, hence, compositions and partial catalytic activity of the latter have been determined. Taking into account the competitive adsorption of metal ions on the supports, some schemes of formation of surface bimetallic complexes have been suggested. The compositions of the supported metal-complex catalysts have been optimized to meet requirements of their use in respirators and plants for air purification from foregoing gaseous toxicants.

  2. Properties- and applications of quasicrystals and complex metallic alloys.

    Science.gov (United States)

    Dubois, Jean-Marie

    2012-10-21

    This article aims at an account of what is known about the potential for applications of quasicrystals and related compounds, the so-called family of Complex Metallic Alloys (CMAs‡). Attention is focused at aluminium-based CMAs, which comprise a large number of crystalline compounds and quasicrystals made of aluminium alloyed with transition metals (like Fe or Cu) or normal metals like Mg. Depending on composition, the structural complexity varies from a few atoms per unit cell up to thousands of atoms. Quasicrystals appear then as CMAs of ultimate complexity and exhibit a lattice that shows no periodicity anymore in the usual 3-dimensional space. Properties change dramatically with lattice complexity and turn the metal-type behaviour of simple Al-based crystals into a far more complex behaviour, with a fingerprint of semi-conductors that may be exploited in various applications, potential or realised. An account of the ones known to the author is given in the light of the relevant properties, namely light absorption, reduced adhesion and friction, heat insulation, reinforcement of composites for mechanical devices, and few more exotic ones. The role played by the search for applications of quasicrystals in the development of the field is briefly addressed in the concluding section.

  3. New hybrid materials as Zn(II) sorbents in water samples

    International Nuclear Information System (INIS)

    Perez-Quintanilla, Damian; Sanchez, Alfredo; Hierro, Isabel del; Fajardo, Mariano; Sierra, Isabel

    2010-01-01

    Mesoporous silicas have been chemically modified with 5-mercapto-1-methyltetrazole (MTTZ) obtaining hybrid materials denominated MTTZ-MSU-2 and MTTZ-HMS. These materials were employed as Zn(II) sorbents from aqueous media at room temperature. The effect of several variables (stirring time, pH, presence of other metals) has been studied using batch and column techniques. Flame atomic absorption spectrometry (FAAS) was used to determinate Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. The results indicate that under pH 8, the maximum adsorption value was 0.94 ± 0.01 and 0.72 ± 0.01 mmol Zn(II)/g for MTTZ-MSU-2 and MTTZ-HMS, respectively. In tap water samples, a preconcentration factor of 200 was obtained. On the basis of these results, it can be concluded that it is possible to modify chemically MSU-2 and HMS with 5-mercapto-1-methyltetrazole and to use the resulting modified mesoporous silica as an effective adsorbent for Zn(II) in aqueous media.

  4. Zeolites as supports for transition-metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    Le Van Mao, R

    1979-01-01

    The unique structural characteristics of the zeolites, including the presence of molecular-size cages and channels and of an internal electrostatic field, make them promising as supports for converting homogeneous to heterogeneous catalysts. The acidic sites on the zeolites may also contribute to catalysis of reactions, such as hydrocracking; may stabilize metal complexes in a highly disperse state; and may improve activity or selectivity. Recent studies on the synthesis of new types of zeolite-supported complexes of transition metals (TM), such as Co, Cu, Ag, Fe, Mo, Ru, Rh, Re, and Os, suggest the feasibility of the direct introduction of some TM complexes into the zeolitic cages during zeolite synthesis, especially during the crystallization phase. This method may considerably reduce the structural limitations associated with the incorporation of TM complexes into zeolites by conventional methods.

  5. New Transition metal assisted complex borohydrides for hydrogen storage

    International Nuclear Information System (INIS)

    Sesha Srinivasan; Elias Lee Stefanakos; Yogi Goswami

    2006-01-01

    High capacity hydrogen storage systems are indeed essential for the on-board vehicular application that leads to the pollution free environment. Apart from the various hydrogen storage systems explored in the past, complex hydrides involving light weight alkali/alkaline metals exhibits promising hydrogenation/ dehydrogenation characteristics. New transition metal assisted complex borohydrides [Zn(BH 4 ) 2 ] have been successfully synthesized by an inexpensive mechano-chemical process. These complex hydrides possesses gravimetric hydrogen storage capacity of ∼8.4 wt.% at around 120 C. We have determined the volumetric hydrogen absorption and desorption of these materials for a number of cycles. Another complex borohydride mixture LiBH 4 /MgH 2 catalyzed with ZnCl 2 has been synthesized and characterized using various analytical techniques. (authors)

  6. Chelation of Cu(II, Zn(II, and Fe(II by Tannin Constituents of Selected Edible Nuts

    Directory of Open Access Journals (Sweden)

    Magdalena Karamać

    2009-12-01

    Full Text Available The tannin fractions isolated from hazelnuts, walnuts and almonds were characterised by colorimetric assays and by an SE-HPLC technique. The complexation of Cu(II and Zn(II was determined by the reaction with tetramethylmurexide, whereas for Fe(II, ferrozine was employed. The walnut tannins exhibited a significantly weaker reaction with the vanillin/HCl reagent than hazelnut and almond tannins, but the protein precipitation capacity of the walnut fraction was high. The SE-HPLC chromatogram of the tannin fraction from hazelnuts revealed the presence of oligomers with higher molecular weights compared to that of almonds. Copper ions were most effectively chelated by the constituents of the tannin fractions of hazelnuts, walnuts and almonds. At a 0.2 mg/assay addition level, the walnut tannins complexed almost 100% Cu(II. The Fe(II complexation capacities of the tannin fractions of walnuts and hazelnuts were weaker in comparison to that of the almond tannin fraction, which at a 2.5 mg/assay addition level, bound Fe(II by ~90%. The capacity to chelate Zn(II was quite varied for the different nut tannin fractions: almond tannins bound as much as 84% Zn(II, whereas the value for walnut tannins was only 8.7%; and for hazelnut tannins, no Zn(II chelation took place at the levels tested.

  7. The metallic ratios as limits of complex valued transformations

    International Nuclear Information System (INIS)

    Falcon, Sergio; Plaza, Angel

    2009-01-01

    We study the presence of the metallic ratios as limits of two complex valued transformations. These complex variable functions are introduced and related with the two geometric antecedents for each triangle in a particular triangle partition, the four-triangle longest-edge (4TLE) partition. In this way, the fractality of a geometric diagram for the classes of dissimilar generated triangles is also explained.

  8. Anticancer Activity of Metal Complexes: Involvement of Redox Processes

    Science.gov (United States)

    Jungwirth, Ute; Kowol, Christian R.; Keppler, Bernhard K.; Hartinger, Christian G.; Berger, Walter; Heffeter, Petra

    2012-01-01

    Cells require tight regulation of the intracellular redox balance and consequently of reactive oxygen species for proper redox signaling and maintenance of metal (e.g., of iron and copper) homeostasis. In several diseases, including cancer, this balance is disturbed. Therefore, anticancer drugs targeting the redox systems, for example, glutathione and thioredoxin, have entered focus of interest. Anticancer metal complexes (platinum, gold, arsenic, ruthenium, rhodium, copper, vanadium, cobalt, manganese, gadolinium, and molybdenum) have been shown to strongly interact with or even disturb cellular redox homeostasis. In this context, especially the hypothesis of “activation by reduction” as well as the “hard and soft acids and bases” theory with respect to coordination of metal ions to cellular ligands represent important concepts to understand the molecular modes of action of anticancer metal drugs. The aim of this review is to highlight specific interactions of metal-based anticancer drugs with the cellular redox homeostasis and to explain this behavior by considering chemical properties of the respective anticancer metal complexes currently either in (pre)clinical development or in daily clinical routine in oncology. PMID:21275772

  9. The role of metal complexes in nuclear reactor decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Prince, A.A.M.; Raghavan, P.S.; Gopalan, R. [Madras Christian College, Tambaram, Chennai (India); Velmurugan, S.; Narasimhan, S.V. [Bhabha Atomic Research Center (BARC) (IN). Water and Steam Chemistry Lab. (WSCL)

    2006-07-15

    Chemical decontamination is the process of removal of radioactivity from corrosion products formed on structural materials in the nuclear reactors. These corrosion products cause problems for the operation and maintenance of the plants. Removal of the radioactive contaminants can be achieved by dissolving the oxide from the system surface using organic complexing agents in low concentrations known as dilute chemical decontamination (DCD) formulations. These organic complexing agents attack the oxide surface and form metal complexes, which further accelerate the dissolution process. The stability of the complexes plays an important role in dissolving the radioactive contaminated oxides. In addition, the DCD process is operated through ion exchange resins for the removal of the dissolved metal ions and radioactive nuclides. In the present study, the kinetics of dissolution of various model corrosion products such as magnetite (Fe{sub 3}O{sub 4}), hematite ({alpha}-Fe{sub 2}O{sub 3}) and maghemite ({gamma}-Fe{sub 2}O{sub 3}) have been studied in the presence of complexing agents such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminepentaacetic acid (HEEDTA), and 2,6 pyridinedicarboxylic acid (PDCA). The reductive roles of metal complexes and organic reducing agents are discussed. (orig.)

  10. Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Li, Juan [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Qiu, Zhuibai [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Xia, Zheng [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Li, Wei [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Yu, Lining; Chen, Hailin; Chen, Jianxing [NPFPC Key Laboratory of Contraceptives and Devices, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032 (China); Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China); Xie, Qiong, E-mail: xiejoanxq@gmail.com [Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032 (China); Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025 (China)

    2012-10-01

    The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC{sub 50} values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC{sub 50} values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

  11. Novel bis-(−)-nor-meptazinol derivatives act as dual binding site AChE inhibitors with metal-complexing property

    International Nuclear Information System (INIS)

    Zheng, Wei; Li, Juan; Qiu, Zhuibai; Xia, Zheng; Li, Wei; Yu, Lining; Chen, Hailin; Chen, Jianxing; Chen, Yan; Hu, Zhuqin; Zhou, Wei; Shao, Biyun; Cui, Yongyao; Xie, Qiong; Chen, Hongzhuan

    2012-01-01

    The strategy of dual binding site acetylcholinesterase (AChE) inhibition along with metal chelation may represent a promising direction for multi-targeted interventions in the pathophysiological processes of Alzheimer's disease (AD). In the present study, two derivatives (ZLA and ZLB) of a potent dual binding site AChE inhibitor bis-(−)-nor-meptazinol (bis-MEP) were designed and synthesized by introducing metal chelating pharmacophores into the middle chain of bis-MEP. They could inhibit human AChE activity with IC 50 values of 9.63 μM (for ZLA) and 8.64 μM (for ZLB), and prevent AChE-induced amyloid-β (Aβ) aggregation with IC 50 values of 49.1 μM (for ZLA) and 55.3 μM (for ZLB). In parallel, molecular docking analysis showed that they are capable of interacting with both the catalytic and peripheral anionic sites of AChE. Furthermore, they exhibited abilities to complex metal ions such as Cu(II) and Zn(II), and inhibit Aβ aggregation triggered by these metals. Collectively, these results suggest that ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency, and may be potential leads of value for further study on disease-modifying treatment of AD. -- Highlights: ► Two novel bis-(−)-nor-meptazinol derivatives are designed and synthesized. ► ZLA and ZLB may act as dual binding site AChEIs with metal-chelating potency. ► They are potential leads for disease-modifying treatment of Alzheimer's disease.

  12. Biodegradation of metal citrate complexes and implications for toxic-metal mobility

    International Nuclear Information System (INIS)

    Francis, A.J.; Dodge, C.J.; Gillow, J.B.

    1992-01-01

    The presence of synthetic and naturally occurring chelating agents in nuclear and toxic-metal wastes is a major concern because of their potential to enhance mobilization of metal ions away from the disposal sites. Of particular interest is citric acid, which is present in low-level and transuranic radioactive wastes and in domestic and industrial wastes (as washing fluids, for instance), as well as being found naturally. Citrate ions form multidentate, stable complexes with a variety of toxic metals and radionuclides; but biodegradation of these complexes, precipitating the metal ions as insoluble hydroxides, oxides or other salts, may retard migration. Here we report a study of the biodegradation of citrate complexes of Ca, Fe(II), Fe(III), Cd, Cu, Ni, Pb and U. Several of these complexes were not readily degraded by bacteria, and the biodegradability depended on the chemical nature of the complex, not on the toxicity of the metal to the bacteria. This resistance to biodegradation implies that citrate complexation may play an important part in migration of these hazardous wastes. (author)

  13. Method for synthesizing metal bis(borano) hypophosphite complexes

    Science.gov (United States)

    Cordaro, Joseph G.

    2013-06-18

    The present invention describes the synthesis of a family of metal bis(borano) hypophosphite complexes. One procedure described in detail is the syntheses of complexes beginning from phosphorus trichloride and sodium borohydride. Temperature, solvent, concentration, and atmosphere are all critical to ensure product formation. In the case of sodium bis(borano) hypophosphite, hydrogen gas was evolved upon heating at temperatures above 150.degree. C. Included in this family of materials are the salts of the alkali metals Li, Na and K, and those of the alkaline earth metals Mg and Ca. Hydrogen storage materials are possible. In particular the lithium salt, Li[PH.sub.2(BH.sub.3).sub.2], theoretically would contain nearly 12 wt % hydrogen. Analytical data for product characterization and thermal properties are given.

  14. Metathesis synthesis and characterization of complex metal fluoride ...

    Indian Academy of Sciences (India)

    Administrator

    V MANIVANNAN*, P PARHI and JONATHAN W KRAMER. Department of Mechanical Engineering, Campus Delivery 1374, Colorado State University, Fort Collins,. CO 80523, USA. MS received 30 April 2008. Abstract. Metathesis synthesis of complex metal fluorides using mechanochemical activation has been reported.

  15. DNA interactions and biocidal activity of metal complexes of ...

    Indian Academy of Sciences (India)

    Narendrula Vamsikrishna

    The Schiff bases and metal complexes were characterized by analytical and spectral methods like elemental analysis, ... cleavages.8–10 Cisplatin and its second generation com- ..... in DMSO. The test microorganisms were grown on nutrient agar medium in ...... effects on polymer characteristics Appl. Organomet. Chem.

  16. Dimeric Complexes of Tryptophan with M2+ Metal Ions

    NARCIS (Netherlands)

    Dunbar, R. C.; Steill, J. D.; Polfer, N. C.; Oomens, J.

    2009-01-01

    IRMPD spectroscopy using the FELIX free electron laser and a Fourier transform ICR mass spectrometer was used to characterize the structures of electrosprayed dimer complexes M(2+)Trp(2) of tryptophan with a series of eight doubly charged metal ions, including alkaline earths Ca, Sr, and Ba, and

  17. Sub-chronic toxicological studies of transition metal complexes of ...

    African Journals Online (AJOL)

    However, Naproxen metal complexes showed comparatively lower side effects than naproxen. Hematological report suggested that naproxen was in process of initiating inflammation which was justified by decreasing the mean value hemoglobin and hematocrit level and increasing the white blood cells level. There were ...

  18. Lability criteria for metal complexes in micro-electrode voltammetry

    NARCIS (Netherlands)

    Leeuwen, van H.P.; Pinheiro, J.P.

    1999-01-01

    Theoretical expressions are derived for the voltammetric lability criteria of metal complexes in the micro-electrode regime. The treatment includes three limiting situations: (i) the macro-electrode limit, where both the diffusion layer and the dissociation reaction layer are linear; (ii) an

  19. Schiff base transition metal complexes for Suzuki–Miyaura cross

    Indian Academy of Sciences (India)

    Schiff base ligand and its complex with iron (Fe), cobalt (Co), nickel (Ni) and copper (Cu) ions were synthesized using 4-aminoacetophenone and salicylaldehyde and characterized. FTIR spectrum shows that bidentate coordination of metal ions with ligand where O, N are electron donating sites of azomethine group.

  20. Group 4 Metal Complexes of Chelating Cyclopentadienyl-ketimide Ligands

    Czech Academy of Sciences Publication Activity Database

    Večeřa, M.; Varga, Vojtěch; Císařová, I.; Pinkas, Jiří; Kucharczyk, P.; Sedlařík, V.; Lamač, Martin

    2016-01-01

    Roč. 35, č. 5 (2016), s. 785-798 ISSN 0276-7333 R&D Projects: GA ČR(CZ) GA14-08531S; GA MŠk(CZ) LO1504 Institutional support: RVO:61388955 Keywords : group 4 metal complexes * cyclopentadienyl-ketimide ligands * metallocenes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.862, year: 2016

  1. Metal-isonitrile adducts for preparing radionuclide complexes

    International Nuclear Information System (INIS)

    Carpenter, A.P.; Linder, K.E.; Maheu, L.J.; Patz, M.A.; Thompson, J.S.; Tulip, T.H.; Subramanyam, V.

    1988-01-01

    An method for preparing a coordination complex of isonitrile ligand and a radioisotope of Te, Ru, Co, Pt, Re, Os, Ir, W, Re, Cr, Mo, Mn, Ni, Rh, Nb and Ta from a non-radioactive metal adduct of the isonitrile

  2. Carbonic anhydrase inhibitors. A general approach for the preparation of water-soluble sulfonamides incorporating polyamino-polycarboxylate tails and of their metal complexes possessing long-lasting, topical intraocular pressure-lowering properties.

    Science.gov (United States)

    Scozzafava, Andrea; Menabuoni, Luca; Mincione, Francesco; Supuran, Claudiu T

    2002-03-28

    Reaction of polyamino-polycarboxylic acids or their dianhydrides with aromatic/heterocyclic sulfonamides possessing a free amino/imino/hydrazino/hydroxy group afforded mono- and bis-sulfonamides containing polyamino-polycarboxylic acid moieties in their molecule. The acids/anhydrides used in synthesis included IDA, NTA, EDDA, EDTA and EDTA dianhydride, DTPA and DTPA dianhydride, EGTA and EGTA dianhydride, and EDDHA, among others. All the newly prepared derivatives showed strong affinity toward isozymes I, II, and IV of carbonic anhydrase (CA). Metal complexes of the new compounds have also been prepared. Metal ions used in such preparations included di- and trivalent main-group and transition cations, such as Zn(II), Cu(II), Al(III), etc. Some of the new sulfonamides/disulfonamides obtained in this way, as well as their metal complexes, behaved as nanomolar CA inhibitors against isozymes II and IV, being slightly less effective in inhibiting isozyme I. Some of these sulfonamides as well as their metal complexes strongly lowered intraocular pressure (IOP) when applied topically, directly into the normotensive/glaucomatous rabbit eye, as 1-2% water solutions/suspensions. The good water solubility of these sulfonamide CA inhibitors, correlated with the neutral pH of their water solutions used in the ophthalmologic applications and the long duration of action of the IOP-lowering effect, makes them interesting candidates for developing novel types of antiglaucoma drugs devoid of serious topical side effects.

  3. Biotransformation of uranium and transition metal citrate complexes by clostridia

    International Nuclear Information System (INIS)

    Francis, A.J.; Joshi-Tope, G.A.; Dodge, C.J.; Gillow, J.B.

    2002-01-01

    Clostridium sphenoides, which uses citric acid as its sole carbon source, metabolized equimolar Fe(III)-citrate with the degradation of citric acid and the reduction of Fe(III) to Fe(II), but not the U(VI)-citrate complex. However, in the presence of excess citric acid or added glucose it was reduced to U(IV)-citrate. In contrast, Clostridium sp., which ferments glucose but not citrate, reduced Fe(III)-citrate to Fe(II)-citrate and U(VI)-citrate to U(IV)-citrate only when supplied with glucose. These results show that complexed uranium is readily accessible as an electron acceptor despite the bacterium's inability to metabolize the organic ligand complexed to the actinide. These results also show that the metabolism of the metal-citrate complex depends upon the type of complex formed between the metal and citric acid. Fe(III) forms a bidentate complex with citric acid and was metabolized, whereas U forms a binuclear complex with citric acid and was recalcitrant. (author)

  4. Synthesis, Physical Characterization and Biological Activity of Some Schiff Base Complexes

    Directory of Open Access Journals (Sweden)

    R. Rajavel

    2008-01-01

    Full Text Available Structural modification of organic molecule has considerable biological relevance. Further, coordination of a biomolecules to the metal ions significantly alters the effectiveness of the biomolecules. In view of the antimicrobial activity ligand [bis-(2-aminobenzaldehyde] malonoyl dihydrazone], metal complexes with Cu(II, Ni(II, Zn(II and oxovanadium(IV have been synthesized and found to be potential antimicrobial agents. An attempt is also made to correlate the biological activities with geometry of the complexes. The complexes have been characterized by elemental analysis, molar conductance, spectra and cyclicvoltammetric measurements. The structural assessment of the complexes has been carried out based on electronic, infrared and molar conductivity values.

  5. Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions. Potentiometrische Untersuchungen der Komplexe von Tetracyclin (TC) und Oxytetracyclin (OTC) mit einigen Metall-Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Ghandour, M A; Azab, H A; Hassan, A; Ali, A M [Assiut Univ. (Egypt)

    1992-01-01

    The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO[sub 2](II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25[+-]0.1 deg C and [mu]=0.1 moll[sup -1] (NaNO[sub 3]). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO[sub 2](II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors).

  6. Intraparticulate Metal Speciation Analysis of Soft Complexing Nanoparticles. The Intrinsic Chemical Heterogeneity of Metal-Humic Acid Complexes

    DEFF Research Database (Denmark)

    Town, R. M.; van Leeuwen, Herman P.

    2016-01-01

    ion condensation potential for higher valency counterions within the intraparticulate double layer zone of the soft NP. The approach offers new insights into the intrinsic heterogeneity of the HA. complexes, as revealed by the intraparticulate speciation as a function of the true degree of inner......-sphere complexation, theta(M). The ensuing intrinsic heterogeneity parameters, Gamma, for CdHA and CuHA complexes are in very good agreement with those obtained from dynamic electrochemical stripping chronopotentiometric measurements. The overall intraparticulate metal ion speciation is found to depend on theta...

  7. Electrospray ionization mass spectrometric investigations of the complexation behavior of macrocyclic thiacrown ethers with bivalent transitional metals (Cu, Co, Ni and Zn).

    Science.gov (United States)

    Tsybizova, Alexandra; Tarábek, Ján; Buchta, Michal; Holý, Petr; Schröder, Detlef

    2012-10-15

    Heavy metals are both a problem for the environment and an important resource for industry. Their selective extraction by means of organic ligands therefore is an attractive topic. The coordination of three thiacrown ethers to late 3d-metal ions was investigated by a combination of electrospray ionization mass spectrometry (ESI-MS) and electron paramagnetic resonance (EPR). The mass spectrometric experiments were carried out in an ion trap mass spectrometer with an ESI source. Absolute binding constants were estimated by comparison with data for 18-crown-6/Na(+). EPR spectroscopy was used as a complementary method for investigating the Cu(I) /Cu(II) redox couple. The study found that thiacrown ethers preferentially bind traces of copper even at an excess of other metal ions (Co(II), Ni(II), and Zn(II)). The absolute association constants of the Cu(I) complexes were about 10(8) M(-1), and about two orders of magnitude lower for the other 3d-metal cations. The EPR spectra demonstrated that the reduction from Cu(II) to Cu(I) upon formation of the [(thiacrown)Cu](+) species takes place in solution. ESI-MS demonstrated that the three thiacrown ligands examined had high binding constants as well as good selectivities for copper(I) at low concentrations, and in the presence of other metal ions. By a combination of ESI-MS and EPR spectrometry it was shown that the reduction from Cu(II) to Cu(I) occurred in solution. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Structurally related hydrazone-based metal complexes with different antitumor activities variably induce apoptotic cell death.

    Science.gov (United States)

    Megger, Dominik A; Rosowski, Kristin; Radunsky, Christian; Kösters, Jutta; Sitek, Barbara; Müller, Jens

    2017-04-05

    Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl 2 (L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl 2 (L)] and [MnCl 2 (L)] are highly cytotoxic with EC 50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.

  9. Ibandronate metal complexes: solution behavior and antiparasitic activity.

    Science.gov (United States)

    Demoro, Bruno; Rostán, Santiago; Moncada, Mauricio; Li, Zhu-Hong; Docampo, Roberto; Olea Azar, Claudio; Maya, Juan Diego; Torres, Julia; Gambino, Dinorah; Otero, Lucía

    2018-03-01

    To face the high costs of developing new drugs, researchers in both industry and academy are looking for ways to repurpose old drugs for new uses. In this sense, bisphosphonates that are clinically used for bone diseases have been studied as agents against Trypanosoma cruzi, causative parasite of Chagas disease. In this work, the development of first row transition metal complexes (M = Co 2+ , Mn 2+ , Ni 2+ ) with the bisphosphonate ibandronate (iba, H 4 iba representing the neutral form) is presented. The in-solution behavior of the systems containing iba and the selected 3d metal ions was studied by potentiometry. Mononuclear complexes [M(H x iba)] (2-x)- (x = 0-3) and [M(Hiba) 2 ] 4- together with the formation of the neutral polynuclear species [M 2 iba] and [M 3 (Hiba) 2 ] were detected for all studied systems. In the solid state, complexes of the formula [M 3 (Hiba) 2 (H 2 O) 4 ]·6H 2 O were obtained and characterized. All obtained complexes, forming [M(Hiba)] - species under the conditions of the biological studies, were more active against the amastigote form of T. cruzi than the free iba, showing no toxicity in mammalian Vero cells. In addition, the same complexes were selective inhibitors of the parasitic farnesyl diphosphate synthase (FPPS) enzyme showing poor inhibition of the human one. However, the increase of the anti-T. cruzi activity upon coordination could not be explained neither through the inhibition of TcFPPS nor through the inhibition of TcSPPS (T. cruzi solanesyl-diphosphate synthase). The ability of the obtained metal complexes of catalyzing the generation of free radical species in the parasite could explain the observed anti-T. cruzi activity.

  10. Screening the efficient biological prospects of triazole allied mixed ligand metal complexes

    Science.gov (United States)

    Utthra, Ponnukalai Ponya; Kumaravel, Ganesan; Raman, Natarajan

    2017-12-01

    Triazole appended mixed ligand complexes (1-8) of the general formula [ML (bpy/phen)2]Cl2, where M = Cu(II), Co(II), Ni(II) and Zn(II), L = triazole appended Schiff base (E)sbnd N-(4-nitrobenzylidene)-1H-1,2,4-triazol-3-amine and bpy/phen = 2,2‧-bipyridine/1,10-phenanthroline, have been synthesized. The design and synthesis of this elaborate ligand has been performed with the aim of increasing stability and conjugation of 1,2,4 triazole, whose Schiff base derivatives are known as biologically active compounds thereby exploring their DNA binding affinity and other biological applications. The compounds have been comprehensively characterized by elemental analysis, spectroscopic methods (IR, UV-Vis, EPR, 1H and 13C NMR spectroscopy), ESI mass spectrometry and magnetic susceptibility measurements. The complexes were found to exhibit octahedral geometry. The complexes 1-8 were subjected to DNA binding techniques evaluated using UV-Vis absorption, CV, CD, Fluorescence spectroscopy and hydrodynamic measurements. Complex 5 showed a Kb value of 3.9 × 105 M-1. The DNA damaging efficacy for the complexes was observed to be high compared to the ligand. The antimicrobial screening of the compounds against bacterial and fungal strains indicates that the complexes possess excellent antimicrobial activity than the ligand. The overall biological activity of the complexes with phen as a co-ligand possessed superior potential than the ligand.

  11. Controlling Magnetism of a Complex Metallic System Using Atomic Individualism

    Science.gov (United States)

    Mudryk, Y.; Paudyal, D.; Pecharsky, V. K.; Gschneidner, K. A., Jr.; Misra, S.; Miller, G. J.

    2010-08-01

    When the complexity of a metallic compound reaches a certain level, a specific location in the structure may be critically responsible for a given fundamental property of a material while other locations may not play as much of a role in determining such a property. The first-principles theory has pinpointed a critical location in the framework of a complex intermetallic compound—Gd5Ge4—that resulted in a controlled alteration of the magnetism of this compound using precise chemical tools.

  12. Charge transfers in complex transition metal alloys (Ti2Fe)

    International Nuclear Information System (INIS)

    Abramovici, G.

    1998-01-01

    We introduce a new non-orthogonal tight-binding model, for complex alloys, in which electronic structure is characterized by charge transfers. We give the analytic calculation of a charge transfer, in which overlapping two-center terms are rigorously taken into account. Then, we apply numerically this result to an approximant phase of a quasicrystal of Ti 2 Fe alloy. This model is more particularly adapted to transition metals, and gives realistic densities of states. (orig.)

  13. The dynamic behavior of the exohedral transition metal complexes ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 7. The dynamic behavior of the exohedral transition metal complexes of B₄₀ : η⁶- and η⁷-B₄₀Cr(CO) ₃ and Cr(CO) ₃η⁷-B₄η₀-Cr(CO) ₃. NAIWRIT KARMODAK ELUVATHINGAL D JEMMIS. REGULAR ARTICLE Volume 129 Issue 7 July 2017 pp ...

  14. Comparative energies of Zn(II) cation localization as a function of the distance between two forming cation position aluminium ions in high-silica zeolites

    NARCIS (Netherlands)

    Kachurovskaya, N.A.; Zhidomirov, G.M.; van Santen, R.A.

    2004-01-01

    Periodical calcns. of Zn(II) metal cation stabilization in cationic positions with distantly placed aluminum ions has been performed for high-silica ferrierite. It was found that decrease of the stabilization energy at large distances between Al ions (more than 10 .ANG.) is about of 2 eV in

  15. Some transition metal ions complexes of tricine (Tn and amino acids: pH-titration, synthesis and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    M.E. Zayed

    2014-12-01

    Full Text Available Equilibrium studies have been carried out on complex formation of M(II (M = Co(II, Cu(II and Zn(II with tricine (Tn and L = amino acids in aqueous solution, at 25 °C and ionic strength of I = 0.1 M (NaNO3. The ternary complexes of amino acids are formed by simultaneous reactions. The concentration distribution of the complexes is evaluated. The solid complexes of [M(II–Tn–Histidine (Hist] have been synthesized and characterized by elemental analysis, infrared, magnetic and conductance measurements. The synthesized complexes have been screened for their antibacterial activities and the complexes show a significant antibacterial activity against four bacterial species: Staphylococcus aureus (Gram +ve, Streptococcus pyogenesr (Gram +ve, Serratia marcescens (Gram −ve and Escherichia coli (Gram −ve. The activity increases by increasing the concentration of the complexes.

  16. The impact of metal transport processes on bioavailability of free and complex metal ions in methanogenic granular sludge

    NARCIS (Netherlands)

    Bartacek, J.; Fermoso, F.G.; Vergeldt, F.; Gerkema, E.; Maca, J.; As, van H.; Lens, P.N.L.

    2012-01-01

    Bioavailability of metals in anaerobic granular sludge has been extensively studied, because it can have a major effect on metal limitation and metal toxicity to microorganisms present in the sludge. Bioavailability of metals can be manipulated by bonding to complexing molecules such as

  17. Mechanics of metal-catecholate complexes: The roles of coordination state and metal types

    Science.gov (United States)

    Xu, Zhiping

    2013-01-01

    There have been growing evidences for the critical roles of metal-coordination complexes in defining structural and mechanical properties of unmineralized biological materials, including hardness, toughness, and abrasion resistance. Their dynamic (e.g. pH-responsive, self-healable, reversible) properties inspire promising applications of synthetic materials following this concept. However, mechanics of these coordination crosslinks, which lays the ground for predictive and rational material design, has not yet been well addressed. Here we present a first-principles study of representative coordination complexes between metals and catechols. The results show that these crosslinks offer stiffness and strength near a covalent bond, which strongly depend on the coordination state and type of metals. This dependence is discussed by analyzing the nature of bonding between metals and catechols. The responsive mechanics of metal-coordination is further mapped from the single-molecule level to a networked material. The results presented here provide fundamental understanding and principles for material selection in metal-coordination-based applications. PMID:24107799

  18. Protection of metal artefacts with the formation of metal-oxalates complexes by Beauveria bassiana.

    Directory of Open Access Journals (Sweden)

    Edith eJoseph

    2012-01-01

    Full Text Available Several fungi present high tolerance to toxic metals and some are able to transform metals into metal-oxalate complexes. In this study, the ability of Beauveria bassiana to produce copper oxalates was evaluated in vitro. Growth performance was tested on various copper-containing media. B. bassiana proved highly resistant to copper, tolerating concentrations of up to 20 g.L-1, and precipitating copper oxalates on all media tested. Chromatographic analyses showed that this species produced oxalic acid as sole metal chelator. The production of metal-oxalates can be used in the restoration and conservation of archaeological and modern metal artefacts. The production of copper-oxalates was confirmed directly using metallic pieces (both archaeological and modern. The conversion of corrosion products into copper oxalates was demonstrated as well. In order to assess whether the capability of B. bassiana to produce metal-oxalates could be applied to other metals, iron and silver were tested as well. Iron appears to be directly sequestered in the wall of the fungal hyphae forming oxalates and probably goethite. However, the formation of a homogeneous layer on the object is not yet optimal. Silver nitrate was extracellularly reduced into nanoparticles of elemental silver by an unknown mechanism. The production of copper oxalates is immediately applicable for the conservation of copper-based artefacts. For iron and silver this is not yet the case. However, the vast ability of B. bassiana to transform toxic metals using different immobilization mechanisms seems to offer considerable possibilities for industrial applications, such as the bioremediation of contaminated soils or the green synthesis of chemicals.

  19. 40 CFR Appendix B to Part 414 - Complexed Metal-Bearing Waste Streams

    Science.gov (United States)

    2010-07-01

    ... 414—Complexed Metal-Bearing Waste Streams Chromium Azo dye intermediates/Substituted diazonium salts + coupling compounds Vat dyes Acid dyes Azo dyes, metallized/Azo dye + metal acetate Acid dyes, Azo...

  20. Metal ion effects on enolase activity

    International Nuclear Information System (INIS)

    Lee, M.E.; Nowak, T.

    1986-01-01

    Most metal binding studies with yeast enolase suggest that two metals per monomer are required for catalytic activity. The functions of metal I and metal II have not been unequivocally defined. In a series of kinetic experiments where the concentration of MgII is kept constant at subsaturating levels (1mM), the addition of MnII or of ZnII gives a hyperbolic decrease in activity. The final velocity of these mixed metal systems is the same velocity obtained with either only MnII or ZnII respectively. The concentration of MnII (40 μM) or of Zn (2μM) which gives half maximal effect in the presence of (1mM) MgII is approximately the same as the Km' value for MnII (9μM) or ZnII (3μM) respectively. Direct binding of MnII to enolase in the absence and presence of MgII shows that MnII and MgII compete for the same metal site on enolase. In the presence of 2-phosphoglycerate (2-PGA) and MgII, only a single site is occupied by MnII. Results suggest MnII at site I and MgII at site II. PRR and high resolution 1 H and 31 P NMR studies of enzyme-ligand complexes containing MnII and MgII and MnII are consistent with this model. 31 P measurements allow a measure of the equilibrium constant (0.36) for enolase. Saturation transfer measurements yield net rate constants (k/sub f/ = 0.49s -1 ; k/sub r/ = 1.3s -1 ) for the overall reaction. These values are smaller than k/sub cat/ (38s -1 ) measured under analogous conditions. The cation at site I appears to determine catalytic activity

  1. Late transition metal m-or chemistry and D6 metal complex photoeliminations

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Paul [Univ. of Missouri, Columbia, MO (United States)

    2015-07-31

    With the goal of understanding and controlling photoreductive elimination reactions from d6 transition metal complexes as part of a solar energy storage cycle we have investigated the photochemistry of Pt(IV) bromo, chloro, hydroxo, and hydroperoxo complexes. Photoreductive elimination reactions occur for all of these complexes and appear to involve initial Pt-Br, Pt-Cl, or Pt-O bond fission. In the case of Pt-OH bond fission, the subsequent chemistry can be controlled through hydrogen bonding to the hydroxo group.

  2. Metal Complexation with Chitosan and its Grafted Copolymer

    International Nuclear Information System (INIS)

    Abo-Hussen, A.A.; Elkholy, S.S.; Elsabee, M.Z.

    2005-01-01

    The adsorption of M (II); Co (II), Ni (If), Cu (II), Zn (II) and Cd (II) from aqueous solutions by chitosan flakes and beads have been studied. The maximum up-take of M (II) ions on chitosan beads was greater than on flakes. Batch adsorption experiments were carried out as a function of ph, agitation period and initial concentration of the metal ions. A ph of 6.0 was found to be optimum for M (II) adsorption on chitosan flakes and beads. The uptake of the ions was determined from the changes in its concentration, as measured by ultraviolet and visible spectroscopy. The metal ions uptake of chitosan grafted with vinyl pyridine (VP) is higher than that of the chitosan. The experimental data of the adsorption equilibrium from M (II)-solutions correlated well with the Langmuir and Freundlich equations. Several spectroscopic methods have been used to study the formation of the polymer/metal cation complex. The cation coordination is accompanied by proton displacement off the polymer or by fixation of a hydroxide ion in aqueous solutions. The largest ionic displacement is observed with Cu (II) and Zn (II) demonstrating the largest affinity of chitosan for these ions. The FT-IR spectral of the complexes show that both the amino and hydroxyl groups of chitosan participated in the chelation process. The ESR spectra of Cu-complex show an absorption at gi 2.06, g// = 2.23, A// x 10-4 (cm-1) = 160 and G = 3.8 indicating the formation of square planar structure. The adsorption of M (II) ions followed the sequence Cu (II) > Zn (II) > Cd (II) > Ni (II) > Co (II), this order seems to be independent on the size and the physical form of chitosan. SEM shows small membranous structure on the surface of chitosan flakes as compared to Cu (Il)- chitosan complex. EDTA was used for the desorption studies

  3. Organodioxygen complexes of some group 4B metal ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Akhter Hossain; Gino Mariotto

    2003-09-01

    Organodioxygen complexes of some group 4B metal ions, viz., zirconium(IV), tin(IV) and lead(II) containing monodentate, bidentate and tridentate ligands were synthesized and characterized. The complexes have the compositions of [Zr(O)(O 2 )2C 5 H 5 N.H 2 O], [Zr(O)(O 2 - ) 2 .2OPPh 3 ], [Sn(O 2 )(C 9 H 6 NO) 2 ], [Sn(0 2 ) 2 .(CH 2 ) 2 (NH 2 ) 2 ], [Pb(O 2 - )(C 5 H 5 N) 2 NO 3 ], [Pb(O 2 )(C 8 H 6 NOH)], [Pb(O 2 - )(det)NO 3 ] and [PbO 2 - ) (C 5 H 4 NCOOH)NO 3 .H 2 O]. Because of apparent linearity of M- O 2 grouping, the V 1 (O-O) stretching modes were only Raman active, giving bands at 810- 841 cm 1 for the peroxo complexes (1, 3, ,4 and 6), while the bands in the superoxo complexes (2, 5, 7 and 8) appeared at 1020- 1100 cm -1 . The peroxo complex of Zr(IV) containing monodentate ligands were found to oxidize trans-stilbene to trans-stilbene oxide under stoichiometric conditions. The organoperoxo complexes of tin and lead were insensitive to oxidative processes. (author)

  4. Infrared Spectroscopy of Metal Ion Complexes: Models for Metal Ligand Interactions and Solvation

    Science.gov (United States)

    Duncan, Michael

    2006-03-01

    Weakly bound complexes of the form M^+-Lx (M=Fe, Ni, Co, etc.; L=CO2, C2H2, H2O, benzene, N2) are prepared in supersonic molecular beams by laser vaporization in a pulsed-nozzle cluster source. These species are mass analyzed and size-selected in a reflectron time-of-flight mass spectrometer. Clusters are photodissociated at infrared wavelengths with a Nd:YAG pumped infrared optical parametric oscillator/amplifier (OPO/OPA) laser or with a tunable infrared free-electron laser. M^+-(CO2)x complexes absorb near the free CO2 asymmetric stretch near 2349 cm-1 but with an interesting size dependent variation in the resonances. Small clusters have blue-shifted resonances, while larger complexes have additional bands due to surface CO2 molecules not attached to the metal. M^+(C2H2)n complexes absorb near the C-H stretches in acetylene, but resonances in metal complexes are red-shifted with repect to the isolated molecule. Ni^+ and Co^+ complexes with acetylene undergo intracluster cyclization reactions to form cyclobutadiene. Transition metal water complexes are studied in the O-H stretch region, and partial rotational structure can be measured. M^+(benzene) and M^+(benzene)2 ions (M=V, Ti, Al) represent half-sandwich and sandwich species, whose spectra are measured near the free benzene modes. These new IR spectra and their assignments will be discussed as well as other new IR spectra for similar complexes.

  5. Chemical bonding of hydrogen molecules to transition metal complexes

    International Nuclear Information System (INIS)

    Kubas, G.J.

    1990-01-01

    The complex W(CO) 3 (PR 3 ) 2 (H 2 ) (CO = carbonyl; PR 3 = organophosphine) was prepared and was found to be a stable crystalline solid under ambient conditions from which the hydrogen can be reversibly removed in vacuum or under an inert atmosphere. The weakly bonded H 2 exchanges easily with D 2 . This complex represents the first stable compound containing intermolecular interaction of a sigma-bond (H-H) with a metal. The primary interaction is reported to be donation of electron density from the H 2 bonding electron pair to a vacant metal d-orbital. A series of complexes of molybdenum of the type Mo(CO)(H 2 )(R 2 PCH 2 CH 2 PR 2 ) 2 were prepared by varying the organophosphine substitutent to demonstrate that it is possible to bond either dihydrogen or dihydride by adjusting the electron-donating properties of the co-ligands. Results of infrared and NMR spectroscopic studies are reported. 20 refs., 5 fig

  6. Chemistry and Properties of Complex Intermetallics from Metallic Fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Kanatzidis, Mercouri G. [Northwestern Univ., Evanston, IL (United States)

    2015-03-28

    This project investigated the reaction chemistry and synthesis of new intermetallic materials with complex compositions and structures using metallic fluxes as solvents. It was found that the metallic fluxes offer several key advantages in facilitating the formation and crystal growth of new materials. The fluxes mostly explored were liquid aluminum, gallium and indium. The main purpose of this project was to exploit the potential of metallic fluxes as high temperature solvent for materials discovery in the broad class of intermetallics. This work opened new paths to compound formation. We discovered many new Si (or Ge)-based compounds with novel structures, bonding and physicochemical properties. We created new insights about the reaction chemistry that is responsible for stabilizing the new materials. We also studied the structural and compositional relationships to understand their properties. We investigated the use of Group-13 metals Al, Ga and In as solvents and have generated a wide variety of new results including several new ternary and quaternary materials with fascinating structures and properties as well as new insights as to how these systems are stabilized in the fluxes. The project focused on reactions of metals from the rare earth element family in combination with transition metals with Si and Ge. For example molten gallium has serves both as a reactive and non-reactive solvent in the preparation and crystallization of intermetallics in the system RE/M/Ga/Ge(Si). Molten indium behaves similarly in that it too is an excellent reaction medium, but it gives compounds that are different from those obtained from gallium. Some of the new phase identified in the aluminide class are complex phases and may be present in many advanced Al-matrix alloys. Such phases play a key role in determining (either beneficially or detrimentally) the mechanical properties of advanced Al-matrix alloys. This project enhanced our basic knowledge of the solid state chemistry

  7. Equilibrium modeling of mono and binary sorption of Cu(II and Zn(II onto chitosan gel beads

    Directory of Open Access Journals (Sweden)

    Nastaj Józef

    2016-12-01

    Full Text Available The objective of the work are in-depth experimental studies of Cu(II and Zn(II ion removal on chitosan gel beads from both one- and two-component water solutions at the temperature of 303 K. The optimal process conditions such as: pH value, dose of sorbent and contact time were determined. Based on the optimal process conditions, equilibrium and kinetic studies were carried out. The maximum sorption capacities equaled: 191.25 mg/g and 142.88 mg/g for Cu(II and Zn(II ions respectively, when the sorbent dose was 10 g/L and the pH of a solution was 5.0 for both heavy metal ions. One-component sorption equilibrium data were successfully presented for six of the most useful three-parameter equilibrium models: Langmuir-Freundlich, Redlich-Peterson, Sips, Koble-Corrigan, Hill and Toth. Extended forms of Langmuir-Freundlich, Koble-Corrigan and Sips models were also well fitted to the two-component equilibrium data obtained for different ratios of concentrations of Cu(II and Zn(II ions (1:1, 1:2, 2:1. Experimental sorption data were described by two kinetic models of the pseudo-first and pseudo-second order. Furthermore, an attempt to explain the mechanisms of the divalent metal ion sorption process on chitosan gel beads was undertaken.

  8. Complexation of metal ions with humic acid: charge neutralization model

    International Nuclear Information System (INIS)

    Kim, J.I.; Czerwinski, K.R.

    1995-01-01

    A number of different approaches are being used for describing the complexation equilibrium of actinide ions with humic or fulvic acid. The approach chosen and verified experimentally by Tu Muenchen will be discussed with notable examples from experiment. This approach is based on the conception that a given actinide ion is neutralized upon complexation with functional groups of humic or fulvic acid, e.g. carboxylic and phenolic groups, which are known as heterogeneously cross-linked polyelectrolytes. The photon energy transfer experiment with laser light excitation has shown that the actinide ion binding with the functional groups is certainly a chelation process accompanied by metal ion charge neutralization. This fact is in accordance with the experimental evidence of the postulated thermodynamic equilibrium reaction. The experimental results are found to be independent of origin of humic or fulvic acid and applicable for a broad range of pH. (authors). 23 refs., 7 figs., 1 tab

  9. Complexing agent and heavy metal removals from metal plating effluent by electrocoagulation with stainless steel electrodes.

    Science.gov (United States)

    Kabdaşli, Işik; Arslan, Tülin; Olmez-Hanci, Tuğba; Arslan-Alaton, Idil; Tünay, Olcay

    2009-06-15

    In the present study, the treatability of a metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation using stainless steel electrodes was experimentally investigated. The study focused on the effect of important operation parameters on electrocoagulation process performance in terms of organic complex former, nickel and zinc removals as well as sludge production and specific energy consumption. The results indicated that increasing the applied current density from 2.25 to 9.0 mA/cm(2) appreciably enhanced TOC removal efficiency from 20% to 66%, but a further increase in the applied current density to 56.25 mA/cm(2) did not accelerate TOC removal rates. Electrolyte concentration did not affect the process performance significantly and the highest TOC reduction (66%) accompanied with complete heavy metal removals were achieved at the original chloride content ( approximately 1500 mg Cl/L) of the wastewater sample. Nickel removal performance was adversely affected by the decrease of initial pH from its original value of 6. Optimum working conditions for electrocoagulation of metal plating effluent were established as follows: an applied current density of 9 mA/cm(2), the effluent's original electrolyte concentration and pH of the composite sample. TOC removal rates obtained for all electrocoagulation runs fitted pseudo-first-order kinetics very well (R(2)>92-99).

  10. Observation of metallic sphere–complex plasma interactions in microgravity

    International Nuclear Information System (INIS)

    Schwabe, M; Zhdanov, S; Hagl, T; Huber, P; Rubin-Zuzic, M; Zaehringer, E; Thomas, H M; Lipaev, A M; Molotkov, V I; Naumkin, V N; Fortov, V E; Vinogradov, P V

    2017-01-01

    The PK-3 Plus laboratory on board the International Space Station is used to study the interaction between metallic spheres and a complex plasma. We show that the metallic spheres significantly affect both the local plasma environment and the microparticle dynamics. The spheres charge under the influence of the plasma and repel the microparticles, forming cavities surrounding the spheres. The size of the cavity around a sphere is used to study the force balance acting on microparticles at the cavity edge. We show that the ion drag force and pressure force from other microparticles balances with the electric force acting from the sphere to within 20%. At intermediate distances from the sphere surface, the interaction between the microparticles and the metallic spheres is attractive due to the drag force stemming from the ions which are moving towards the highly charged spheres. The spheres thus strongly affect the plasma fluxes. This modification of the plasma flux can lead to an effective surface tension acting on the microparticles, and to the excitation of dust-density waves near the spheres, as the local electric field crosses a threshold. (paper)

  11. Designer ligands. Part 15. Synthesis and characterisation of novel Mn(lI), Ni(II) and Zn(II) complexes of 1,10-phenanthroline-derived ligands

    CSIR Research Space (South Africa)

    Wellington, Kevin W

    2009-01-01

    Full Text Available Series of manganese(II), nickel(II) and zinc(II) complexes have been prepared using 1,10-phenanthroline-derived ligands, and their coordination geometries have been assigned using infrared data. It is apparent that, depending on the ligand...

  12. Synthesis and photocatalytic studies of ZnS nanoparticles from heteroleptic complex of Zn(II) 1-cyano-1-carboethoxy-2,-2-ethylenedithiolato diisopropylthiourea and its adducts with N-donor ligands

    Science.gov (United States)

    Osuntokun, Jejenija; Ajibade, Peter A.; Onwudiwe, Damian C.

    2016-12-01

    Zinc complexes of the type [Zn(diptu)2(ced)] (1), [Zn(diptu)2(ced)py] (2), [Zn(diptu)2(ced)bpy] (3), and [Zn(diptu)2(ced)phen] (4), (where (diptu)2(ced) = 1-cyano-1-carboethoxyethylene-2,2-dithiolato-κS,S‧-bis(N,N-diisopropyllthiourea), py = pyridine, bpy = 2, 2‧ bipyridine and phen = 1, 10 phenanthroline have been synthesized and characterized by elemental analyses, Fourier transform infra-red (FTIR) and Nuclear magnetic resonance (NMR) spectroscopies. The parent complex (1) was formulated as four coordinate species, which gave rise to 5 coordinate complex in (2) and six coordinate compounds in (3) and (4), with the dithiolate acting as bidentate chelating ligand. The complexes were used as single-source precursors for the synthesis of HDA-capped ZnS nanoparticles. The nanoparticles gave different morphologies with sizes in the range of 1.92-4.72 nm as observed from the TEM analysis and supported by XRD. The UV-vis spectroscopy showed that all the ZnS nanoparticles are blue shifted, with respect to the bulk, which confirmed quantum confinement. The photoluminescence spectra showed narrow and broad emission peaks around 290 and 360 nm which are ascribed to spontaneous emission peaks from band to band transition and surface states respectively. Photocatalytic activities of all the nanoparticles were investigated with methylene blue (MB) acting as the organic dye, and the UV-vis spectral revealed a gradual decrease in absorption peak that confirmed the degradation of the MB.

  13. A new trinuclear Zn(II) complex {[Zn(μ-ONN)(μ.sub.2./sub.-O)(μ-OO)].sub.2./sub.Zn}: Synthesis, characterization, thermal decomposition and antibacterial activity

    Czech Academy of Sciences Publication Activity Database

    Far, B.S.; Grivani, G.; Khalaji, A.D.; Khorshidi, M.; Eigner, Václav; Dušek, Michal

    2017-01-01

    Roč. 28, č. 6 (2017), s. 3217-3227 ISSN 1040-7278 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : trinuclear complex * Schiff base * single-crystal structure analysis * ZnO nano particle * antibacterial activity Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.471, year: 2016

  14. Synthesis, Spectral Analysis and Preliminary in Vitro Evaluation of Some Tetrapyrrolic Complexes with 3d Metal Ions

    Directory of Open Access Journals (Sweden)

    Radu Socoteanu

    2015-08-01

    Full Text Available In this paper, two tetrapyrrolic complexes, Zn(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin and Cu(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin were synthesized, and characterized from a spectral and biological point of view. The study provided data concerning the behavior of identical external substituents vs. two different core insertions. Some of the properties of the proposed tetrapyrrolic structures were highlighted, having photodynamic therapy of cancer as a targeted biomedical application. Elemental analysis, NMR, FTIR and UV-Vis data in various solvents were provided. A preliminary in vitro study on normal and cancer cultured cells was carried out for biocompatibility assessment in dark conditions. The preliminary in vitro study performed on human peripheral mononuclear cells exposed to tetrapyrrolic compounds (2 µM showed that the proposed compounds had a convenient cytotoxic profile on human normal peripheral blood mononuclear cells under dark conditions. Meanwhile, the investigated compounds reduced the number of metabolically active breast tumor MCF-7 cells, with the exception of Zn(II complex-containing a symmetrical ligand. Accordingly, preliminary in vitro data suggest that the proposed tetrapyrrolic compounds are good candidates for PDT, as they limit tumor expansion even under dark conditions, whilst sparing normal cells.

  15. IRMPD Action Spectroscopy of Alkali Metal Cation-Cytosine Complexes: Effects of Alkali Metal Cation Size on Gas Phase Conformation

    NARCIS (Netherlands)

    Yang, B.; Wu, R.R.; Polfer, N.C.; Berden, G.; Oomens, J.; Rodgers, M.T.

    2013-01-01

    The gas-phase structures of alkali metal cation-cytosine complexes generated by electrospray ionization are probed via infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. IRMPD action spectra of five alkali metal cation-cytosine complexes exhibit both

  16. Porous carbon-coated ZnO nanoparticles derived from low carbon content formic acid-based Zn(II) metal-organic frameworks towards long cycle lithium-ion anode material

    International Nuclear Information System (INIS)

    Gao, Song; Fan, Ruiqing; Li, Bingjiang; Qiang, Liangsheng; Yang, Yulin

    2016-01-01

    Graphical abstract: The nanocomposites constructed from Zn-based MOFs exhibit low carbon content with super-high rate capability and long cycling life. - Highlights: • Novel ZnO@porous carbon matrix nanocomposites are constructed by pyrolysis of Zn-based MOFs. • The nanocomposites constructed with Zn-based MOFs show low carbon content. • The constructed nanocomposites exhibit high energy density, super-high rate capability and long cycling life. - Abstract: Single-C formic acid-based metal-organic frameworks (MOFs) are used to construct novel ZnO@porous carbon matrix nanocomposites by controlled pyrolysis. In the constructed nanocomposites, the porous carbon matrices act as a confined support to prevent agglomeration of the ZnO nanoparticles and create a rapid electron conductive network. Meanwhile, the well-defined, continuous porous structured MOFs provide a large specific surface area, which increases the contact of electrolyte-electrode and improves the penetration of electrolyte. Especially, the reasonable choice of formic acid-based MOFs construct the low carbon content composite, which contribute to the high energy density and long cycle life. The constructed nanocomposites show stable, ultrahigh rate lithium ion storage properties of 650 mAh g −1 at charge/discharge rate of 1 C even after 200 cycles.

  17. Hydrogen storage and evolution catalysed by metal hydride complexes.

    Science.gov (United States)

    Fukuzumi, Shunichi; Suenobu, Tomoyoshi

    2013-01-07

    The storage and evolution of hydrogen are catalysed by appropriate metal hydride complexes. Hydrogenation of carbon dioxide by hydrogen is catalysed by a [C,N] cyclometalated organoiridium complex, [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoic acid-κC(3))(OH(2))](2)SO(4) [Ir-OH(2)](2)SO(4), under atmospheric pressure of H(2) and CO(2) in weakly basic water (pH 7.5) at room temperature. The reverse reaction, i.e., hydrogen evolution from formate, is also catalysed by [Ir-OH(2)](+) in acidic water (pH 2.8) at room temperature. Thus, interconversion between hydrogen and formic acid in water at ambient temperature and pressure has been achieved by using [Ir-OH(2)](+) as an efficient catalyst in both directions depending on pH. The Ir complex [Ir-OH(2)](+) also catalyses regioselective hydrogenation of the oxidised form of β-nicotinamide adenine dinucleotide (NAD(+)) to produce the 1,4-reduced form (NADH) under atmospheric pressure of H(2) at room temperature in weakly basic water. In weakly acidic water, the complex [Ir-OH(2)](+) also catalyses the reverse reaction, i.e., hydrogen evolution from NADH to produce NAD(+) at room temperature. Thus, interconversion between NADH (and H(+)) and NAD(+) (and H(2)) has also been achieved by using [Ir-OH(2)](+) as an efficient catalyst and by changing pH. The iridium hydride complex formed by the reduction of [Ir-OH(2)](+) by H(2) and NADH is responsible for the hydrogen evolution. Photoirradiation (λ > 330 nm) of an aqueous solution of the Ir-hydride complex produced by the reduction of [Ir-OH(2)](+) with alcohols resulted in the quantitative conversion to a unique [C,C] cyclometalated Ir-hydride complex, which can catalyse hydrogen evolution from alcohols in a basic aqueous solution (pH 11.9). The catalytic mechanisms of the hydrogen storage and evolution are discussed by focusing on the reactivity of Ir-hydride complexes.

  18. Frustration across the periodic table: heterolytic cleavage of dihydrogen by metal complexes.

    Science.gov (United States)

    Bullock, R Morris; Chambers, Geoffrey M

    2017-08-28

    This perspective examines frustrated Lewis pairs (FLPs) in the context of heterolytic cleavage of H 2 by transition metal complexes, with an emphasis on molecular complexes bearing an intramolecular Lewis base. FLPs have traditionally been associated with main group compounds, yet many reactions of transition metal complexes support a broader classification of FLPs that includes certain types of transition metal complexes with reactivity resembling main group-based FLPs. This article surveys transition metal complexes that heterolytically cleave H 2 , which vary in the degree that the Lewis pairs within these systems interact. Many of the examples include complexes bearing a pendant amine functioning as the base with the metal functioning as the hydride acceptor. Consideration of transition metal compounds in the context of FLPs can inspire new innovations and improvements in transition metal catalysis.This article is part of the themed issue 'Frustrated Lewis pair chemistry'. © 2017 The Author(s).

  19. Oligomeric rare-earth metal cluster complexes with endohedral transition metal atoms

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, Simon; Zimmermann, Sina; Brühmann, Matthias; Meyer, Eva; Rustige, Christian; Wolberg, Marike; Daub, Kathrin; Bell, Thomas; Meyer, Gerd, E-mail: gerd.meyer@uni-koeln.de

    2014-11-15

    Comproportionation reactions of rare-earth metal trihalides (RX{sub 3}) with the respective rare-earth metals (R) and transition metals (T) led to the formation of 22 oligomeric R cluster halides encapsulating T, in 19 cases for the first time. The structures of these compounds were determined by single-crystal X-ray diffraction and are composed of trimers ((T{sub 3}R{sub 11})X{sub 15}-type, P6{sub 3}/m), tetramers ((T{sub 4}R{sub 16})X{sub 28}(R{sub 4}) (P-43m), (T{sub 4}R{sub 16})X{sub 20} (P4{sub 2}/nnm), (T{sub 4}R{sub 16})X{sub 24}(RX{sub 3}){sub 4} (I4{sub 1}/a) and (T{sub 4}R{sub 16})X{sub 23} (C2/m) types of structure) and pentamers ((Ru{sub 5}La{sub 14}){sub 2}Br{sub 39}, Cc) of (TR{sub r}){sub n} (n=2–5) clusters. These oligomers are further enveloped by inner (X{sup i}) as well as outer (X{sup a}) halido ligands, which possess diverse functionalities and interconnect like oligomers through i–i, i–a and/or a–i bridges. The general features of the crystal structures for these new compounds are discussed and compared to literature entries as well as different structure types with oligomeric T centered R clusters. Dimers and tetramers originating from the aggregation of (TR{sub 6}) octahedra via common edges are more frequent than trimers and pentamers, in which the (TR{sub r}) clusters share common faces. - Graphical abstract: Rare earth-metal cluster complexes with endohedral transition metal atoms (TR{sub 6}) may connect via common edges or faces to form dimers, trimers, tetramers and pentamers of which the tetramers are the most prolific. Packing effects and electron counts play an important role. - Highlights: • Rare-earth metal cluster complexes encapsulate transition metal atoms. • Oligomers are built via connection of octahedral clusters via common edges or faces. • Dimers through pentamers with closed structures are known. • Tetramers including a tetrahedron of endohedral atoms are the most prolific.

  20. Differential Binding of Co(II) and Zn(II) to Metallo-beta-Lactamase Bla2 from Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, M.; Breece, R; Hajdin, C; Bender, K; Hu, Z; Costello, A; Bennett, B; Tierney, D; Crowder, M

    2009-01-01

    In an effort to probe the structure, mechanism, and biochemical properties of metallo-{beta}-lactamase Bla2 from Bacillus anthracis, the enzyme was overexpressed, purified, and characterized. Metal analyses demonstrated that recombinant Bla2 tightly binds 1 equiv of Zn(II). Steady-state kinetic studies showed that mono-Zn(II) Bla2 (1Zn-Bla2) is active, while di-Zn(II) Bla2 (ZnZn-Bla2) was unstable. Catalytically, 1Zn-Bla2 behaves like the related enzymes CcrA and L1. In contrast, di-Co(II) Bla2 (CoCo-Bla2) is substantially more active than the mono-Co(II) analogue. Rapid kinetics and UV-vis, 1H NMR, EPR, and EXAFS spectroscopic studies show that Co(II) binding to Bla2 is distributed, while EXAFS shows that Zn(II) binding is sequential. To our knowledge, this is the first documented example of a Zn enzyme that binds Co(II) and Zn(II) via distinct mechanisms, underscoring the need to demonstrate transferability when extrapolating results on Co(II)-substituted proteins to the native Zn(II)-containing forms.

  1. Neutron diffraction studies of transition metal hydride complexes

    International Nuclear Information System (INIS)

    Koetzle, T.F.; Bau, R.

    1976-01-01

    Investigations of H 3 Ta(C 5 H 5 ) 2 (III), HW 2 (CO) 9 (NO) (IV), and HW 2 (CO) 8 (NO) (P(OCH 3 ) 3 ) (V) have been completed. Preliminary results are available for HFeCo 3 (CO) 9 [P(OCH 3 ) 3 ] 3 (VII). This work, together with studies of HMo 2 (C 5 H 5 ) 2 (CO) 4 (P(CH 3 ) 2 ) (VI) and [(C 2 H 5 ) 4 N] + [HCr 2 (CO) 10 ] - carried out at Argonne has led to some general observations on the geometry and the nature of bonding in these compounds. For example, in the structures of IV and V, both of which have bent W--H--W linkages (less than W--H--W in the range 125-130 0 ), there is conclusive evidence for the existence of a closed three-center W--H--W bond with significant metal-metal interaction. Such is the case, because extensions of the axial W--C and W--N bonds trans to the hydride intersect at a point near the center of the W--H--W triangle. The geometry of VI, which also contains a bent M--H--M bond, is consistent with that of IV and V. Bridging M--H bonds in these second- and third-row hydrides range in length from 1.85 to 1.89 A, compared to 1.75 A in the first-row polynuclear complex VII. For metals of corresponding rows, bridging M--H bonds are about 0.1 A longer than terminal bonds, which are classified as single covalent bonds

  2. Energetic Surface Smoothing of Complex Metal-Oxide Thin Films

    International Nuclear Information System (INIS)

    Willmott, P.R.; Herger, R.; Schlepuetz, C.M.; Martoccia, D.; Patterson, B.D.

    2006-01-01

    A novel energetic smoothing mechanism in the growth of complex metal-oxide thin films is reported from in situ kinetic studies of pulsed laser deposition of La 1-x Sr x MnO 3 on SrTiO 3 , using x-ray reflectivity. Below 50% monolayer coverage, prompt insertion of energetic impinging species into small-diameter islands causes them to break up to form daughter islands. This smoothing mechanism therefore inhibits the formation of large-diameter 2D islands and the seeding of 3D growth. Above 50% coverage, islands begin to coalesce and their breakup is thereby suppressed. The energy of the incident flux is instead rechanneled into enhanced surface diffusion, which leads to an increase in the effective surface temperature of ΔT≅500 K. These results have important implications on optimal conditions for nanoscale device fabrication using these materials

  3. Derivatized Pentadentate Macrocyclic Ligands and Their Transition Metal Complexes

    Directory of Open Access Journals (Sweden)

    Muhammad S. Khan

    2002-06-01

    Full Text Available The reaction of the pendant hydroxyethyl group in the planar pentadentate macrocyclic ligand,1,11-bis(2’-hydroxyethyl-4,8;12,16;17,21-trinitrilo-1,2,10,11-tetraazacyclohenicosa- 2,4,6,9,12,14,18,20-octaene (L2, derived from the condensation of 2,6-pyridinedialdehyde with 6,6’-bis(2’ hydroxyethylhydrazino -2,2’-bipyridine (L1, has been investigated. Esterification reactions are facile, and the reaction of the hydroxyethyl-substituted macrocycle with thionyl chloride yields a chloroethyl derivative. Metal complexes of the new derivatized macrocyclic ligands L3-6having general formula ML3-6X2.nH2O (M = Mn, Fe, Co, Ni, Cu, Zn are readily prepared.

  4. Electron spin resonance of radicals and metal complexes

    International Nuclear Information System (INIS)

    1993-01-01

    The materials are a collection of extended synopsis of papers presented at the conference sessions. The broad area of magnetic techniques applications has been described as well as their spectra interpretation methods. The ESR, NMR, ENDOR and spin echo were applied for studying the radiation and UV induced radicals in chemical and biological systems. Also in the study of complexes of metallic ions (having the paramagnetic properties) and their interaction with the matrix, the magnetic techniques has been commonly used. They are also very convenient tool for the study of reaction kinetics and mechanism as well as interaction of paramagnetic species with themselves and crystal lattice or with the surface as for thee catalytic processes

  5. Friction and solid-solid adhesion on complex metallic alloys

    Science.gov (United States)

    Dubois, Jean-Marie; Belin-Ferré, Esther

    2014-01-01

    The discovery in 1987 of stable quasicrystals in the Al–Cu–Fe system was soon exploited to patent specific coatings that showed reduced friction in ambient air against hard antagonists. Henceforth, it was possible to develop a number of applications, potential or commercially exploited to date, that will be alluded to in this topical review. A deeper understanding of the characteristics of complex metallic alloys (CMAs) may explain why material made of metals like Al, Cu and Fe offers reduced friction; low solid–solid adhesion came later. It is linked to the surface energy being significantly lower on those materials, in which translational symmetry has become a weak property, that is determined by the depth of the pseudo-gap at the Fermi energy. As a result, friction is anisotropic in CMAs that builds up according to the translation symmetry along one direction, but is aperiodic along the other two directions. A review is given in this article of the most salient data found along these lines during the past two decades or so. PMID:27877675

  6. A detailed in vitro study of naproxen metal complexes in quest of ...

    African Journals Online (AJOL)

    Md. Sharif Hasan

    2016-07-01

    Jul 1, 2016 ... possibilities of using Naproxen metal complexes for different therapeutic ..... FTIR spectra, scanning electron microscopy and HPLC study of Naproxen metal ..... aminobenzoic acid and 2-aminophenol and their coordination.

  7. Stimulated X-Ray Emission Spectroscopy in Transition Metal Complexes

    Science.gov (United States)

    Kroll, Thomas; Weninger, Clemens; Alonso-Mori, Roberto; Sokaras, Dimosthenis; Zhu, Diling; Mercadier, Laurent; Majety, Vinay P.; Marinelli, Agostino; Lutman, Alberto; Guetg, Marc W.; Decker, Franz-Josef; Boutet, Sébastien; Aquila, Andy; Koglin, Jason; Koralek, Jake; DePonte, Daniel P.; Kern, Jan; Fuller, Franklin D.; Pastor, Ernest; Fransson, Thomas; Zhang, Yu; Yano, Junko; Yachandra, Vittal K.; Rohringer, Nina; Bergmann, Uwe

    2018-03-01

    We report the observation and analysis of the gain curve of amplified K α x-ray emission from solutions of Mn(II) and Mn(VII) complexes using an x-ray free electron laser to create the 1 s core-hole population inversion. We find spectra at amplification levels extending over 4 orders of magnitude until saturation. We observe bandwidths below the Mn 1 s core-hole lifetime broadening in the onset of the stimulated emission. In the exponential amplification regime the resolution corrected spectral width of ˜1.7 eV FWHM is constant over 3 orders of magnitude, pointing to the buildup of transform limited pulses of ˜1 fs duration. Driving the amplification into saturation leads to broadening and a shift of the line. Importantly, the chemical sensitivity of the stimulated x-ray emission to the Mn oxidation state is preserved at power densities of ˜1020 W /cm2 for the incoming x-ray pulses. Differences in signal sensitivity and spectral information compared to conventional (spontaneous) x-ray emission spectroscopy are discussed. Our findings build a baseline for nonlinear x-ray spectroscopy for a wide range of transition metal complexes in inorganic chemistry, catalysis, and materials science.

  8. Co(II), Ni(II) and Zn(II)

    Indian Academy of Sciences (India)

    Unknown

    . .... In all the metal complexes, the azomethine group is shifted to lower .... According to Overtone's concept of cell permeability the lipid membrane that surrounds the cell favours the passage of only lipid soluble materials due to which ...

  9. Direct synthesis of metal complexes starting from zero-valent metals

    Energy Technology Data Exchange (ETDEWEB)

    Gojon-Zorrilla, Gabriel; Kharisov, Boris I. [Universidad Autonoma de Nuevo Leon, Monterrey, Nuevo Leon (Mexico); Garnovskii, Alexander D. [Institute of Physical and Organic Chemistry (Russian Federation)

    1996-06-01

    The recent (1980-1994) literature on metal-vapor synthesis of coordination and organometallic compounds is reviewed. An account is given of the high-and low-temperature reactions between free metal atoms and a large variety of substrates, mainly alkenes, alkynes, dienes, arenes, funtionalized arenes, alkyl halides {beta}-diketones and simple inorganic molecules. The main experimental methods are described, as well as the results obtained thereby. It is shown that in many instances these methods present significant advantages over conventional synthetic procedures, offering unique access to some metal complexes. [Spanish] Se reviso la literatura reciente (1980-1994) sobre la sintesis de compuestos de coordinacion y compuestos organometalicos a partir de vapores metalicos. Se examinan las reacciones de los atomos metalicos libres con una gran variedad de substratos, principalmente alquenos, alquinos, dienos, hidrocarburos aromaticos y sus derivados, haluros de alquilo y arilo, {beta}-dicetonas y moleculas inorganicas simples. Se presentan los principales metodos experimentales, asi como los resultados obtenidos; se concluye que la crisintesis presenta en muchos casos ventajas significativas sobre los procedimientos sinteticos tradicionales, constituyendo frecuentemente la unica opcion disponible.

  10. Group 12 dithiocarbamate complexes: Synthesis, spectral studies and their use as precursors for metal sulfides nanoparticles and nanocomposites

    Science.gov (United States)

    Ajibade, Peter A.; Ejelonu, Benjamin C.

    2013-09-01

    Zn(II), Cd(II) and Hg(II) dithiocarbamate complexes have been synthesized and characterized by elemental analysis, thermogravimetric analysis, UV-Vis, FTIR, 1H- and 13C NMR spectroscopy. The complexes were thermolysed at 180 °C and used as single molecule precursors for the synthesis of HDA capped ZnS, CdS and HgS nanoparticles and polymethylmethacrylate (PMMA) nanocomposites. The optical and structural properties of the nanoparticles and nanocomposites were studied by UV-Vis, PL, XRD and SEM. The crystallites sizes of the nanoparticles varied between 3.03 and 23.45 nm. SEM and EDX analyses of the nanocomposites confirmed the presence of the nanoparticles in the polymer matrix.

  11. Group 4 Metalloporphyrin diolato Complexes and Catalytic Application of Metalloporphyrins and Related Transition Metal Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Du, Guodong [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    -, bis-alkoxo, and chelating diolato complexes, depending on the identity of diols and the stoichiometry employed. It was also found that tin porphyrin complexes promoted the oxidative cleavage of vicinal diols and the oxidation of α-ketols to α-diketones with dioxygen. In extending the chemistry of metalloporphyrins and analogous complexes, a series of chiral tetraaza macrocyclic ligands and metal complexes were designed and synthesized. Examination of iron(II) complexes showed that they were efficient catalysts for the cyclopropanation of styrene by diazo reagents. Good yields and high diastereoselectivity were obtained with modest enantioselectivity. A rationalization of the stereoselectivity was presented on the basis of structural factors in a carbene intermediate.

  12. Synthesis and structural characterization of nickel(II), cobalt(II), Zinc(II), manganese(II), cadmium(II) and uranium(VI) complexes of α-oximinoacetoacet-o/p-anisidide thiosemicarbazone

    International Nuclear Information System (INIS)

    Patel, P.S.; Patel, M.M.; Ray, R.M.

    1993-01-01

    A few metal complexes of α-oximinoacetoacet-o/p-anisidide thiosemicarbazones (OAOATS)/(OAPATS) with Ni(II), Co(II), Zn(II), Mn(II), Hg(II), Cd(II) and UO 2 (II) have been prepared and characterized by elemental analyses, conductivity, differential scanning calorimetry study, thermogravimetric analyses and infrared and electronic spectral measurements in conjunction with magnetic susceptibility measurements at room temperature. They have also been tested for their antimicrobial activities. (author). 24 refs., 2 tabs

  13. Synthesis, spectroscopic, biological activity and thermal characterization of ceftazidime with transition metals

    Science.gov (United States)

    Masoud, Mamdouh S.; Ali, Alaa E.; Elasala, Gehan S.; Kolkaila, Sherif A.

    2018-03-01

    Synthesis, physicochemical characterization and thermal analysis of ceftazidime complexes with transition metals (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)) were discussed. It's obtained that ceftazidime act as bidentate ligand. From magnetic measurement and spectral data, octahedral structures were proposed for all complexes except for cobalt, nickel and mercury had tetrahedral structural. Hyper chemistry program confirmed binding sites of ceftazidime. Ceftazidime complexes show higher activity than ceftazidime for some strains. From TG and DTA curves the thermal decomposition mechanisms of ceftazidime and their metal complexes were suggested. The thermal decomposition of the complexes ended with the formation of metal oxides as a final product except in case of Hg complex.

  14. Photoluminescent properties of complex metal oxide nanopowders for gas sensing

    Science.gov (United States)

    Bovhyra, R. V.; Mudry, S. I.; Popovych, D. I.; Savka, S. S.; Serednytski, A. S.; Venhryn, Yu. I.

    2018-03-01

    This work carried out research on the features of photoluminescence of the mixed and complex metal oxide nanopowders (ZnO/TiO2, ZnO/SnO2, Zn2SiO4) in vacuum and gaseous ambient. The nanopowders were obtained using pulsed laser reactive technology. The synthesized nanoparticles were characterized by X-ray diffractometry, energy-dispersive X-ray analysis, and scanning and transmission electron microscopy analysis for their sizes, shapes and collocation. The influence of gas environment on the photoluminescence intensity was investigated. A change of ambient gas composition leads to a rather significant change in the intensity of the photoluminescence spectrum and its deformation. The most significant changes in the photoluminescent spectrum were observed for mixed ZnO/TiO2 nanopowders. This obviously is the result of a redistribution of existing centers of luminescence and the appearance of new adsorption centers of luminescence on the surface of nanopowders. The investigated nanopowders can be effectively used as sensing materials for the construction of the multi-component photoluminescent sensing matrix.

  15. Self-assembled systems of water soluble metal 8-hydroxyquinolates with surfactants and conjugated polyelectrolytes

    DEFF Research Database (Denmark)

    Burrows, Hugh D.; Costa, Telma; Luisa Ramos, M.

    2016-01-01

    We have studied the interaction of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the metal ions Al(III) and Zn(II) in aqueous solution in the presence of tetraalkylammonium surfactants using UV/vis absorption, fluorescence, NMR spectroscopy and electrical conductivity measurements, complemented by ...... assembly between the conjugated polyelectrolyte and the metal/8-HQS complex, as demonstrated by electronic energy transfer. The potential of these systems in sensing, light harvesting, and electron injection/transport layers in organic semiconductor devices is discussed....

  16. Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

    Directory of Open Access Journals (Sweden)

    Poomalai Jayaseelan

    2016-09-01

    Full Text Available A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II, Ni(II, Co(II and Mn(II complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi.

  17. SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A Zn(II COORDINATION POLYMER BASED ON 4,4’-BIPYRIDINE AND ACETATO

    Directory of Open Access Journals (Sweden)

    LI-HUA WANG

    2015-05-01

    Full Text Available A novel Zn(II coordination polymer, [Zn(bpy(acetato2]n (bpy = 4,4’-bipyridine, has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Zn(II coordination polymer is triclinic, space group P-1 with a = 8.046(3 Å, b = 9.161(3 Å, c = 10.663(3 Å, α = 109.769(4º, β = 99.966(5º, γ = 101.666(5º, V= 699.1(4 Å3, Z = 2, Dc = 1.614 mg·m-3, μ = 1.774 mm-1, F(000 = 348, and final R1 = 0.0541, ωR2 = 0.1605. X-ray diffraction analysis reveals that the Zn(II center is six-coordination with a N2O4 distorted octahedral coordination environment. The Zn(II complex forms 1D chain structure by the bridge of 4,4’-bipyridine and acetato.

  18. Hydrogen storage in metal hydrides and complex hydrides; Wasserstoffspeicherung in Metall- und komplexen Hydriden - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bielmann, M.; Zuettel, A.

    2007-07-01

    This final report for the Swiss Federal Office of Energy (SFOE), reports on work done in 2007 at the Swiss Federal Laboratories for Materials Science and Technology EMPA on the storage of hydrogen in metal hydrides and complex hydrides. In particular, the use of tetrahydroborates is noted. The potential of this class of materials is stressed. The structures at room-temperature were examined using neutron and X-ray diffraction methods. Thermodynamic methods helped determine the thermodynamic stability of the materials. Also, a complete energy diagram for the materials was developed. The use of silicon oxide to reduce activation energy and its catalytic effects are discussed. The challenges placed by desorption mechanisms are noted. The authors note that reversibility is basically proven.

  19. Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline.

    Science.gov (United States)

    Patel, Yogesh S

    2014-01-01

    Novel oligomer metal complexes (2a-f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesized compounds 1 and 2a-f were evaluated for their antibacterial and antifungal activity. The results showed significantly higher antibacterial and antifungal activity of oligomer metal complexes compared to the ligand.

  20. Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand

    Energy Technology Data Exchange (ETDEWEB)

    Mruthyunjayaswamy, B.H.M.; Ijare, Omkar B.; Jadegoud, Y. [Gulbarga University (India). Dept. of Chemistry]. E-mail: bhmmswamy53@rediffmail.com

    2005-07-15

    A phenol based novel macrocyclic binucleating compartmental ligand N,N-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. The complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of Cu(II), Ni(II), Co(II), Cd(II), Zn(II) and Hg(II) in methanol to get a series of dinuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, ESR, NMR and FAB mass spectral data. The dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, ESR and FAB mass spectral data. The ligand as well as Cu(II), Ni(II), Co(II) and Zn(II) complexes were tested for their antibacterial and antifungal properties against Escherichia coli, Staphyloccocus aureus, Aspergillus niger and Fusarium oxysporum. Magnetic susceptibility measurements of Cu(II), Ni(II) and Co(II) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. FAB mass spectrum of the Cu(II) complex gave a clear evidence for the dinuclear nature. The ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus Fusarium oxysporum. (author)

  1. Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand

    International Nuclear Information System (INIS)

    Mruthyunjayaswamy, B.H.M.; Ijare, Omkar B.; Jadegoud, Y.

    2005-01-01

    A phenol based novel macrocyclic binucleating compartmental ligand N,N-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. The complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of Cu(II), Ni(II), Co(II), Cd(II), Zn(II) and Hg(II) in methanol to get a series of dinuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, ESR, NMR and FAB mass spectral data. The dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, ESR and FAB mass spectral data. The ligand as well as Cu(II), Ni(II), Co(II) and Zn(II) complexes were tested for their antibacterial and antifungal properties against Escherichia coli, Staphyloccocus aureus, Aspergillus niger and Fusarium oxysporum. Magnetic susceptibility measurements of Cu(II), Ni(II) and Co(II) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. FAB mass spectrum of the Cu(II) complex gave a clear evidence for the dinuclear nature. The ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus Fusarium oxysporum. (author)

  2. Heterobimetallic coordination polymers involving 3d metal complexes and heavier transition metals cyanometallates

    Energy Technology Data Exchange (ETDEWEB)

    Peresypkina, Eugenia V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Samsonenko, Denis G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Vostrikova, Kira E., E-mail: vosk@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); LMI, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France)

    2015-04-15

    The results of the first steps in the design of coordination polymers based on penta- and heptacyanometallates of heavier d transitions metals are presented. The 2D structure of the coordination polymers: [(Mn(acacen)){sub 2}Ru(NO)(CN){sub 5}]{sub n} and two complexes composed of different cyanorhenates, [Ni(cyclam)]{sub 2}[ReO(OH)(CN){sub 4}](ClO{sub 4}){sub 2}(H{sub 2}O){sub 1.25} and [Cu(cyclam)]{sub 2}[Re(CN){sub 7}](H{sub 2}O){sub 12}, was confirmed by single crystal XRD study, the rhenium oxidation state having been proved by the magnetic measurements. An amorphism of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} (M=Ni, Cu) polymers does not allow to define strictly their dimensionality and to model anisotropic magnetic behavior of the compounds. However, with high probability a honey-comb like layer structure could be expected for [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} complexes, studied in this work, because such an arrangement is the most common among the bimetallic assemblies of hexa- and octacyanometallates with a ratio [M(cyclam)]/[M(CN){sub n}]=3/2. For the first time was prepared and fully characterized a precursor (n-Bu{sub 4}N){sub 2}[Ru(NO)(CN){sub 5}], soluble in organic media. - Graphical abstract: The very first results in the design of 2D coordination polymers based on penta- and heptacyanometallates of 4d and5d transitions metals are presented. - Highlights: • Design of coordination polymers based on penta- and heptacyanometallates. • New Ru and Re cyanide based heterobimetallic coordination complexes. • Hydrolysis and ox/red processes involving [Re(CN){sub 7}]{sup 3+} during crystallization. • High magnetic anisotropy of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2}(H{sub 2}O){sub n}, M=Cu, Ni, complexes.

  3. On the possibility of removing of transition metal ions from sewage using polymeric complexes

    International Nuclear Information System (INIS)

    Tazhibaeva, S.M.; Abilov, Zh.A.; Musabekov, K.V.

    1997-01-01

    The possibility of using of complexation in the system polyethylene-imine transition metal ions (Cu 2+ , Ni 2+ , Co 2+ )-surface active substance for removing of metal ions from solution and sewage has been investigated. It is shown, that pH of medium, hydro-fugitive of system and ratio between component of the triply complex effect on purification of solution. (author)

  4. Complexation with dissolved organic matter and solubility control of heavy metals in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Lofts, S.; Tipping, E.; Riemsdijk, van W.H.

    2002-01-01

    The complexation of heavy metals with dissolved organic matter (DOM) in the environment influences the solubility and mobility of these metals. In this paper, we measured the complexation of Cu, Cd, Zn, Ni, and Pb with DOM in the soil solution at pH 3.7-6.1 using a Donnan membrane technique. The

  5. Reactivity of olefin and allyl ligands in π-complexes of metals

    International Nuclear Information System (INIS)

    Kukushkin, Yu.N.

    1987-01-01

    The data on reactivity of olefin and allyl ligands in transition metal (Ru, W) π-complexes, published up to 1984 are presented. Metal ion coordination of olefins causes their appreciable reactivity change. Transformations of π-olefin ligands into σ-alkyl ones, interaction of π-complexes with oxygen nucleophilic reagents, amines, halogenides and pseudohalogenides are considered

  6. Studies on Oligomer Metal Complexes Derived from Bisamic Acid of Pyromellitic Dianhydride and 4-Bromoaniline

    OpenAIRE

    Patel, Yogesh S.

    2014-01-01

    Novel oligomer metal complexes (2a–f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesi...

  7. Colour interceptions, thermal stability and surface morphology of polyester metal complexes

    International Nuclear Information System (INIS)

    Zohdy, M.H.

    2005-01-01

    Chelating copolymers via grafting of acrylic acid (AAc) and acrylamide (AAm/AAc) comonomer mixture onto polyester micro fiber fabrics (PETMF) using gamma-radiation technique were prepared. The prepared graft chains (PETMF-g-AAc) and (PETMF-g-PAAc/PAAm) acted as chelating sites for some selected transition metal ions. The prepared graft copolymers and their metal complexes were characterized using thermogravimetric analysis (TGA), colour parameters and surface morphology measurements. The colour interception and strength measurements showed that the metal complexation is homogeneously distributed. The results showed that the thermal stability of PETMF was improved after graft copolymerization and metal complexes. Moreover, the degree of grafting enhanced the thermal stability values of the grafted and complexed copolymers up to 25% of magnitude, on the other hand the activation energy of the grafted-copolymer with acrylic acid increased up to 80%. The SEM observation gives further supports to the homogenous distribution of grafting and metal complexation

  8. Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyldiazenyl-2-((p-tolyliminomethylphenol

    Directory of Open Access Journals (Sweden)

    C. Anitha

    2013-01-01

    Full Text Available Azo Schiff base complexes of VO(II, Mn(II, Co(II, Ni(II, Cu(II, and Zn(II have been synthesized from 4-((4-chlorophenyldiazenyl-2-((p-tolyliminomethylphenol (CDTMP. The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis, 1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate. SEM image of copper(II complex implies the crystalline state and surface morphology of the complex.

  9. Structure investigation, spectral, thermal, X-ray and mass characterization of piroxicam and its metal complexes

    Science.gov (United States)

    Zayed, M. A.; Nour El-Dien, F. A.; Mohamed, Gehad G.; El-Gamel, Nadia E. A.

    2004-10-01

    [M(H 2L) 2](A) 2. yH 2O (where H 2L: neutral piroxicam (Pir), A: Cl - in case of Ni(II) or acetate anion in case of Cu(II) and Zn(II) ions and y=0-2.5) and [M(H 2L) 3](A) z. yH 2O (A: SO 42- in case of Fe(II) ion ( z=1) or Cl - in case of Fe(III) ( z=3) and Co(II) ions ( z=2) and y=1-4) chelates are prepared and characterized using elemental analyses, IR, magnetic and electronic reflectance measurements, mass spectra and thermal analyses. IR spectra reveal that Pir behaves a neutral bidentate ligand coordinated to the metal ions through the pyridyl-N and carbonyl-O of the amide moiety. The reflectance and magnetic moment measurements reveal that these chelates have tetrahedral, square planar and octahedral geometrical structures. Mass spectra and thermal analyses are also used to confirm the proposed formulae and the possible fragments resulted from fragmentation of Pir and its chelates. The thermal behaviour of the chelates (TGA and DTA) are discussed in detail and the thermal stability of the anhydrous chelates follow the order Ni(II)≅Cu(II)

  10. On the capacity to the complexing of alkaline earth metal and magnesium chromates

    International Nuclear Information System (INIS)

    Orekhov, O.L.

    1978-01-01

    Considered is the capacity to the complexing of magnesium chromates and alkaline earth metal chromates with ammonium chromates in aqueous solutions. It has been established that the complexing of alkaline earth metal and magnesium chromates is effected by a nature of initial salts as well as their solubilities and the presence of crystallization water. Capacity of magnesium ions and alkaline rare earth metals to the complexing decreases in a series of Mg-Ca-Sr-Ba. Ca complexes exceed magnesium derivatives in respect of stability

  11. Speciation Studies of Some Toxic Metal Complexes of Glycylglycine ...

    African Journals Online (AJOL)

    NICO

    mixtures apart from its established utility in understanding ... Chemical speciation of metals is important for an understand- ... Titrations with differ- ent ratios (1:2.5, 1:3.5 and 1:5) of metal-ligand were performed with 0.4 mol L–1 sodium hydroxide solution. The mixtures obtained from PG and water are non-ideal due.

  12. Multiheteromacrocycles that Complex Metal Ions. Sixth Progress Report, 1 May 1979-30 April 1980

    Science.gov (United States)

    Cram, D. J.

    1980-01-15

    Objective is to design synthesize, and evaluate cyclic and polycyclic host organic compounds for their 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; number of binding sites; character of binding sites; and valences. During this period, hemispherands based on an aryloxy or cyclic urea unit, spherands based on aryloxyl units only, and their complexes with alkali metals and alkaline earths were investigated. An attempt to separate {sup 6}Li and {sup 7}Li by gel permeation chromatography of lithiospherium chloride failed. (DLC)

  13. Structure and catalytic properties of metal β-diketonate complexes with oxygen-containing compounds

    International Nuclear Information System (INIS)

    Nizel'skij, Yu.N.; Ishchenko, S.S.; Lipatova, T.Eh.

    1985-01-01

    The results of researches published in recent 15-20 years of complexes of metal β-diketonates (including Cr 3+ , VO 2+ , MoOΛ2 2+ , Co 3+ , Mn 3+ , Ni 2+ , Fe 3+ ) with oxygen-containing compounds (alcohols, glycols, phenols, hydroperoxides, aldehydes, esters, etc.) playing an important role in catalytic processes of oxidation, addition, polymerization and copolymerization are reviewed. Data on the nature of chemical bond of oxygen-containing reacting agents with metal β-diketonates, on structure of metal β-diketonate complexes with oxygen-containing reacting agents and thermodynamics of complexing as well as on activation of reacting agents in complexes and catalytic properties of metal β-diketonates are discussed. Stored materials make it possible to exercise directed control of metal β-diketonate activity

  14. Synthesis, characterization, in-vitro antimicrobial properties, molecular docking and DFT studies of 3-{(E-[(4,6-dimethylpyrimidin-2-ylimino]methyl} naphthalen-2-ol and Heteroleptic Mn(II, Co(II, Ni(II and Zn(II complexes

    Directory of Open Access Journals (Sweden)

    Chioma Festus

    2018-03-01

    Full Text Available Heteroleptic divalent metal complexes [M(L (bipy(Y]•nH2O (where M = Mn, Co, Ni, and Zn; L = Schiff base; bipy = 2,2’-bipyridine; Y = OAc and n = 0, 1 have been synthesized from pyrimidine Schiff base ligand 3-{(E-[(4,6-dimethylpyrimidin-2-ylimino]methyl} naphthalen-2-ol, 2,2’-bipyridine and metal(II acetate salts. The Schiff base and its complexes were characterized by analytical (CHN elemental analyses, solubility, melting point, conductivity measurements, spectral (IR, UV-vis, 1H and 13C-NMR and MS and magnetometry. The elemental analyses, Uv-vis spectra and room temperature magnetic moment data provide evidence of six coordinated octahedral geometry for the complexes. The metal complexes’ low molar conductivity values in dimethylsulphoxide suggested that they were non-ionic in nature. The compounds displayed moderate to good antimicrobial and antifungal activities against S. aureus, P. aeruginosa, E. coli, B. cereus, P. mirabilis, K. oxytoca, A. niger, A. flevus and R. Stolonifer. The compounds also exhibited good antioxidant potentials with ferrous ion chelation and, 1-diphenyl-2-picryl-hydrazyl (DPPH radical scavenging assays. Molecular docking studies showed a good interaction with drug targets used. The structural and electronic properties of complexes were further confirmed by density functional theory calculations.

  15. studies on transition metal complexes of herbicidal compounds. ii

    African Journals Online (AJOL)

    a

    derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ) --- a well known herbicide has ... development while the other is the metal ion associated degradation or deactivation of the herbicides .... Colour M.p./decomp.

  16. Electron Spin Resonance Studies of Carbonic Anhydrase: Transition Metal Ions and Spin-Labeled Sulfonamides*

    Science.gov (United States)

    Taylor, June S.; Mushak, Paul; Coleman, Joseph E.

    1970-01-01

    Electron spin resonance (esr) spectra of Cu(II) and Co(II) carbonic anhydrase, and a spin-labeled sulfonamide complex of the Zn(II) enzyme, are reported. The coordination geometry of Cu(II) bound in the enzyme appears to have approximately axial symmetry. Esr spectra of enzyme complexes with metal-binding anions also show axial symmetry and greater covalency, in the order ethoxzolamide cyanide complex suggests the presence of two, and probably three, equivalent nitrogen ligands from the protein. Esr spectra of the Co(II) enzyme and its complexes show two types of Co(II) environment, one typical of the native enzyme and the 1:1 CN- complex, and one typical of a 2:1 CN- complex. Co(II) in the 2:1 complex appears to be low-spin and probably has a coordination number of 5. Binding of a spin-labeled sulfonamide to the active center immobilizes the free radical. The similarity of the esr spectra of spin-labeled Zn(II) and Co(II) carbonic anhydrases suggests that the conformation at the active center is similar in the two metal derivatives. PMID:4320976

  17. Transition metal complexes with oxygen donor ligands: a synthesis, spectral, thermal and antimicrobial study

    Directory of Open Access Journals (Sweden)

    VAIBHAV N. PATANGE

    2008-10-01

    Full Text Available Transition metal complexes of chalcones derived from the conden¬sation of 3-acetyl-6-methyl-2H-pyran-2,4(3H-dione (dehydroacetic acid and p-methoxybenzaldehyde (HL1 or p-nitrobenzaldehyde (HL2 were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR, UV–Vis spectroscopy and a microbial study. From the analytical and thermal data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand. The molar conductance data revealed that all the metal chelates were non-electrolytes. The thermal stability of the complexes was studied by thermogravimetry and the decomposition schemes of the complexes are given. The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.

  18. Determination of stability constants of aminoglycoside antibiotics with their metal complexes

    Science.gov (United States)

    Tiwow, Vanny M. A.

    2014-03-01

    One group of aminoglycoside antibiotics contains aminosugars. The aminosugar neomycin B with its derivate product neamine (2-Deoxy-4-0-(2,6-diamino-2,6-dideoxy-α-D-glucopyranosyl)-D-Streptamine) was identified as a free ligands and metal complexes. In particular, the stability constants of metal complexes by potentiometric titration techniques were investigated. Our previous study had determined the acid dissociation constants of these aminosugars with few metal complexes in fair depth. In this work, the complexation of two pyridine-containing amino alcohols and an amino sugar (neamine) have been measured potentiometrically. For instance, the stability constant of copper(II) complexation were determine and the model system generated an excellent fit. Stability constants with several metals have been determined and will be reported.

  19. Potentiometric and spectroscopic study of the interaction of 3d transition metal ions with inositol hexakisphosphate

    Science.gov (United States)

    Veiga, Nicolás; Macho, Israel; Gómez, Kerman; González, Gabriel; Kremer, Carlos; Torres, Julia

    2015-10-01

    Among myo-inositol phosphates, the most abundant in nature is the myo-inositol hexakisphosphate, InsP6. Although it is known to be vital to cell functioning, the biochemical research into its metabolism needs chemical and structural analysis of all the protonation, complexation and precipitation processes that it undergoes in the biological media. In view of its high negative charge at physiological level, our group has been leading a thorough research into the InsP6 chemical and structural behavior in the presence of the alkali and alkaline earth metal ions essential for life. The aim of this article is to extend these studies, dealing with the chemical and structural features of the InsP6 interaction with biologically relevant 3d transition metal ions (Fe(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)), in a non-interacting medium and under simulated physiological conditions. The metal-complex stability constants were determined by potentiometry, showing under ligand-excess conditions the formation of mononuclear species in different protonation states. Under metal ion excess, polymetallic species were detected for Fe(II), Fe(III), Zn(II) and Cu(II). Additionally, the 31P NMR and UV-vis spectroscopic studies provided interesting structural aspects of the strong metal ion-InsP6 interaction.

  20. Metal-ion complexes of functionalised 1,10-Phenanthrolines as hydrolytic synzymes

    NARCIS (Netherlands)

    Weijnen, J.G.J.

    1993-01-01

    In this thesis metal-ion complexes of functionalised 1,10-phenanthroline derivatives have been studied as model systems for hydrolytic metallo-enzymes. Amphiphilic metallo- complexes incorporated into micelles or vesicles and water-soluble complexes in pure aqueous buffer solutions, have

  1. Synthesis, spectral, thermal, potentiometric and antimicrobial studies of transition metal complexes of tridentate ligand

    Directory of Open Access Journals (Sweden)

    Sarika M. Jadhav

    2014-01-01

    Full Text Available A series of metal complexes of Cu(II, Ni(II, Co(II, Fe(III and Mn(II have been synthesized with newly synthesized biologically active tridentate ligand. The ligand was synthesized by condensation of dehydroacetic acid (3-acetyl-6-methyl-(2H pyran-2,4(3H-dione or DHA, o-phenylene diamine and fluoro benzaldehyde and characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, 1H-NMR, UV–Vis spectroscopy and mass spectra. From the analytical data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand with octahedral geometry. The molar conductance values suggest the non-electrolyte nature of metal complexes. The IR spectral data suggest that the ligand behaves as a dibasic tridentate ligand with ONN donor atoms sequence towards central metal ion. Thermal behaviour (TG/DTA and kinetic parameters calculated by the Coats–Redfern and Horowitz–Metzger method suggest more ordered activated state in complex formation. To investigate the relationship between stability constants of metal complexes and antimicrobial activity, the dissociation constants of Schiff bases and stability constants of their binary metal complexes have been determined potentiometrically in THF–water (60:40% solution at 25 ± 1 °C and at 0.1 M NaClO4 ionic strength. The potentiometric study suggests 1:1 and 1:2 complexation. Antibacterial and antifungal activities in vitro were performed against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma, respectively. The stability constants of the metal complexes were calculated by the Irving–Rosotti method. A relation between the stability constant and antimicrobial activity of complexes has been discussed. It is observed that the activity enhances upon complexation and the order of antifungal activity is in accordance with stability order of metal ions.

  2. Adsorption of Zn(II) and Cd(II) ions in batch system by using the Eichhornia crassipes.

    Science.gov (United States)

    Módenes, A N; Espinoza-Quiñones, F R; Borba, C E; Trigueros, D E G; Lavarda, F L; Abugderah, M M; Kroumov, A D

    2011-01-01

    In this work, the displacement effects on the sorption capacities of zinc and cadmium ions of the Eichornia crassipes-type biosorbent in batch binary system has been studied. Preliminary single metal sorption experiments were carried out. An improvement on the Zn(II) and Cd(II) ions removal was achieved by working at 30 °C temperature and with non-uniform biosorbent grain sizes. A 60 min equilibrium time was achieved for both Zn(II) and Cd(II) ions. Furthermore, it was found that the overall kinetic data were best described by the pseudo second-order kinetic model. Classical multi-component adsorption isotherms have been tested as well as a modified extended Langmuir isotherm model, showing good agreement with the equilibrium binary data. Around 0.65 mequiv./g maximum metal uptake associated with the E. crassipes biosorbent was attained and the E. crassipes biosorbent has shown higher adsorption affinity for the zinc ions than for the cadmium ones in the binary system.

  3. Self-Assembly of Discrete Metal Complexes in Aqueous Solution via Block Copolypeptide Amphiphiles

    Directory of Open Access Journals (Sweden)

    Timothy J. Deming

    2013-01-01

    Full Text Available The integration of discrete metal complexes has been attracting significant interest due to the potential of these materials for soft metal-metal interactions and supramolecular assembly. Additionally, block copolypeptide amphiphiles have been investigated concerning their capacity for self-assembly into structures such as nanoparticles, nanosheets and nanofibers. In this study, we combined these two concepts by investigating the self-assembly of discrete metal complexes in aqueous solution using block copolypeptides. Normally, discrete metal complexes such as [Au(CN2]−, when molecularly dispersed in water, cannot interact with one another. Our results demonstrated, however, that the addition of block copolypeptide amphiphiles such as K183L19 to [Au(CN2]− solutions induced one-dimensional integration of the discrete metal complex, resulting in photoluminescence originating from multinuclear complexes with metal-metal interactions. Transmission electron microscopy (TEM showed a fibrous nanostructure with lengths and widths of approximately 100 and 20 nm, respectively, which grew to form advanced nanoarchitectures, including those resembling the weave patterns of Waraji (traditional Japanese straw sandals. This concept of combining block copolypeptide amphiphiles with discrete coordination compounds allows the design of flexible and functional supramolecular coordination systems in water.

  4. Synthesis, crystal structures, spectral, thermal and antimicrobial properties of new Zn(II) 5-iodo- and 5-bromosalicylates

    Science.gov (United States)

    Košická, Petra; Győryová, Katarína; Smolko, Lukáš; Gyepes, Róbert; Hudecová, Daniela

    2018-03-01

    Two new analogous zinc(II) complexes containing 5-iodo- and 5-bromosalicylate ligands, respectively, were prepared in single-crystal form and characterized by IR spectroscopy, thermal analysis and elemental analysis. The solid-state structures of prepared complexes were determined by single crystal X-ray crystallography. Both complexes are isostructural and their crystal structures composed of neutral molecules [Zn(5-Xsal)2(H2O)2] (where X = Br, I, sal = salicylato). Central Zn(II) atom is in both complexes coordinated by six oxygen atoms, four of which are from two chelate bonded 5-halosalicylates and remaining two from coordinated water molecules. The found chelate binding mode is in line with the Δ values calculated from IR spectral data. Antimicrobial activity of prepared complexes was studied against selected bacteria, yeast and filamentous fungi. Obtained results indicate that 5-iodosalicylate complex is more antimicrobially active than its 5-bromo substituted analogue.

  5. Lanthanide Single-Molecule Magnets Framed by Alkali Metals & Magnetic and Spectroscopic Studies of 3d Transition Metal Complexes

    DEFF Research Database (Denmark)

    Konstantatos, Andreas

    -molecule magnets (SMMs). Starting from the archetype SMM Mn12 we present the details of the mechanisms governing the relaxation of the magnetization of these systems. In Chapter 2 we present our work on the coordination chemistry of lanthanides with a new Schiff-base ligand, H3L [(E)-3-((2-hydroxyphenyl...... complexes of M3+ or M2+ metal ions (M: 3d transition metal) with the preference to either approximate octahedral or trigonal prismatic coordination geometry. A detailed magnetic characterization for most of the complexes is presented where a trinuclear Co2+ cluster stands out for its pronounced SMM...

  6. Theoretical investigation, biological evaluation and VEGFR2 kinase studies of metal(II) complexes derived from hydrotris(methimazolyl)borate.

    Science.gov (United States)

    Jayakumar, S; Mahendiran, D; Srinivasan, T; Mohanraj, G; Kalilur Rahiman, A

    2016-02-01

    The reaction of soft tripodal scorpionate ligand, sodium hydrotris(methimazolyl)borate with M(ClO4)2·6H2O [MMn(II), Ni(II), Cu(II) or Zn(II)] in methanol leads to the cleavage of B-N bond followed by the formation of complexes of the type [M(MeimzH)4](ClO4)2·H2O (1-4), where MeimzH=methimazole. All the complexes were fully characterized by spectro-analytical techniques. The molecular structure of the zinc(II) complex (4) was determined by X-ray crystallography, which supports the observed deboronation reaction in the scorpionate ligand with tetrahedral geometry around zinc(II) ion. The electronic spectra of complexes suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complex. Frontier molecular orbital analysis (HOMO-LUMO) was carried out by B3LYP/6-31G(d) to understand the charge transfer occurring in the molecules. All the complexes exhibit significant antimicrobial activity against Gram (-ve) and Gram (+ve) bacterial as well as fungal strains, which are quite comparable to standard drugs streptomycin and clotrimazole. The copper(II) complex (3) showed excellent free radical scavenging activity against DPPH in all concentration with IC50 value of 30μg/mL, when compared to the other complexes. In the molecular docking studies, all the complexes showed hydrophobic, π-π and hydrogen bonding interactions with BSA. The cytotoxic activity of the complexes against human hepatocellular liver carcinoma (HepG2) cells was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Synthesis and characterization of transition metal complexes derived from some biologically active furoic acid hydrazones

    Directory of Open Access Journals (Sweden)

    P. Venkateswar Rao

    2007-04-01

    Full Text Available Two new physiologically active ligands, N’-2-[(E-1-hydroxy-4-methyl-2-oxo-2H-8-chromenyl ethylidene-2-furan carbohydrazide (HMCFCH and N’-2-[(Z-1-(4-hydroxy-6-methyl-2-oxo-2H-pyranyl ethylidene]-furan carbohydrazide (HMPFCH and their VO(II, Mn(II, Fe(II, Co(II, Ni(II and Cu(II complexes have been prepared. The ligands and the metal complexes have been characterized by elemental analyses, electrical conductance, magnetic susceptibility measurements, UV-Vis, IR, and ESR spectroscopic data. Basing on the above data, Fe(II and Co(II complexes of HMCFCH and HMPFCH have been assigned a dimeric octahedral geometry. VO(II complexes of HMCFCH and HMPFCH have been assigned sulfate bridged dimeric square pyramidal geometry. Mn(II complex of HMCFCH has been assigned a dimeric octahedral geometry, where as Mn(II complex of HMPFCH has been ascribed to monomeric octahedral geometry. Cu(II and Ni(II complexes of HMCFCH have been ascribed to a polymeric structure. Ni(II complex of HMPFCH has been assigned a dimeric square planar geometry. Cu(II complex of HMPFCH has been proposed an octahedral geometry. The ligands and their metal chelates were screened against S. aureus and P. aeruginosa. The ligands and the metal complexes have been found to be active against these microorganisms. The ligands show more activity than the metal complexes.

  8. Transition metal M(II complexes with isonicotinoylhydrazone-9-anthraldehyde

    Directory of Open Access Journals (Sweden)

    Dianu M.L.

    2010-01-01

    Full Text Available New complexes of isonicotinoylhydrazone-9-anthraldehyde with Cu(II, Co(II and Ni(II have been prepared and characterized by analytical and physico-chemical techniques, such as elemental and thermal analyses, magnetic susceptibility and conductivity measurements, and electronic, EPR and IR spectral studies. The infrared spectral studies revealed the bidentate or monodentate nature of the Schiff base in the complexes; the pyridine nitrogen does not participate in the coordination. A tetrahedral geometry is suggested for the nitrate-complexes and an octahedral geometry for the others. Thermal studies support the chemical formulation of these complexes.

  9. Effects of complexing compounds on sorption of metal ions to cement

    Energy Technology Data Exchange (ETDEWEB)

    Loevgren, Lars [Umeaa Univ. (Sweden). Inorganic chemistry

    2005-12-15

    This present report is a literature review addressing the effects of complexing ligands on the sorption of radionuclides to solid materials of importance for repositories of radioactive waste. Focus is put on laboratory studies of metal ion adsorption to cement in presence of chelating agents under strongly alkaline conditions. As background information, metal sorption to different mineral and cement phases in ligand free systems is described. Furthermore, surface complexation model (SCM) theories are introduced. According to surface complexation theories these interactions occur at specific binding sites at the particle/water interface. Adsorption of cationic metals is stronger at high pH, and the adsorption of anions occurs preferentially at low pH. The adsorption of ions to mineral surfaces is a result of both chemical bonding and electrostatic attraction between the ions and charged mineral surfaces. By combining uptake data with spectroscopic information the sorption can be explained on a molecular level by structurally sound surface complexation models. Most of the metal sorption studies reviewed are dealing with minerals exhibiting oxygen atoms at their surfaces, mainly oxides of Fe(II,III) and Al(III), and aluminosilicates. Investigations of radionuclides are focused on clay minerals, above all montmorillonite and illite. Which mechanism that is governing the metal ion adsorption to a given mineral is to a large extent depending on the metal adsorbed. For instance, sorption of Ni to montmorillonite can occur by formation of inner-sphere mononuclear surface complexes located at the edges of montmorillonite platelets and by formation of a Ni phyllosilicate phase parallel to montmorillonite layers. Also metal uptake to cement materials can occur by different mechanisms. Cationic metals can both be attached to cement (calcium silicate hydrate, CSH) and hardened cement paste (HCP) by formation of inner-sphere complexes at specific surface sites and by

  10. Physicochemical properties of 3,4,5-trimethoxybenzoates of Mn(II, Co(II, Ni(II and Zn(II

    Directory of Open Access Journals (Sweden)

    W. FERENC

    2005-09-01

    Full Text Available The complexes of Mn(II, Co(II, Ni(II, Cu(II and Zn(II with 3,4,5-trimethoxybenzoic acid anion of the formula: M(C10H11O52·nH2O, where n = 6 for Ni(II, n = 1 for Mn(II, Co(II, Cu(II, and n = 0 for Zn, have been synthesized and characterized by elemental analysis, IR spectroscopy, X–ray diffraction measurements, thermogravimetry and magnetic studies. They are crystalline compounds characterized by various symmetry. They decompose in various ways when heated in air to 1273 K. At first, they dehydrate in one step and form anhydrous salts. The final products of decomposition are oxides of the respective metals (Mn2O3, Co3O4, NiO, CuO, ZnO. The solubilities of the analysed complexes in water at 293 K are in the orders of 10-2 – 10-4 mol dm-3. The magnetic susceptibilities of the Mn(II, Co(II, Ni(II and Cu(II complexes were measured over the range of 76–303 K and the magnetic moments were calculated. The results show that the 3,4,5-trimethoxybenzoates of Mn(II, Co(II and Ni(II are high-spin complexes but that of Cu(II forms a dimer [Cu2(C10H11O54(H2O2]. The carboxylate groups bind as monodentate or bidentate chelating or bridging ligands.

  11. Reactions of transition metal complexes with cyclic ethers

    International Nuclear Information System (INIS)

    Milstein, D.

    1977-02-01

    Three novel reactions of epoxides with homogeneous transition-metal catalysts have been explored: (a) the selective rearrangement of internal epoxides to ketones; (b) the cleavage of C-C bond in epoxides having electron-attracting substituents; (c) the transformation of terminal epoxides into esters. Based on an intensive kinetic study, a general mechanism for the transformations of epoxides is postulated

  12. Biological activities of some Fluoroquinolones-metal complexes

    African Journals Online (AJOL)

    McRoy

    Background: Metal ions play a vital role in the design of more biologically active drugs. Aim: The paper reviewed the .... 2H2O by direct reaction of copper(II) sulphate pentahydrate with ciprofloxacin in distilled water. ... membered ring and the chloride ion completes the seven coordination around the Ca2+ion.[37-39].

  13. Theoretical NMR spectroscopy of N-heterocyclic carbenes and their metal complexes

    KAUST Repository

    Falivene, Laura; Cavallo, Luigi

    2016-01-01

    Recent theoretical analysis of the NMR properties of free N-heterocyclic carbenes (NHC) and Metal-NHC complexes has complemented experiments, allowing the establishment of structure/property relationships and the rationalization of otherwise

  14. Basic deuteroexchange in complexes of transition metals with nitrogen-containing aromatic heterocycles

    International Nuclear Information System (INIS)

    Tupitsyn, I.F.

    1986-01-01

    A study was made of the kinetics of deuteroexchange in the methyl group in complexes of one metal [nickel(II)] with different methyl-substituted aromatic heterocycles and in isostructural complexes of one ligand (2-methylquinoline) with different central metal atoms (Mn 2+ , Ni 2+ , Cu 2+ , Zn 2+ ). The order in which the structures of the ligands influence the rate of deuteroexchange in the complexes does not correspond qualitatively with the order of increase in the rate of deuteroexchange in the noncoordinated ligands. The rate of deuteroexchange is only weakly influenced by change in the identity of the metal complex former. A deuteroexchange mechanism is proposed and discussed. A structure arising in the course of the exchange process with transfer of electron density from the heterocyclic ligand to the metal ion forms the transition state of the reaction

  15. Basic deuteroexchange in transition metal complexes with nitrogen-containing aromatic heterocycles

    International Nuclear Information System (INIS)

    Tupitsyn, I.F.

    1986-01-01

    Kinetics of deuteroexchange in the methyl group of nitrate complexes of a metal - nickel (2) - with different methyl-substituted aromatic heterocycles and isostructural complexes of a ligand - 2 - methyl quinoline - with different central metal atoms (Mn(2), Ni(2), Cu(2), Zn(2)) is studied. Series for influence of ligand structure on deuteroexchange rate in complexes doesn't correspond qualitatively to series for deuteroexchange rate increase in noncoordinated ligands. Deuteroexchange rate is weakly subjected to influence of exchange in metal-complexing agent. Deuteroexchange mechanism is suggested and discussed. According to this mechanism the structure developed in the course of the exchange process with electron density transfer from the heterocyclic ligand to a metal ion is a transition state of the reaction

  16. Multiheteromacrocycles that complex metal ions. Third progress report, 1 May 1976--30 April 1977

    International Nuclear Information System (INIS)

    Cram, D.J.

    1977-01-01

    The overall objective of this research is to design, synthesize and evaluate cyclic and polycyclic host organic compounds for their abilities to complex and lipophilize guest metal ions, their complexes and 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 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 specific compounds synthesized and their complexing and lipophilizing properties are summarized

  17. Density functional study of isoguanine tetrad and pentad sandwich complexes with alkali metal ions.

    Science.gov (United States)

    Meyer, Michael; Steinke, Thomas; Sühnel, Jürgen

    2007-02-01

    Isoguanine tetraplexes and pentaplexes contain two or more stacked polyads with intercalating metal ions. We report here the results of a density functional study of sandwiched isoguanine tetrad and pentad complexes consisting of two polyads with Na(+), K(+) and Rb(+) ions at the B3LYP level. In comparison to single polyad metal ion complexes, there is a trend towards increased non-planarity of the polyads in the sandwich complexes. In general, the pentad sandwiches have relatively planar polyad structures, whereas the tetrad complexes contain highly non-planar polyad building blocks. As in other sandwich complexes and in metal ion complexes with single polyads, the metal ion-base interaction energy plays an essential role. In iG sandwich structures, this interaction energy is slightly larger than in the corresponding guanine sandwich complexes. Because the base-base interaction energy is even more increased in passing from guanine to isoguanine, the isoguanine sandwiches are thus far the only examples where the base-base interaction energy is larger than the base-metal ion interaction energy. Stacking interactions have been studied in smaller models consisting of two bases, retaining the geometry from the complete complex structures. From the data obtained at the B3LYP and BH&H levels and with Møller-Plesset perturbation theory, one can conclude that the B3LYP method overestimates the repulsion in stacked base dimers. For the complexes studied in this work, this is only of minor importance because the direct inter-tetrad or inter-pentad interaction is supplemented by a strong metal ion-base interaction. Using a microsolvation model, the metal ion preference K(+) approximately Rb(+) > Na(+) is found for tetrad complexes. On the other hand, for pentads the ordering is Rb(+) > K(+) > Na(+). In the latter case experimental data are available that agree with this prediction.

  18. Insights into aquatic toxicities of the antibiotics oxytetracycline and ciprofloxacin in the presence of metal: Complexation versus mixture

    International Nuclear Information System (INIS)

    Zhang Yu; Cai Xiyun; Lang Xianming; Qiao Xianliang; Li Xuehua; Chen Jingwen

    2012-01-01

    Co-contamination of ligand-like antibiotics (e.g., tetracyclines and quinolones) and heavy metals prevails in the environment, and thus the complexation between them is involved in environmental risks of antibiotics. To understand toxicological significance of the complex, effects of metal coordination on antibiotics' toxicity were investigated. The complexation of two antibiotics, oxytetracycline and ciprofloxacin, with three heavy metals, copper, zinc, and cadmium, was verified by spectroscopic techniques. The antibiotics bound metals via multiple coordination sites and rendered a mixture of various complexation speciations. Toxicity analysis indicated that metal coordination did modify the toxicity of the antibiotics and that antibiotic, metal, and their complex acted primarily as concentration addition. Comparison of EC 50 values revealed that the complex commonly was highest toxic and predominately correlated in toxicity to the mixture. Finally, environmental scenario analysis demonstrated that ignoring complexation would improperly classify environmental risks of the antibiotics. - Highlights: ► The complex of antibiotic with metal is a mixture of various complexation modes. ► Antibiotic and metal act as various combined interactions when their complexation is ignored. ► Antibiotic, metal, and their complex act as concentration addition interaction. ► Complex commonly is the highest toxicant. ► Neglecting complexation renders improper classification of risks for antibiotics. - Antibiotic, heavy metal and their complex act primarily as concentration addition interaction and the complex commonly is highest toxic.

  19. Insights into aquatic toxicities of the antibiotics oxytetracycline and ciprofloxacin in the presence of metal: Complexation versus mixture

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhang [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Cai Xiyun, E-mail: xiyuncai@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Xianming, Lang [Liaoning Academy of Environmental Sciences, Shenyang 110031 (China); Xianliang, Qiao; Xuehua, Li; Jingwen, Chen [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)

    2012-07-15

    Co-contamination of ligand-like antibiotics (e.g., tetracyclines and quinolones) and heavy metals prevails in the environment, and thus the complexation between them is involved in environmental risks of antibiotics. To understand toxicological significance of the complex, effects of metal coordination on antibiotics' toxicity were investigated. The complexation of two antibiotics, oxytetracycline and ciprofloxacin, with three heavy metals, copper, zinc, and cadmium, was verified by spectroscopic techniques. The antibiotics bound metals via multiple coordination sites and rendered a mixture of various complexation speciations. Toxicity analysis indicated that metal coordination did modify the toxicity of the antibiotics and that antibiotic, metal, and their complex acted primarily as concentration addition. Comparison of EC{sub 50} values revealed that the complex commonly was highest toxic and predominately correlated in toxicity to the mixture. Finally, environmental scenario analysis demonstrated that ignoring complexation would improperly classify environmental risks of the antibiotics. - Highlights: Black-Right-Pointing-Pointer The complex of antibiotic with metal is a mixture of various complexation modes. Black-Right-Pointing-Pointer Antibiotic and metal act as various combined interactions when their complexation is ignored. Black-Right-Pointing-Pointer Antibiotic, metal, and their complex act as concentration addition interaction. Black-Right-Pointing-Pointer Complex commonly is the highest toxicant. Black-Right-Pointing-Pointer Neglecting complexation renders improper classification of risks for antibiotics. - Antibiotic, heavy metal and their complex act primarily as concentration addition interaction and the complex commonly is highest toxic.

  20. Some transition metal complexes derived from mono- and di-ethynyl perfluorobenzenes

    NARCIS (Netherlands)

    Armitt, D.J.; Bruce, M.I.; Gaudio, M.; Zaitseva, N.N.; Skelton, B.W.; White, A.H.; Le Guennic, B.; Halet, J.-F.; Fox, M.A.; Roberts, R.L.; Hartl, F.; Low, P.J.

    2008-01-01

    Transition metal alkynyl complexes containing perfluoroaryl groups have been prepared directly from trimethylsilyl-protected mono- and di-ethynyl perfluoroarenes by simple desilylation/metallation reaction sequences. Reactions between Me3SiC CC6F5 and RuCl(dppe)Cp'[Cp' = Cp, Cp*] in the presence of

  1. Shrinking the Synchrotron : Tabletop Extreme Ultraviolet Absorption of Transition-Metal Complexes

    NARCIS (Netherlands)

    Zhang, Kaili; Lin, Ming Fu; Ryland, Elizabeth S.; Verkamp, Max A.; Benke, Kristin; De Groot, Frank M F; Girolami, Gregory S.; Vura-Weis, Josh

    2016-01-01

    We show that the electronic structure of molecular first-row transition-metal complexes can be reliably measured using tabletop high-harmonic XANES at the metal M2,3 edge. Extreme ultraviolet photons in the 50-70 eV energy range probe 3p → 3d transitions, with the same selection rules as soft X-ray

  2. Design, synthesis and photoelectrochemical properties of hexagonal metallomacrocycles based on triphenylamine: [M6(4,4'-bis(2,2':6',2''-terpyridinyl)triphenylamine)6(X)12]; [M = Fe(II), PF6- and Zn(II), BF4-].

    Science.gov (United States)

    Hwang, Seok-Ho; Moorefield, Charles N; Wang, Pingshan; Fronczek, Frank R; Courtney, Brandy H; Newkome, George R

    2006-08-07

    Synthesis of a novel bis(terpyridine) ligand, 4,4'-bis(2,2':6',2''-terpyridinyl)triphenylamine, utilizing triphenylamine, as a specific angle controller, has led to the self-assembly of a unique hexagonal metallomacrocycle family, [Fe6(2)6(PF6)12] and [Zn6(2)6(BF4)12], utilizing terpyridine-metal(II)-terpyridine connectivity. The crystal structure of the novel ligand shows that the angle between the two terpyridinyl moieties is 119.69 degrees , which enabled the formation of the hexagonal-shaped macrocycles. The crystal packing architectures of this starting ligand revealed channels induced by solvent encapsulation. Following complexation of this ligand with transition metals [Fe(II) or Zn(II)] in a one-pot reaction, the resultant structures were characterized by (1)H and (13)C NMR, UV/Vis and mass spectroscopies. The expected metal-to-ligand charge transfer (MLCT; lambda(max) = 582 nm) and emission (lambda(em) = 575 nm) characteristics were exhibited by both [Fe6(2)6(PF6)12] and[Zn6(2)6(BF4)12]. The photoelectrochemical characteristics of these hexagonal metallomacrocycles demonstrate that they can be used as sensitizers in dye-sensitized solar cells.

  3. Proton magnetic resonance spectra of metal ammine complexes, 8

    International Nuclear Information System (INIS)

    Taura, Toshiaki; Sakaguchi, Ushio; Yoneda, Hayami

    1976-01-01

    The rates of amine hydrogen isotopic exchange in the [Co(O) 2 (N) 4 ] + complex ions, where (O) 2 represents carbonate, oxalate, or malonate ions, and (N) 4 , tetraamine, bis(ethylenediamine), or bis(trimethylenediamine), were measured in D 2 O at 35 0 C by the PMR technique. It was found that: (1) the rates for trans (to oxygen) amines are faster than those for cis amines; (2) the rates, especially for trans amines, in the carbonato complexes are slower than those in the oxalato and malonato analogs, and (3) the difference between the rates for cis and trans amines is smaller in the bis(diamine) complexes than in the tetraammine complexes. These results are discussed in terms of the influence of the chelate geometry in the complex on the exchange reaction. (auth.)

  4. Chiral phosphites as ligands in asymmetric metal complex catalysis and synthesis of coordination compounds

    International Nuclear Information System (INIS)

    Gavrilov, Konstantin N; Bondarev, Oleg G; Polosukhin, Aleksei I

    2004-01-01

    The data published during the last five years on the application of chiral derivatives of phosphorous acid in coordination chemistry and enantioselective catalysis are summarised and discussed. The effect of the nature of these ligands on the structure of metal complexes and on the efficiency of catalytic organic syntheses is shown. Hydroformylation, hydrogenation, allylic substitution and conjugate addition catalysed by transition metal complexes with optically active phosphites and hydrophosphoranes are considered. The prospects for the development of this field of research are demonstrated.

  5. Design, synthesis, characterization and antibacterial and antifungal activity of a new 2-{(E-[(4-aminophenylimino]-methyl}-4,6-dichlorophenol and its complexes with Co(II, Ni(II, Cu(II and Zn(II: An experimental and DFT study

    Directory of Open Access Journals (Sweden)

    Bakirdere Emine Gulhan

    2016-01-01

    Full Text Available In this study, the complexes of Co (II, Ni (II, Cu (II and Zn (II with 2-(E-(4-aminophenyliminomethyl-4,6-dichlorophenol were prepared and characterized by physical, spectral and analytical data. The metal: ligand stoichiometric ratio is 1:2 in all the complexes. The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Their structures were elucidated on the basis of elemental analysis, IR, 1H and 13C NMR spectra, UV-VIS, magnetic susceptibility measurements and thermogravimetric analyses. Both the antibacterial and antifungal activities and MIC values of compounds were reported. Among the tested compounds, the most effective compound providing a MIC value of 64 μg/mL is Zn(L2 against C. tropicalis and B. subtilis. The theoretically optimized geometries of complexes have tetrahedral structures. The computed stretching frequencies of C=N, C-O and N-H bonds were found to be in good agreement with experimental data. All calculated frequencies fall within about 5% of the experimental frequency regions.

  6. 3d/4f Metal Complexes of Phenolic Oximes New Binding Sites on Anderson Polyoxometalates Metal Complexes of the New THAME Ligand

    DEFF Research Database (Denmark)

    Sethi, Waqas

    to be coordinatedto SMMs as well as onto other transition metal complexes, via different synthetic strategies. These synthetic routes did not result in the crystallisation of any new compounds. A new hexadentate ligand tris(((2-hydroxyethyl)-amino)methyl)ethane (THAME) was synthesised and characterised. THAME...

  7. Near-infrared dichroism of a mesogenic transition metal complex and its solubility in nematic hosts

    International Nuclear Information System (INIS)

    Marshall, K.L.; Jacobs, S.D.

    1987-01-01

    A transition metal complex possessing the nematic phase, bis (p-n-butylstyryl-1, 2-dithiolato) nickel, was synthesized and its optical properties and solubility in the nematic hosts K15 and MBBA were investigated. The metal complex displayed a high solubility in both host materials (up to 10% wt/wt) and a strong near-infrared absorption band centered at 860 nm. A blocking extinction of greater than OD = 3 was obtained with a 100 micron pathlength of a 0.5% wt/wt mixture of the nematic metal complex in K15, suggesting its usefulness for passive blocking of near infrared radiation. A 24 micron thick, homogeneously aligned guest-host cell containing a 1% wt/wt mixture of the metal complex in K15 possessed a contrast ratio of nearly 5:1 and a blocking extinction of OD = 3.5 at 860 nm, demonstrating for the first time the existence of near-infrared dichroism in this class of materials. The solubility and blocking extinction of the mesogenic metal complex in K15 was considerably superior to the non-mesogenic near ir laser dye bis(dimethylaminodithiobenzil) nickel in the same host. An interaction of the nematic metal complex in mixtures with MBBA which resulted in the creation of a new absorption band at 1050 nm was also observed. 21 refs., 9 figs

  8. Using metal complex-labeled peptides for charge transfer-based biosensing with semiconductor quantum dots

    Science.gov (United States)

    Medintz, Igor L.; Pons, Thomas; Trammell, Scott A.; Blanco-Canosa, Juan B.; Dawson, Philip E.; Mattoussi, Hedi

    2009-02-01

    Luminescent colloidal semiconductor quantum dots (QDs) have unique optical and photonic properties and are highly sensitive to charge transfer in their surrounding environment. In this study we used synthetic peptides as physical bridges between CdSe-ZnS core-shell QDs and some of the most common redox-active metal complexes to understand the charge transfer interactions between the metal complexes and QDs. We found that QD emission underwent quenching that was highly dependent on the choice of metal complex used. We also found that quenching traces the valence or number of metal complexes brought into close proximity of the nanocrystal surface. Monitoring of the QD absorption bleaching in the presence of the metal complex provided insight into the charge transfer mechanism. The data suggest that two distinct charge transfer mechanisms can take place. One directly to the QD core states for neutral capping ligands and a second to surface states for negatively charged capping ligands. A basic understanding of the proximity driven charge-transfer and quenching interactions allowed us to construct proteolytic enzyme sensing assemblies with the QD-peptide-metal complex conjugates.

  9. Dissolution of Fe(III) (hydr) oxides by metal-EDTA complexes

    Science.gov (United States)

    Ngwack, Bernd; Sigg, Laura

    1997-03-01

    The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA CaEDTA ≫ PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced.

  10. Solvation Effect on Complexation of Alkali Metal Cations by a Calix[4]arene Ketone Derivative.

    Science.gov (United States)

    Požar, Josip; Nikšić-Franjić, Ivana; Cvetnić, Marija; Leko, Katarina; Cindro, Nikola; Pičuljan, Katarina; Borilović, Ivana; Frkanec, Leo; Tomišić, Vladislav

    2017-09-14

    The medium effect on the complexation of alkali metal cations with a calix[4]arene ketone derivative (L) was systematically examined in methanol, ethanol, N-methylformamide, N,N-dimethylformamide, dimethyl sulfoxide, and acetonitrile. In all solvents the binding of Na + cation by L was rather efficient, whereas the complexation of other alkali metal cations was observed only in methanol and acetonitrile. Complexation reactions were enthalpically controlled, while ligand dissolution was endothermic in all cases. A notable influence of the solvent on NaL + complex stability could be mainly attributed to the differences in complexation entropies. The higher NaL + stability in comparison to complexes with other alkali metal cations in acetonitrile was predominantly due to a more favorable complexation enthalpy. The 1 H NMR investigations revealed a relatively low affinity of the calixarene sodium complex for inclusion of the solvent molecule in the calixarene hydrophobic cavity, with the exception of acetonitrile. Differences in complex stabilities in the explored solvents, apart from N,N-dimethylformamide and acetonitrile, could be mostly explained by taking into account solely the cation and complex solvation. A considerable solvent effect on the complexation equilibria was proven to be due to an interesting interplay between the transfer enthalpies and entropies of the reactants and the complexes formed.

  11. Features of proteolytic properties of tetraphenylporphyrin complex with lanthanide group metals

    Science.gov (United States)

    Tobolkina, Elena A.; Skripnikova, Tatiana A.; Starikova, Anna A.; Shumilova, Galina I.; Pendin, Andrey A.

    2018-01-01

    Demetallation of metalloporphyrin molecules is one of the essential degradation reactions in photosynthesis. The effect of metalloporphyrin nature on removal of central metals from tetraphenylporphyrin complexes based on lanthanide group metals (Dy, Er, Lu, Ho) has been studied. pH values, at which the metal ions leave the metalloporphyrin complex were established using two-phase spectrophotometric titration with potentiometric pH-control. The pH values decrease with the increase of atomic numbers of lanthanide groups, as well as with increase of 4f-electrons. The reaction of an extra ligand exchange for the hydroxide ion was studied. For Dy-, Er- and Ho-tetraphenylporphyrin complexes one particle of extra ligand coordinates with one porphyrin complex. A complex with dimeric particles can be formed for the system of Lu-tetraphenylporphyrin. Constants of the ion exchange reactions were calculated.

  12. Transition metal complexes of some biologically active ligands; synthesis characterization and bioactivities

    International Nuclear Information System (INIS)

    Rehman, S.; Ali, N.; Nisar, M.

    2009-01-01

    Transition/representative transition metals complexes of biologically active chelating agent 1,2-dipyrolodinoethane were synthesized and characterized through spectral and analytical data. The complexes are of the formula (M(L)X/sub 2/). Where (M = Co (II), Ni (II), Cu (II), Zn (II), Hg (II) and Cd (II) and X = CI, Br, NO/sub 3/). Tetrahedral geometry has been proposed to these-metal complexes with the help of magnetic measurements, elemental analysis, chemical stoichiometry and spectroscopic data Antibacterial activity of the ligand and its metal complexes were screened against Eschereschi coli, Klebsiello pneumonia, Proteus mirabilis, Proteus vulhari, Streptococcus pneumonia, Salmonella Iyphi, Bacilh,s anthrax, Streptococcus fecalis and Staphylococcus aureus. Complexes were found to be active against Eschereschi coli, Klebsiella pneumonia, Proteus mirabilis and Proteus vulharis. (author)

  13. Preparation of Palladium-Impregnated Ceria by Metal Complex Decomposition for Methane Steam Reforming Catalysis

    Directory of Open Access Journals (Sweden)

    Worawat Wattanathana

    2017-01-01

    Full Text Available Palladium-impregnated ceria materials were successfully prepared via an integrated procedure between a metal complex decomposition method and a microwave-assisted wetness impregnation. Firstly, ceria (CeO2 powders were synthesized by thermal decomposition of cerium(III complexes prepared by using cerium(III nitrate or cerium(III chloride as a metal source to form a metal complex precursor with triethanolamine or benzoxazine dimer as an organic ligand. Palladium(II nitrate was consequently introduced to the preformed ceria materials using wetness impregnation while applying microwave irradiation to assist dispersion of the dopant. The palladium-impregnated ceria materials were obtained by calcination under reduced atmosphere of 10% H2 in He stream at 700°C for 2 h. Characterization of the palladium-impregnated ceria materials reveals the influences of the metal complex precursors on the properties of the obtained materials. Interestingly, the palladium-impregnated ceria prepared from the cerium(III-benzoxazine dimer complex revealed significantly higher BET specific surface area and higher content of the more active Pdδ+ (δ > 2 species than the materials prepared from cerium(III-triethanolamine complexes. Consequently, it exhibited the most efficient catalytic activity in the methane steam reforming reaction. By optimization of the metal complex precursors, characteristics of the obtained palladium-impregnated ceria catalysts can be modified and hence influence the catalytic activity.

  14. High capacity hydrogen absorption in transition-metal ethylene complexes: consequences of nanoclustering

    International Nuclear Information System (INIS)

    Phillips, A B; Shivaram, B S

    2009-01-01

    We have recently shown that organo-metallic complexes formed by laser ablating transition metals in ethylene are high hydrogen absorbers at room temperature (Phillips and Shivaram 2008 Phys. Rev. Lett. 100 105505). Here we show that the absorption percentage depends strongly on the ethylene pressure. High ethylene pressures (>100 mTorr) result in a lowered hydrogen uptake. Transmission electron microscopy measurements reveal that while low pressure ablations result in metal atoms dispersed uniformly on a near atomic scale, high pressure ones yield distinct nanoparticles with electron energy-loss spectroscopy demonstrating that the metal atoms are confined solely to the nanoparticles.

  15. Complexes of 3.6 kDa Maltodextrin with Some Metals

    Directory of Open Access Journals (Sweden)

    Christopher H. Schilling

    2004-06-01

    Full Text Available Preparation of magnesium, lanthanum, and bismuth(III complexes of 3.6 kDa maltodextrin and some properties of the resulting materials are presented. The metal derivatives contain metals bound to the oxygen atoms of the hydroxyl groups of maltodextrin. Additionally, the metal atoms are coordinated to the hydroxyl groups of the D-glucose units of the macroligand. Such coordination stabilized the metal – oxygen bond against hydrolysis, even in boiling water. The presence of magnesium and lanthanum atoms increased the thermal stability of maltodextrin, whereas bismuth atoms decreased it.

  16. Competitive adsorption of Pb(II), Cu(II), and Zn(II) ions onto hydroxyapatite-biochar nanocomposite in aqueous solutions

    Science.gov (United States)

    Wang, Yu-Ying; Liu, Yu-Xue; Lu, Hao-Hao; Yang, Rui-Qin; Yang, Sheng-Mao

    2018-05-01

    A hydroxyapatite-biochar nanocomposite (HAP-BC) was successfully fabricated and its physicochemical properties characterized. The analyses showed that HAP nanoparticles were successfully loaded on the biochar surface. The adsorption of Pb(II), Cu(II), and Zn(II) by HAP-BC was systematically studied in single and ternary metal systems. The results demonstrated that pH affects the adsorption of heavy metals onto HAP-BC. Regarding the adsorption kinetics, the pseudo-second-order model showed the best fit for all three heavy metal ions on HAP-BC. In both single and ternary metal ion systems, the adsorption isotherm of Pb(II) by HAP-BC followed Langmuir model, while those of Cu(II) and Zn(II) fitted well with Freundlich model. The maximum adsorption capacity for each tested metal by HAP-BC was higher than that of pristine rice straw biochar (especially for Pb(II)) or those of other reported adsorbents. Therefore, HAP-BC could explore as a new material for future application in heavy metal removal.

  17. Quantitative Interpretation of Multifrequency Multimode EPR Spectra of Metal Containing Proteins, Enzymes, and Biomimetic Complexes.

    Science.gov (United States)

    Petasis, Doros T; Hendrich, Michael P

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy has long been a primary method for characterization of paramagnetic centers in materials and biological complexes. Transition metals in biological complexes have valence d-orbitals that largely define the chemistry of the metal centers. EPR spectra are distinctive for metal type, oxidation state, protein environment, substrates, and inhibitors. The study of many metal centers in proteins, enzymes, and biomimetic complexes has led to the development of a systematic methodology for quantitative interpretation of EPR spectra from a wide array of metal containing complexes. The methodology is now contained in the computer program SpinCount. SpinCount allows simulation of EPR spectra from any sample containing multiple species composed of one or two metals in any spin state. The simulations are quantitative, thus allowing determination of all species concentrations in a sample directly from spectra. This chapter will focus on applications to transition metals in biological systems using EPR spectra from multiple microwave frequencies and modes. © 2015 Elsevier Inc. All rights reserved.

  18. Preconcentration of metallic elements by complexation with ammonium pyrrolidine dithiocarbamate (APDC) for atomic absorption analysis

    International Nuclear Information System (INIS)

    Santos Coelho, Ricardo dos; Dantas, Elizabeth S.K.

    1997-01-01

    Ammonium pyrrolidine dithiocarbamate (APDC) forms stable chelates with many metals being therefore, used in systems of preconcentration for determination of heavy metals in water. In this work, the metals were complexed with APDC and extracted with methyl isobutyl ketone (MIBK). The results showed that the studied metals (Co, Cu, Fe, Ni, Pb, Cr and Cd), in the range of 2 to 5 μg, in 100 ml of sample, were quantitatively extracted in only one stage using 10 ml of MIBK and 5 ml of 4% APDC. The pH must be between 4 and 5. The complexes stability was also studied. The proposed method can be applied to pre concentrate heavy metals in natural waters. (author). 4 refs., 1 fig., 3 tabs

  19. Selective transport of metal ions through cation exchange membrane in the presence of a complexing agent

    Energy Technology Data Exchange (ETDEWEB)

    Tingchia Huang; Jaukai Wang (National Cheng Kung Univ., Tainan (Taiwan, Province of China))

    1993-01-01

    Selective transport of metal ions through a cation exchange membrane was studied in stirred batch dialyzer for the systems Ni[sup 2+]-Cu[sup 2+] and Cu[sup 2+]-Fe[sup 3+]. Oxalic acid, malonic acid, citric acid, glycine, and ethylenediaminetetraacetic acid were employed as the complexing agents added in the feed solution in order to increase the permselectivity of metal ions. The experimental results show that the selective transport behavior of metal ions depends on the valence and the concentration of metal ions, the stoichiometric ratio of complexing agent to metal ions, and the pH value of the feed solution, but is independent of the concentration of counterion in the stripping phase. A theoretical approach was formulated on the basis of the Nernst-Planck equation and interface quasi-equilibrium. Theoretical solutions obtained from numerical calculation were in agreement with the experimental data.

  20. N-heterocyclic carbene metal complexes as bio-organometallic antimicrobial and anticancer drugs.

    Science.gov (United States)

    Patil, Siddappa A; Patil, Shivaputra A; Patil, Renukadevi; Keri, Rangappa S; Budagumpi, Srinivasa; Balakrishna, Geetha R; Tacke, Matthias

    2015-01-01

    Late transition metal complexes that bear N-heterocyclic carbene (NHC) ligands have seen a speedy growth in their use as both, metal-based drug candidates and potentially active homogeneous catalysts in a plethora of C-C and C-N bond forming reactions. This review article focuses on the recent developments and advances in preparation and characterization of NHC-metal complexes (metal: silver, gold, copper, palladium, nickel and ruthenium) and their biomedical applications. Their design, syntheses and characterization have been reviewed and correlated to their antimicrobial and anticancer efficacies. All these initial discoveries help validate the great potential of NHC-metal derivatives as a class of effective antimicrobial and anticancer agents.

  1. Alkali-crown ether complexes at metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Thontasen, Nicha; Deng, Zhitao; Rauschenbach, Stephan [Max Planck Institute for Solid State Research, Stuttgart (Germany); Levita, Giacomo [University of Trieste, Trieste (Italy); Malinowski, Nikola [Max Planck Institute for Solid State Research, Stuttgart (Germany); Bulgarian Academy of Sciences, Sofia (Bulgaria); Kern, Klaus [Max Planck Institute for Solid State Research, Stuttgart (Germany); EPFL, Lausanne (Switzerland)

    2010-07-01

    Crown ethers are polycyclic ethers which, in solution, selectively bind cations depending on the size of the ring cavity. The study of a single host-guest complex is highly desirable in order to reveal the characteristics of these specific interactions at the atomic scale. Such detailed investigation is possible at the surface where high resolution imaging tools like scanning tunneling microscopy (STM) can be applied. Here, electrospray ion beam deposition (ES-IBD) is employed for the deposition of Dibenzo-24-crown-8 (DB24C8)-H{sup +}, -Na{sup +} and -Cs{sup +} complexes on a solid surface in ultrahigh vacuum (UHV). Where other deposition techniques have not been successful, this deposition technique combines the advantages of solution based preparation of the complex ions with a highly clean and controlled deposition in UHV. Single molecular structures and the cation-binding of DB24C8 at the surface are studied in situ by STM and MALDI-MS (matrix assisted laser desorption ionization mass spectrometry). The internal structure of the complex, i.e. ring and cavity, is observable only when alkali cations are incorporated. The BD24C8-H{sup +} complex in contrast appears as a compact feature. This result is in good agreement with theoretical models based on density functional theory calculations.

  2. Catalytic hydrogenation using complexes of base metals with tridentate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Susan K.; Zhang, Guoqi; Vasudevan, Kalyan V.

    2017-02-14

    Complexes of cobalt and nickel with tridentate ligand PNHP.sup.R are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHP.sup.Cy)Co(CH.sub.2SiMe.sub.3)]BAr.sup.F.sub.4 (PNHP.sup.Cy=bis[2-(dicyclohexylphosphino)ethyl]amine, BAr.sup.F.sub.4=B(3,5-(CF.sub.3).sub.2C.sub.6H.sub.3).sub.4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60.degree. C., 1-4 atm H.sub.2). Nickel complex [(PNHP.sup.Cy)Ni(H)]BPh.sub.4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNP.sup.Cy)Ni(H) was used for hydrogenating alkenes.

  3. Catalytic hydrogenation using complexes of base metals with tridentate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Kalyan V.; Zhang, Guoqi; Hanson, Susan K.

    2016-09-06

    Complexes of cobalt and nickel with tridentate ligand PNHP.sup.R are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHP.sup.Cy)Co(CH.sub.2SiMe.sub.3)]BAr.sup.F.sub.4 (PNHP.sup.Cy=bis[2-(dicyclohexylphosphino)ethyl]amine, BAr.sup.F.sub.4=B(3,5-(CF.sub.3).sub.2C.sub.6H.sub.3).sub.4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60.degree. C., 1-4 atm H.sub.2). Nickel complex [(PNHP.sup.Cy)Ni(H)]BPh.sub.4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNP.sup.Cy)Ni(H) was used for hydrogenating alkenes.

  4. Light induced electron transfer reactions of metal complexes

    International Nuclear Information System (INIS)

    Sutin, N.; Creutz, C.

    1980-01-01

    Properties of the excited states of tris(2,2'-bipyridine) and tris(1,10-phenanthroline) complexes of chromium(III), iron(II), ruthenium(II), osmium(II), rhodium(III), and iridium(III) are described. The electron transfer reactions of the ground and excited states are discussed and interpreted in terms of the driving force for the reaction and the distortions of the excited states relative to the corresponding ground states. General considerations relevant to the conversion of light into chemical energy are presented and progress in the use of polypyridine complexes to effect the light decomposition of water into hydrogen and oxygen is reviewed

  5. Electron transfer reactions of metal complexes in solution

    International Nuclear Information System (INIS)

    Sutin, N.

    1977-01-01

    A few representative electron-transfer reactions are selected and their kinetic parameters compared with the predictions of activated complex models. Since Taube has presented an elegant treatment of intramolecular electron-transfer reactions, emphasis is on bimolecular reactions. The latter electron-transfer reactions are more complicated to treat theoretically since the geometries of their activated complexes are not as well known as for the intramolecular case. In addition in biomolecular reactions, the work required to bring the two reactants together needs to be calculated. Since both reactants generally carry charges this presents a non-trivial problem at the ionic strengths usually used to study bimolecular electron transfer

  6. One Dimensional Coordination Polymer of Zn(II) for Developing Multifunctional Nanoparticles.

    Science.gov (United States)

    Agarwal, Rashmi A

    2017-10-16

    A variety of nanoparticles (NPs) including Ag, Au, Pd, Cr and mixed Cu/Fe have been synthesized in a non-activated (without solvent removal) one dimensional coordination polymer (CP) of Zn(II) via two different mechanisms, acid formation and redox activity of the framework. Main driving force to grow these NPs within the cavities of CP is the presence of free oxygens of one of the monodentate carboxylate groups of BDC ligand. These free oxygens act as anchoring sites for the metal ions of the metal precursors. Chemical and physical characteristics of the NPs within the framework have been evaluated by the high resolution transmission electron microscopic (HRTEM) images. Excluding Ag(0) and Pd(0) other NPs are present as combinations of their elemental as well as oxide forms (Au/Au 2 O 3 , Cr/Cr 2 O 3 /CrO 2 and Cu/Cu 2 O, Fe/FeO). Synthesized Ag NPs within the framework show remarkable antibacterial efficacy at extremely low concentrations. Ag, Au and Cu/Fe NPs show ferromagnetic properties within the framework at room temperature. This polymer has potential to sequester highly toxic Cr(VI) to non toxic Cr(0), Cr(III) and Cr(IV) species.

  7. Confirmation of molecular formulas of metallic complexes through X-ray fluorescence quantitative analysis

    International Nuclear Information System (INIS)

    Filgueiras, C.A.L.; Marques, E.V.; Machado, R.M.

    1984-01-01

    X-ray fluorescence spectrophotometry was employed to determined the metal content in a series of five transition element complexes (Mn, Ti, Zn, V). The results confirmed the molecular formulas of these complexes, already proposed on the basis of elemental microanalysis, solution condutimetry and other analytical methods. (C.L.B.) [pt

  8. BIOASSAY STUDIES OF METAL(II) COMPLEXES OF 2,2'-(ETHANE ...

    African Journals Online (AJOL)

    Preferred Customer

    diyldiimino)diacetic acid (EDDA) were prepared and characterized. Coordination complexes of the EDDA ... corresponding amines with alkyl halide to bear diammines of the same class with different substituents. ... Bioassay studies of metal(II) complexes of 2,2'-(ethane-1,2-diyldiimino)diacetic acid. Bull. Chem. Soc. Ethiop.

  9. Hydrogen storage material and process using graphite additive with metal-doped complex hydrides

    Science.gov (United States)

    Zidan, Ragaiy [Aiken, SC; Ritter, James A [Lexington, SC; Ebner, Armin D [Lexington, SC; Wang, Jun [Columbia, SC; Holland, Charles E [Cayce, SC

    2008-06-10

    A hydrogen storage material having improved hydrogen absorbtion and desorption kinetics is provided by adding graphite to a complex hydride such as a metal-doped alanate, i.e., NaAlH.sub.4. The incorporation of graphite into the complex hydride significantly enhances the rate of hydrogen absorbtion and desorption and lowers the desorption temperature needed to release stored hydrogen.

  10. Equilibrium and kinetic studies of Pb(II, Cd(II and Zn(II sorption by Lagenaria vulgaris shell

    Directory of Open Access Journals (Sweden)

    Mitić-Stojanović Dragana-Linda

    2012-01-01

    Full Text Available The sorption of lead, cadmium and zinc ions from aqueous solution by Lagenaria vulgaris shell biosorbent (LVB in batch system was investigated. The effect of relevant parameters such as contact time, biosorbent dosage and initial metal ions concentration was evaluated. The Pb(II, Cd(II and Zn(II sorption equilibrium (when 98% of initial metal ions were sorbed was attained within 15, 20 and 25 min, respectively. The pseudo first, pseudo-second order, Chrastil’s and intra-particle diffusion models were used to describe the kinetic data. The experimental data fitted the pseudo-second order kinetic model and intra-particle diffusion model. Removal efficiency of lead(II, cadmium(II and zinc(II ions rapidly increased with increasing biosorbent dose from 0.5 to 8.0 g dm-3. Optimal biosorbent dose was set to 4.0 g dm-3. An increase in the initial metal concentration increases the sorption capacity. The sorption data of investigated metal ions are fitted to Langmuir, Freundlich and Temkin isotherm models. Langmuir model best fitted the equilibrium data (r2 > 0.99. Maximal sorption capacities of LVB for Pb(II, Cd(II and Zn(II at 25.0±0.5°C were 0.130, 0.103 and 0.098 mM g-1, respectively. The desorption experiments showed that the LVB could be reused for six cycles with a minimum loss of the initial sorption capacity.

  11. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review

    International Nuclear Information System (INIS)

    Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

    1985-07-01

    Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs

  12. A comprehensive in vitro biological investigation of metal complexes ...

    African Journals Online (AJOL)

    Md. Mahabob Ullah Mazumder

    ... Journal of Medicine journal homepage: http://www.elsevier.com/locate/ajme .... two new complexes containing Fe (III) and Mo(VI) of two tridentate ONO donor · sets ligands. Der Chem Sin. .... Pharmaceuticals (Basel). 2014;7(4):453–463. 13.

  13. Synthesis of first row transition metal carboxylate complexes by ring ...

    Indian Academy of Sciences (India)

    tion of pyromellitic dianhydride with methanol and ring opening of pyromellitic dianhydride takes place. The corresponding carboxylate complex formed dur- ing the process can be crystallised by adding biden- tate nitrogen donor ligands such as 1,10-phenanthroline or 2,2 - bipyridine.20 From the reaction with 1,10-.

  14. Stability constant of the trisglycinto metal complexes | Na'aliya ...

    African Journals Online (AJOL)

    The stability constants of iron, manganese, cobalt, and nickel complexes of glycine have been determined in aqueous solution by potentiometric titration with standard sodium hydroxide solution. The values of the stepwise stability constants were obtained by ORIGIN '50' program. The overall stability constants of the ...

  15. Quantification of trace metals in water using complexation and filter concentration.

    Science.gov (United States)

    Dolgin, Bella; Bulatov, Valery; Japarov, Julia; Elish, Eyal; Edri, Elad; Schechter, Israel

    2010-06-15

    Various metals undergo complexation with organic reagents, resulting in colored products. In practice, their molar absorptivities allow for quantification in the ppm range. However, a proper pre-concentration of the colored complex on paper filter lowers the quantification limit to the low ppb range. In this study, several pre-concentration techniques have been examined and compared: filtering the already complexed mixture, complexation on filter, and dipping of dye-covered filter in solution. The best quantification has been based on the ratio of filter reflectance at a certain wavelength to that at zero metal concentration. The studied complex formations (Ni ions with TAN and Cd ions with PAN) involve production of nanoparticle suspensions, which are associated with complicated kinetics. The kinetics of the complexation of Ni ions with TAN has been investigated and optimum timing could be found. Kinetic optimization in regard to some interferences has also been suggested.

  16. Thin film assembly of nano-sized Zn(II)-8-hydroxy-5,7-dinitroquinolate by using successive ion layer adsorption and reaction (SILAR) technique: characterization and optical-electrical-photovoltaic properties.

    Science.gov (United States)

    Farag, A A M; Haggag, Sawsan M S; Mahmoud, Mohamed E

    2012-07-01

    A method is described for thin film assembly of nano-sized Zn(II)-8-hydroxy-5,7-dinitroquinolate complex, Zn[((NO(2))(2)-8HQ)(2)] by using successive ion layer adsorption and reaction (SILAR) technique. Highly homogeneous assembled nano-sized metal complex thin films with particle size distribution in the range 27-47nm was identified by using scanning electron microscopy (SEM). Zn[((NO(2))(2)-8HQ)(2)] and [(NO(2))(2)-8HQ] ligand were studied by thermal gravimetric analysis (TGA). Graphical representation of temperature dependence of the dark electrical conductivity produced two distinct linear parts for two activation energies at 0.377eV and 1.11eV. The analysis of the spectral behavior of the absorption coefficient in the intrinsic absorption region reveals a direct allowed transition with a fundamental band gap of 2.74eV. The dark current density-voltage (J-V) characteristics showed the rectification effect due to the formation of junction barrier of Zn[((NO(2))(2)-8HQ)(2)] complex film/n-Si interface. The photocurrent in the reverse direction is strongly increased by photo-illumination and the photovoltaic characteristics were also determined and evaluated. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Selective Decontamination Effect of Metal Ions in Soil Using Supercritical CO2 and TBP Complex

    International Nuclear Information System (INIS)

    Park, Jihye; Park, Kwangheon; Jung, Wonyoung

    2014-01-01

    Decontamination of soil pollution is difficult because the type of contamination largely depends on the characteristics of the pollutant and the area. Also, existing soil decontamination methods generate large quantities of secondary waste and additional process costs. For this reason, new decontamination methods are always under active investigation. A method involving the use of supercritical carbon dioxide with excellent permeability in place of chemical solvents is currently being studied. Unlike other heavy metals in fission products, uranium is used as fuel, and must be handled carefully. Therefore, in this paper, we studied a supercritical carbon dioxide method for decontaminating heavy metal ions in soil using tri-n-butyl phosphate(TBP), which is well known as a ligand for the extraction of metal ions of actinium. We investigated the decontamination effect of heavy metal ions in the soil using TBP-HNO 3 Complex and supercritical carbon dioxide. The study results showed that when heavy metals in soil are extracted using supercritical carbon dioxide, the extraction efficiency is different according to the type of pollutant metal ions in the soil. When TBP-HNO 3 Complex is used with an extractant, uranium extraction is very effective, but lithium, strontium, and cesium extraction is not effective. Therefore, in the case of a mixture of uranium and other metals such as lithium, strontium, cesium, and so on in soil contaminated by fission product leaks from nuclear power plants, we can selectively decontaminate uranium with supercritical carbon dioxide and TBP-HNO 3 Complex

  18. Synthesis of complex plutonium oxides with alkaline-earth metals

    International Nuclear Information System (INIS)

    Suzuki, Yasufumi; Nakajima, Kunihisa; Iwai, Takashi; Ohmichi, Toshihiko; Yamawaki, Michio.

    1995-03-01

    Complex plutonium(IV) oxides with strontium and barium, SuPuO 3 and BaPuO 3 , were synthesized and their crystal structure was analyzed. Compacted mixture of plutonium dioxide powder and the carbonate of strontium or barium was heated in a stream of argon gas using a cell with a small orifice. The products obtained were found to be composed of a nearly single phase showing the structure of orthorhombic slightly distorted from cubic. (author)

  19. On complexing of trivalent iron alcoholates. On transition metal alkoxyaluminates

    International Nuclear Information System (INIS)

    Rogova, T.V.; Turova, N.Ya.; Kozlova, N.I.

    1986-01-01

    When studying solubility in system Y(OR) 3 -Fe(OR) 3 -ROH (where R=i-Pr), the existence in solution of two complexes YF 2 (OR) 9 and YFe 3 (OR) 12 is ascertained, the range of X-ray amorphous glass formation being located between the two compositions. Preparative, IR- and mass-spectrometric studies of the glasses testify to the absence of bimetal alcoholates of Fe and Y of a definite composition in solid and gaseous phases

  20. Poly-functional description of metal complexation by natural organic matter: theory and practice

    International Nuclear Information System (INIS)

    Buffle, J.; Filella, M.; Altmann, R.S.

    1995-01-01

    The Differential Equilibrium Function (DEF) approach to metal complexation interpretation and prediction is compared to other models or approaches. The basic features of DEF are summarized, both from the experimental and theoretical points of view. The relation of DEF with key environmental concepts or parameters, in particular minor vs major complexing sites, the buffering intensity of natural organic matter (NOM), and their poly functional vs polyelectrolyte properties, is discussed. The relation between DEF and Freundlich isotherm is described quantitatively. The practical applications of DEF are discussed for (i) interpretation of metal complexation by NOM, and (ii) prediction of metal complexation by NOM. It is shown that DEF (i.e. sound extrapolation is possible with care). DEF cans be readily incorporated in metal species distribution codes (e.g. MINEQL). DEF is not equivalent to a molecular complexation model which describes complexation at each individual site; DEF gives a rigorous representation of complexation by NOM as a whole chemical system. (authors). 23 refs., 6 figs

  1. Application of Carrier Element-Free Co-precipitation Method for Ni(II), Cu(II) and Zn(II) Ions Determination in Water Samples Using Chrysin

    International Nuclear Information System (INIS)

    Layth Imad Abd Ali; Wan Aini Wan Ibrahim; Azli Sulaiman; Mohd Marsin Sanagi

    2015-01-01

    A co-precipitation method was developed to separate and pre-concentrate Ni(II), Cu(II) and Zn(II) ions using an organic co precipitant, chrysin without adding any carrier element termed as carrier element-free co-precipitation (CEFC). Analytes were determined using flame atomic absorption spectrometry (FAAS). The influence of analytical conditions, such as pH of the solution, quantity of co-precipitant, standing time, centrifugation rate and time, sample volume, and interference of concomitant ions were investigated over the recovery yields of the trace metals. The limit of detection, the limit of quantification and linearity range obtained from the FAAS measurements were found to be in the range of 0.64 to 0.86 μg L -1 , 2.13 to 2.86 μg L -1 and 0.9972 to 0.9989 for Ni(II), Cu(III) and Zn(II) ions, respectively. The precision of the method, evaluated as the relative standard deviation (RSD) obtained after analyzing a series of 10 replicates, was between 2.6 % to 3.9 % for the trace metal ions. The proposed procedure was applied and validated by analyzing river water reference material for trace metals (SLRS-5) and spiking trace metal ions in some water samples. The recoveries of the analyte metal ions were between 94.7-101.2 %. (author)

  2. Wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite

    Directory of Open Access Journals (Sweden)

    Malkin Polad

    2018-04-01

    Full Text Available Despite the wide practical use of sorption methods and complexones in treatment of industrial wastewater, some problems are still to be solved in this field. These are the most significant: insufficient sorption capacity of materials, lack of reliable methods for regenerating sorbents and resource-saving ecology friendly treatment technologies with the use of sorbents as well as methods of utilization of heavy metals from waste by complex formation. An important factor affecting the behavior of heavy metals in the soil is the medium acidity. With a neutral and slightly alkaline reaction of the medium, hardly soluble compounds are formed: hydroxides, sulphides, phosphates, carbonates, and oxalates of heavy metals. When acidity increases the reverse process runs in the soil: hardly soluble compounds become more mobile, while mobility of many heavy metals increases. However, the effect of soil acidity on mobility of heavy metals is ambiguous. Although mobility of many heavy metals decreases with increasing pH of the medium (for example, Fe, Mn, Zn, Co, etc., there are a number of metals whose mobility increases with soil neutralization. These include molybdenum and chromium, which are able to form soluble salts in a weak ly acidic and alkaline medium. In addition, heavy metals such as mercury and cadmium are able to maintain mobility in an alkaline medium through formation of complex compounds with organic matter in soils. Heavy metals interact with a solid phase of the soil by mechanisms of specific and nonspecific adsorption. In this article, a technique of wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite is proposed. This technique can reduce significant costs in preparation of raw materials and subsequent chemical modification of them. Technological solutions aimed at disposal and recycling of industrial wastewater have been proposed. These solutions make it possible to obtain the water

  3. Enantioseparation of dansyl amino acids and dipeptides by chiral ligand exchange capillary electrophoresis based on Zn(II)-L-hydroxyproline complexes coordinating with γ-cyclodextrins.

    Science.gov (United States)

    Mu, Xiaoyu; Qi, Li; Qiao, Juan; Yang, Xinzheng; Ma, Huimin

    2014-10-10

    A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and L-4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to L-4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0mM boric acid, 5.0mM ammonium acetate, 3.0mM Zn(II), 6.0mM L-hydroxyproline and 4.0mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity (r(2)≥0.997) and favorable repeatability (RSD≤3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Molecular Speciation of Trace Metal Organic Complexes in the Pacific Ocean

    Science.gov (United States)

    Repeta, D.; Boiteau, R. M.; Bundy, R. M.; Babcock-Adams, L.

    2017-12-01

    Microbial production across approximately one third of the surface ocean is limited by extraordinarily low (picomolar) concentrations of dissolved iron, essentially all of which is complexed to strong organic ligands of unknown composition. Other biologically important trace metals (cobalt, copper, zinc, nickel) are also complexed to strong organic ligands, which again have not been extensively characterized. Nevertheless, organic ligands exert a strong influence on metal bioavailability and toxicity. For example, amendment experiments using commercially available siderophores, organic compounds synthesized by microbes to facilitate iron uptake, show these ligands can both facilitate or impede iron uptake depending on the siderophore composition and available uptake pathways. Over the past few years we have developed analytical techniques using high pressure liquid chromatography interfaced with inductively coupled plasma and electrospray ionization mass spectrometry to identify and quantify trace metal organic complexes in laboratory cultures of marine microbes and in seawater. We found siderophores to be widely distributed in the ocean, particularly in regions characterized by low iron concentrations. We also find chemically distinct complexes of copper, zinc, colbalt and nickel that we have yet to fully characterize. We will discuss some of our recent work on trace metal organic speciation in seawater and laboratory cultures, and outline future efforts to better understand the microbial cycling of trace metal organic complexes in the sea.

  5. Spectroscopic characterization of metal complexes of novel Schiff base. Synthesis, thermal and biological activity studies

    Science.gov (United States)

    Omar, M. M.; Mohamed, Gehad G.; Ibrahim, Amr A.

    2009-07-01

    Novel Schiff base (HL) ligand is prepared via condensation of 4-aminoantipyrine and 2-aminobenzoic acid. The ligand is characterized based on elemental analysis, mass, IR and 1H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA, DrTGA and DTA). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a uninegatively tridentate manner with NNO donor sites of the azomethine N, amino N and deprotonated caroxylic-O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, ΔH*, ΔS* and ΔG* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia Coli, Pseudomonas aeruginosa, Staphylococcus Pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Shciff base ligand against one or more bacterial species.

  6. Metal complexes in cancer therapy – an update from drug design perspective

    Directory of Open Access Journals (Sweden)

    Ndagi U

    2017-03-01

    Full Text Available Umar Ndagi, Ndumiso Mhlongo, Mahmoud E Soliman Molecular Modelling and Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal, Westville, Durban, South Africa Abstract: In the past, metal-based compounds were widely used in the treatment of disease conditions, but the lack of clear distinction between the therapeutic and toxic doses was a major challenge. With the discovery of cisplatin by Barnett Rosenberg in 1960, a milestone in the history of metal-based compounds used in the treatment of cancers was witnessed. This forms the foundation for the modern era of the metal-based anticancer drugs. Platinum drugs, such as cisplatin, carboplatin and oxaliplatin, are the mainstay of the metal-based compounds in the treatment of cancer, but the delay in the therapeutic accomplishment of other metal-based compounds hampered the progress of research in this field. Recently, however, there has been an upsurge of activities relying on the structural information, aimed at improving and developing other forms of metal-based compounds and nonclassical platinum complexes whose mechanism of action is distinct from known drugs such as cisplatin. In line with this, many more metal-based compounds have been synthesized by redesigning the existing chemical structure through ligand substitution or building the entire new compound with enhanced safety and cytotoxic profile. However, because of increased emphasis on the clinical relevance of metal-based complexes, a few of these drugs are currently on clinical trial and many more are awaiting ethical approval to join the trial. In this review, we seek to give an overview of previous reviews on the cytotoxic effect of metal-based complexes while focusing more on newly designed metal-based complexes and their cytotoxic effect on the cancer cell lines, as well as on new approach to metal-based drug design and molecular target in cancer therapy. We are optimistic that the concept of selective

  7. Synthesis and optical properties of enantiomeric cinchonidine/cinchonine-terpyridine derivatives and their metal complexes

    International Nuclear Information System (INIS)

    Wang, Hui-Ting; Wu, Wen-Jie; Liu, Jiang; Chen, Meng; Qian, Dong-Jin; Zhang, Li; Liu, Minghua

    2016-01-01

    We report here the synthesis and spectroscopic properties of two enantiomeric chiral tridentate ligands (TPyCCD and TPyCCN) composed of terpyridine (TPy) and cinchonidine (CCD) or cinchonine (CCN) substituent, as well as their metal complexes with Zn 2+ , Fe 2+ , Eu 3+ , and Tb 3+ ions. For the pure ligands, the fluorescent emission intensity increased as their concentrations increased in the dilute solutions, but they decreased when the concentrations were greater than 6.9×10 −6 mol/l due to concentration quenching. No significant influence on ligand luminescence was observed for the Zn 2+ /Fe 2+ –TPyCCD and –TPyCCN metal complexes. Their lanthanide (Eu 3+ and Tb 3+ ) complexes displayed both ligand and lanthanide ion emissions, suggesting that the excited energy of both ligands could be transferred to the central Eu 3+ and Tb 3+ ions. Mirror-image circular dichroism spectra were recorded, with several signals centered at about 230, 250–270, 296, and 320 nm; the first ones corresponded to the chiral CCD and CCN substituents, while the latter ones corresponded to the TPy substituent and the metal–TPy (M-TPy) coordination units. It is suggested that the chirality of TPy and the metal complexes was induced by the coexisting chiral CCD and CCN substituents. In addition, due to formation of the metal complexes, the relative intensity of the chiral signals of M–TPy coordination units was enhanced at about 320 nm. - Highlights: • Cinchona alkaloid-terpyridine derivatives and metal complexes were prepared. • Cinchona alkaloid-terpyridine derivatives gave off luminescence at 362 nm. • Ligand excited energy could efficiently transferred to lanthanide ions. • Chirality of terpyridine and metal complexes was induced.

  8. The preparation and use of metal salen complexes derived from cyclobutane diamine

    Science.gov (United States)

    Patil, Smita

    The helix is an important chiral motif in nature, there is increasing development in field of helical transition metal complexes and related supramolecular structures. Hence, the goals of this work are to apply the principles of helicity in order to produce metal complexes with predictable molecular shapes and to study their properties as asymmetric catalysts. Computational studies suggest that the (1R,2 R)-cyclobutyldiamine unit can produce highly twisted salen complexes with a large energy barrier between the M and P helical forms. To test this prediction, the tartrate salt of (1R,2R)-cyclobutyldiamine was synthesized and condensed with a series of saliclaldehydes to produce novel salen ligands. The salicylaldehydes chosen have extended phenanthryl or benz[a]anthryl sidearms to encourage formation of helical coordination complexes. These ligands were metallated with zinc, iron and manganese salts to produce salen metal complexes which were characterized by NMR analysis, high-resolution mass spectrometry, and IR spectroscopy. A second ligand type, neutral bis(pyridine-imine) has also been synthesized from (1R,2R)-cyclobutyldiamine and quinolylaldehydes. The synthesis of bis(pyridine-imine) ligands was conducted using greener method, solvent assisted grinding. These ligands, in-situ with nickel metal salts, showed good catalytic activity for asymmetric Diels-Alder reactions. The third ligand type studied was chiral acid-functionalized Schiff-base ligands. These were synthesized by the condensation of 3-formyl-5-methyl salicylic acid and (1R,2R)-cyclobutyldiamine. With this type of ligand, there is possibility of producing both mono and dinuclear metal complexes. In our studies, we were only able to synthesize mononuclear complexs. These were tested as catalysts for asymmetric direct Mannich-type reaction, but were found to be ineffective.

  9. Al(III), Pd(II), and Zn(II) phthalocyanines for inactivation of dental pathogen Aggregatibacter actinomycetemcomitans as planktonic and biofilm-cultures

    Science.gov (United States)

    Kussovski, V.; Mantareva, V.; Angelov, I.; Avramov, L.; Popova, E.; Dimitrov, S.

    2012-06-01

    The Gram-negative, oral bacterium Aggregatibacter actinomycetemcomitans has been implicated as the causative agent of several forms of periodontal disease in humans. The new periodontal disease treatments are emergence in order to prevent infection progression. Antimicrobial photodynamic therapy (a-PDT) can be a useful tool for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and appears effective in photoinactivation of microorganisms. The phthalocyanine metal complexes of Pd(II)- (PdPcC) and Al(III)- (AlPc1) were evaluated as photodynamic sensitizers towards a dental pathogen A. actinomycetemcomitans in comparison to the known methylpyridyloxy-substituted Zn(II) phthalocyanine (ZnPcMe). The planktonic and biofilm-cultivated species of A. actinomycetemcomitans were treated. The photophysical results showed intensive and far-red absorbance with high tendency of aggregation for Pd(II)-phthalocyanine. The dark toxicities of both photosensitizers were negligible at concentrations used (bacteria was full photoinactivation after a-PDT with ZnPcMe. In case of the newly studied complexes, the effect was lower for PdPcC (4 log) as well as for AlPc1 (1.5-2 log). As it is known the bacterial biofilms were more resistant to a-PDT, which was confirmed for A. actinomycetemcomitans biofilms with 3 log reductions of viable cells after treatment with ZnPcMe and approximately 1 log reduction of biofilms after PdPcC and AlPc1. The initial results suggest that a-PDT can be useful for effective inactivation of dental pathogen A. actinomycetemcomitans.

  10. Interaction of natural complexing agents with soil bound heavy metals -geochemical and environmental technical aspects

    International Nuclear Information System (INIS)

    Fischer, K.

    1994-01-01

    The sanitation of heavy metal polluted soils requires the application of an adequate technology, which should be consistent in its ecological aims and methodology. Therefore a research programme has been developed at the 'Institute of Ecological Chemistry' of the 'GSF-Research Center', Neuherberg, which has its starting point in the study of influences of natural organic complexing agents on the chemical activity and dynamic of heavy metals in soils. The groundlaying idea is to elevate the concentration of complexing agents in the soil solution by additional application and possible stimulation of their microbial production to such an extent, that heavy metals will be enhanced solubilized, mobilized and removed together with the seepage water. Batch experiments in order to extract heavy metals from typical soil components (bentonite, peat) by amino acids demonstrate, that removal rates up to 95% can be obtained. (orig.) [de

  11. A molecular mechanics (MM3(96)) force field for metal-amide complexes

    International Nuclear Information System (INIS)

    Hay, B.P.; Clement, O.; Sandrone, G.; Dixon, D.A.

    1998-01-01

    A molecular mechanics (MM3(96)) force field is reported for modeling metal complexes of amides in which the amide is coordinated through oxygen. This model uses a points-on-a-sphere approach which involves the parameterization of the Msingle bondO stretch, the Msingle bondO double-bond C bend, and the Msingle bondO double-bond Csingle bondX (X = C, H, N) torsion interactions. Relationships between force field parameters and metal ion properties (charge, ionic radius, and electronegativity) are presented that allow the application of this model to a wide range of metal ions. The model satisfactorily reproduces the structures of over fifty amide complexes with the alkaline earths, transition metals, lanthanides, and actinides

  12. Selective transport and incorporation of highly charged metal and metal complex ions in self-assembled polyelectrolyte multilayer membranes

    International Nuclear Information System (INIS)

    Toutianoush, Ali; Tieke, Bernd

    2002-01-01

    The transport of aqueous salts containing mono-, di- and trivalent metal and tetravalent metal complex ions across ultrathin polyvinylammonium/polyvinylsulphate (PVA/PVS) membranes is described. The membranes were prepared by electrostatic layer-by-layer (LBL) assembly of the two polyelectrolytes. Using spectroscopic measurements and permeability studies, it is demonstrated that the transport of copper(II) chloride, lanthanum(III) chloride, barium chloride and potassium hexacyanoferrate(II) is accompanied by the permanent incorporation of the metal and metal complex ions in the membrane. Upon the uptake of copper, lanthanum and hexacyanoferrate ions, the membranes become cross-linked so that the permeation rates of other salts not taken up by the membrane, e.g. sodium chloride, potassium chloride and magnesium chloride, are decreased. The uptake of barium ions leads to a decrease of the cross-linking density of the membrane so that the permeation rate of NaCl is increased. Possible mechanisms for the ion uptake are discussed

  13. Metal distributions in complexes with Chlorella vulgaris in seawater and wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, P.R.; Kowalak, A.D.

    1999-10-01

    Divalent cadmium (Cd), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) simultaneous complexes with an algal biomass Chlorella vulgaris were studied for bioremediation purposes in various aqueous media: distilled-deionized water (DDIW), seawater, nuclear-reactor pool water, and process wastewater. Reactions were monitored using various dry masses of algae at constant temperature and constant metal concentrations for reaction times ranging from 0 to 150 minutes. Complexes occurred within 30 minutes and reached a steady state after 80 to 120 minutes. Distribution constants (K{prime}{sub d}) were calculated for the complexes and relative orders of K{prime}{sub d} were reported. The K{prime}{sub d} are used to evaluate relative efficiency of metal remediation from waters. Lead, Cu, and Ni complexes had the greatest K{prime}{sub d} values and those metals were most efficiently removed from these waters. Zinc and Fe formed the most labile complexes. The order of K{prime}{sub d} values for complexes in DDIW was Pb > Cu > Cd > Zn, then Cu > Cd > Zn in seawater, Cd > Cu > Zn in reactor pool water, and Ni > Cd > Cu > Zn > Fe in wastewater. C. vulgaris biomass may potentially be used as an alternative to traditional water treatment methods for simultaneous extraction of metals from seawater, process wastewater, or drinking water.

  14. High-performance liquid chromatography of metal complexes of pheophytins a and b

    International Nuclear Information System (INIS)

    Brykina, G.D.; Lazareva, E.E.; Uvarova, M.I.; Shpigun, O.A.

    1997-01-01

    Cu(2), Zn(2), Pb(2), Hg(2), and Ce(4) complexes of phenophytins a and b were synthesized. The chromatographic retention parameters of pheophytins a and b, chlorophylls a and b, and the above complexes were determined under conditions of normal-phase and reversed-phase high-performance liquid chromatography (HPLC). The adsorption of metal pheophytinates in the hexane-n-butanol (96:4)-Silasorb 600 and acetonitrile-ethanol-acetic acid (40:40:16)-Nucleosil C 18 systems was studied by HPLC. Factors that affect the chromatographic and adsorption characteristics of compounds (structural differences between pheophytinates of the a and b series, the nature of the central metal atom, and the nature of the mobile and stationary phases) are discussed. It is demonstrated that pheophytins a and b their metal complexes can be identified and quantiatively determined by HPLC in the concentration range (0.6-44.0)[10 -6 M

  15. Structural and Spectral Properties of Curcumin and Metal- Curcumin Complex Derived from Turmeric (Curcuma longa)

    Science.gov (United States)

    Bich, Vu Thi; Thuy, Nguyen Thi; Binh, Nguyen Thanh; Huong, Nguyen Thi Mai; Yen, Pham Nguyen Dong; Luong, Tran Thanh

    Structural and spectral properties of curcumin and metal- curcumin complex derived from turmeric (Curcuma longa) were studied by SEM and vibrational (FTIR and Raman) techniques. By comparison between curcumin commercial, fresh turmeric and a yellow powder obtained via extraction and purification of turmeric, we have found that this insoluble powder in water is curcumin. The yellow compound could complex with certain ion metal and this metal-curcumin coloring complex is water soluble and capable of producing varying hues of the same colors and having antimicrobial, cytotoxicity activities for use in foodstuffs and pharmacy. The result also demonstrates that Micro-Raman spec-troscopy is a valuable non-destructive tool and fast for investigation of a natural plant even when occurring in low concentrations.

  16. New trends in the optical and electronic applications of polymers containing transition-metal complexes.

    Science.gov (United States)

    Liu, Shu-Juan; Chen, Yang; Xu, Wen-Juan; Zhao, Qiang; Huang, Wei

    2012-04-13

    Polymers containing transition-metal complexes exhibit excellent optical and electronic properties, which are different from those of polymers with a pure organic skeleton and combine the advantages of both polymers and metal complexes. Hence, research about this class of polymers has attracted more and more interest in recent years. Up to now, a number of novel polymers containing transition-metal complexes have been exploited, and significant advances in their optical and electronic applications have been achieved. In this article, we summarize some new research trends in the applications of this important class of optoelectronic polymers, such as chemo/biosensors, electronic memory devices and photovoltaic devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Kinetic studies of the solvent extraction of metal complexes

    International Nuclear Information System (INIS)

    Mirza, M.Y.; Nwabue, F.I.; Okafo, E.N.

    1981-01-01

    The rate of forward extraction of Zr(IV) from 2M sulphuric acid into 1-phenyl-3-methyl-4-benzoyl-pyrazole-5-one (HPsub (z)) dissolved in chloroform and backward extraction of the tetrakis-chelate, Zr(Pz) 4 have been measured under various conditions. The rate of forward reaction is proportional to [Zr 4+ ], [HPsub(z)] 2 and [H + ] -2 , while that of back extraction to [Zr(Pz) 4 ]sub(org), [HPsub(z)] -2 sub(org) and [H + ] 2 . The rate determining step in the forward extraction is established to be the formation of the second complex between the dissociated form of HPz, Pz - and the Zr(H 2 O) 2 SO 4 Pz + species in the aqueous phase while it is the reverse in the backward extraction. The velocity constants for both rate controlling steps have been determined and the extraction constant agrees with the value obtained from the equilibrium data. (author)

  18. Paramagnetic metal complexes as potential relaxation agents for NMR imaging

    International Nuclear Information System (INIS)

    Coroiu, Ilioara; Demco, D. E.; Darabont, Al.; Bogdan, M.

    1997-01-01

    The development of nuclear magnetic resonance (NMR) imaging technique as a clinical diagnostic modality has prompted the need for a new class of pharmaceuticals. These drugs must be administered to a patient in order to enhance the image contrast between the normal and diseased tissue and/or indicate the status of organ function or blood flow. Paramagnetic compounds are presently undergoing extensive evaluation as contrast agents in magnetic resonance imaging (MRI). These agents increase contrast in MRI by differentially localizing in tissue where they increase the relaxation rates of nearby water protons. The longitudinal R 1 and transverse R 2 relaxivities were measured as a function of molar concentrations for some new paramagnetic complexes like the following: dysprosium, erbium and gadolinium citrates, gadolinium methylene diphosphonate, dysprosium and gadolinium iminodiacetate, manganese para-aminobenzoate and copper nicotinate. The available theoretical approaches for quantitative understanding are presented. (authors)

  19. 'Pincer' dicarbene complexes of some early transition metals and uranium.

    Science.gov (United States)

    Pugh, David; Wright, Joseph A; Freeman, Sandra; Danopoulos, Andreas A

    2006-02-14

    The complexes [(C-N-C)MX(n)(thf)(m)] with the 'pincer' 2,6-bis(imidazolylidene)pyridine, (C-N-C) = 2,6-bis(arylimidazol-2-ylidene)pyridine, aryl = 2,6-Pr(i)2C6H3, M = V, X = Cl, n = 2, m = 1 1a; M = Cr, X = Cl, n = 2, m = 0, 2a, X = Br, 2b; M = Mn, X = Br, n = 2, m = 0, 3; M = Nb, X = Cl, n = 3, m = 0, 4; and M = U, X = Cl, n = 4, m = 0, 5, were synthesised by (a) substitution of labile tmed (1a), thf (2a, 3, 5) or dme (4) by free (C-N-C) or by (b) reaction of the bisimidazolium salt (CH-N-CH)Br2 with {Cr[N(SiMe3)2]2(thf)2} followed by amine elimination (2b). Attempted alkylation of 1a, 2, 3a and 4 with Grignard or alkyl lithiums gave intractable mixtures, and in one case [reaction of 1a with (mesityl)MgBr] resulted in exchange of Cl by Br (1b). Oxidation of 1a or [(C-N-C)VCl3] with 4-methylmorpholine N-oxide afforded the trans-V(C-N-C)(=O)Cl2, 6, which by reaction with AgBF4 in MeCN gave trans-[V(C-N-C)(=O)(MeCN)2][BF4]2, 7. Reaction of 1a with p-tolyl azide gave trans-V(C-N-C)(=N-p-tolyl)Cl2 8. The complex trans-Ti(C-N-C)(=NBu(t))Cl2, 9, was prepared by substitution of the pyridine ligands in Ti(NBu(t))Cl2(py)3 by C-N-C.

  20. High-sensitivity determination of Zn(II) and Cu(II) in vitro by fluorescence polarization

    Science.gov (United States)

    Thompson, Richard B.; Maliwal, Badri P.; Feliccia, Vincent; Fierke, Carol A.

    1998-04-01

    Recent work has suggested that free Cu(II) may play a role in syndromes such as Crohn's and Wilson's diseases, as well as being a pollutant toxic at low levels to shellfish and sheep. Similarly, Zn(II) has been implicated in some neural damage in the brain resulting from epilepsy and ischemia. Several high sensitivity methods exist for determining these ions in solution, including GFAAS, ICP-MS, ICP-ES, and electrochemical techniques. However, these techniques are generally slow and costly, require pretreatment of the sample, require complex instruments and skilled personnel, and are incapable of imaging at the cellular and subcellular level. To address these shortcomings we developed fluorescence polarization (anisotropy) biosensing methods for these ions which are very sensitivity, highly selective, require simple instrumentation and little pretreatment, and are inexpensive. Thus free Cu(II) or Zn(II) can be determined at picomolar levels by changes in fluorescence polarization, lifetime, or wavelength ratio using these methods; these techniques may be adapted to microscopy.

  1. Alkali Metal Variation and Twisting of the FeNNFe Core in Bridging Diiron Dinitrogen Complexes.

    Science.gov (United States)

    McWilliams, Sean F; Rodgers, Kenton R; Lukat-Rodgers, Gudrun; Mercado, Brandon Q; Grubel, Katarzyna; Holland, Patrick L

    2016-03-21

    Alkali metal cations can interact with Fe-N2 complexes, potentially enhancing back-bonding or influencing the geometry of the iron atom. These influences are relevant to large-scale N2 reduction by iron, such as in the FeMoco of nitrogenase and the alkali-promoted Haber-Bosch process. However, to our knowledge there have been no systematic studies of a large range of alkali metals regarding their influence on transition metal-dinitrogen complexes. In this work, we varied the alkali metal in [alkali cation]2[LFeNNFeL] complexes (L = bulky β-diketiminate ligand) through the size range from Na(+) to K(+), Rb(+), and Cs(+). The FeNNFe cores have similar Fe-N and N-N distances and N-N stretching frequencies despite the drastic change in alkali metal cation size. The two diketiminates twist relative to one another, with larger dihedral angles accommodating the larger cations. In order to explain why the twisting has so little influence on the core, we performed density functional theory calculations on a simplified LFeNNFeL model, which show that the two metals surprisingly do not compete for back-bonding to the same π* orbital of N2, even when the ligand planes are parallel. This diiron system can tolerate distortion of the ligand planes through compensating orbital energy changes, and thus, a range of ligand orientations can give very similar energies.

  2. Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

    Directory of Open Access Journals (Sweden)

    Bipin Bihari Mahapatra

    2013-01-01

    Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

  3. pyridine-carboxamide complexes

    Indian Academy of Sciences (India)

    of the solution was reduced by slow evaporation. The prod- uct was ... Data collection, data reduction, structure solu- ... and a selection of bond lengths and angles are shown in. Table 2. ...... Zn(II) complexes featuring a disulfide bridge and H-.

  4. Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

    KAUST Repository

    Kaur, Sukhmanpreet

    2017-07-04

    Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4 ± 0.05, 7 ± 0.05 and 9 ± 0.05) and three different temperatures (15 ± 0.5°C, 30 ± 0.5°C and 45 ± 0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

  5. Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

    Science.gov (United States)

    Kaur, Sukhmanpreet; Kumar, Vijay; Chawla, Mohit; Cavallo, Luigi; Poater, Albert; Upadhyay, Niraj

    2017-07-01

    Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4±0.05, 7±0.05 and 9±0.05) and three different temperatures (15±0.5°C, 30±0.5°C and 45±0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

  6. Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

    KAUST Repository

    Kaur, Sukhmanpreet; Kumar, Vijay; Chawla, Mohit; Cavallo, Luigi; Poater, Albert; Upadhyay, Niraj

    2017-01-01

    Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4 ± 0.05, 7 ± 0.05 and 9 ± 0.05) and three different temperatures (15 ± 0.5°C, 30 ± 0.5°C and 45 ± 0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

  7. Photoactivatable metal complexes: from theory to applications in biotechnology and medicine.

    Science.gov (United States)

    Smith, Nichola A; Sadler, Peter J

    2013-07-28

    This short review highlights some of the exciting new experimental and theoretical developments in the field of photoactivatable metal complexes and their applications in biotechnology and medicine. The examples chosen are based on some of the presentations at the Royal Society Discussion Meeting in June 2012, many of which are featured in more detail in other articles in this issue. This is a young field. Even the photochemistry of well-known systems such as metal-carbonyl complexes is still being elucidated. Striking are the recent developments in theory and computation (e.g. time-dependent density functional theory) and in ultrafast-pulsed radiation techniques which allow photochemical reactions to be followed and their mechanisms to be revealed on picosecond/nanosecond time scales. Not only do some metal complexes (e.g. those of Ru and Ir) possess favourable emission properties which allow functional imaging of cells and tissues (e.g. DNA interactions), but metal complexes can also provide spatially controlled photorelease of bioactive small molecules (e.g. CO and NO)--a novel strategy for site-directed therapy. This extends to cancer therapy, where metal-based precursors offer the prospect of generating excited-state drugs with new mechanisms of action that complement and augment those of current organic photosensitizers.

  8. Preparation and Characterization of Styrene Bearing Diethanolamine Side Group, Styrene Copolymer Systems, and Their Metal Complexes

    Directory of Open Access Journals (Sweden)

    Aslışah Açıkses

    2018-01-01

    Full Text Available The two copolymer systems of styrene bearing diethanol amine side group and styrene were prepared by free radical polymerization method at 60°C in presence of 1,4-dioxane as solvent and AIBN as initiator. Their metal complexes were prepared by reaction of the copolymer used as ligand P(DEAMSt-co-StL′′ and Ni(II and Co(II metal ions, which was carried out in presence of ethanol and NaOH at 65°C for 48 h in pH = 7.5. The structures of the copolymers used as ligand and metal complexes were identified by FT-IR, 1H-NMR spectra, and elemental analysis. The properties of the copolymers used as ligand and metal complexes were characterized by SEM-EDX, AAS, DSC, TGA, and DTA techniques. Then, the electrical properties of the copolymers and metal complexes were examined as a function of the temperature and frequency, and the activation energies (Ea were estimated with conductivity measurements.

  9. Effect of Cu(II), Cd(II) and Zn(II) on Pb(II) biosorption by algae Gelidium-derived materials.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2008-06-15

    Biosorption of Pb(II), Cu(II), Cd(II) and Zn(II) from binary metal solutions onto the algae Gelidium sesquipedale, an algal industrial waste and a waste-based composite material was investigated at pH 5.3, in a batch system. Binary Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II) solutions have been tested. For the same equilibrium concentrations of both metal ions (1 mmol l(-1)), approximately 66, 85 and 86% of the total uptake capacity of the biosorbents is taken by lead ions in the systems Pb(II)/Cu(II), Pb(II)/Cd(II) and Pb(II)/Zn(II), respectively. Two-metal results were fitted to a discrete and a continuous model, showing the inhibition of the primary metal biosorption by the co-cation. The model parameters suggest that Cd(II) and Zn(II) have the same decreasing effect on the Pb(II) uptake capacity. The uptake of Pb(II) was highly sensitive to the presence of Cu(II). From the discrete model it was possible to obtain the Langmuir affinity constant for Pb(II) biosorption. The presence of the co-cations decreases the apparent affinity of Pb(II). The experimental results were successfully fitted by the continuous model, at different pH values, for each biosorbent. The following sequence for the equilibrium affinity constants was found: Pb>Cu>Cd approximately Zn.

  10. Batch adsorptive removal of Fe(III), Cu(II) and Zn(II) ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

    OpenAIRE

    Aboul-Magd, Abdul-Aleem Soliman; Al-Husain, Salwa Al-Rashed; Al-Zahrani, Salma Ahmed

    2016-01-01

    Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III), Cd(II), Zn(II), Cu(II), Mn(II), Mg(II), and Pb(II) from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion ...

  11. Electron density in non-ideal metal complexes. Pt. 1

    International Nuclear Information System (INIS)

    Varghese, J.N.; Maslen, E.N.

    1985-01-01

    The structure of copper sulphate pentahydrate was refined using an accurate set of X-ray data: Msub(r)=249.68, triclinic, Panti 1, a=6.1224(4), b=10.7223(4), c=5.9681(4) A, α=82.35(2), β=107.33(2), γ=102.60(4) 0 , V=364.02(3) A 3 , Z=2, Dsub(x)=2.278 Mg m -3 , Mo Kα, lambda=0.71069 A, μ=3.419 mm -1 , F(000)=254.0, T=298 K, R=0.039 for 7667 reflections. The structural parameters are compared with those obtained by neutron diffraction. The differences between X-ray and neutron positions are related to the hydrogen bonding in the structure. The dominant features in the residual density near the two crystallographically independent Cu atoms result from the redistribution of 3d electrons due to bonding. The density is anisotropic, as expected in view of the Jahn-Teller distortion in the structure. Marked differences in the d-electron distributions for the two Cu atoms correlate with small variations in molecular geometry. Second-nearest-neighbour effects, such as those arising from differently oriented ligating waters, are significant in this structure. Sharp features in the difference density close to the Cu nuclei are similar to those in other Cu 2+ complexes, indicating that the electron density in this region is more reliable than previously believed. (orig.)

  12. Density functional theory study on Herzberg-Teller contribution in Raman scattering from 4-aminothiophenol-metal complex and metal-4-aminothiophenol-metal junction

    Science.gov (United States)

    Liu, Shasha; Zhao, Xiuming; Li, Yuanzuo; Zhao, Xiaohong; Chen, Maodu

    2009-06-01

    Density functional theory (DFT) and time-dependent DFT calculations have been performed to investigate the Raman scattering spectra of metal-molecule complex and metal-molecule-metal junction architectures interconnected with 4-aminothiophenol (PATP) molecule. The simulated profiles of normal Raman scattering (NRS) spectra for the two complexes (Ag2-PATP and PATP-Au2) and the two junctions (Ag2-PATP-Au2 and Au2-PATP-Ag2) are similar to each other, but exhibit obviously different Raman intensities. Due to the lager static polarizabilities of the two junctions, which directly influence the ground state chemical enhancement in NRS spectra, the calculated normal Raman intensities of them are stronger than those of two complexes by the factor of 102. We calculate preresonance Raman scattering (RRS) spectra with incident light at 1064 nm, which is much lower than the S1 electronic transition energy of complexes and junctions. Ag2-PATP-Au2 and Au2-PATP-Ag2 junctions yield higher Raman intensities than those of Ag2-PATP and PATP-Au2 complexes, especially for b2 modes. This effect is mainly attributed to charge transfer (CT) between the metal gap and the PAPT molecule which results in the occurrence of CT resonance enhancement. The calculated pre-RRS spectra strongly depend on the electronic transition state produced by new structures. With excitation at 514.5 nm, the calculated pre-RRS spectra of two complexes and two junctions are stronger than those of with excitation at 1064 nm. A charge difference densities methodology has been used to visually describe chemical enhancement mechanism of RRS spectrum. This methodology aims at visualizing intermolecular CT which provides direct evidence of the Herzberg-Teller mechanism.

  13. Solventless acid-free synthesis of mesostructured titania: Nanovessels for metal complexes and metal nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Dag, Oe.; Celik, Oe.; Ozin, G.A. [Department of Chemistry, Bilkent University, 06533 Ankara (Turkey); Soten, I.; Polarz, S.; Coombs, N. [Materials Chemistry Research Group, Chemistry Department, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada)

    2003-01-01

    A new and highly reproducible method to obtain mesostructured titania materials is introduced in this contribution. The mesostructured titania is obtained by employing self-assembled structures of non-ionic alkyl-poly(ethylene oxide) surfactants as templates. The materials are produced without additional solvents such as alcohols, or even water. Only the titanium(IV) ethoxide and the surfactant (C{sub 12}EO{sub 10}) are needed. Water, in the form of that attached to the surfactant and from the atmosphere, induces growth of titania nanoclusters in the synthesis sol. It is indicated that these nanoclusters interact with the surfactant EO-head groups to form a new titanotropic amphiphile. The new amphiphiles self-assemble into titanium nanocluster-surfactant hybrid lyotropic phases, which are transformed to the final mesostructured materials by further condensation of the titania network. The titania materials can be obtained also with noble-metal particles immobilized in the mesostructured framework. It is seen that when different metal salts are used as the metal precursors, different interactions with the titania walls are found. The materials are characterized by X-ray diffraction (XRD), polarization optical microscopy (POM), transmission electron microscopy (TEM), UV-vis spectroscopy, and micro-Raman analysis. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  14. Synthesis and antimalarial activity of metal complexes of cross-bridged tetraazamacrocyclic ligands.

    Science.gov (United States)

    Hubin, Timothy J; Amoyaw, Prince N-A; Roewe, Kimberly D; Simpson, Natalie C; Maples, Randall D; Carder Freeman, TaRynn N; Cain, Amy N; Le, Justin G; Archibald, Stephen J; Khan, Shabana I; Tekwani, Babu L; Khan, M O Faruk

    2014-07-01

    Using transition metals such as manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II), several new metal complexes of cross-bridged tetraazamacrocyclic chelators namely, cyclen- and cyclam-analogs with benzyl groups, were synthesized and screened for in vitro antimalarial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of Plasmodium falciparum. The metal-free chelators tested showed little or no antimalarial activity. All the metal complexes of the dibenzyl cross-bridged cyclam ligand exhibited potent antimalarial activity. The Mn(2+) complex of this ligand was the most potent with IC50s of 0.127 and 0.157μM against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) P. falciparum strains, respectively. In general, the dibenzyl hydrophobic ligands showed better anti-malarial activity compared to the activity of monobenzyl ligands, potentially because of their higher lipophilicity and thus better cell penetration ability. The higher antimalarial activity displayed by the manganese complex for the cyclam ligand in comparison to that of the cyclen, correlates with the larger pocket of cyclam compared to that of cyclen which produces a more stable complex with the Mn(2+). Few of the Cu(2+) and Fe(2+) complexes also showed improvement in activity but Ni(2+), Co(2+) and Zn(2+) complexes did not show any improvement in activity upon the metal-free ligands for anti-malarial development. Published by Elsevier Ltd.

  15. Photochemical activation and reactivity of polynuclear transition metal complex molecules. Final report

    International Nuclear Information System (INIS)

    Endicott, J.F.; Lintvedt, R.L.

    1982-06-01

    Several bi- and trinuclear metal complexes containing ligands from β-polyketonates have been synthesized and characterized including homo- and hetero-polynuclear complexes. New synthetic approaches to the preparation of heterobi- and trinuclear complexes have been developed that allow the preparation of a large number of molecules containing heavy-metal ions such as Pd 2+ or UO 2 2+ and a first-row transition-metal ion. The electrochemical properties of these complexes have been investigated and many exhibit the ability to transfer two electrons at very nearly the same potential. Photochemical studies on binuclear Cu(II) and Ni(II) showed that these compounds yielded reduced metal species and decomposition upon irradiation. Luminescence of hetero-complexes of uranyl polyketonates is observed at 77 0 K with the UO 2 2+ moiety functioning as an isolated chromophore in which emission is observed only on direct excitation of UO 2 2+ and energy transfer to lower states in the molecule is not observed

  16. [Ultraviolet-visible spectrometry analysis of insoluble xanthate heavy metal complexes].

    Science.gov (United States)

    Qiu, Bo; Liu, Jin-Feng; Liu, Yao-Chi; Yang, Zhao-Guang; Li, Hai-Pu

    2014-11-01

    A ultraviolet-visible spectrometry method of determining insoluble xanthate heavy metal complexes in flotation wastewater was the first time to be put forward. In this work, the changes of ultraviolet-visible spectra of xanthate solution after the addition of various heavy metal ions were investigated firstly. It was found that Pb2+ and Cu2+ can form insoluble complexes with xanthate, while Fe2+, Zn2+ and Mn2+ have little effect on the ultraviolet absorption of xanthate solution. Then the removal efficiencies of filter membrane with different pore sizes were compared, and the 0.22 μm membrane was found to be effective to separate copper xanthate or lead xanthate from the filtrate. Furthermore, the results of the study on the reaction of sodium sulfide and insoluble xanthate heavy metal complexes showed that S(2-) can release the xanthate ion quantitatively from insoluble complexes to solution. Based on the above research, it was concluded that the amount of insoluble xanthate heavy metal complexes in water samples can be obtained through the increase of free xanthate in the filtrate after the addition of sodium sulfide. Finally, the feasibility of this method was verified by the application to the analysis of flotation wastewater from three ore-dressing plants in the Thirty-six Coves in Chenzhou.

  17. Antimicrobial and thermal properties of metal complexes of grafted fabrics with acrylic acid by gamma irradiation

    International Nuclear Information System (INIS)

    Hassan, M.S.; Attia, R.M.; Zohdy, M.H.; Khalil, E.M.

    2009-01-01

    Cotton, cotton/ ET blend and PET fabrics were treated against microbial effect by radiation -induced grafting of acrylic acid followed by metal complexation with some divalent transition metal ions like Co (l l), Ni(l l) and Cu(l l).The microbial resistance was evaluated by testing the mechanical properties of the treated fabrics after burring for one and two weeks in a moist soil reach with microorganisms. Also, the structural damage of the fabrics caused by biodegradation was examined by scanning electron microscope (SEM). Moreover, the effect of this treatment on the thermal decomposition behaviour was investigated by thermogravimetric analysis (TGA). On the basis of microbial studies, it was found that the metal complexation of the grafted fabrics with acrylic acid enhanced the microbial resistance of the fabrics and the microbial resistance could be arranged according to the complexed metal ions as follows: copper> nickel> cobalt. Also, the thermal stability of different fabrics could be arranged as follow: grafted fabrics complexes with Cu (l l) grafted fabrics complexes with Co (l l)

  18. Antimicrobial and Thermal Properties of Metal Complexes of Grafted Fabrics with Acrylic Acid by Gamma Irradiation

    International Nuclear Information System (INIS)

    Hassan, M.S.; Attia, R.M.; Zohdy, M.H.

    2008-01-01

    Cotton, cotton/PET blend and PET fabrics were treated against microbial effect by radiation - induced grafting of acrylic acid followed by metal complexation with some divalent transition metal ions Co (II), Ni (II) and Cu (II). The microbial resistance was evaluated by testing the mechanical properties of the treated fabrics after burring for one and two weeks in a moist soil reach with microorganisms. Also, the growth of microorganisms was examined by scanning electron microscope (SEM). Moreover, the effect of this treatment on the thermal decomposition behavior was investigated by thermogravimetric analysis (TGA). On the basis of microbial studies, it was found that the metal complexation of the grafted fabrics with acrylic acid enhanced the antimicrobial resistance of the fabrics and the antimicrobial resistance could be arranged according to the metal ions as follows: copper> nickel> cobalt. Also, the thermal stability of different fabrics could be arranged as follow: grafted fabrics complexed with Cu (II) > grafted fabrics complexed with Ni (II) > grafted fabrics complexed with Co (II)

  19. A new family of NxOy pyridine-containing macrocycles: synthesis and characterization of their Y(III), Ln(III), Zn(II), and Cd(II) coordination compounds

    International Nuclear Information System (INIS)

    Lodeiro, C.; Bastida, R.; Bertolo, E.; Rodriguez, A.

    2004-01-01

    Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris(2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands, five of them never reported previously. They all feature different pendant arms, which provide a wide range of coordination possibilities. The Schiff base macrocycles L 1 and L 4 and their reduced ligands L 2 and L 5 are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine, respectively. The reaction of L 1 with salicylaldehyde forms L 3 , which features an imine bond in the pendant arm. The ligand L 5 has been the precursor for the pendant-armed L 6 and L 7 , by alkylation of the free NH groups with methyl-imidazole or methyl-indole. By a template or a nontemplate approach, we have synthesized different mono- and dinuclear complexes with Y(III), Ln(III), Zn(II), and Cd(II) cations. Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis, IR, UV-vis, 1 H and 13 C NMR spectroscopy, FAB mass spectrometry, MS electrospray, and conductivity measurements. (author)

  20. Preparation and properties of chitosan-metal complex: Some factors influencing the adsorption capacity for dyes in aqueous solution.

    Science.gov (United States)

    Rashid, Sadia; Shen, Chensi; Yang, Jing; Liu, Jianshe; Li, Jing

    2018-04-01

    Chitosan-metal complexes have been widely studied in wastewater treatment, but there are still various factors in complex preparation which are collectively responsible for improving the adsorption capacity need to be further studied. Thus, this study investigates the factors affecting the adsorption ability of chitosan-metal complex adsorbents, including various kinds of metal centers, different metal salts and crosslinking degree. The results show that the chitosan-Fe(III) complex prepared by sulfate salts exhibited the best adsorption efficiency (100%) for various dyes in very short time duration (10min), and its maximum adsorption capacity achieved 349.22mg/g. The anion of the metal salt which was used in preparation played an important role to enhance the adsorption ability of chitosan-metal complex. SO 4 2- ions not only had the effect of crosslinking through electrostatic interaction with amine group of chitosan polymer, but also could facilitate the chelation of metal ions with chitosan polymer during the synthesis process. Additionally, the pH sensitivity and the sensitivity of ionic environment for chitosan-metal complex were analyzed. We hope that these factors affecting the adsorption of the chitosan-metal complex can help not only in optimizing its use but also in designing new chitosan-metal based complexes. Copyright © 2017. Published by Elsevier B.V.

  1. The first example of intensive luminescence of LMCT state based on metal complexes in solution

    International Nuclear Information System (INIS)

    Lukova, G.V.; Vasil'ev, V.P.; Smirnov, V.A.; Huhn, W.

    2007-01-01

    A bridge complex rac-C 6 H 10 (IndH 4 ) 2 ZrC 2 , featuring a unique long-living luminescence in liquid solutions at 20 deg C, has been prepared for the first time by catalytic hydrogenation of bis-indinyl complex C 6 H 10 (Ind) 2 Zr 2 Cl 2 . It has been identified that quantum yields of luminescence of the complex solutions at room temperature are the greatest ones for the known compounds possessing emission states of charge transfer from ligand to metal. Linear correlations of quantum yield of metal complex luminescence in a solution with steric features of the solvent molecules have been detected for the first time [ru

  2. Photochemical activation and reactivity of polynuclear transition-metal-complex molecules. Progress report, June 1981-May 31, 1982

    International Nuclear Information System (INIS)

    Endicott, J.F.; Lintvedt, R.L.

    1982-01-01

    Significant results obtained during the year are summarized for the following programs: (1) reversible, two electron transfer at a single potential in binuclear complexes; (2) photophysics of polyketonate complexes; (3) synthetic strategies and characterization of heavy metal heterobinuclear complexes; (4) high yield synthesis of ligands capable of binding 3 and 4 metal ions per molecule. Electrochemical studies have uncovered a number of new binuclear metal complexes that undergo reversible two-electron reduction at single potential including Cu(II) complexes with two different coordination environments, mixed Ni(II), Cu(II) complexes and binuclear Ni(II) complexes. In each case the species that exhibit these electron transfer properties have been shown to be Na + ion-paired complexes. Several new trinuclear molecular complexes have been prepared and characterized that contain two UO 2 2+ ions and one transition metal ion. The electrochemistry, absorption spectra, and luminescence have been investigated

  3. Spatial structure of transition metal complexes in solution determined by EXAFS spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Erenburg, S.B. E-mail: simon@che.nsk.su; Bausk, N.V.; Zemskova, S.M.; Mazalov, L.N

    2000-06-21

    CdK EXAFS, ZnK and CuK EXAFS and XANES spectra were measured for solutions of cadmium, zinc and copper dialkyldithiocarbamates in organic solvents with varying donating abilities: tributylphosphine, methylene chloride, benzene, dibutylsulfide, pyridine, dimethylsulfoxide and for some model compounds. The parameters of the local surroundings of the Cd, Zn and Cu atoms for complex forms in solutions were determined using EXAFS spectroscopy. Spatial structure models of the complex forms in a metal chelate - nonaqueous solvent system are suggested.

  4. Spatial structure of transition metal complexes in solution determined by EXAFS spectroscopy

    International Nuclear Information System (INIS)

    Erenburg, S.B.; Bausk, N.V.; Zemskova, S.M.; Mazalov, L.N.

    2000-01-01

    CdK EXAFS, ZnK and CuK EXAFS and XANES spectra were measured for solutions of cadmium, zinc and copper dialkyldithiocarbamates in organic solvents with varying donating abilities: tributylphosphine, methylene chloride, benzene, dibutylsulfide, pyridine, dimethylsulfoxide and for some model compounds. The parameters of the local surroundings of the Cd, Zn and Cu atoms for complex forms in solutions were determined using EXAFS spectroscopy. Spatial structure models of the complex forms in a metal chelate - nonaqueous solvent system are suggested

  5. Investigation of complexing ability of ionites with various groups to some heavy and transition metal ions

    Directory of Open Access Journals (Sweden)

    Yedil Yergozhin

    2013-05-01

    Full Text Available The physico-chemical and complexing properties of the sorbent based on chloromethylated styrene and divinylbenzene copolymer with nicotinamide groups and copolymers based on metacryloilaminobenzene acids with 2-methyl-5-vinylpyridineisomers are studied. By potentiometric titration method the constant of polyelectrolytes functional groups ionization, the composition and strength of the resulting complexes with ions of some heavy and transition metals are determined.

  6. Supramolecular assembly of group 11 phosphorescent metal complexes for chemosensors of alcohol derivatives

    Science.gov (United States)

    Lintang, H. O.; Ghazalli, N. F.; Yuliati, L.

    2018-04-01

    We report on systematic study on vapochromic sensing of ethanol by using phosphorescent trinuclear metal pyrazolate complexes with supramolecular assembly of weak intermolecular metal-metal interactions using 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligand (1) and group 11 metal ions (Cu(I), Ag(I), Au(I)). Upon excitation at 284, the resulting complexes showed emission bands with a peak centered at 616, 473 and 612 nm for 2(Cu), 2(Ag) and 2(Au), respectively. Chemosensor 2(Cu) showed positive response to ethanol vapors in 5 mins by blue-shifting its emission band from 616 to 555 nm and emitting bright orange to green. Otherwise 2(Au) gave shifting from its emission band centered at 612 to 587 nm with Δλ of 25 nm (41%) and color changes from red-orange to light green-orange while 2(Ag) showed quenching in its original emission intensity at 473 nm in 40% with color changes from dark green to less emissive. These results demonstrate that sensing capability of chemosensor 2(Cu) with suitable molecular design of ligand and metal ion in the complex is due to the formation of a weak intermolecular hydrogen bonding interaction of O atom at the methoxy of the benzyl ring with the OH of the vapors at the outside of the molecules.

  7. Molybdenum/alkali metal/ethylene glycol complexes useful as epoxidation catalysts

    International Nuclear Information System (INIS)

    Marquis, E.T.; Sanderson, J.R.; Keating, K.P.

    1987-01-01

    This patent describes a clear, storage stable solution of a molybdenum/alkali metal/ethylene glycol complex in ethylene glycol made by the process comprising: reacting at an elevated temperature between about 25 0 and 150 0 C a solid ammonium molybdate or a hydrate thereof and a solid alkali metal molybdate or a hydrate thereof with ethylene glycol, such that the ratio of moles of ethylene glycol to total gram atoms of molybdenum in the molybdates ranges from about 7:10 to 10:1, and the ratio of gram atoms of molybdenum in the ammonium molybdate or hydrate thereof to gram atoms of molybdenum in the alkali metal molybdate is from about 1:1 to about 20:1 to thereby provide a reaction product composed of a solution of an alkali metal-containing complex of molybdenum, alkali metal and ethylene glycol and by-products, including water, in the ethylene glycol and subsequently stripping the solution at a reduced pressure to remove from about 5 to about 25% of the reaction product, as distillate, to thereby provide a storage stable solution of the complex in the ethylene glycol having a molybdenum content of about 6 wt. % to about 20 wt. %, a water concentration of about 0.1 wt. % to about 6 wt. % and an acid number of more than about 60

  8. Ultrafast Transient Absorption Spectroscopy of Polymer-Based Organophotoredox Catalysts Mimicking Transition-Metal Complexes

    Science.gov (United States)

    Jamhawi, Abdelqader; Paul, Anam C.; Smith, Justin D.; Handa, Sachin; Liu, Jinjun

    2017-06-01

    Transition-metal complexes of rare earth metals including ruthenium and iridium are most commonly employed as visible-light photocatalysts. Despite their highly important and broad applications, they have many disadvantages including high cost associated with low abundance in earth crust, potential toxicity, requirement of specialized ligands for desired activity, and difficulty in recycling of metal contents as well as associated ligands. Polymer-based organophotoredox catalysts are promising alternatives and possess unique advantages such as easier synthesis from inexpensive starting material, longer excited state life time, broad range of activity, sustainability, and recyclability. In this research talk, time-resolved photoluminescence and femtosecond transient absorption (TA) spectroscopy measurements of three novel polymer-based organophotoredox catalysts will be presented. By our synthetic team, their catalytic activity has been proven in some highly valuable chemical transformations, that otherwise require transition metal complexes. Time-resolved spectroscopic investigations have demonstrated that photoinduced processes in these catalysts are similar to the transition metal complexes. Especially, intramolecular vibrational relaxation, internal conversion, and intersystem crossing from the S1 state to the T1 state all occur on a sub-picosecond timescale. The long lifetime of the T1 state ( 2-3 microsecond) renders these polymers potent oxidizing and reducing agents. A spectroscopic and kinetic model has been developed for global fitting of TA spectra in both the frequency and time domains. Implication of the current ultrafast spectroscopy studies of these novel molecules to their roles in photocatalysis will be discussed.

  9. Microwave synthesis, spectral, thermal, and antimicrobial activities of some transition metal complexes involving 5-bromosalicylaldehyde moiety

    Directory of Open Access Journals (Sweden)

    Rajendra K. Jain

    2012-07-01

    Full Text Available The coordination complexes of Co(II, Ni(II and Cu(II derived from 5-bromosalicylidene-3,4-dimethylaniline (BSMA and 5-bromosalicylidene-3,4-dichloroaniline (BSCA have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, molar conductance, electronic spectra, 1H-NMR, FAB-mass, ESR, magnetic susceptibility, electrical conductivity and thermal analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand ratio with coordination number 4 or 6. IR data shows that the ligand coordinates with the metal ions in a bidentate manner through the phenolic oxygen and azomethine nitrogen. FAB-mass and thermal data show degradation pattern of the complexes. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans.

  10. Coordination diversity of new mononucleating hydrazone in 3d metal complexes: Synthesis, characterization and structural studies

    Directory of Open Access Journals (Sweden)

    RAJESH S. BALIGAR

    2006-12-01

    Full Text Available The mononucleating hydrazone ligand LH3, a condensation product of salicyloylhydrazine and (2-formylphenoxyacetic acid, was synthesized and its coordination behavior with first row transition metal(II ions was investigated by isolating and elucidating the structure of the complexes using elemental analysis, conductivity and magnetic susceptibility measurements, as well as IR, 1H-NMR, electronic and EPR spectral techniques. The ligand forms mononuclear metal(II complexes of the type [CoLH(H2O2], [NiLH(H2O2, [CuLH] and [ZnLH]. The ligand field parameters, Dq, B and b values, in the case of the cobalt and nickel complexes support not only the octahedral geometry around the metal ion, but also imply the covalent nature of the bonding in the complexes. The EPR study revealed the presence of a spin exchange interaction in the solid copper complex and the covalent nature of the bonding. The 1H-NMR study of the zinc(II complex indicated the non-involvement of the COOH group in the coordination. The physico-chemical study supports for the presence of octahedral geometry around cobalt(II, nickel(II and tetrahedral geometry around copper(II and zinc(II ions.

  11. A review on versatile applications of transition metal complexes incorporating Schiff bases

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abu-Dief

    2015-06-01

    Full Text Available Schiff bases and their complexes are versatile compounds synthesized from the condensation of an amino compound with carbonyl compounds and widely used for industrial purposes and also exhibit a broad range of biological activities including antifungal, antibacterial, antimalarial, antiproliferative, anti-inflammatory, antiviral, and antipyretic properties. Many Schiff base complexes show excellent catalytic activity in various reactions and in the presence of moisture. Over the past few years, there have been many reports on their applications in homogeneous and heterogeneous catalysis. The high thermal and moisture stabilities of many Schiff base complexes were useful attributes for their application as catalysts in reactions involving at high temperatures. The activity is usually increased by complexation therefore to understand the properties of both ligands and metal can lead to the synthesis of highly active compounds. The influence of certain metals on the biological activity of these compounds and their intrinsic chemical interest as multidentate ligands has prompted a considerable increase in the study of their coordination behaviour. Development of a new chemotherapeutic Schiff bases and their metal complexes is now attracting the attention of medicinal chemists. This review compiles examples of the most promising applied Schiff bases and their complexes in different areas.

  12. Interaction of Zn(II) with hematite nanoparticles and microparticles: Part 2. ATR-FTIR and EXAFS study of the aqueous Zn(II)/oxalate/hematite ternary system.

    Science.gov (United States)

    Ha, Juyoung; Trainor, Thomas P; Farges, François; Brown, Gordon E

    2009-05-19

    Sorption of Zn(II) to hematite nanoparticles (HN) (av diam=10.5 nm) and microparticles (HM) (av diam=550 nm) was studied in the presence of oxalate anions (Ox2-(aq)) in aqueous solutions as a function of total Zn(II)(aq) to total Ox2-(aq) concentration ratio (R=[Zn(II)(aq)]tot/[Ox2-(aq)]tot) at pH 5.5. Zn(II) uptake is similar in extent for both the Zn(II)/Ox/HN and Zn(II)/Ox/HM ternary systems and the Zn(II)/HN binary system at [Zn(II)(aq)](tot)system than for the Zn(II)/Ox/HM ternary and the Zn(II)/HN and Zn(II)/HM binary systems at [Zn(II)(aq)]tot>4 mM. In contrast, Zn(II) uptake for the Zn(II)/HM binary system is a factor of 2 greater than that for the Zn(II)/Ox/HM and Zn(II)/Ox/HN ternary systems and the Zn(II)/HN binary system at [Zn(II)(aq)]totternary system at both R values examined (0.16 and 0.68), attenuated total reflectance Fourier transform infrared (ATR-FTIR) results are consistent with the presence of inner-sphere oxalate complexes and outer-sphere ZnOx(aq) complexes, and/or type A ternary complexes. In addition, extended X-ray absorption fine structure (EXAFS) spectroscopic results suggest that type A ternary surface complexes (i.e., >O2-Zn-Ox) are present. In the Zn(II)/Ox/HN ternary system at R=0.15, ATR-FTIR results indicate the presence of inner-sphere oxalate and outer-sphere ZnOx(aq) complexes; the EXAFS results provide no evidence for inner-sphere Zn(II) complexes or type A ternary complexes. In contrast, ATR-FTIR results for the Zn/Ox/HN sample with R = 0.68 are consistent with a ZnOx(s)-like surface precipitate and possibly type B ternary surface complexes (i.e., >O2-Ox-Zn). EXAFS results are also consistent with the presence of ZnOx(s)-like precipitates. We ascribe the observed increase of Zn(II)(aq) uptake in the Zn(II)/Ox/HN ternary system at [Zn(II)(aq)]tot>or=4 mM relative to the Zn(II)/Ox/HM ternary system to formation of a ZnOx(s)-like precipitate at the hematite nanoparticle/water interface.

  13. Peptide-mediated vectorization of metal complexes: conjugation strategies and biomedical applications.

    Science.gov (United States)

    Soler, Marta; Feliu, Lidia; Planas, Marta; Ribas, Xavi; Costas, Miquel

    2016-08-16

    The rich chemical and structural versatility of transition metal complexes provides numerous novel paths to be pursued in the design of molecules that exert particular chemical or physicochemical effects that could operate over specific biological targets. However, the poor cell permeability of metallodrugs represents an important barrier for their therapeutic use. The conjugation between metal complexes and a functional peptide vector can be regarded as a versatile and potential strategy to improve their bioavailability and accumulation inside cells, and the site selectivity of their effect. This perspective lies in reviewing the recent advances in the design of metallopeptide conjugates for biomedical applications. Additionally, we highlight the studies where this approach has been directed towards the incorporation of redox active metal centers into living organisms for modulating the cellular redox balance, as a tool with application in anticancer therapy.

  14. Predicting the stability constants of metal-ion complexes from first principles

    Czech Academy of Sciences Publication Activity Database

    Gutten, Ondrej; Rulíšek, Lubomír

    2013-01-01

    Roč. 52, č. 18 (2013), s. 10347-10355 ISSN 0020-1669 Institutional support: RVO:61388963 Keywords : stability constants * solvation energy * metal-ion complexation * theoretical calculations * DFT methods Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.794, year: 2013

  15. Novel D–π–A dye sensitizers of polymeric metal complexes with ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 38; Issue 2. Novel D––A dye sensitizers of polymeric metal complexes with triphenylamine derivatives as donor for dye-sensitized solar cells: synthesis, characterization and application. Guipeng Tang Jun Zhou Wei Zhang Jiaomei Hu Dahai Peng Qiufang Xie ...

  16. Thermochemistry of the complex oxides of uranium, vanadium, and alkali metals

    International Nuclear Information System (INIS)

    Karyakin, N.V.; Chernorukov, N.G.; Suleimanov, E.V.; Kharyushina, E.A.

    1992-01-01

    The standard enthalpies of the formation at T 298.15 K of complex oxides of uranium(VI), vanadium(V) and alkali metals with the general formula M 1 VUO 6 where M 1 = Na, K, Rb, and Cs, were calculated from the results of calorimetric experiments and from published data. 8 refs., 1 tab

  17. Characterization of tannin-metal complexes by UV-visible spectrophotometry

    Science.gov (United States)

    Tannins enter soils by plant decay and rain throughfall, but little is known of their effects on soils. Tannins may influence bioavailability and toxicity of metals by forming complexes and by mediating redox reactions. We evaluated the affinity and stoichiometry of Al(III) for a gallotannin, pent...

  18. Direct observation of surface reconstruction and termination on a complex metal oxide catalyst by electron microscopy

    KAUST Repository

    Zhu, Yihan

    2012-03-19

    On the surface: The surface reconstruction of an MoVTeO complex metal oxide catalyst was observed directly by various electron microscopic techniques and the results explain the puzzling catalytic behavior. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Isotope exchange study of the dissociation of metal - humic substance complexes

    Czech Academy of Sciences Publication Activity Database

    Mizera, J.; Jansová, A.; Hvoždová, I.; Beneš, P.; Novák, František

    2003-01-01

    Roč. 53, A (2003), s. A97-A101 ISSN 0011-4626 Institutional research plan: CEZ:AV0Z6066911; CEZ:MSM 210000019 Keywords : isotope exchange * dissociation of metal * humic substance complexes Subject RIV: EH - Ecology, Behaviour Impact factor: 0.263, year: 2003

  20. Macromolecules containing bipyridine and terpyridine metal complexes: towards metallo-supramolecular polymers

    NARCIS (Netherlands)

    Schubert, U.S.; Eschbaumer, C.

    2002-01-01

    The ability of a broad range of N-heterocycles to act as very effective and stable complexation agents for several transition metal ions, such as cobalt(II), copper(II), nickel(II), and ruthenium(II), has long been known in analytical chemistry. This behavior was later utilized in supramolecular

  1. The treatment of complex airway diseases with inverted Y-shaped self-expandable metal stent

    International Nuclear Information System (INIS)

    Li Jianming; Jia Guangzhi

    2011-01-01

    Objective: To investigate the application and therapeutic effects of inverted Y-shaped self-expandable metal airway stent in treating complex airway diseases (stenosis or fistula). Methods: According to the distinctive anatomic structure and the pathological changes of complex airway stenosis or fistula, the inverted y-shaped self-expandable metal airway stent was designed. Under fluoroscopic monitoring, a total of 12 inverted Y-shaped self-expandable metal stents were implanted in 12 patients with complex airway diseases. Results: Stent placement in the trachea-bronchial tree was technically successful in all patients. After the operation, the symptom of dyspnea was immediately relieved and the bucking following food intake disappeared. The general physical condition and living quality were much improved in all patients. Conclusion: The use of inverted Y-shaped self-expandable metal airway stent for the management of complex airway stenosis involving the tracheal carina was a simple and safe procedure and it has satisfactory short-term clinical results. (authors)

  2. Group 4 Transition-Metal Complexes of an Aniline–Carbene–Phenol Ligand

    KAUST Repository

    Despagnet-Ayoub, Emmanuelle

    2013-05-24

    Attempts to install a tridentate aniline-NHC-phenol (NCO) ligand on titanium and zirconium led instead to complexes resulting from unexpected rearrangement pathways that illustrate common behavior in carbene-early- transition-metal chemistry. © 2013 American Chemical Society.

  3. Various types of metal complexes based on chelating {beta}-diketones and their structural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Skopenko, Viktor V; Amirkhanov, Vladimir M; Sliva, T Yu [Department of Chemistry, Kyiv National Taras Shevchenko University (Ukraine); Vasilchenko, Igor S; Anpilova, E L; Garnovskii, Alexander D [Institute of Physical and Organic Chemistry, Rostov State University, Rostov-on-Don (Russian Federation)

    2004-08-31

    Data on the synthesis and structures of {beta}-diketonates and their N,P-containing structural analogues are generalised and described systematically. The possibility of creating diverse metal complexes with various modes of coordination of typical chelating ligands is discussed.

  4. Various types of metal complexes based on chelating β-diketones and their structural analogues

    International Nuclear Information System (INIS)

    Skopenko, Viktor V; Amirkhanov, Vladimir M; Sliva, T Yu; Vasilchenko, Igor S; Anpilova, E L; Garnovskii, Alexander D

    2004-01-01

    Data on the synthesis and structures of β-diketonates and their N,P-containing structural analogues are generalised and described systematically. The possibility of creating diverse metal complexes with various modes of coordination of typical chelating ligands is discussed.

  5. Metal-containing Complexes of Lactams, Imidazoles, and Benzimidazoles and Their Biological Activity

    Science.gov (United States)

    Kukalenko, S. S.; Bovykin, B. A.; Shestakova, S. I.; Omel'chenko, A. M.

    1985-07-01

    The results of the latest investigations of the problem of the synthesis of metal-containing complexes of lactams, imidazoles, and benzimidazoles, their structure, and their stability in solutions are surveyed. Some data on their biological activity (pesticide and pharmacological) and the mechanism of their physiological action are presented. The bibliography includes 190 references.

  6. Multiheteromacrocycles that complex metal ions. Fourth progress report, 1 May 1977--30 April 1978

    International Nuclear Information System (INIS)

    Cram, D.J.

    1978-01-01

    Results are reported in a program to design, synthesize, and evaluate polycyclic host organic compounds for their abilities to complex and lipophilize guest metal ions. Work during the reporting period was devoted to synthesis and study of cyclohexametaphenylenes and cyclic phosphine oxides

  7. Site-selective electroless nickel plating on patterned thin films of macromolecular metal complexes.

    Science.gov (United States)

    Kimura, Mutsumi; Yamagiwa, Hiroki; Asakawa, Daisuke; Noguchi, Makoto; Kurashina, Tadashi; Fukawa, Tadashi; Shirai, Hirofusa

    2010-12-01

    We demonstrate a simple route to depositing nickel layer patterns using photocross-linked polymer thin films containing palladium catalysts, which can be used as adhesive interlayers for fabrication of nickel patterns on glass and plastic substrates. Electroless nickel patterns can be obtained in three steps: (i) the pattern formation of partially quaterized poly(vinyl pyridine) by UV irradiation, (ii) the formation of macromolecular metal complex with palladium, and (iii) the nickel metallization using electroless plating bath. Metallization is site-selective and allows for a high resolution. And the resulting nickel layered structure shows good adhesion with glass and plastic substrates. The direct patterning of metallic layers onto insulating substrates indicates a great potential for fabricating micro/nano devices.

  8. Electronic structures and magnetic/optical properties of metal phthalocyanine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shintaro; Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture. 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

    2016-02-01

    Electronic structures and magnetic / optical properties of metal phthalocyanine complexes were studied by quantum calculations using density functional theory. Effects of central metal and expansion of π orbital on aromatic ring as conjugation system on the electronic structures, magnetic, optical properties and vibration modes of infrared and Raman spectra of metal phthalocyanines were investigated. Electron and charge density distribution and energy levels near frontier orbital and excited states were influenced by the deformed structures varied with central metal and charge. The magnetic parameters of chemical shifts in {sup 13}C-nuclear magnetic resonance ({sup 13}C-NMR), principle g-tensor, A-tensor, V-tensor of electric field gradient and asymmetry parameters derived from the deformed structures with magnetic interaction of nuclear quadruple interaction based on electron and charge density distribution with a bias of charge near ligand under crystal field.

  9. Isotope exchange study of the dissociation of metal-humic substance complexes

    International Nuclear Information System (INIS)

    Mizera, J.; Jansova, A.; Hvozdova, I.; Benes, P.; Novak, F.

    2003-01-01

    Isotope exchange was employed to study dissociation of metal cations from their complexes with humic substances (HS). Dissociation of cation from HS controls the rate of isotope exchange between two identical metal-HS solutions (but for the presence of a radiotracer) divided by a dialysis membrane. The rate of isotope exchange of Eu/ 152 Eu and Co/ 60 Co in the systems with various HS was monitored as a function of pH, ionic strength, and the degree of HS loading with metal. The apparent rate of Eu-HS dissociation was found to be enhanced by decreasing pH, increasing ionic strength, and increasing metal loading. Co-HS dissociation was too fast to be followed by the method. For interpretation of the experimental kinetic data, the multiple first order law has been applied. Based on the results, a concept of HS as a mixture of two types of binding sites is discussed. (author)

  10. Effect of the type of metal on the electrical conductivity and thermal properties of metal complexes: The relation between ionic radius of metal complexes and electrical conductivity

    Science.gov (United States)

    Morgan, Sh. M.; El-Ghamaz, N. A.; Diab, M. A.

    2018-05-01

    Co(II) complexes (1-4) and Ni(II) complexes (5-8) were prepared and characterized by elemental analysis, IR spectra and thermal analysis data. Thermal decomposition of all complexes was discussed using thermogravimetric analysis. The dielectric properties and alternating current conductivity were investigated in the frequency range 0.1-100 kHz and temperature range 300-660 K. The thermal activation energies of electrical conductivity (ΔE1 and ΔE2) values for complexes were calculated and discussed. The values of ΔE1 and ΔE2 for complexes (1-8) were found to decrease with increasing the frequency. Ac electrical conductivity (σac) values increases with increasing temperatures and the values of σac for Co(II) complexes are greater than Ni(II) complexes. Co(II) complexes showed a higher conductivity than other Ni(II) complexes due to the higher crystallinity as confirmed by X-ray diffraction analysis.

  11. Bibliographies on radiation chemistry. 9. Metal ions and complexes. Part A: Cobalt, rhodium, iridium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, M Z; Ross, A B

    1986-01-01

    The one-electron oxidation and reduction of metal ions and complexes can yield species in unusual oxidation states, and ligand-radicals coordinated to the central metal. These often unstable species can be mechanistically important intermediates in thermal, photochemical, and electrochemical reactions involving metal-containing substances. Their generation via radiolysis provides an alternate means of characterizing them using kinetic and spectroscopic techniques. We hope these bibliographies on the radiation chemistry of metal ions and complexes, presented according to periodic groups, will prove useful to researchers in metallo-redox chemistry. These bibliographies contain only primary literature sources; reviews are not included. However, a list of general review articles on the radiation chemistry of metal ions and complexes is presented here in the first section which covers cobalt, rhodium and iridium, Group 9 in the new IUPAC notation. Additional parts of the bibliography are planned, covering other periodic groups. Part A of the bibliography was prepared by a search of the Radiation Chemistry Data Center Bibliographic Data Base (RCDCbib) through January 1986 for papers on rhodium, iridium and cobalt compounds, and radiolysis (both continuous and pulsed). Papers in which the use of metal compounds was incidental to the primary objective of the study were excluded. Excluded also were publications in unrefereed and obscure sources such as meeting proceedings, internal reports, dissertations, and patents. The majority of the studies in the resultant compilation deal with experiments performed on solutions, mainly aqueous, although a substantial fraction is devoted to solid-state esr measurements. The references are listed in separate sections for each of the metals, and are presented in approximate chronological order.

  12. Effect of bisquaternary ammonium salts on complexing of metal ions with pyrocatechol violet

    International Nuclear Information System (INIS)

    Tananajko, M.M.; Kofanova, N.K.

    1984-01-01

    Conditions for the improvement of contrast and sensitivity of reactions of high-charge ions of metals (Mo, W, La, Cd, Zr, Hf, Th) in the process of their photometric determination with pyrocatechol violet (PV), using bisquaternary ammonium salts (BQAS), have been studied. It is shown that in the systems investigated the BQAS play the role of ''shifting'' reagents, shifting bathochromically the absorption bands of different ligand complexes as compared with absorption bands of the Me-PV binary complexes. The effect of the BQAS on complexing with PV in aqueous and organic phases (chloroform) is studied and potential flotation of the compounds in the phase interface is considered

  13. Antibacterial evaluation of some Schiff bases derived from 2-acetylpyridine and their metal complexes.

    Science.gov (United States)

    Gwaram, Nura Suleiman; Ali, Hapipah Mohd; Khaledi, Hamid; Abdulla, Mahmood Ameen; Hadi, A Hamid A; Lin, Thong Kwai; Ching, Chai Lay; Ooi, Cher Lin

    2012-05-18

    A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

  14. A Mononuclear Non-Heme Manganese(IV)-Oxo Complex Binding Redox-Inactive Metal Ions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junying; Lee, Yong-Min; Davis, Katherine M.; Wu, Xiujuan; Seo, Mi Sook; Cho, Kyung-Bin; Yoon, Heejung; Park, Young Jun; Fukuzumi, Shunichi; Pushkar, Yulia N.; Nam, Wonwoo [Ewha; (Purdue); (Osaka)

    2013-05-29

    Redox-inactive metal ions play pivotal roles in regulating the reactivities of high-valent metal–oxo species in a variety of enzymatic and chemical reactions. A mononuclear non-heme Mn(IV)–oxo complex bearing a pentadentate N5 ligand has been synthesized and used in the synthesis of a Mn(IV)–oxo complex binding scandium ions. The Mn(IV)–oxo complexes were characterized with various spectroscopic methods. The reactivities of the Mn(IV)–oxo complex are markedly influenced by binding of Sc3+ ions in oxidation reactions, such as a ~2200-fold increase in the rate of oxidation of thioanisole (i.e., oxygen atom transfer) but a ~180-fold decrease in the rate of C–H bond activation of 1,4-cyclohexadiene (i.e., hydrogen atom transfer). The present results provide the first example of a non-heme Mn(IV)–oxo complex binding redox-inactive metal ions that shows a contrasting effect of the redox-inactive metal ions on the reactivities of metal–oxo species in the oxygen atom transfer and hydrogen atom transfer reactions.

  15. Alkali metal cation complexation and solvent interactions by robust chromium(III) fluoride complexes

    DEFF Research Database (Denmark)

    Birk, T.; Magnussen, M.J.; Piligkos, Stergios

    2010-01-01

    )] have been synthesized from mer-[CrF3(py)(3)] and shown to precipitate sodium salts from solution, of which 3[CrF3(Me(3-)tacn)]center dot 2Na(Bph(4)).solv and 6[CrF3(terpy)]center dot 4Na(Bph(4)).solv have been crystallographically characterized. In these clusters, the neutral fluoride complexes bring...

  16. A series of 2D metal-quinolone complexes: Syntheses, structures, and physical properties

    Energy Technology Data Exchange (ETDEWEB)

    He, Jiang-Hong [College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Xiao, Dong-Rong, E-mail: xiaodr98@yahoo.com.cn [College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chen, Hai-Yan; Sun, Dian-Zhen; Yan, Shi-Wei; Wang, Xin; Ye, Zhong-Li [College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Luo, Qun-Li, E-mail: qlluo@swu.edu.cn [College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Wang, En-Bo, E-mail: wangeb889@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, Department of Chemistry, Northeast Normal University, Changchun 130024 (China)

    2013-02-15

    Six novel 2D metal-quinolone complexes, namely [Cd(cfH)(bpdc)]{center_dot}H{sub 2}O (1), [M(norfH)(bpdc)]{center_dot}H{sub 2}O (M=Cd (2) and Mn (3)), [Mn{sub 2}(cfH)(odpa)(H{sub 2}O){sub 3}]{center_dot}0.5H{sub 2}O (4), [Co{sub 2}(norfH)(bpta)({mu}{sub 2}-H{sub 2}O)(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O (5) and [Co{sub 3}(saraH){sub 2}(Hbpta){sub 2}(H{sub 2}O){sub 4}]{center_dot}9H{sub 2}O (6) (cfH=ciprofloxacin, norfH=norfloxacin, saraH=sarafloxacin, bpdc=4,4 Prime -biphenyldicarboxylate, odpa=4,4 Prime -oxydiphthalate, bpta=3,3 Prime ,4,4 Prime -biphenyltetracarboxylate) have been synthesized and characterized. Compounds 1-3 consist of 2D arm-shaped layers based on the 1D {l_brace}M(COO){r_brace}{sub n}{sup n+} chains. Compounds 4 and 5 display 2D structures based on tetranuclear manganese or cobalt clusters with (3,6)-connected kgd topology. Compound 6 exhibits a 2D bilayer structure, which represents the first example of metal-quinolone complexes with 2D bilayer structure. By inspection of the structures of 1-6, it is believed that the long aromatic polycarboxylate ligands are important for the formation of 2D metal-quinolone complexes. The magnetic properties of compounds 3-6 was studied, indicating the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compounds 1-2 are discussed. - Graphical abstract: Six novel 2D metal-quinolone complexes have been prepared by self-assemblies of the quinolones and metal salts in the presence of long aromatic polycarboxylates. Highlights: Black-Right-Pointing-Pointer Compounds 1-3 consist of novel 2D arm-shaped layers based on the 1D {l_brace}M(COO){r_brace}{sub n}{sup n+} chains. Black-Right-Pointing-Pointer Compounds 4 and 5 are two novel 2D layers based on tetranuclear Mn or Co clusters with kgd topology. Black-Right-Pointing-Pointer Compound 6 is the first example of metal-quinolone complexes with 2D bilayer structure. Black-Right-Pointing-Pointer Compounds 1-6 represent six unusual

  17. Soil Heavy Metal Concentrations in Green Space of Mobarake Steel Complex

    Directory of Open Access Journals (Sweden)

    vahid Moradinasab

    2017-01-01

    Full Text Available Introduction: Water shortage in arid and semiarid regions of the world is a cause of serious concerns. The severe water scarcity urges the reuse of treated wastewater effluent and marginal water as a resource for irrigation. Mobarake Steel Complex has been using treated industrial wastewater for drip-irrigation of trees in about 1350 ha of its green space. However, wastewater may contain some amounts of toxic heavy metals, which create problems. Excessive accumulation of heavy metals in agricultural soils through wastewater irrigation may not only result in soil contamination, but also affect food quality and safety. Improper irrigation management, however, can lead to the loss of soil quality through such processes as contamination and salination. Soil quality implies its capacity to sustain biological productivity, maintain environmental quality, and enhance plants, human and animal health. Soil quality assessment is a tool that helps managers to evaluate short-term soil problems and appropriate management strategies for maintaining soil quality in the long time. Mobarakeh Steel Complex has been using treated wastewater for irrigation of green space to combat water shortage and prevent environmental pollution. This study was performed to assess the impact of short- middle, and long-term wastewater irrigation on soil heavy metal concentration in green space of Mobarake Steel complex. Materials and Methods: The impacts of wastewater irrigation on bioavailable and total heavy metal concentrations in the soils irrigated with treated wastewater for 2, 6 and 18 years as compared to those in soils irrigated with groundwater and un-irrigated soils. Soils were sampled from the wet bulb produced by under-tree sprinklers in three depths (0-20, 20-40 and 40-60 cm. Soil samples were air-dried, and crushed to pass through a 2-mm sieve. Plant-available metal concentrations were extracted from the soil with diethylenetriaminepentaacetic acid-CaCl2

  18. Comparison of trace metal bioavailabilities in European coastal waters using mussels from Mytilus edulis complex as biomonitors

    NARCIS (Netherlands)

    Przytarska, J.E.; Sokołowski, A.; Wołowicz, M.; Hummel, H.; Jansen, J.M.

    2010-01-01

    Mussels from Mytilus edulis complex were used as biomonitors of the trace metals Fe, Mn, Pb, Zn, and Cu at 17 sampling sites to assess the relative bioavailability of metals in coastal waters around the European continent. Because accumulated metal concentrations in a given area can differ

  19. Exploring the Photovoltaic Properties of Metal Bipyridine Complexes (Metal = Fe, Zn, Cr, and Ru) by Density Functional Theory

    Science.gov (United States)

    Irfan, Ahmad; Abbas, Ghulam

    2018-03-01

    The synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure-property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

  20. Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

    Science.gov (United States)

    Refat, Moamen S.

    2013-03-01

    Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

  1. Oxalate metal complexes in aerosol particles: implications for the hygroscopicity of oxalate-containing particles

    Directory of Open Access Journals (Sweden)

    T. Furukawa

    2011-05-01

    Full Text Available Atmospheric aerosols have both a direct and an indirect cooling effect that influences the radiative balance at the Earth's surface. It has been estimated that the degree of cooling is large enough to weaken the warming effect of carbon dioxide. Among the cooling factors, secondary organic aerosols (SOA play an important role in the solar radiation balance in the troposphere as SOA can act as cloud condensation nuclei (CCN and extend the lifespan of clouds because of their high hygroscopic and water soluble nature. Oxalic acid is an important component of SOA, and is produced via several formation pathways in the atmosphere. However, it is not certain whether oxalic acid exists as free oxalic acid or as metal oxalate complexes in aerosols, although there is a marked difference in their solubility in water and their hygroscopicity. We employed X-ray absorption fine structure spectroscopy to characterize the calcium (Ca and zinc (Zn in aerosols collected at Tsukuba in Japan. Size-fractionated aerosol samples were collected for this purpose using an impactor aerosol sampler. It was shown that 10–60% and 20–100% of the total Ca and Zn in the finer particles (<2.1 μm were present as Ca and Zn oxalate complexes, respectively. Oxalic acid is hygroscopic and can thus increase the CCN activity of aerosol particles, while complexes with various polyvalent metal ions such as Ca and Zn are not hygroscopic, which cannot contribute to the increase of the CCN activity of aerosols. Based on the concentrations of noncomplexed and metal-complexed oxalate species, we found that most of the oxalic acid is present as metal oxalate complexes in the aerosols, suggesting that oxalic acid does not always increase the hygroscopicity of aerosols in the atmosphere. Similar results are expected for other dicarboxylic acids, such as malonic and succinic acids. Thus, it is advisable that the cooling effect of organic aerosols should be estimated by including the

  2. Metal ion-mediated agonism and agonist enhancement in melanocortin MC1 and MC4 receptors

    DEFF Research Database (Denmark)

    Holst, Birgitte; Elling, Christian E; Schwartz, Thue W

    2002-01-01

    -melanocortin stimulating hormone (alpha-MSH) in the MC1 and MC4 receptors, respectively. In the presence of peptide agonist, Zn(II) acted as an enhancer on both receptors, because it shifted the dose-response curves to the left: most pronounced was a 6-fold increase in alpha-MSH potency on the MC1 receptor. The effect......An endogenous metal-ion site in the melanocortin MC1 and MC4 receptors was characterized mainly in transiently transfected COS-7 cells. ZnCl(2) alone stimulated signaling through the Gs pathway with a potency of 11 and 13 microm and an efficacy of 50 and 20% of that of alpha...... affinities and profiles were similar for a number of the 2,2'-bipyridine and 1,10-phenanthroline analogs in complex with Zn(II) in the MC1 and MC4 receptors. However, the potencies and efficacies of the metal-ion complexes were very different in the two receptors, and close to full agonism was obtained...

  3. Complexation of trichlorosalicylic acids by alkaline and first row transition metals as a switch for their antibacterial activity

    KAUST Repository

    Kumar, Vijay

    2017-09-14

    3,5,6-trichlorosalicylic acid (TCSA) does not show a good antibacterial activity. In contrast, here metal complexes with TCSA have shown better antibacterial activity for selected bacterial strains with a good degree of selectivity. Amongst the eight synthesized essential metal complexes complexed with TCSA, Mn(II)-TCSA and Ni(II)-TCSA have been found to be more effective with MIC range 20-50 µg/L as compared to control (chloramphenicol). The activity of an individual complex against different microbes was not found to be identical, indicating the usage of an individual metal chelate against a targeted bacterial strain. Further, the protein (BSA) binding constant of TCSA and its metal complexes were determined and ordered as Ca(II)-TCSA > Cu(II)-TCSA > Mg(II)-TCSA >> Mn(II)-TCSA >> Zn(II)-TCSA >>> Ni(II)-TCSA >>> Co(II)-TCSA > Fe(II)-TCSA > TCSA. The present study has confirmed enhanced antibacterial activities and binding constants for metal chelates of TCSA as compared to free TCSA, which seems directly related with the antioxidant activities of these complexes. Further, bearing the ambiguity related to the structural characterization of the metal complexed with TCSA ligands, DFT calculations have been used as the tool to unravel the right environment around the metals, studying basically the relative stability of square planar and octahedral metal complexes with TCSA.

  4. Electrochemistry of metal complexes applications from electroplating to oxide layer formation

    CERN Document Server

    Survila, Arvydas

    2015-01-01

    This book aims to sequentially cover all the major stages of electrochemical processes (mass transport, adsorption, charge transfer), with a special emphasis on their deep interrelation. Starting with general considerations on equilibria in solutions and at interfaces as well as on mass transport, the text acquaints readers with the theory and common experimental practice for studying electrochemical reactions of metals complexes. The core part of the book deals with all important aspects of electroplating, including a systematic discussion of co-deposition of metals and formation of alloys.

  5. Direct measurement and modulation of single-molecule coordinative bonding forces in a transition metal complex

    DEFF Research Database (Denmark)

    Hao, Xian; Zhu, Nan; Gschneidtner, Tina

    2013-01-01

    remain a daunting challenge. Here we demonstrate an interdisciplinary and systematic approach that enables measurement and modulation of the coordinative bonding forces in a transition metal complex. Terpyridine is derived with a thiol linker, facilitating covalent attachment of this ligand on both gold...... substrate surfaces and gold-coated atomic force microscopy tips. The coordination and bond breaking between terpyridine and osmium are followed in situ by electrochemically controlled atomic force microscopy at the single-molecule level. The redox state of the central metal atom is found to have...

  6. Complex C: A Low-Metallicity, High-Velocity Cloud Plunging into the Milky Way

    Science.gov (United States)

    Tripp, Todd M.; Wakker, Bart P.; Jenkins, Edward B.; Bowers, C. W.; Danks, A. C.; Green, R. F.; Heap, S. R.; Joseph, C. L.; Kaiser, M. E.; Linsky, J. L.; Woodgate, B. E.

    2003-06-01

    We present evidence that high-velocity cloud (HVC) complex C is a low-metallicity gas cloud that is plunging toward the disk and beginning to interact with the ambient gas that surrounds the Milky Way. This evidence begins with a new high-resolution (7 km s-1 FWHM) echelle spectrum of 3C 351 obtained with the Space Telescope Imaging Spectrograph (STIS). 3C 351 lies behind the low-latitude edge of complex C, and the new spectrum provides accurate measurements of O I, Si II, Al II, Fe II, and Si III absorption lines at the velocity of complex C; N I, S II, Si IV, and C IV are not detected at 3 σ significance in complex C proper. However, Si IV and C IV as well as O I, Al II, Si II and Si III absorption lines are clearly present at somewhat higher velocities associated with a ``high-velocity ridge'' (HVR) of 21 cm emission. This high-velocity ridge has a similar morphology to and is roughly centered on complex C proper. The similarities of the absorption-line ratios in the HVR and complex C suggest that these structures are intimately related. In complex C proper we find [O/H]=-0.76+0.23-0.21. For other species the measured column densities indicate that ionization corrections are important. We use collisional and photoionization models to derive ionization corrections; in both models we find that the overall metallicity Z=0.1-0.3 Zsolar in complex C proper, but nitrogen must be underabundant. The iron abundance indicates that the complex C contains very little dust. The size and density implied by the ionization models indicate that the absorbing gas is not gravitationally confined. The gas could be pressure confined by an external medium, but alternatively we may be viewing the leading edge of the HVC, which is ablating and dissipating as it plunges into the Milky Way. O VI column densities observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) toward nine QSOs/AGNs behind complex C support this conclusion: N(O VI) is highest near 3C 351, and the O VI/H I

  7. Metal-induced gap states in ferroelectric capacitors and its relationship with complex band structures

    Science.gov (United States)

    Junquera, Javier; Aguado-Puente, Pablo

    2013-03-01

    At metal-isulator interfaces, the metallic wave functions with an energy eigenvalue within the band gap decay exponentially inside the dielectric (metal-induced gap states, MIGS). These MIGS can be actually regarded as Bloch functions with an associated complex wave vector. Usually only real values of the wave vectors are discussed in text books, since infinite periodicity is assumed and, in that situation, wave functions growing exponentially in any direction would not be physically valid. However, localized wave functions with an exponential decay are indeed perfectly valid solution of the Schrodinger equation in the presence of defects, surfaces or interfaces. For this reason, properties of MIGS have been typically discussed in terms of the complex band structure of bulk materials. The probable dependence on the interface particulars has been rarely taken into account explicitly due to the difficulties to include them into the model or simulations. We aim to characterize from first-principles simulations the MIGS in realistic ferroelectric capacitors and their connection with the complex band structure of the ferroelectric material. We emphasize the influence of the real interface beyond the complex band structure of bulk materials. Financial support provided by MICINN Grant FIS2009-12721-C04-02, and by the European Union Grant No. CP-FP 228989-2 ``OxIDes''. Computer resources provided by the RES.

  8. Half-sandwich cobalt complexes in the metal-organic chemical vapor deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Georgi, Colin [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany); Hapke, Marko; Thiel, Indre [Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT), Albert-Einstein-Straße 29a, Rostock 18059 (Germany); Hildebrandt, Alexander [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany); Waechtler, Thomas; Schulz, Stefan E. [Fraunhofer Institute of Electronic Nano Systems (ENAS), Technologie-Campus 3, Chemnitz 09126 (Germany); Technische Universität Chemnitz, Center for Microtechnologies (ZfM), Chemnitz 09107 (Germany); Lang, Heinrich, E-mail: heinrich.lang@chemie.tu-chemnitz.de [Technische Universität Chemnitz, Faculty of Natural Science, Institute of Chemistry, Inorganic Chemistry, Chemnitz 09107 (Germany)

    2015-03-02

    A series of cobalt half-sandwich complexes of type [Co(η{sup 5}-C{sub 5}H{sub 5})(L)(L′)] (1: L, L′ = 1,5-hexadiene; 2: L = P(OEt){sub 3}, L′ = H{sub 2}C=CHSiMe{sub 3}; 3: L = L′ = P(OEt){sub 3}) has been studied regarding their physical properties such as the vapor pressure, decomposition temperature and applicability within the metal-organic chemical vapor deposition (MOCVD) process, with a focus of the influence of the phosphite ligands. It could be shown that an increasing number of P(OEt){sub 3} ligands increases the vapor pressure and thermal stability of the respective organometallic compound. Complex 3 appeared to be a promising MOCVD precursor with a high vapor pressure and hence was deposited onto Si/SiO{sub 2} (100 nm) substrates. The resulting reflective layer is closed, dense and homogeneous, with a slightly granulated surface morphology. X-ray photoelectron spectroscopy (XPS) studies demonstrated the formation of metallic cobalt, cobalt phosphate, cobalt oxide and cobalt carbide. - Highlights: • Thermal studies and vapor pressure measurements of cobalt half-sandwich complexes was carried out. • Chemical vapor deposition with cobalt half-sandwich complexes is reported. • The use of Co-phosphites results in significant phosphorous-doped metallic layers.

  9. The coordination chemistry of dipyridylbenzene: N-deficient terpyridine or panacea for brightly luminescent metal complexes?

    Science.gov (United States)

    Williams, J A Gareth

    2009-06-01

    1,3-Di(2-pyridyl)benzene (dpybH) structurally resembles the widely-used ligand terpyridine (tpy), with which it is isoelectronic. In this critical review, following a brief overview of synthetic strategies for dpybH and derivatives, we survey the different types of complex that are possible with these ligands. Whilst metals such as ruthenium(ii), osmium(ii) and platinum(ii) give a terdentate N--C--N binding mode in which cyclometallation occurs at C(2), the ions iridium(iii), rhodium(iii) and palladium(ii) favour C(4) metallation. The latter process can be blocked by appropriate ligand modification, to allow the N--C--N mode to be accessed with these metal ions too. The luminescence properties of the complexes are discussed. A huge range of emission efficiencies are encountered amongst Ir(iii) complexes containing dpyb derivatives, according to the other ligands present. Trends can be rationalised with the aid of simple frontier-orbital considerations. The Pt(ii) complexes of dipyridylbenzenes are also intensely luminescent. Their application to contemporary organic light-emitting device (OLED) technology is discussed, including white light emitters exploiting excimer emission. Their potential as cell imaging agents amenable to time-resolved detection procedures on the microsecond timescale has also been demonstrated (118 references).

  10. Synthesis, spectral and thermal studies of pyridyl adducts of Zn(II) and Cd(II) dithiocarbamates, and their use as single source precursors for ZnS and CdS nanoparticles.

    Science.gov (United States)

    Onwudiwe, Damian C; Strydom, Christien A; Oluwafemi, Oluwatobi S; Hosten, Eric; Jordaan, Anine

    2014-06-21

    The synthesis, spectroscopic characterisation, and thermal studies of pyridyl adducts of Zn(II) and Cd(II) complexes of N-ethyl-N-phenyl dithiocarbamate, represented as [ZnL2py] and [CdL2py2], are reported. Single-crystal X-ray structural analysis of the Zn compound showed that it is five-coordinate with four sulphurs from dithiocarbamate and one nitrogen from pyridine in a distorted square pyramidal geometry. The thermogravimetric studies indicate that the zinc and cadmium compounds undergo fast weight loss, and the temperature at maximum rate of decomposition is at 277 °C and 265 °C respectively, to give the metal (Zn or Cd) sulphide residues. These compounds were used as single molecule precursors to produce nanocrystalline MS (M = Zn, Cd) after thermolysis in hexadecylamine. The morphological and optical properties of the resulting MS nanocrystallites were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-Vis absorption and photoluminescence (PL) spectroscopy, and powdered X-ray diffraction (XRD). By varying the growth time, the temporal evolution of the optical properties and morphology of the nanocrystals were investigated.

  11. Metal complexes of the fourth generation quinolone antimicrobial drug gatifloxacin: Synthesis, structure and biological evaluation

    Science.gov (United States)

    Sadeek, Sadeek A.; El-Shwiniy, Walaa H.

    2010-08-01

    Three metal complexes of the fourth generation quinolone antimicrobial agent gatifloxacin (GFLX) with Y(ΙΙΙ), Zr(ΙV) and U(VΙ) have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, gatifloxacin acts as a bidentate deprotonated ligand bound to the metal through the ketone oxygen and a carboxylato oxygen. The complexes are six-coordinated with distorted octahedral geometry. The kinetic parameters for gatifloxacin and the three prepared complexes have been evaluated from TGA curves by using Coats-Redfern (CR) and Horowitz-Metzeger (HM) methods. The calculated bond length and force constant, F(U dbnd O), for the UO 2 bond in uranyl complex are 1.7522 Å and 639.46 N m -1. The antimicrobial activity of the complexes has been tested against microorganisms, three bacterial species, such as Staphylococcus aureus ( S. aureus), Escherichia coli ( E. coli) and Pseudomonas aeruginosa ( P. aeruginosa) and two fungi species, penicillium ( P. rotatum) and trichoderma ( T. sp.), showing that they exhibit higher activity than free ligand.

  12. Multiheteromacrocycles that Complex Metal Ions. Second Progress Report, 1 May 1975 -- 30 April 1976

    Science.gov (United States)

    Cram, D. J.

    1976-01-15

    Objective is to develop cyclic and polycyclic host organic compounds to complex and lipophilize metal ions. Macrorings were synthesized: (OCH{sub 2} CH{sub 2} O CH{sub 2}COCH{sub 2} COCH{sub 2}){sub 2} and (OCH{sub 2} CH{sub 2} O CH{sub 2} COCH{sub 2} COCH{sub 2}){sub 3}. The smaller ring complexes divalent metals 10{sup 1+9} times better than the open-chain model CH{sub 3} O CH{sub 2} CO CH{sub 2} COCH{sub 2} O CH{sub 3}, and the order in which metal ions are complexed is Cu{sup 2+}, UO{sub 2}{sup 2+} greater than Ni{sup 2+} greater than Fe{sup 2+}, Co{sup 2+}, Zn{sup 2+}, Cd{sup 2+} greater than Mn{sup 2+}. The UO{sub 2}{sup 2+} and Cu{sup 2+} complexes were isolated and characterized. The larger ring complexes trivalent metals 10{sup 0.9-1.7} times better than the open- chain model compound, and the order is La{sup 3+}, Ce{sup 3+} greater than Cr{sup 3+}. Five other macrocycles were also synthesized, and their binding constants with Na, K, NH{sub 4}, and Cs picrates were measured. Six compounds containing one macroring and two inward-pointing ArOH or ArOCH{sub 3} groups were also prepared and tested for binding of Li, Na, K, Rb, and NH{sub 4} picrates. Racemic compounds containing two binaphthyls and its sulfur analog were prepared. Cage-shaped multiheteromacrocycles containing ten O ligand sites or four S and six O ligand sites were prepared and the binding capability of the first compound for picrates studied. Two ring systems with phosphonate ester groups were also prepared. (DLC)

  13. Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

    Science.gov (United States)

    Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

    2014-11-01

    A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

  14. Isotope exchange study of the dissociation of metal-humic complexes

    International Nuclear Information System (INIS)

    Mizera, J.; Jansova, A.; Hvozdova, I.; Benes, P.

    2002-01-01

    Prediction of the migration of toxic metals and radionuclides in the environment requires knowledge of equilibrium and kinetic parameters characterising their interaction with humic substance (HS). In this work, isotope exchange of Eu and Co in the systems containing HS has been used to study dissociation of the cations from their complexes with HS under quasi-stationary conditions. In the experimental arrangement of the so-called diaphragm method, a dialysis membrane divides two compartments containing solutions of metal and HS, identical in both half-cells but for radiolabeling ( 152 Eu and 60 Co) applied only in one cell. The membrane is permeable for free metal cation but not for the metal-HS complex. The slow dissociation of metal cation from HS is reflected by retardation (compared to a reference system in the absence of HS) of the rate of the isotope exchange between the two compartments. However, only an apparent dissociation rate can be observed, as detection of fast dissociation is limited by the rate of diffusion of dissociated cations through membrane and by their recombination with available binding sites of HS. The rate of isotope exchange of Eu and Co in the systems with HS (Aldrich sodium humate, soil humic and fulvic acid) was monitored as function of pH (4 and 6), ionic strength (0.01 and 0.1 M), and the degree of HS loading with metal ([M] 0 = 10 -7 - 2x10 -5 M at 10 mg/L HS). For Co, the rate of 60 Co 2+ diffusion through the membrane showed up to control the rate of the isotope exchange indicating that the Co-HS dissociation is too fast to be followed by the diaphragm method, and that the abundance of non-complexed Co is not negligible. The apparent rate of Eu-HS dissociation was found to be enhanced by decreasing pH value, increasing ionic strength, and increasing metal loading (i.e., metal/HS ratio). For interpretation of the experimental kinetic data, a discrete 2-component model (bi-exponential decay function) was applied. Based on

  15. Conventional and microwave synthesis, spectral, thermal and antimicrobial studies of some transition metal complexes containing 2-amino-5-methylthiazole moiety

    Directory of Open Access Journals (Sweden)

    A.P. Mishra

    2014-12-01

    Full Text Available Schiff base metal complexes of Cr(III, Co(II, Ni(II and Cu(II derived from 5-chlorosalicylidene-2-amino-5-methylthiazole (HL1 and 2-hydroxy-1-naphthylidene-2-amino-5-methylthiazole (HL2 have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, 1H-NMR, ESR, magnetic susceptibility, thermal, electrical conductivity and XRD analyses. The complexes exhibit coordination number 4 or 6. The complexes are coloured and stable in air. Analytical data reveal that all the complexes exhibit 1:2 (metal:ligand ratio. IR data show that the ligand coordinates with the metal ions in a bidentate manner through the phenolic oxygen and azomethine nitrogen. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behaviour of metal complexes shows that the hydrated complexes lose water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. XRD patterns indicate crystalline nature for the complexes. The Schiff bases and metal complexes show good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases.

  16. MECHANISMS OF THE COMPLEX FORMATION BY d-METALS ON POROUS SUPPORTS AND THE CATALYTIC ACTIVITY OF THE FORMED COMPLEXES IN REDOX REACTIONS

    Directory of Open Access Journals (Sweden)

    T. L. Rakitskaya

    2015-11-01

    Full Text Available The catalytic activity of supported complexes of d metals in redox reactions with participation of gaseous toxicants, PH3, CO, O3, and SO2, depends on their composition. Owing to the variety of physicochemical and structural-adsorption properties of available supports, their influence on complex formation processes, the composition and catalytic activity of metal complexes anchored on them varies over a wide range. The metal complex formation on sup-ports with weak ion-exchanging properties is similar to that in aqueous solutions. In this case, the support role mainly adds up to the ability to reduce the activity of water adsorbed on them. The interaction between a metal complex and a support surface occurs through adsorbed water molecules. Such supports can also affect complex formation processes owing to protolytic reactions on account of acidic properties of sorbents used as supports. The catalytic activity of metal complexes supported on polyphase natural sorbents considerably depends on their phase relationship. In the case of supports with the nonsimple structure and pronounced ion-exchanging properties, for instance, zeolites and laminar silicates, it is necessary to take into account the variety of places where metal ions can be located. Such location places determine distinctions in the coordination environment of the metal ions and the strength of their bonding with surface adsorption sites and, therefore, the catalytic activity of surface complexes formed by theses metal ions. Because of the energy surface inhomogeneity, it is important to determine a relationship between the strength of a metal complex bonding with a support surface and its catalytic activity. For example, bimetallic complexes are catalytically active in the reactions of oxidation of the above gaseous toxicants. In particular, in the case of carbon monoxide oxidation, the most catalytic activity is shown by palladium-copper complexes in which copper(II is strongly

  17. The effect of environmental conditions on the stability of heavy metal-filter material complex as assessed by the leaching of adsorbed metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Khokhotva, Oleksandr, E-mail: khokhotva@bigmir.net [School of Sustainable Development of Society and Technology, Maelardalen University, Box 883, SE-721 23, Vaesteras (Sweden); Waara, Sylvia, E-mail: sylvia.waara@hh.se [School of Sustainable Development of Society and Technology, Maelardalen University, Box 883, SE-721 23, Vaesteras (Sweden)

    2011-06-15

    In this study the influence of environmental conditions, most likely prevailing in filter beds used for intermittently discharged pollutant streams such as landfill leachate and storm water, on the stability of the heavy metal-filter complex was investigated for 2 filter materials; non-treated and urea treated pine bark, using leaching experiments. The metal-filter complex stability was higher for urea treated than for non-treated pine bark and dependent on the metal adsorbed. The type of environmental condition applied was of less importance for the extent of leaching. - Highlights: > Metal-pine bark complex stability under changing environmental conditions is studied. > Metal leaching from non-treated bark is much higher than from urea-treated bark. > No significant influence of changing environmental conditions on the leaching extent. > Metal leaching from wet bark samples exposed to freezing is somewhat higher.> Zn leaching is the highest and Cu leaching is the lowest for both bark samples. - The study assess the metal-filter material complex stability when metal removal using filter material is used in locations with fluctuating environmental conditions.

  18. The effect of environmental conditions on the stability of heavy metal-filter material complex as assessed by the leaching of adsorbed metal ions

    International Nuclear Information System (INIS)

    Khokhotva, Oleksandr; Waara, Sylvia

    2011-01-01

    In this study the influence of environmental conditions, most likely prevailing in filter beds used for intermittently discharged pollutant streams such as landfill leachate and storm water, on the stability of the heavy metal-filter complex was investigated for 2 filter materials; non-treated and urea treated pine bark, using leaching experiments. The metal-filter complex stability was higher for urea treated than for non-treated pine bark and dependent on the metal adsorbed. The type of environmental condition applied was of less importance for the extent of leaching. - Highlights: → Metal-pine bark complex stability under changing environmental conditions is studied. → Metal leaching from non-treated bark is much higher than from urea-treated bark. → No significant influence of changing environmental conditions on the leaching extent. → Metal leaching from wet bark samples exposed to freezing is somewhat higher.→ Zn leaching is the highest and Cu leaching is the lowest for both bark samples. - The study assess the metal-filter material complex stability when metal removal using filter material is used in locations with fluctuating environmental conditions.

  19. Reactive solute transport in streams: A surface complexation approach for trace metal sorption

    Science.gov (United States)

    Runkel, Robert L.; Kimball, Briant A.; McKnight, Diane M.; Bencala, Kenneth E.

    1999-01-01

    A model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented. Linkage between a surface complexation submodel and the stream transport equations provides a framework for modeling sorption onto static and/or dynamic surfaces. A static surface (e.g., an iron- oxide-coated streambed) is defined as a surface with a temporally constant solid concentration. Limited contact between solutes in the water column and the static surface is considered using a pseudokinetic approach. A dynamic surface (e.g., freshly precipitated metal oxides) has a temporally variable solid concentration and is in equilibrium with the water column. Transport and deposition of solute mass sorbed to the dynamic surface is represented in the stream transport equations that include precipitate settling. The model is applied to a pH-modification experiment in an acid mine drainage stream. Dissolved copper concentrations were depressed for a 3 hour period in response to the experimentally elevated pH. After passage of the pH front, copper was desorbed, and dissolved concentrations returned to ambient levels. Copper sorption is modeled by considering sorption to aged hydrous ferric oxide (HFO) on the streambed (static surface) and freshly precipitated HFO in the water column (dynamic surface). Comparison of parameter estimates with reported values suggests that naturally formed iron oxides may be more effective in removing trace metals than synthetic oxides used in laboratory studies. The model's ability to simulate pH, metal oxide precipitation-dissolution, and pH-dependent sorption provides a means of evaluating the complex interactions between trace metal chemistry and hydrologic transport at the field scale.

  20. Development of Hydrogen Storage Tank Systems Based on Complex Metal Hydrides

    Directory of Open Access Journals (Sweden)

    Morten B. Ley

    2015-09-01

    Full Text Available This review describes recent research in the development of tank systems based on complex metal hydrides for thermolysis and hydrolysis. Commercial applications using complex metal hydrides are limited, especially for thermolysis-based systems where so far only demonstration projects have been performed. Hydrolysis-based systems find their way in space, naval, military and defense applications due to their compatibility with proton exchange membrane (PEM fuel cells. Tank design, modeling, and development for thermolysis and hydrolysis systems as well as commercial applications of hydrolysis systems are described in more detail in this review. For thermolysis, mostly sodium aluminum hydride containing tanks were developed, and only a few examples with nitrides, ammonia borane and alane. For hydrolysis, sodium borohydride was the preferred material whereas ammonia borane found less popularity. Recycling of the sodium borohydride spent fuel remains an important part for their commercial viability.

  1. Development of Hydrogen Storage Tank Systems Based on Complex Metal Hydrides

    Science.gov (United States)

    Ley, Morten B.; Meggouh, Mariem; Moury, Romain; Peinecke, Kateryna; Felderhoff, Michael

    2015-01-01

    This review describes recent research in the development of tank systems based on complex metal hydrides for thermolysis and hydrolysis. Commercial applications using complex metal hydrides are limited, especially for thermolysis-based systems where so far only demonstration projects have been performed. Hydrolysis-based systems find their way in space, naval, military and defense applications due to their compatibility with proton exchange membrane (PEM) fuel cells. Tank design, modeling, and development for thermolysis and hydrolysis systems as well as commercial applications of hydrolysis systems are described in more detail in this review. For thermolysis, mostly sodium aluminum hydride containing tanks were developed, and only a few examples with nitrides, ammonia borane and alane. For hydrolysis, sodium borohydride was the preferred material whereas ammonia borane found less popularity. Recycling of the sodium borohydride spent fuel remains an important part for their commercial viability. PMID:28793541

  2. Complex Metal Hydrides for hydrogen storage and solid-state ion conductors

    DEFF Research Database (Denmark)

    Payandeh GharibDoust, SeyedHosein

    and electricity in batteries. However, both hydrogen and electricity must be stored in a very dense way to be useful, e.g. for mobile applications. Complex metal hydrides have high hydrogen density and have been studied during the past twenty years in hydrogen storage systems. Moreover, they have shown high ionic...... conductivities which promote their application as solid electrolytes in batteries. This dissertation presents the synthesis and characterization of a variety of complex metal hydrides and explores their hydrogen storage properties and ionic conductivity. Five halide free rare earth borohydrides RE(BH4)3, (RE...... = La, Ce, Pr, Nd, Er) have been synthesized, which pave the way for studying the polymorphic transition in these compounds, obtaining new bimetallic borohydrides and designing new reactive hydride composites with improved hydrogen storage capacities. Two novel polymorphs of Pr(BH4)3 are identified...

  3. Equation of limiting plasticity of the metal upon complex stress state

    International Nuclear Information System (INIS)

    Tin'gaev, A.K.

    2002-01-01

    A method for evaluation of the limiting plasticity of the metal in the zones of complex 3D stress state is presented. An analytic equation is derived for limiting plasticity. Parameters of the equation are expresses through the standard characteristics of the mechanical properties determined upon static tension of the smooth sample. Introduced into the obtained analytical equation is a universal fracture constant which indirectly characterizes the state of the material from the point of view of its capacity for elastic overstrain relaxation in the form of plastic flow or fracture. The new equation makes it possible to estimate the limiting plasticity of the metal in a state of complex stress on the basis of traditional characteristics of mechanical properties, which are not difficult to determine [ru

  4. Atomic Resolution Imaging of Nanoscale Structural Ordering in a Complex Metal Oxide Catalyst

    KAUST Repository

    Zhu, Yihan

    2012-08-28

    The determination of the atomic structure of a functional material is crucial to understanding its "structure-to-property" relationship (e.g., the active sites in a catalyst), which is however challenging if the structure possesses complex inhomogeneities. Here, we report an atomic structure study of an important MoVTeO complex metal oxide catalyst that is potentially useful for the industrially relevant propane-based BP/SOHIO process. We combined aberration-corrected scanning transmission electron microscopy with synchrotron powder X-ray crystallography to explore the structure at both nanoscopic and macroscopic scales. At the nanoscopic scale, this material exhibits structural and compositional order within nanosized "domains", while the domains show disordered distribution at the macroscopic scale. We proposed that the intradomain compositional ordering and the interdomain electric dipolar interaction synergistically induce the displacement of Te atoms in the Mo-V-O channels, which determines the geometry of the multifunctional metal oxo-active sites.

  5. The importance of the Maillard-metal complexes and their silicates in astrobiology

    Science.gov (United States)

    Liesch, Patrick J.; Kolb, Vera M.

    2007-09-01

    The Maillard reaction occurs when sugars and amino acids are mixed together in the solid state or in the aqueous solution. Since both amino acids and sugar-like compounds are found on meteorites, we hypothesized that they would also undergo the Maillard reaction. Our recent work supports this idea. We have shown previously that the water-insoluble Maillard products have substantial similarities with the insoluble organic materials from the meteorites. The Maillard organic materials are also part of the desert varnish on Earth, which is a dark, shiny, hard rock coating that contains iron and manganese and is glazed in silicate. Rocks that are similar in appearance to the desert varnish have been observed on the Martian surface. They may also contain the organic materials. We have undertaken study of the interactions between the Maillard products, iron and other metals, and silicates, to elucidate the role of the Maillard products in the chemistry of desert varnish and meteorites. Specifically, we have synthesized a series of the Maillard-metal complexes, and have tested their reactivity towards silicates. We have studied the properties of these Maillard-metal-silicate products by the IR spectroscopy. The astrobiological potential of the Maillard-metal complexes is assessed.

  6. Synthesis, characterization, antiplasmodial and antitrypanosomal activity of some metal(III complexes of sulfadiazine

    Directory of Open Access Journals (Sweden)

    P.A. Ajibade

    2008-08-01

    Full Text Available The Fe(III, Ru(III, Rh(III, and Cr(III complexes of 4-amino-N-(2-pyrimidinylbenzene sulfonamide (sulfadiazine have been synthesized and characterized by elemental analysis, electronic and IR spectroscopy, conductance and room temperature magnetic susceptibility measurements. Sulfadiazine acts as a bidentate ligand through the sulfonamido and the pyrimidinic N-atoms. The compounds are non-electrolytes and the electronic spectra are consistent with the proposed octahedral geometry around the metal ions. The complexes were tested for in vitro activity against cultures of the resistant strains of Plasmodium falciparum, tripamastigotes T. b. rhodesiense and amastigotes L. donovani to determine their antiprotozoal activities. The Fe(III complex is more active than the other complexes against the parasitic protozoa.

  7. Tridentate hydrazone metal complexes derived from cephalexin and 2-hydrazinopyridine: Synthesis, characterization and antibacterial activity

    Science.gov (United States)

    Anacona, J. R.; Rincones, Maria

    2015-04-01

    Metal(II) coordination compounds of a tridentate hydrazone ligand (HL) derived from the condensation of cephalexin antibiotic with 2-hydrazinopyridine were synthesized. The hydrazone ligand and mononuclear [ML(OAc)(H2O)] (M(II) = Mn, Co, Ni, Cu, Zn, Ag) complexes were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and 1H NMR spectral studies. The cephalexin 2-pyridinylhydrazone ligand HL behaves as a monoanionic tridentate NNO chelating agent. The biological applications of complexes have been studied on three bacteria strains (Escherichia coli, Acinetobacter baumannii and Enterococcus faecalis) by agar diffusion disc method.

  8. Metadislocation reactions and metadislocation networks in the complex metallic alloy ξ'-Al-Pd-Mn

    International Nuclear Information System (INIS)

    Heggen, Marc; Feuerbacher, Michael

    2005-01-01

    Metadislocations are novel structural defects firstly observed in the complex metallic alloy ξ'-Al-Pd-Mn. We present a transmission electron microscopy study on metadislocation reactions and networks. It is shown that metadislocations can dissociate into partials, which leads to a decrease of the elastic line energy. Connected groups of metadislocations can assume large and complex network structures with large total Burgers vectors. However, the local elastic strain at the individual metadislocation cores as well as the fault-plane energies remain small. By this mechanism, effective large Burgers vectors, contributing massively to plastic strain, can be distributed over a large portion of the material

  9. Theoretical NMR spectroscopy of N-heterocyclic carbenes and their metal complexes

    KAUST Repository

    Falivene, Laura

    2016-12-26

    Recent theoretical analysis of the NMR properties of free N-heterocyclic carbenes (NHC) and Metal-NHC complexes has complemented experiments, allowing the establishment of structure/property relationships and the rationalization of otherwise surprising experimental results. In this review, the main conclusions from recent literature are discussed, with the aim to offer a vision of the potential of theoretical analyses of NMR properties.

  10. Synthesis and properties of complexes of 1-phenyl-2,3-dimetylpyrazolone-5-thione with metals

    International Nuclear Information System (INIS)

    Bikkulova, A.T.; Kapina, A.P.; Medvedeva, E.A.

    1985-01-01

    Cadmium complexes with thiopyrine (1-phenyl-2.3-dimethylpyrazolone-5-thione) (R) of the composition CdR 2 X 2 are obtained by precipitation from hydrochloric acid solutions at pH=1 and at chloride and bromide (X) excess. The formation of coordination bond of a metal through the sulphur atom is established by the IR- and NMR-spectroscopy methods. Fungicidal activity of the compositions obtained is detected

  11. Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

    Directory of Open Access Journals (Sweden)

    J. Senthil Kumaran

    2013-01-01

    Full Text Available A new series of Cu (II, Ni (II, Co (II and Zn (II complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis, 1H-NMR, 13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2 type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–H⋯O and C–H⋯N hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such as Bacillus subtilis, Staphylococcus aureus, Proteus vulgaris and fungal species such as Candida albicans by the well-diffusion method.

  12. Copper-based metal coordination complexes with Voriconazole ligand: Syntheses, structures and antimicrobial properties

    Science.gov (United States)

    Zhao, Yan-Ming; Tang, Gui-Mei; Wang, Yong-Tao; Cui, Yue-Zhi; Ng, Seik Weng

    2018-03-01

    Three new chiral metal coordination complexes, namely, [Cu(FZ)2(CH3COO)2(H2O)]·2H2O (1), [Cu(FZ)2(NO3)2] (2), and [Cu2(FZ)2 (H2O)8](SO4)2·4H2O (3) [FZ = (2R,3S)-2-(2,4-difluorophenyl)-3-(5-fluoro-4-pyrimidiny)-1-(1H-1,2,4-triazol-1-yl)-2-butanol) (Voriconazole)] have been obtained by the reaction of Cu(II) salts and the free ligand FZ at room temperature. Complexes 1-3 were structurally characterized by X-ray single-crystal diffraction, IR, UV-vis, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). Complex 1 crystallizes in the chiral space group C2, which exhibits a mono-nuclear structure. Both complexes 2 and 3 display a one-dimensional (1D) tape structure, which crystallize in chiral space group P21212 and P212121, respectively. Among these complexes, there exist a variety of hydrogen bonds and stacking interactions, through which a three-dimensional supramolecular architecture will be generated. Compared with the standard (Voriconazole), these Cu-based complexes show the more potent inhibiting efficiency against the species of Candida and Aspergillus. Moreover, among these complexes, complex 1 shows the most excellent efficiency.

  13. Synthesis, Characterization and Antimicrobial Activities of Transition Metal Complexes of methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate

    International Nuclear Information System (INIS)

    Ikram, M.; Rehman, S.

    2016-01-01

    New metal complexes with Schiff base ligand methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate, were synthesized and characterized. Elemental analyses, EI-MS, 1H and 13C(1H)-NMR were used for ligand characterization whereas elemental analyses, EI-MS, IR and UV-Visible spectroscopic techniques were used for the transition metal compounds. All these analyses reveal the bis arrangement of the ligand around the metal centres. The compounds were studied for their antimicrobial activities against different pathogenic microbial species. It was found that the Schiff base ligand was completely inactive in comparison to the transition metal compounds. It was also observed that nickel based metal complex shown good results against Candida albican (25 mm) and zinc based metal complex against Agrobacterium tumefaciens (16 mm). (author)

  14. Characterization of metal-bound water in bioactive Fe(III)-cyclophane complexes

    Science.gov (United States)

    Salazar-Medina, A. J.; Gámez-Corrales, R.; Ramírez, J. Z.; González-Aguilar, G. A.; Velázquez-Contreras, E. F.

    2018-02-01

    Binuclear Fe(III) complexes, Fe2PO and Fe2PC, have functions of antioxidants as well as superoxide dismutase and peroxidase mimickers. The role of water molecules in the non-cytotoxic properties of these complexes have been studied by thermogravimetric and IR/Raman-spectroscopic methods. The thermogravimetric analysis of Fe2PO shows the presence of nine water molecules (Fe2PO·9H2O), three of which are directly coordinated to the metallic ion; the remaining six molecules occupy the secondary coordination sphere. For Fe2PC, eight water molecules were detected (Fe2PC·8H2O), and only one of them directly coordinates to the metallic ion. IR/Raman spectrum analyses corroborate the presence of water molecules in both metallic complexes and the mode of coordination to the ligand, on the basis of bands characteristic of hydration water at ∼3300 cm-1 and bands of adsorbed water between 430 and 490 cm-1. A pentacoordinate geometry is proposed for Fe2PO and a hexacoordinated geometry for Fe2PC. Those results are consistent with theoretical calculations performed through a semiempirical PM7 method. The presence of coordinated water molecules is closely related to the reactivity of Fe2PO and Fe2PC in solution.

  15. Complex band structures of transition metal dichalcogenide monolayers with spin–orbit coupling effects

    International Nuclear Information System (INIS)

    Szczęśniak, Dominik; Ennaoui, Ahmed; Ahzi, Saïd

    2016-01-01

    Recently, the transition metal dichalcogenides have attracted renewed attention due to the potential use of their low-dimensional forms in both nano- and opto-electronics. In such applications, the electronic and transport properties of monolayer transition metal dichalcogenides play a pivotal role. The present paper provides a new insight into these essential properties by studying the complex band structures of popular transition metal dichalcogenide monolayers (MX 2 , where M   =  Mo, W; X   =  S, Se, Te) while including spin–orbit coupling effects. The conducted symmetry-based tight-binding calculations show that the analytical continuation from the real band structures to the complex momentum space leads to nonlinear generalized eigenvalue problems. Herein an efficient method for solving such a class of nonlinear problems is presented and yields a complete set of physically relevant eigenvalues. Solutions obtained by this method are characterized and classified into propagating and evanescent states, where the latter states manifest not only monotonic but also oscillatory decay character. It is observed that some of the oscillatory evanescent states create characteristic complex loops at the direct band gap of MX 2 monolayers, where electrons can directly tunnel between the band gap edges. To describe these tunneling currents, decay behavior of electronic states in the forbidden energy region is elucidated and their importance within the ballistic transport regime is briefly discussed. (paper)

  16. Complex band structures of transition metal dichalcogenide monolayers with spin-orbit coupling effects

    Science.gov (United States)

    Szczęśniak, Dominik; Ennaoui, Ahmed; Ahzi, Saïd

    2016-09-01

    Recently, the transition metal dichalcogenides have attracted renewed attention due to the potential use of their low-dimensional forms in both nano- and opto-electronics. In such applications, the electronic and transport properties of monolayer transition metal dichalcogenides play a pivotal role. The present paper provides a new insight into these essential properties by studying the complex band structures of popular transition metal dichalcogenide monolayers (MX 2, where M  =  Mo, W; X  =  S, Se, Te) while including spin-orbit coupling effects. The conducted symmetry-based tight-binding calculations show that the analytical continuation from the real band structures to the complex momentum space leads to nonlinear generalized eigenvalue problems. Herein an efficient method for solving such a class of nonlinear problems is presented and yields a complete set of physically relevant eigenvalues. Solutions obtained by this method are characterized and classified into propagating and evanescent states, where the latter states manifest not only monotonic but also oscillatory decay character. It is observed that some of the oscillatory evanescent states create characteristic complex loops at the direct band gap of MX 2 monolayers, where electrons can directly tunnel between the band gap edges. To describe these tunneling currents, decay behavior of electronic states in the forbidden energy region is elucidated and their importance within the ballistic transport regime is briefly discussed.

  17. Highly Fluorescent Group 13 Metal Complexes with Cyclic, Aromatic Hydroxamic Acid Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Michael; Moore, Evan G.; Raymond, Kenneth N.

    2008-02-11

    The neutral complexes of two ligands based on the 1-oxo-2-hydroxy-isoquinoline (1,2-HOIQO) motif with group 13 metals (Al, Ga, In) show bright blue-violet luminescence in organic solvents. The corresponding transition can be attributed to ligand-centered singlet emission, characterized by a small Stokes shifts of only a few nm combined with lifetimes in the range between 1-3 ns. The fluorescence efficiency is high, with quantum yields of up to 37% in benzene solution. The crystal structure of one of the indium(III) complexes (trigonal space group R-3, a = b = 13.0384(15) {angstrom}, c = 32.870(8) {angstrom}, ? = {beta} = 90{sup o}, {gamma} = 120{sup o}, V = 4839.3(14) {angstrom}{sup 3}, Z = 6) shows a six-coordinate geometry around the indium center which is close to trigonal-prismatic, with a twist angle between the two trigonal faces of 20.7{sup o}. Time-dependent density functional theory (TD-DFT) calculations (Al and Ga: B3LYP/6-31G(d)); In: B3LYP/LANL2DZ of the fac and mer isomers with one of the two ligands indicate that there is no clear preference for either one of the isomeric forms of the metal complexes. In addition, the metal centers do not have a significant influence on the electronic structure, and as a consequence, on the predominant intraligand optical transitions.

  18. Artificial neural network (ANN) approach for modeling Zn(II) adsorption in batch process

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, Sayiter [Engineering Faculty, Cumhuriyet University, Sivas (Turkmenistan)

    2017-09-15

    Artificial neural networks (ANN) were applied to predict adsorption efficiency of peanut shells for the removal of Zn(II) ions from aqueous solutions. Effects of initial pH, Zn(II) concentrations, temperature, contact duration and adsorbent dosage were determined in batch experiments. The sorption capacities of the sorbents were predicted with the aid of equilibrium and kinetic models. The Zn(II) ions adsorption onto peanut shell was better defined by the pseudo-second-order kinetic model, for both initial pH, and temperature. The highest R{sup 2} value in isotherm studies was obtained from Freundlich isotherm for the inlet concentration and from Temkin isotherm for the sorbent amount. The high R{sup 2} values prove that modeling the adsorption process with ANN is a satisfactory approach. The experimental results and the predicted results by the model with the ANN were found to be highly compatible with each other.

  19. Artificial neural network (ANN) approach for modeling Zn(II) adsorption in batch process

    International Nuclear Information System (INIS)

    Yildiz, Sayiter

    2017-01-01

    Artificial neural networks (ANN) were applied to predict adsorption efficiency of peanut shells for the removal of Zn(II) ions from aqueous solutions. Effects of initial pH, Zn(II) concentrations, temperature, contact duration and adsorbent dosage were determined in batch experiments. The sorption capacities of the sorbents were predicted with the aid of equilibrium and kinetic models. The Zn(II) ions adsorption onto peanut shell was better defined by the pseudo-second-order kinetic model, for both initial pH, and temperature. The highest R"2 value in isotherm studies was obtained from Freundlich isotherm for the inlet concentration and from Temkin isotherm for the sorbent amount. The high R"2 values prove that modeling the adsorption process with ANN is a satisfactory approach. The experimental results and the predicted results by the model with the ANN were found to be highly compatible with each other.

  20. Bis(imidazolin-2-iminato) rare earth metal complexes: synthesis, structural characterization, and catalytic application.

    Science.gov (United States)

    Trambitas, Alexandra G; Melcher, Daniel; Hartenstein, Larissa; Roesky, Peter W; Daniliuc, Constantin; Jones, Peter G; Tamm, Matthias

    2012-06-18

    Reaction of anhydrous rare earth metal halides MCl(3) with 2 equiv of 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-imine (Im(Dipp)NH) and 2 equiv of trimethylsilylmethyl lithium (Me(3)SiCH(2)Li) in THF furnished the complexes [(Im(Dipp)N)(2)MCl(THF)(n)] (M = Sc, Y, Lu). The molecular structures of all three compounds were established by single-crystal X-ray diffraction analyses. The coordination spheres around the pentacoordinate metal atoms are best described as trigonal bipyramids. Reaction of YbI(2) with 2 equiv of LiCH(2)SiMe(3) and 2 equiv of the imino ligand Im(Dipp)NH in tetrahydrofuran did not result in a divalent complex, but instead the Yb(III) complex [(Im(Dipp)N)(2)YbI(THF)(2)] was obtained and structurally characterized. Treatment of [(Im(Dipp)N)(2)MCl(THF)(n)] with 1 equiv of LiCH(2)SiMe(3) resulted in the formation of [(Im(Dipp)N)(2)M(CH(2)SiMe(3))(THF)(n)]. The coordination arrangement of these compounds in the solid state at the metal atoms is similar to that found for the starting materials, although the introduction of the neosilyl ligand induces a significantly greater distortion from the ideal trigonal-bipyramidal geometry. [(Im(Dipp)N)(2)Y(CH(2)SiMe(3))(THF)(2)] was used as precatalyst in the intramolecular hydroamination/cyclization reaction of various terminal aminoalkenes and of one aminoalkyne. The complex showed high catalytic activity and selectivity. A comparison with the previously reported dialkyl yttrium complex [(Im(Dipp)N)Y(CH(2)SiMe(3))(2)(THF)(3)] showed no clear tendency in terms of activity.