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Sample records for 8-hydroxyquinoline

  1. Yellow-green electroluminescence of samarium complexes of 8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Behzad, Sara Karimi; Najafi, Ezzatollah [Department of Chemistry Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Amini, Mostafa M., E-mail: m-pouramini@sbu.ac.ir [Department of Chemistry Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Janghouri, Mohammad; Mohajerani, Ezeddin [Laser Research Institute Shahid Beheshti University G.C., Tehran 1983963113 (Iran, Islamic Republic of); Ng, Seik Weng [Department of Chemistry, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-12-15

    Four novel samarium complexes were prepared by reacting samarium(III) nitrate with 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline, and 1,10-phenanthroline and utilized as emitting materials in the electroluminescence device. All complexes were characterized by elemental analysis, infrared, UV–vis and {sup 1}H NMR spectroscopes and the molecular structure of a representative complex, [Sm{sub 2}(Me-HQ){sub 4}(NO{sub 3}){sub 6}] (1), was determined by single-crystal X-ray diffraction. Utilization of a π-conjugated (phenanthroline) ligand as a second ligand in the structure of the samarium complexes resulted in red shifts in both absorption and fluorescence spectra of complexes and moderately enhanced the photoluminescence intensity and the fluorescence quantum yield. The maximum emission peaks showed that a good correlation exists between the nature of the substituent group on the 8-hydroxyquinoline and the addition of the π-conjugated ligand in the structure of samarium complexes and emission wavelength. Devices with samarium(III) complexes with structure of ITO/PEDOT:PSS (90 nm)/PVK:PBD:Sm(III) complexes (75 nm)/Al (180 nm) were fabricated. In the electroluminescence (EL) spectra of the devices, a strong ligand-centered emission and narrow bands arising from the {sup 4}G{sub 5/2}→{sup 6}H{sub J} transitions (J=7/2, 9/2, and 11/2) of the samarium ion were observed for the complexes. The electroluminescent spectra of the samarium complexes were red-shifted as compared with the PVK:PBD blend. We believe that the electroluminescence performance of OLED devices based on samarium complexes relies on overlaps between the absorption of the samarium compounds and the emission of PVK:PBD. This revealed that it is possible to evaluate the electroluminescence performance of the samarium compounds-doped OLED devices based on the emission of PVK:PBD and the absorption of the dopants. - Highlights: • Four novel photoluminescence samarium complexes have been synthesized.

  2. Synthesis of Novel 5-(-Substituted-Anilino)-8-Hydroxyquinolines via Hartwig-Buchwald Amination Reaction

    Indian Academy of Sciences (India)

    Walaa A E Omar; Osmo E O Hormi

    2015-11-01

    Three novel 5-(-substituted-anilino)-8-benzyloxyquinoline derivatives were efficiently synthesized via Hartwig–Buchwald amination reaction. The new 5-(-substituted-anilino)-8-benzyloxyquinolines were reduced for 1–3 h to give the corresponding 5-(-substituted-anilino)-8-hydroxyquinolines. Extending the reduction reaction time to 7 h afforded the corresponding 1,2,3,4-tetrahydro-8-hydroxyquinoline derivatives.

  3. Cyclodextrins 3-Functionalized with 8-Hydroxyquinolines: Copper-Binding Ability and Inhibition of Synuclein Aggregation.

    Science.gov (United States)

    Oliveri, Valentina; Sgarlata, Carmelo; Vecchio, Graziella

    2016-09-06

    Neurodegenerative diseases such as Parkinson's and Alzheimer's diseases are multifactorial disorders related to protein aggregation, metal dyshomeostasis, and oxidative stress. To advance understanding in this area and to contribute to therapeutic development, many efforts have been directed at devising suitable agents that can target metal ions associated with relevant biomolecules such as α-synuclein. This paper presents a new cyclodextrin-8-hydroxyquinoline conjugate and discusses the properties of four cyclodextrins 3-functionalized with 8-hydroxyquinoline as copper(II) chelators and inhibitors of copper-induced synuclein aggregation. The encouraging results establish the potential of cyclodextrin-8-hydroxyquinoline conjugates as chelators for the control of copper toxicity.

  4. Corrosion Inhibition Synergism between Lanthanum(Ⅲ) Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    木冠南; 唐丽斌; 李学铭

    2002-01-01

    The effects of La3+ ion and chelate reagent 8-hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La3+ ion and 8-hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.

  5. Synthesis and photoluminescence properties of 8-hydroxyquinoline derivatives and their metallic complexes

    Institute of Scientific and Technical Information of China (English)

    OUYANG Xinhua; ZENG Heping; XIE Yan

    2007-01-01

    Three new 8-hydroxyquinoline derivatives, I.e.5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), 1H nuclear magnetic resonance(1H NMR), Fourier transform infrared spectrometer (FTIR),mass spectrometry (MS) spectra and elemental analyses.Their fluorescence properties were studied by photolumines-cence, which indicated that the luminescence wavelength of 5- and 2-substitued-8-hydroxyquinoline derivatives shifted to red in comparison with that of 8-hydroxyquinoline.Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol and its zinc complex showed long lifetime in benzene solution.

  6. Gelation Behavior of 5-Chloro-8-hydroxyquinoline, an Antituberculosis Agent in Aqueous Alcohol Solutions

    OpenAIRE

    Jukka Korpela; Hannu Salo; Erkki Kolehmainen

    2012-01-01

    It was shown that 5-chloro-8-hydroxyquinoline, an antituberculosis agent, gels aqueous alcohol solutions efficiently. Thermal stability and gel-to-sol transition temperature of 1% gel in CD3OD/D2O (2:1) was studied by 1H-NMR. Fibrous structures of four xerogels have been characterized by scanning electron microscope.

  7. Hydrogen-bonded Lamellar Network of Pyromellitic Acid Pillared by 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    WANG, Lei; ZHANG, Hong; ZHANG, Jing-Ping; GAO, Fei-Xue; HUA, Rui-Mao; ZHOU, Guang-Yuan

    2006-01-01

    8-Hydroxyquinoline (8-q) salt of pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid, H4bta) forms robust lamellar structure where [H2bta]2- anions build up sheets through strong hydrogen bonds in two dimensions and[H-8-q]+ cations act as pillars to afford an extended three dimensional network.

  8. Gelation Behavior of 5-Chloro-8-hydroxyquinoline, an Antituberculosis Agent in Aqueous Alcohol Solutions

    Directory of Open Access Journals (Sweden)

    Jukka Korpela

    2012-09-01

    Full Text Available It was shown that 5-chloro-8-hydroxyquinoline, an antituberculosis agent, gels aqueous alcohol solutions efficiently. Thermal stability and gel-to-sol transition temperature of 1% gel in CD3OD/D2O (2:1 was studied by 1H-NMR. Fibrous structures of four xerogels have been characterized by scanning electron microscope.

  9. Preparation and study of new poly-8-hydroxyquinoline chelators for an anti-Alzheimer strategy.

    Science.gov (United States)

    Deraeve, Céline; Boldron, Christophe; Maraval, Alexandrine; Mazarguil, Honoré; Gornitzka, Heinz; Vendier, Laure; Pitié, Marguerite; Meunier, Bernard

    2008-01-01

    Fourteen different ligands have been synthesized with two covalently linked 8-hydroxyquinoline motifs that favor metal complexation. These bis-chelators include different bridges at the C2 positions and different substituents to modulate their physicochemical properties. They can form metal complexes in a ratio of one ligand per metal ion with Cu II and Zn II, two metal ions involved in the formation of amyloid aggregates of the toxic Abeta-peptides in the Alzheimer disease. The apparent affinity of all bis-8-hydroxyquinoline ligands for Cu II and Zn II are similar with logK Cu II approximately 16 and logK Zn II approximately 13 and are 10,000 times more efficient than for the corresponding 8-hydroxyquinoline monomers. Their strong chelating capacities allow them to inhibit more efficiently than the corresponding monomers the precipitation of Abeta-peptides induced by Cu II and Zn II and also to inhibit the toxic formation of H2O2 due to copper complexes of Abeta. The best results were obtained with a one-atom linker between the two quinoline units. X-ray analyses of single-crystals of Cu II, Zn II or Ni II complexes of 2,2'-(2,2-propanediyl)-bis(8-hydroxyquinoline), including a one-atom linker, showed that all heteroatoms of the bis-8-hydroxyquinoline ligand chelate the same metal ion in a distorted square-planar geometry. The Cu II and Zn II complexes include a fifth axial ligand and are pentacoordinated.

  10. Magnetic susceptibility of Alq{sub 3} powder, pure and Al-doped 8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Burke, Franklyn, E-mail: frburke@tcd.i [School of Physics and CRANN, Trinity College, Dublin 2 (Ireland); Abid, Mohamed; Stamenov, Plamen; Coey, J.M.D. [School of Physics and CRANN, Trinity College, Dublin 2 (Ireland)

    2010-05-15

    Single-crystal nanowires several microns long and 100-200 nm in diameter were grown by physical vapour deposition from mixed Alq{sub 3}/gamma-Al{sub 2}O{sub 3} powder. The crystals are orthorhombic Al-doped 8-hydroxyquinoline. The molar susceptibility is -3x10{sup -9} at room temperature, and it shows a Curie-law upturn below about 50 K. The approach to saturation at low temperature indicates a density of S=1/2 defects 4x10{sup -4} per formula unit. Pure 8-hydroxyquinoline and aluminium (Alq{sub 3}) behave similarly. Pressed pellets exhibit much increased paramagnetic susceptibility due to iron ions scavanged from the steel die. Subsequent melting of these samples produces a ferromagnetic signal of order 0.01 A m{sup 2} kg{sup -1}, which is attributed to metallic iron nanoclusters in the organic material.

  11. Structure and simulation of a Zundel ion stabilized by 8-hydroxyquinoline-5, 7 disulphonic acid

    Science.gov (United States)

    Venkatakrishnan, Hasthi Annapurna; Venkatakrishnan, Ramaseshan; Pennathur, Anuj Krishnasundar; Pennathur, Gautam

    2016-07-01

    8-hydroxyquinoline-5, 7 disulphonic was synthesized and recrystallized in methanol to strip away molecules of water. The structure of the molecule revealed that Zundel ion was stabilized in the crystal. Ab-initio molecular dynamics simulation was then carried out to understand the dynamics of proton hopping in this complex. During the course of simulation, the Zundel ion coordinates with a water molecule to form an open H7O3+ structure. This transition state structure de-solvated rapidly forming Zundel ion facilitating proton hopping in the first solvation shell. One of the sulphonic acid groups in the 5 or 7 position of the 8-hydroxyquinoline 5,7 disulphonic acid bonds with the Zundel ion favoring the proton to be transferred to the nearby water molecule through the formation of proton defects. The simulation results support the structural diffusion mechanism and that charged complex migrates through the hydrogen bond network.

  12. Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qian; WU Dong-bei; BAO Bo-rong

    2009-01-01

    The synergistic extraction of Pr3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr3+ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration on extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinolinc was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr3+.

  13. A novel method for preparation of 8-hydroxyquinoline functionalized mesoporous silica: Aluminum complexes and photoluminescence studies

    Science.gov (United States)

    Badiei, Alireza; Goldooz, Hassan; Ziarani, Ghodsi Mohammadi

    2011-03-01

    8-Hydroxyquinoline (8-HQ) was attached to mesoporous silica by sulfonamide bond formation between 8-hydroxyquinoline-5-sulfonyl chloride (8-HQ-SO 2Cl) and aminopropyl functionalized SBA-15 (designated as SBA-SPS-Q) and then aluminum complexes of 8-HQ was covalently bonded to SBA-SPS-Q using coordinating ability of grafted 8-HQ.The prepared materials were characterized by powder X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FT-IR), thermal analysis (TGA-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analysis and fluorescence spectra. The environmental effects on the emission spectra of grafted 8-HQ and its complexes were studied and discussed in details.

  14. Novel Chromogenic Chemosensors for Fluoride Anion Based on 8-Hydroxyquinoline Azo Derivatives

    Institute of Scientific and Technical Information of China (English)

    CHENG,Yun-Fei; LIU,Zhi-Qiang; SHI,Mei; ZHAO,Qiang; LI,Fu-You; YI,Tao; HUANG,Chun-Hui

    2007-01-01

    A series of 8-hydroxyquinoline azo derivatives with diverse conjugated structures were synthesized and studied to chromogenically detect anions. All the dyes allowed selective detection for fluoride anion in CH3CN via instant deprotonation of the compounds, which was affirmed by UV-Vis absorption and 1H NMR spectra. The chromogenically responding ability increases as the substituent changes from phenyl to naphthyl or anthryl. This result is likely to be related to the enhancement of intramolecular charge transfer (ICT) induced by extension of conjugated structure.

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

    Science.gov (United States)

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

    2009-05-01

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

  16. Differential pulse polarographic determination of molybdenum after separation by 8-hydroxyquinoline extraction into dichloromethane.

    Science.gov (United States)

    Nagaosa, Y; Kobayashi, K

    1984-08-01

    A polarographic investigation of several metal 8-hydroxyquinolinates in dichloromethane medium following solvent extraction has been made. From the data obtained, a selective, specific and sensitive method for the determination of molybdenum at ng ml levels has been developed involving direct differential pulse polarographic measurement on the dichloromethane extract. In this work, EDTA is used as an effective masking agent to separate molybdenum from other metals. The proposed method has been applied to the determination of molybdenum in a variety of steels and NBS-SRM 1577 bovine liver with good accuracy and precision.

  17. Two 8-Hydroxyquinolinate Based Supramolecular Coordination Compounds: Synthesis, Structures and Spectral Properties

    Directory of Open Access Journals (Sweden)

    Chengfeng Zhu

    2017-03-01

    Full Text Available Two new Cr(III complexes based on 2-substituted 8-hydroxyquinoline ligands, namely [Cr(L13] (1, (HL1=(E-2-[2-(4-nitro-phenyl-vinyl]-8-hydroxy-quinoline and [Cr(L23] (2, (HL2=(E-2-[2-(4-chloro-phenylvinyl]-8-hydroxy-quinoline, were prepared by a facile hydrothermal method and characterized thoroughly by single crystal X-ray diffraction, powder X-ray diffraction, FTIR, TGA, ESI-MS, UV-Visible absorption spectra and fluorescence emission spectra. Single crystal X-ray diffraction analyses showed that the two compounds featured 3D supramolecular architectures constructed from noncovalent interactions, such as π···π stacking, C-H···π, C-H···O, C-Cl···π, C-H···Cl interactions. The thermogravimetric analysis and ESI-MS study of compounds 1 and 2 suggested that the Cr(III complexes possessed good stability both in solid and solution. In addition, the ultraviolet and fluorescence response of the HL1 and HL2 shown marked changes upon their complexation with Cr(III ion, which indicated that the two 8-hydroxyquinolinate based ligand are promising heavy metal chelating agent for Cr3+.

  18. Post-harvest longevity of ornamental grasses conditioned in gibberellic acid and 8-hydroxyquinoline sulphate

    Directory of Open Access Journals (Sweden)

    Henschke Monika

    2016-06-01

    Full Text Available Florists’ greens are becoming increasingly important in contemporary floristry. Numerous studies conducted on cut flowers have led to the development of technologies for their post-harvest handling; however, in the case of florists’ greens they are still insufficient. Moreover, the extensive range of florists’ greens lacks leaves and the leafy culms of grasses. The aim of this study was to determine the post-harvest longevity of the leaves and leafy culms of ornamental grasses conditioned in water solutions of gibberellic acid and 8-hydroxyquinoline sulphate. The post-harvest longevity of leaves was examined in cultivars of the following species: Glyceria maxima Hartm. ‘Variegata’, Miscanthus sinensis Thunb. ‘Zebrinus’ and Spartina pectinata Link. ‘Aureomarginata’. The post-harvest longevity of leafy culms was investigated in Alopecurus pratensis L. ‘Aureovariegatus’, Chasmanthium latifolium Michx., Miscanthus sinensis Thunb. ‘Silberspinne’, Pennisetum alopecuroides L. and Phalaris arundinacea L. ‘Picta’. Conditioning in gibberellic acid had a positive effect on the post-harvest longevity and fresh weight loss and the index of leaf greenness of leaves in the case of Miscanthus sinensis ‘Zebrinus’, while conditioning in 8-hydroxyquinoline sulphate improved fresh weight loss and the index of leaf greenness of the leafy culms of Miscanthus sinensis ‘Zebrinus’, Pennisetum alopecuroides and the leaves of Glyceria maxima ‘Variegata’.

  19. Synthesis, Fluorescence Properties and Biological Activity of 8-Hydroxyquinoline Conjugate Bonded Aromatic Heterocyclic Derivatives

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Four kinds of 8-hydroxyquinoline conjugate bonded aromatic heterocyclic derivatives were designed and syn-thesized for potential use in the emission and electron conduction layers in organic light emitting devices, and as luminescent probes for metal ions. These novel compounds were characterized by IR, 1H NMR,13C NMR, Mass and UV-visible spectra. The photoluminescent properties of the new compounds including the spectra (shape of bands,λex, λem), quantum yield (pf) and lifetime (t) were investigated. Moreover, density functional theory method was used to study the relationship between the geometric configuration and emission wavelength. MTT assays of cell proliferation of rMSC and DPPH radical-scavenging tests suggested that the new compounds generate a sig-nificant increase of rMSC and demonstrate a good antioxidant activity.

  20. Electronic property and molecule design for luminescent metal complexes of tris(8-hydroxyquinoline) gallium

    Institute of Scientific and Technical Information of China (English)

    苏忠民; 高洪泽; 程红; 初蓓; 陈丽华; 王荣顺; 王悦; 沈家骢

    2000-01-01

    By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent materials were discussed. The regularities and characteristic of energy bands of Gaq3 and its derivatives were also investigated. The results show that the electronic π-π* transitions in Gaq3 are localized on the quinolate ligands. The emission of Gaq3 is due to the electron transitions from a phenoxide donor to a pyridyl acceptor. Two possible electron transfer pathways are presented, one by carbon atoms, and the other via metal cation Ga3+. The derivatives of Gaq3 may possess high luminescence efficiency.

  1. Multifunctional 8-hydroxyquinoline-appended cyclodextrins as new inhibitors of metal-induced protein aggregation.

    Science.gov (United States)

    Oliveri, Valentina; Attanasio, Francesco; Puglisi, Antonino; Spencer, John; Sgarlata, Carmelo; Vecchio, Graziella

    2014-07-14

    Mounting evidence suggests a pivotal role of metal imbalances in protein misfolding and amyloid diseases. As such, metal ions represent a promising therapeutic target. In this context, the synthesis of chelators that also contain complementary functionalities to combat the multifactorial nature of neurodegenerative diseases is a highly topical issue. We report two new 8-hydroxyquinoline-appended cyclodextrins and highlight their multifunctional properties, including their Cu(II) and Zn(II) binding abilities, and capacity to act as antioxidants and metal-induced antiaggregants. In particular, the latter property has been applied in the development of an effective assay that exploits the formation of amyloid fibrils when β-lactoglobulin A is heated in the presence of metal ions.

  2. Synthesis and Characterization of 8-Hydroxyquinoline Derivative Containing a Triphenylamine Unit and Its Metal Complexes

    Institute of Scientific and Technical Information of China (English)

    JING, Hui-Lian; ZENG, He-Ping; ZHOU, Ya-Dong; WANG, Ting-Ting; YUAN, Guo-Zan; OUYANG, Xin-Hua

    2006-01-01

    A new 8-hydroxyquinoline derivative (5) was synthesized and characterized by ESI-MS, 1H NMR spectroscopy,elemental analysis and IR spectroscopy. The photophysical properties of compounds 5, 6 and 7 were also detemined by UV-vis and FL spectroscopy. The vibrational frequency of ligand 5 predicted by using B3LYP method is in good agreement with experimentally determined values. The compositions of the corresponding copper(Ⅱ) and zinc(Ⅱ)complexes were confirmed to be Cu(C29H21N2O)2·H2O (6) and Zn(C29H21N2O)2·H2O (7) by elementary analysis,thermogravimetry analysis and IR spectroscopy.

  3. Electron Donor-Acceptor Interaction of 8-Hydroxyquinoline with Citric Acid in Different Solvents: Spectroscopic Studies

    Directory of Open Access Journals (Sweden)

    Demelash Jado

    2014-01-01

    Full Text Available Charge transfer complex formation between 8-hydroxyquinoline as the electron donor and citric acid as the electron acceptor has been studied spectrophotometrically in ethanol and methanol solvents at room temperature. Absorption band due to charge transfer complex formation was observed near 320 and 325 nm in ethanol and methanol, respectively. The stoichiometric ratio of the complex has been found 3 : 1 by using Job’s and conductometric titration methods. Benesi-Hildebrand equation has been applied to estimate the formation constant and molecular extinction coefficient. It was found that the value of formation constant was larger in ethanol than in methanol. The physical parameters, ionization potential, and standard free energy change of the formed complex were determined and evaluated in the ethanol and methanol solvents.

  4. 3-[(E-2-(5,7-Dichloro-8-hydroxyquinolin-2-ylvinyl]-4-hydroxyphenyl acetate

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The two symmetry independent molecules of the title compound, C19H13Cl2NO4, show similar conformations with the acetyl group twisted strongly relative to the remaining, virtually flat (r.m.s. deviations = 0.0173 and 0.0065 Å, part of the molecule. The hydroxyl groups of the 8-hydroxyquinoline residues are involved in intramolecular O—H...N hydrogen bonds, which, in one case, forms a part of a three-center interaction. Intermolecular O—H...O hydrogen bonds assemble the molecules into a one-dimensional polymeric structure extended along the a axis. The 4-hydroxyphenyl group of one molecule forms an O—H...O hydrogen bond, in which the hydroxyl H atom is disordered, with its inversion center counterpart.

  5. Direct spectrophotometric determination of Nd and Er in mixed rare earths with 8-hydroxyquinoline-5-sulphonic acid and cetylpyridinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Shifu Zhou; Naixing Wang (Shandong Univ., Jinan (China). Dept. of Chemistry)

    1990-03-01

    Neodymium and erbium can form stable ternary complexes with 8-hydroxyquinoline-5-sulphonic acid and cetylpyridinium chloride, but a photometric method based on this does not give high enough sensitivity and is subject to interference by cerium. Use of the third derivative spectra, however, eliminates the interference by cerium and increases the sensitivity. (author).

  6. Grafting aluminum(III) 8-hydroxyquinoline derivatives on MCM-41 mesoporous silica for tuning of the light emitting color.

    Science.gov (United States)

    Fazaeli, Yousef; Amini, Mostafa M; Mohajerani, Ezeddin; Sharbatdaran, Masoomeh; Torabi, Naime

    2010-06-15

    Fluorescent materials (Q)(3-n)(2-BuO)(n)Al (Q = 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline and 5-chloro-8-hydroxyquinoline, n = 1 or n = 2) were prepared in toluene by reacting aluminum 2-butoxide with 8-hydroxyquinoline and its derivatives. The compounds were characterized by (1)H, (13)C and (27)Al NMR in solution, and the coordination status of the aluminum atom in the complexes were determined by (27)Al NMR chemical shifts. The compounds were grafted on mesoporous silica (MCM-41) at room temperature without isolation of the complexes. The prepared materials were characterized by elemental analysis, FT-IR spectroscopy, low-angle X-ray diffraction (XRD), thermal analysis (TGA/DSC) and N(2) adsorption and desorption measurements. The results showed that the characteristic mesoporous structure of MCM-41 after grafting aluminum complexes remains intact. The photoluminescence (PL) properties of (Q)(3-n)(2-BuO)(n-1)@Al-MCM-41 were investigated. The results revealed that the maximum wavelength is modulated by the MCM-41 guest.

  7. TD-DFT Study on the Electronic Spectrum Properties of 2,7'-(Ethylene)-bis-8-hydroxyquinoline and Its Derivatives

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Feng; ZHU Yuan-Cheng; YUAN Kun; KANG Jing-Wan

    2008-01-01

    The structures of 2,7'-(ethylene)-bis-8-hydroxyquinoline and its derivatives were optimized at the ground states using ab initio HF and B3LYP methods. At the same time, the molecular structures of the first singlet excited state for 2,7'-(ethylene)-bis-8-hydroxyquinoline and its derivatives were optimized by CIS/6-31G(d). The absorption and emission spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31G(d) basis set. The calculated results of luminescence originate from the electronic transition from the hydroxphenol ring of 8-hydroxyquinoline A to the pyridine ring of 8-hydroxyquinoline B. Their luminescence wave bands can be tuned by different substituents on the ligand of 8-hydroxyquinoline.

  8. The complexation of mercury (2) and organomercurial compounds by 8-Hydroxyquinoline-bovine serum albumin conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Giraudi, G.; Baggiani, C.; Anfossi, L.; Tozzi, C.; Giovannoli, C.; Vanni, A. [Turin Univ., Turin (Italy). Dipt. di Chimica Analitica

    2001-10-01

    The complexing properties of conjugates between 8-Hydroxyquinoline and bovine serum albumin (Ox-BSA) towards inorganic and organic mercury were studied. Two Ox-BSA conjugates (different substitution ratio) were prepared and their complexing properties were studied. Through the use of titration curves with mercury (2), methylmercury and ethylmercury an evaluation of the complex stoichiometry and stability was obtained, showing that Ox-BSA has good affinity for all investigated mercuric compounds and that the stability increases in the order: Hg (2) < CH{sub 3}Hg{sup +} < C{sub 2}H{sub 5}Hg{sup +}, whatever conjugate is considered. Complexes show a stoichiometry of 1:1 between mercury and 8-Hydroxyquinoline residues, except with the high substituted conjugate and Hg{sup 2}+ ion. The skill of the high substituted conjugate to bind inorganic and organic mercury in the presence of NaCl was also studied. Organic mercuric complexes do not show significant modification due to NaCl. Nevertheless, considering inorganic mercury, the number of retained metal ions per protein molecule increases if the NaCl concentration becomes higher than 0.1 M, probably because at high NaCl concentrations 1:1 complexes between mercury and 8-Hydroxyquinoline are preferred to 1:2 complexes. [Italian] Sono state studiate le proprieta' complessanti di coniugati tra l'8-idrossichinolina e l'albumina di siero bovino (Ox-BSA) nei confronti di mercurio sia inorganico sia organico. Sono stati preparati due coniugati (a differente grado di sostituzione) e ne sono state studiate le proprieta' complessanti. Per mezzo di curve di titolazione con mercurio, metilmercurio ed etilmercurio, sono state valutate la stechiometria e la stabilita' dei complessi, che dimostrano per entrambi i coniugati una buona affinita' verso tutti i composti investigati e una stabilita' crescente nell'ordine: Hg (2) < CH{sub 3}Hg{sup +}

  9. Phosphorescent emissions of phosphine copper(I) complexes bearing 8-hydroxyquinoline carboxylic acid analogue ligands

    Energy Technology Data Exchange (ETDEWEB)

    Małecki, Jan G., E-mail: gmalecki@us.edu.pl [Department of Crystallography, Institute of Chemistry, University of Silesia, Szkolna 9 street, 40-006 Katowice (Poland); Łakomska, Iwona, E-mail: iwolak@chem.umk.pl [Department of Chemistry, Nicolaus Copernicus University, Toruń (Poland); Maroń, Anna [Department of Crystallography, Institute of Chemistry, University of Silesia, Szkolna 9 street, 40-006 Katowice (Poland); Szala, Marcin [Institute of Chemistry, University of Silesia, ul. Szkolna 9, 40-006 Katowice (Poland); Fandzloch, Marzena [Department of Chemistry, Nicolaus Copernicus University, Toruń (Poland); Nycz, Jacek E., E-mail: jacek.nycz@us.edu.pl [Institute of Chemistry, University of Silesia, ul. Szkolna 9, 40-006 Katowice (Poland)

    2015-05-15

    The pseudotetrahedral complexes of [Cu(PPh{sub 3}){sub 2}(L)], where L=8-hydroxy-2-methylquinoline-7-carboxylic acid (1), 8-hydroxy-2,5-dimethylquinoline-7-carboxylic acid (2) or 5-chloro-8-hydroxy-2-methylquinoline-7-carboxylic acid (3) have been synthesized and structurally characterized by X-ray crystallography. Their properties have been examined through combinations of IR, NMR, electronic absorption spectroscopy and cyclic voltammetry. The complexes exhibit extraordinary photophysical properties. Complex (1) in solid state exhibits an emission quantum yield of 4.67% and an excited life time of 1.88 ms (frozen DCM solution up to 6.7 ms). When dissolved in a coordinating solvent (acetonitrile) the charge transfer emission was quenched on a microsecond scale. - Highlights: • Synthesis of copper(I) complexes with 8-hydroxyquinoline carboxylic acid ligands. • Very long lived phosphorescent copper(I) complexes. • [Cu(PPh{sub 3}){sub 2}(L)] where L=8-hydroxy-2-methylquinoline-7-carboxylic acid luminesce in the solid state exhibits extremely long lifetime on millisecond scale (1.9 ms). • In frozen MeOH:EtOH solution lifetime increases to 7 ms. • Quantum efficiency equal to 4.7%.

  10. Thermoanalytical Study and Kinetics of New 8-Hydroxyquinoline 5-sulphonic Acid-Oxamide-Formaldehyde Terpolymer Resins

    Directory of Open Access Journals (Sweden)

    Rajesh N. Singru

    2009-01-01

    Full Text Available The terpolymer resins (8-HQ5-SAOF have been synthesized by the condensation of 8-hydroxyquinoline 5-sulphonic acid (8-HQ5-SA and oxamide (O with formaldehyde (F in the presence of acid catalyst and using varied molar proportion of the reacting monomers. The synthesized terpolymer resins have been characterized by different physico-chemical techniques. Thermogravimetric analysis of all terpolymer resins in present study have been carried out by non-isothermal thermogravimetric analysis technique in which sample is subjected to condition of continuous increase in temperature at linear rate. Thermal study of the resins was carried out to determine their mode of decomposition and relative thermal stabilities. Thermal decomposition curves were studied carefully with minute details. The Freeman-Carroll and Sharp-Wentworth methods have been used in the present investigation to calculate thermal activation energy and different kinetic parameter of the terpolymer resins. Thermal activation energy (Ea calculated with above two mentioned methods are in close agreement. The advantage of Freeman-Carroll method is to calculate both the order of reaction (n and energy of activation in one single stage by keeping heating rate constant. By using data of thermogravimetric analysis, various thermodynamic parameters like frequency factor (Z, entropy change (Δ S, free energy change (Δ F and apparent entropy (S* have been determined using Freeman-Carroll method.

  11. Thermodynamic Study of 8-Hydroxyquinoline by Adiabatic Calorimetry and Thermal Analysis

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-Xu; TAN Zhi-Cheng; LI Yan-Sheng; TONG Bo; LI Ying; SHI Quan; ZHANG Jing-Nan

    2008-01-01

    A calorimetric study and thermal analysis for 8-hydroxyquinoline were performed.The low-temperature heat capacity of this compound was measured with a precise automated adiabatic calorimeter over the temperature range from 78 to 370 K.The melting point True,molar enthalpy △fusHm and molar entropy △fusSm of fusion of this sub-tively.The thermodynamic functions of the substance,such as molar enthalpy and entropy of fusion,and thermo-dynamic functions [Hr-H298.15] and [ST-S298.15] were derived from two polynomial equations of the experi-mental molar heat capacities against the reduced temperature fitted by the least square method.The melting tem-peratures for the sample and the absolutely pure compound have been obtained from fractional melting experiments to be 345.601 and 345.761 K,respectively,and the molar fraction purity of the sample was calculated to be 0.9978 according to the van't Hoff equation.The thermal stability of the compound was further investigated by differential scanning calorimetry(DSC).

  12. Removal of copper, nickel and zinc ions from aqueous solution by chitosan-8-hydroxyquinoline beads

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Francisco C.F.; Dias, Francisco S.; Vasconcellos, Luiz C.G. [Departamento de Quimica Organica e Inorganica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Sousa, Francisco W. [Departamento de Engenharia Hidraulica e Ambiental, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Cavalcante, Rivelino M.; Carvalho, Tecia V.; Queiroz, Danilo C. [Departamento de Quimica Analitica e Fisico Quimica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Nascimento, Ronaldo F.

    2008-03-15

    In this work, 8-hydroxyquinoline is used as the active sites in cross-linked chitosan beads with epichlorohydrin (CT-8HQ). The CT-8HQ material was shaped in bead form and used for heavy metal removal from aqueous solution. The study was carried out at pH 5.0 with both batch and column methods and the maximum adsorption capacity of metal ions by the CT-8HQ was attained in 4 h in the batch experiment. The adsorption capacity order was: Cu{sup 2+} > Ni{sup 2+} > Zn{sup 2+} for both mono- and multi-component systems with batch conditions. From breakthrough curves with column conditions, the adsorption capacity followed the order Cu{sup 2+} > Zn{sup 2+} > Ni{sup 2+} for both mono- and multi-component systems. The CT-8HQ beads maintained good metal adsorption capacity for all five cycles with absorbent restoration achieved with the use of 1.0 mol L{sup -1} HCl solution, with 90% regeneration. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  13. Five 8-hydroxyquinolinate-based coordination polymers with tunable structures and photoluminescent properties for sensing nitroaromatics.

    Science.gov (United States)

    Zhang, Liyan; Sun, Liying; Li, Xinyuan; Tian, Yulan; Yuan, Guozan

    2015-01-01

    Using two 8-hydroxyquinolinate ligands (L1-MOM and L2-MOM) containing 3-pyridyl or 4-pyridyl groups, five novel coordination polymers, namely, [Zn3(L1)6] (1), [Zn(L1)2]·2MeOH (2), [Zn(L2)2] (3), [Cd(L2)2] (4), and [Cd4(L1)6]·13H2O (5), were synthesized and characterized by a variety of techniques. Single-crystal X-ray structures have revealed that these coordination polymers exhibit a structural diversification due to the different choices of metal salts and the effect of pyridyl nitrogen position. Compounds 1-5 exhibited different fluorescence emissions and lifetimes upon excitation in the solid state. The sensing behavior of these polymers was also investigated upon exposure to vapors of various nitroaromatic molecules (analytes). The results show that all five polymers are capable of sensing these nitroaromatic molecules in the vapor phase through fluorescence quenching. Interestingly, 3 exhibits superior sensitivity to the analytes in comparison with other polymers. 2-Nitrotoluene quenches the emission of 3 by as much as 96%.

  14. 8-Hydroxyquinolines: a review of their metal chelating properties and medicinal applications

    Directory of Open Access Journals (Sweden)

    Prachayasittikul V

    2013-10-01

    Full Text Available Veda Prachayasittikul,1 Supaluk Prachayasittikul,2 Somsak Ruchirawat,3 Virapong Prachayasittikul11Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, 2Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 3Laboratory of Medicinal Chemistry, Chulabhorn Research Institute and Chulabhorn Graduate Institute, Bangkok, ThailandAbstract: Metal ions play an important role in biological processes and in metal homeostasis. Metal imbalance is the leading cause for many neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. 8-Hydroxyquinoline (8HQ is a small planar molecule with a lipophilic effect and a metal chelating ability. As a result, 8HQ and its derivatives hold medicinal properties such as antineurodegenerative, anticancer, antioxidant, antimicrobial, anti-inflammatory, and antidiabetic activities. Herein, diverse bioactivities of 8HQ and newly synthesized 8HQ-based compounds are discussed together with their mechanisms of actions and structure–activity relationships.Keywords: metal binding compound, antineurodegenerative, anticancer, antidiabetic, multifunctional actions, structure–activity relationships

  15. Quantitative high-throughput screening identifies 8-hydroxyquinolines as cell-active histone demethylase inhibitors.

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    Oliver N F King

    Full Text Available BACKGROUND: Small molecule modulators of epigenetic processes are currently sought as basic probes for biochemical mechanisms, and as starting points for development of therapeutic agents. N(ε-Methylation of lysine residues on histone tails is one of a number of post-translational modifications that together enable transcriptional regulation. Histone lysine demethylases antagonize the action of histone methyltransferases in a site- and methylation state-specific manner. N(ε-Methyllysine demethylases that use 2-oxoglutarate as co-factor are associated with diverse human diseases, including cancer, inflammation and X-linked mental retardation; they are proposed as targets for the therapeutic modulation of transcription. There are few reports on the identification of templates that are amenable to development as potent inhibitors in vivo and large diverse collections have yet to be exploited for the discovery of demethylase inhibitors. PRINCIPAL FINDINGS: High-throughput screening of a ∼236,000-member collection of diverse molecules arrayed as dilution series was used to identify inhibitors of the JMJD2 (KDM4 family of 2-oxoglutarate-dependent histone demethylases. Initial screening hits were prioritized by a combination of cheminformatics, counterscreening using a coupled assay enzyme, and orthogonal confirmatory detection of inhibition by mass spectrometric assays. Follow-up studies were carried out on one of the series identified, 8-hydroxyquinolines, which were shown by crystallographic analyses to inhibit by binding to the active site Fe(II and to modulate demethylation at the H3K9 locus in a cell-based assay. CONCLUSIONS: These studies demonstrate that diverse compound screening can yield novel inhibitors of 2OG dependent histone demethylases and provide starting points for the development of potent and selective agents to interrogate epigenetic regulation.

  16. Formation and Entrapment of Tris(8-hydroxyquinolinealuminum from 8-Hydroxyquinoline in Anodic Porous Alumina

    Directory of Open Access Journals (Sweden)

    Shohei Yamaguchi

    2016-08-01

    Full Text Available The formation and entrapment of tris(8-hydroxyquinolinealuminum (Alq3 molecules on the surface of anodic porous alumina (APA immersed in an ethanol solution of 8-hydroxyquinoline (HQ were investigated by absorption, fluorescence, and Raman spectroscopies. The effects of the selected APA preparation conditions (galvanostatic or potentiostatic anodization method, anodizing current and voltage values, one- or two-step anodizing process, and sulfuric acid electrolyte concentration on the adsorption and desorption of Alq3 species were examined. Among the listed parameters, sulfuric acid concentration was the most important factor in determining the Alq3 adsorption characteristics. The Alq3 content measured after desorption under galvanostatic conditions was 2.5 times larger than that obtained under potentiostatic ones, regardless of the adsorbed quantities. The obtained results suggest the existence of at least two types of adsorption sites on the APA surface characterized by different magnitudes of the Alq3 bonding strength. The related fluorescence spectra contained two peaks at wavelengths of 480 and 505 nm, which could be attributed to isolated Alq3 species inside nanovoids and aggregated Alq3 clusters in the pores of APA, respectively. The former species were attached to the adsorption sites with higher binding energies, whereas the latter ones were bound to the APA surface more weakly. Similar results were obtained for the Alq3 species formed from the HQ solution, which quantitatively exceeded the number of the Alq3 species adsorbed from the Alq3 solution. Alq3 molecules were formed in the HQ solution during the reaction of HQ molecules with the Al3+ ions in the oxide dissolution zone near the oxide/electrolyte interface through the cracks and the Al3+ ions adsorbed on surface of pore and cracks. In addition, it was suggested that HQ molecules could penetrate the nanovoids more easily than Alq3 species because of their smaller sizes, which

  17. Thermochemical Study on Coordination Complex of Samarium with Salicylic Acid and 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The coordination complex Sm(C7H5O3)2·(C9H6NO), synthesized from the reaction of samarium chloride six-hydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [SmCl3·6H2O(s)], [2C7H6O3(s)], [C9H7NO(s)] and [Sm(C7H5O3)2·(C9H6NO)(s)] in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be ΔsHΘm[SmCl3·6H2O (s), 298.15 K]=-103.98±0.04 kJ·mol-1, ΔsHΘm[2 C7H6O3 (s), 298.15 K]=16.35±0.14 kJ·mol-1, ΔsHΘm[C9H7NO (s), 298.15 K]=-6.11±0.08 kJ·mol-1 and ΔsHΘm[Sm(C7H5O3)2·(C9H6NO) (s), 298.15 K]=-130.08±0.04 kJ·mol-1, respectively. The enthalpy was determined to be ΔrHΘm=89.59±0.18 kJ·mol-1 for the reaction SmCl3·6H2O(s)+2C7H6O3(s)+C9H7NO(s)=Sm(C7H5O3)2·(C9H6NO)(s)+3HCl(g)+6H2O(l). According to the above results and the data given in literature and through Hess' law, the standard molar enthalpy of formation of Sm(C7H5O3)2·(C9H7NO)(s) was estimated to be ΔrHΘm[Sm(C7H5O3)2·(C9H6NO)(s), 298.15 K]=-2055.9±3.03 kJ·mol-1.

  18. Investigation of aromatase inhibitory activity of metal complexes of 8-hydroxyquinoline and uracil derivatives

    Directory of Open Access Journals (Sweden)

    Prachayasittikul V

    2014-08-01

    Full Text Available Veda Prachayasittikul,1 Ratchanok Pingaew,2 Chanin Nantasenamat,3 Supaluk Prachayasittikul,3 Somsak Ruchirawat,4,5 Virapong Prachayasittikul1 1Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 2Department of Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok, Thailand; 3Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 4Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 5Chulabhorn Graduate Institute, Bangkok, Thailand Purpose: Estrogens play important roles in the pathogenesis and progression of breast cancer as well as estrogen-related diseases. Aromatase is a key enzyme in the rate-limiting step of estrogen production, in which its inhibition is one strategy for controlling estrogen levels to improve prognosis of estrogen-related cancers and diseases. Herein, a series of metal (Mn, Cu, and Ni complexes of 8-hydroxyquinoline (8HQ and uracil derivatives (4–9 were investigated for their aromatase inhibitory and cytotoxic activities. Methods: The aromatase inhibition assay was performed according to a Gentest™ kit using CYP19 enzyme, wherein ketoconazole and letrozole were used as reference drugs. The cytotoxicity was tested on normal embryonic lung cells (MRC-5 using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results: Only Cu complexes (6 and 9 exhibited aromatase inhibitory effect with IC50 0.30 and 1.7 µM, respectively. Cytotoxicity test against MRC-5 cells showed that Mn and Cu complexes (5 and 6, as well as free ligand 8HQ, exhibited activity with IC50 range 0.74–6.27 µM. Conclusion: Cu complexes (6 and 9 were found to act as a novel class of aromatase inhibitor. Our findings suggest that these 8HQ–Cu–uracil complexes are promising agents that could be potentially developed as a selective anticancer agent for breast cancer

  19. Bipolar resistive switching based on bis(8-hydroxyquinoline)cadmium complex: Mechanism and non-volatile memory application

    Institute of Scientific and Technical Information of China (English)

    Wang Ying; Yang Ting; Xie Ji-Peng; Lü Wen-Li; Fan Guo-Ying; Liu Su

    2013-01-01

    Stable and persistent bipolar resistive switching was observed in an organic diode with the structure of indium-tin oxide (ITO)/bis(8-hydroxyquinoline) cadmium (Cdq2)/Al.Aggregate formation and electric field driven trapping and detrapping of charge carriers in the aggregate states that lie in the energy gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the organic molecule were proposed as the mechanism of the observed bipolar resistive switching,and this was solidly supported by the results of AFM investigations.Repeatedly set,read,and reset measurements demonstrated that the device is potentially applicable in non-volatile memories.

  20. Ultrasonic Spray-Assisted Solution-Based Vapor-Deposition of Aluminum Tris(8-hydroxyquinoline) Thin Films

    Science.gov (United States)

    Piao, Jinchun; Katori, Shigetaka; Ikenoue, Takumi; Fujita, Shizuo

    2011-02-01

    Aluminum tris(8-hydroxyquinoline) (Alq3) thin films were fabricated by a vapor-deposition technique from its methanol solution, that is, by the ultrasonic-assisted mist deposition technique. The application of high ultrasonic power to the Alq3-methanol mixture resulted in a stable and transparent solution. Mist particles formed by ultrasonic atomization of the solution were used as the source for vapor-deposition at the substrate temperature of 100-200 °C. Optical absorption and photoluminescence characteristics indicated the formation of Alq3 thin films. The results promise the formation of thin films of a variety of organic materials by the solution-based technique.

  1. Thermochemical analysis on rare earth complex of gadolinium with salicylic acid and 8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Sheng-Xiong, E-mail: 54xsx@163.com [Hunan Provincial Key Laboratory of Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan Province (China); Li, Ai-Tao; Jiang, Jian-Hong; Huang, Shuang; Xu, Xiao-Yan; Li, Qiang-Guo [Hunan Provincial Key Laboratory of Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan Province (China)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer A new novel rare earth complex Gd(C{sub 7}H{sub 5}O{sub 3}){sub 2}{center_dot}(C{sub 9}H{sub 6}NO) was synthesized and characterized. Black-Right-Pointing-Pointer The dissolution enthalpies of the relevant substances were determined. Black-Right-Pointing-Pointer The enthalpy change of the reaction was determined to be (211.54 {+-} 0.69) kJ mol{sup -1}. Black-Right-Pointing-Pointer The standard molar enthalpy of formation of complex was -(1890.7 {+-} 3.1) kJ mol{sup -1}. - Abstract: The rare earth complex, Gd(C{sub 7}H{sub 5}O{sub 3}){sub 2}{center_dot}(C{sub 9}H{sub 6}NO), was synthesized by the reaction of Gadolinium nitrate hexahydrate with salicylic acid (C{sub 7}H{sub 6}O{sub 3}) and 8-hydroxyquinoline (C{sub 9}H{sub 7}NO). And it was characterized by elemental analysis, UV spectra, IR spectra, molar conductance and thermogravimetric analysis. In a optimalizing calorimetric solvent, the dissolution enthalpies were determined by an advanced solution-reaction isoperibol microcalorimeter, respectively: {Delta}{sub s}H{sub m}{sup {Theta}} [2 C{sub 7}H{sub 6}O{sub 3}(s) + C{sub 9}H{sub 7}NO(s), 298.15 K] = 41.95 {+-} 0.44 kJ mol{sup -1}, {Delta}{sub s}H{sub m}{sup {Theta}} [Gd(NO{sub 3}){sub 3}{center_dot}6H{sub 2}O(s), 298.15 K] = -29.11 {+-} 0.39 kJ mol{sup -1}, {Delta}{sub s}H{sub m}{sup {Theta}} [Gd(C{sub 7}H{sub 5}O{sub 3}){sub 2}{center_dot}(C{sub 9}H{sub 6}NO)(s), 298.15 K] = -46.99 {+-} 0.39 kJ mol{sup -1} and {Delta}{sub s}H{sub m}{sup {Theta}} [Solution D(aq), 298.15 K] = -90.33 {+-} 0.37 kJ mol{sup -1}. The enthalpy change of the synthesized reaction was estimated to be {Delta}{sub r}H{sub m}{sup {Theta}}=211.54{+-}0.69 kJ mol{sup -1}. From data in the literature, through Hess' law, the standard molar enthalpy of formation of Gd(C{sub 7}H{sub 5}O{sub 3}){sub 2}{center_dot}(C{sub 9}H{sub 7}NO)(s) was calculated to be {Delta}{sub f}H{sub m}{sup {Theta}} [Gd(C{sub 7}H{sub 5}O{sub 3}){sub 2}{center_dot}(C{sub 9}H

  2. Effect of 8-Hydroxyquinoline Citrate, Sucrose and Peroxidase Inhibitors on Vase Life of Lisianthus (EUSTOMA GRANDIFLORUM L. Cut Flowers

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    Sharifzadeh Kamaladin

    2014-09-01

    Full Text Available Cut lisianthus flowers have a short vase life, possibly due to blockage of xylem vessels. The effect of 8-hydroxyquinoline citrate, sucrose and peroxidase inhibitors on delaying senescence and extending vase life of cut lisianthus flowers was tested. The peroxidase inhibitors used in this experiment were catechol (CH (5, 10, 15 mM and p-phenylenediamine (PD (5, 10, 15 mM. All vase solutions contained 200 mg-dm-3 8-hydroxyquinoline citrate (8-HQC and 3% sucrose. 10 mM CH treatment was the most effective for vase life extension (13.3 days, increasing water uptake, and delaying fresh weight loss. The vase solution containing 10 mM CH significantly increased superoxide dismutase (SOD and decreased peroxidase (POD activities. Similarly, 10 mM PD increased anthocyanin content more than the other treat–ments. Protein degradation was significantly delayed by application of 5 mM PD. The malondialdehyde (MDA accumulation was reduced when CH at 5 mM and PD in 5 and 15 mM were added to the vase solution. Results indicated that peroxidase inhibitors in combination with 8-HQC and sucrose increase vase life of lisianthus by improving water uptake and delaying fresh weight loss.

  3. Study of 5-azidomethyl-8-hydroxyquinoline structure by X-ray diffraction and HF-DFT computational methods

    Science.gov (United States)

    Bougharraf, H.; Benallal, R.; Sahdane, T.; Mondieig, D.; Negrier, Ph.; Massip, S.; Elfaydy, M.; Lakhrissi, B.; Kabouchi, B.

    2017-02-01

    5-Azidomethyl-8-hydroxyquinoline has been synthesized and characterized using IR, 1H and 13C NMR spectroscopic methods. Thermal analysis revealed no solid-solid phase transitions. The crystal structure of this compound was refined by Rietveld method from powder X-ray diffraction data at 295 K. The single- crystal structure of the compound at 260 K was solved and refined using SHELX 97 program. According to the data obtained by both methods, the structure of the compound is monoclinic, space group P21/ c, with Z = 4 and Z' = 1. For the single crystal at 260 K, a = 12.2879 (9) Å, b = 4.8782 (3) Å, c = 15.7423 (12) Å, β=100.807(14)°. Mechanisms of deformation resulting from intra- and intermolecular interactions, such as hydrogen bonding, induced slight torsions in the crystal structure. The optimized molecular geometry of 5-azidomethyl-8-hydroxyquinoline in the ground state is calculated using density functional theory (B3LYP) and Hartree-Fock (HF) methods with the 6-311G( d,p) basis set. The calculated results show good agreement with experimental values. Energy gap of the molecule was found using HOMO and LUMO calculation which reveals that charge transfer occurs within the molecule.

  4. Synthesis, structure and photophysical properties of a binuclear Zn(II) complex based on 8-hydroxyquinoline ligand with naphthyl unit

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Guozan, E-mail: yuanguozan@163.com [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian (China); Shan, Weilong; Chen, Jiangbo; Tian, Yulan; Wang, Haitao [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2015-04-15

    A 2-substituted-8-hydroxyquinoline ligand (E)-2-[2-naphthyl-ethenyl]-8-hydroxyquinoline (HL) was synthesized and characterized by LC–MS, NMR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Using a solvothermal method, a binuclear complex [Zn{sub 2}L{sub 4}] (1) was fabricated by self-assembly of Zn(II) ion with ligand HL. X-ray structural analysis shows that the binuclear Zn(II) units are linked into 1D chain along the b axis via aromatic stacking. The coordination assembly of zinc salt and HL in solutions was investigated by UV–vis and photoluminescence (PL). Additionally, we also studied the thermal stability and photophysical properties of (fluorescent emission and lifetime) complex 1. The experimental results show that the complex 1 emits yellow luminescence in the solid state. - Highlights: • Ligand HL and binuclear complex 1 were synthesized and characterized. • Complex 1 features a 2D network constructed by non-covalent interactions. • Complex 1 emits yellow luminescence in the solid state.

  5. Studies on the growth, structural, optical, mechanical properties of 8-hydroxyquinoline single crystal by vertical Bridgman technique

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, SP. [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Velusamy, P.; Ramamurthi, K. [Crystal Growth and Thin Film Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India)

    2011-11-15

    Highlights: {yields} Growth of bulk single crystal of 8-hydroxyquinoline (8-HQ) by vertical Bridgman technique for the first time. {yields} The crystalline perfection is reasonably good. {yields} The photoluminescence spectrum shows that the material is suitable for blue light emission. -- Abstract: Single crystal of organic nonlinear optical material, 8-hydroxyquinoline (8-HQ) of dimension 52 mm (length) x 12 mm (dia.) was grown from melt using vertical Bridgman technique. The crystal system of the material was confirmed by powder X-ray diffraction analysis. The crystalline perfection of the grown crystal was examined by high-resolution X-ray diffraction study. Low angular spread around 400'' of the diffraction curve and the low full width half maximum values show that the crystalline perfection is reasonably good. The recorded photoluminescence spectrum shows that the material is suitable for blue light emission. Optical transmittance for the UV and visible region was measured and mechanical strength was estimated from Vicker's microhardness test along the growth face of the grown crystal.

  6. Modulating the near-infrared luminescence of neodymium and ytterbium complexes with tridentate ligands based on benzoxazole-substituted 8-hydroxyquinolines.

    Science.gov (United States)

    Shavaleev, Nail M; Scopelliti, Rosario; Gumy, Frédéric; Bünzli, Jean-Claude G

    2009-04-01

    An improved synthesis of 2-(2'-benzothiazole)- and 2-(2'-benzoxazole)-8-hydroxyquinoline ligands that combine a tridentate N,N,O-chelating unit for metal binding and extended chromophore for light harvesting is developed. The 2-(2'-benzoxazole)-8-hydroxyquinoline ligands form mononuclear nine-coordinate complexes with neodymium, [Nd(kappa(3)-ligand)(3)], and an eight-coordinate complex with ytterbium, [Yb(kappa(3)-ligand)(2) x (kappa(1)-ligand) x H(2)O], as verified by crystallographic characterization of five complexes with four different ligands. The chemical stability of the complexes increases when the ligand contains 5,7-dihalo-8-hydroxyquinoline versus an 8-hydroxyquinoline group. The complexes feature a ligand-centered visible absorption band with a maximum at 508-527 nm and an intensity of (7.5-9.6) x 10(3) M(-1) x cm(-1). Upon excitation with UV and visible light within ligand absorption transitions, the complexes display characteristic lanthanide luminescence in the near-infrared at 850-1450 nm with quantum yields and lifetimes in the solid state at room temperature as high as 0.33% and 1.88 micros, respectively. The lanthanide luminescence in the complexes is enhanced upon halogenation of the 5,7-positions in the 8-hydroxyquinoline group and upon the addition of electron-donating substituents to the benzoxazole ring. Facile modification of chromophore units in 2-(2'-benzoxazole)-8-hydroxyquinoline ligands provides means for controlling the luminescence properties of their lanthanide complexes.

  7. Preconcentration of Rare Earth Elements with 8-Hydroxyquinoline-5-sulfonic Acid Chelated Cellulose Filter Prior to Determination by Inductively Coupled Plasma Atomic Emission Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    8-Hydroxyquinoline-5-sulfonic acid,covalently bound to filter cellulose,was used for preconcentrating trace rare earth element(REE) ions from complex matrices and matrix separation,respectively.Multi-REE ions were preconcentrated on the column filled with 8-hydroxyquinoline-5-sulfonic acid cellulose filter and analysed by ICP-AES after being eluted with dilute HNO3.In the given pH range,alkali and alkaline earth metal ions can be separated as matrix elements;a high concentration factor is obtained and the eluates can be measured without interference.The usefulness of the method is shown by the control analyses of standard reference materials.

  8. Enhanced performance of C60 organic field effect transistors using a tris(8-hydroxyquinoline) aluminum buffer layer

    Institute of Scientific and Technical Information of China (English)

    Zheng Hong; Cheng Xiaoman; Tian Haijun; Zhao Geng

    2011-01-01

    We have investigated the properties of C60-based organic field effect transistors (OFETs) with a tris(8-hydroxyquinoline) aluminum (Alq3) buffer layer inserted between the source/drain electrodes and the active material.The electrical characteristics of OFETs are improved with the insertion of Aiq3 film.The peak field effect mobility is increased to 1.28 × 10-2 cm2/(V.s) and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm.The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films.

  9. Organometallic tris(8-hydroxyquinoline)aluminum complexes as buffer layers and dopants in inverted organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tolkki, Antti, E-mail: antti.tolkki@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101, Tampere (Finland); Kaunisto, Kimmo [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101, Tampere (Finland); Heiskanen, Juha P. [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101, Tampere (Finland); Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014, Oulu (Finland); Omar, Walaa A.E. [Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014, Oulu (Finland); Chemistry Branch, Department of Science and Mathematics, Suez Canal University, Suez 43721 (Egypt); Huttunen, Kirsi; Lehtimaeki, Suvi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101, Tampere (Finland); Hormi, Osmo E.O. [Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014, Oulu (Finland); Lemmetyinen, Helge [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101, Tampere (Finland)

    2012-04-30

    Tris(8-hydroxyquinoline)aluminum (Alq{sub 3}) is a frequently used material for organic light emitting diodes. The electronic properties and solubility can be tuned by chemical tailoring of the quinoline part, which makes it an interesting candidate for organic solar cells. Steady-state absorption and fluorescence, as well as time-resolved fluorescence properties of the parent Alq{sub 3} and a series of complexes consisting of derivatives, such as 4-substituted pyrazol, methylpyrazol, arylvinyl, and pyridinoanthrene moieties, of the quinoline ligand, were studied in solutions and in thin films. Suitability of the complexes as anodic buffer layers or dopants in inverted organic solar cells based on the well known bulk heterojunction of poly(3-hexylthiophene) (P3HT) and phenyl-C{sub 61}-butyric acid methyl ester (PCBM) was tested. The devices equipped with the derivatives showed higher power conversion efficiency ({eta}) compared to the photocells containing the parent Alq{sub 3}. Open circuit voltage (V{sub oc}) was increased when the derivatives were utilized as the anodic buffer layer. Doping of the P3HT:PCBM with a small amount of Alq{sub 3} or its derivative improved short circuit current density, V{sub oc}, fill factor, and {eta}, while the series resistance decreased. In addition, the devices were stable in air over several weeks without encapsulation. Possible mechanisms leading to the improvements in the photovoltaic performance by using the parent Alq{sub 3} or its derivative as buffer layer or dopant are discussed. - Highlights: Black-Right-Pointing-Pointer Tris(8-hydroxyquinoline)aluminum (Alq{sub 3}) complexes in inverted organic solar cells. Black-Right-Pointing-Pointer The Alq{sub 3} complexes were used as an anodic buffer layer and as a dopant. Black-Right-Pointing-Pointer Efficiency increased and the derivatives revealed varying open circuit voltage. Black-Right-Pointing-Pointer Photovoltaic performance was stable after storage in a dark ambient

  10. Complexation efficiency of differently fixed 8-hydroxyquinoline and salicylic acid ligand groups for labile aluminium species determination in soils--comparison of two methods.

    Science.gov (United States)

    Matús, Peter; Kubová, Jana

    2006-07-28

    Two methods utilizing the complexation of labile Al species by 8-hydroxyquinoline (HQN) and salicylic acid (SA) ligand groups were developed for aluminium operationally defined fractionation in acid soils. First, the solid phase extraction (SPE) procedure by a short-term ion-exchange batch reaction with chelating resins Iontosorb Oxin and Iontosorb Salicyl containing both ligand groups was used previously. Second, the 8-hydroxyquinoline, salicylic acid and ammonium salicylate agents with different concentrations by a single extraction protocol were applied in this paper. The flame atomic absorption spectrometry (FAAS) and optical emission spectrometry with inductively coupled plasma were used for aluminium quantification. The comparison of results from both methods show the possibility to supersede the first laborious method for the second simpler one in Al environmental risk assessment. The use of 1% 8-hydroxyquinoline in 2% acetic acid and 0.2% salicylic acid by a single extraction protocol without a need of sample filtration can supersede the SPE procedure in the Al pollution soil monitoring. Finally, the new scheme usable in a laboratory and moreover, directly in a field was proposed for Al fractionation in solid and liquid environmental samples. The labile Al species in soils and sediments are separated after their single leaching by 8-hydroxyquinoline or salicylic acid without a need of sample filtration. The labile Al species in soil solutions and natural waters are separated after their ultrafiltration followed by the SPE procedure with Iontosorb Oxin or Iontosorb Salicyl.

  11. Complexation efficiency of differently fixed 8-hydroxyquinoline and salicylic acid ligand groups for labile aluminium species determination in soils-comparison of two methods

    Energy Technology Data Exchange (ETDEWEB)

    Matus, Peter [Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina, 842 15 Bratislava (Slovakia)]. E-mail: matus@fns.uniba.sk; Kubova, Jana [Comenius University in Bratislava, Faculty of Natural Sciences, Mlynska dolina, 842 15 Bratislava (Slovakia)

    2006-07-28

    Two methods utilizing the complexation of labile Al species by 8-hydroxyquinoline (HQN) and salicylic acid (SA) ligand groups were developed for aluminium operationally defined fractionation in acid soils. First, the solid phase extraction (SPE) procedure by a short-term ion-exchange batch reaction with chelating resins Iontosorb Oxin and Iontosorb Salicyl containing both ligand groups was used previously. Second, the 8-hydroxyquinoline, salicylic acid and ammonium salicylate agents with different concentrations by a single extraction protocol were applied in this paper. The flame atomic absorption spectrometry (FAAS) and optical emission spectrometry with inductively coupled plasma were used for aluminium quantification. The comparison of results from both methods show the possibility to supersede the first laborious method for the second simpler one in Al environmental risk assessment. The use of 1% 8-hydroxyquinoline in 2% acetic acid and 0.2% salicylic acid by a single extraction protocol without a need of sample filtration can supersede the SPE procedure in the Al pollution soil monitoring. Finally, the new scheme usable in a laboratory and moreover, directly in a field was proposed for Al fractionation in solid and liquid environmental samples. The labile Al species in soils and sediments are separated after their single leaching by 8-hydroxyquinoline or salicylic acid without a need of sample filtration. The labile Al species in soil solutions and natural waters are separated after their ultrafiltration followed by the SPE procedure with Iontosorb Oxin or Iontosorb Salicyl.

  12. An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid

    Science.gov (United States)

    Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

    2007-01-01

    A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

  13. Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sumaira, E-mail: skhanzai@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem G., E-mail: tgkazi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jameel A., E-mail: jab_mughal@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Young Welfare Society Mughalabad, Near Akri, Taluka Faiz Ganj, District Khairpur Sindh (Pakistan); Kolachi, Nida F., E-mail: nidafatima6@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan I., E-mail: hassanimranafridi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Wadhwa, Sham Kumar [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Q., E-mail: aqshah07@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kandhro, Ghulam A. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Faheem, E-mail: shah_ceac@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2010-10-15

    A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 {mu}g/L, respectively.

  14. Site-specific tagging proteins with a rigid, small and stable transition metal chelator, 8-hydroxyquinoline, for paramagnetic NMR analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yin; Huang, Feng [Nankai University, State Key Laboratory of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) (China); Huber, Thomas [Australian National University, Research School of Chemistry (Australia); Su, Xun-Cheng, E-mail: xunchengsu@nankai.edu.cn [Nankai University, State Key Laboratory of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) (China)

    2016-02-15

    Design of a paramagnetic metal binding motif in a protein is a valuable way for understanding the function, dynamics and interactions of a protein by paramagnetic NMR spectroscopy. Several strategies have been proposed to site-specifically tag proteins with paramagnetic lanthanide ions. Here we report a simple approach of engineering a transition metal binding motif via site-specific labelling of a protein with 2-vinyl-8-hydroxyquinoline (2V-8HQ). The protein-2V-8HQ adduct forms a stable complex with transition metal ions, Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The paramagnetic effects generated by these transition metal ions were evaluated by NMR spectroscopy. We show that 2V-8HQ is a rigid and stable transition metal binding tag. The coordination of the metal ion can be assisted by protein sidechains. More importantly, tunable paramagnetic tensors are simply obtained in an α-helix that possesses solvent exposed residues in positions i and i + 3, where i is the residue to be mutated to cysteine, i + 3 is Gln or Glu or i − 4 is His. The coordination of a sidechain carboxylate/amide or imidazole to cobalt(II) results in different structural geometries, leading to different paramagnetic tensors as shown by experimental data.

  15. Intermolecular interactions in the solid state structures of neutral and N-protonated 5-alkoxymethyl-8-hydroxyquinolines

    Science.gov (United States)

    Schulze, Mathias M.; Böhme, Uwe; Schwarzer, Anke; Weber, Edwin

    2017-04-01

    A series of five different alkoxymethyl substituted derivatives of 8-hydroxyquinoline was synthesised both in protonated (1a-1e) and neutral (2a-2e) form. The alkoxymethyl groups are MeO (1a, 2a), EtO (1b, 2b), n-PrO (1c, 2c), iso-PrO (1d, 2d), n-BuO (1e, 2e). The compounds were characterised by single crystal X-ray diffraction and spectroscopic methods. Hirshfeld surface analysis was performed to analyse the crystal packing quantitatively. Topological analysis of the electron density distribution delivers information about the strength of the hydrogen bonds. The overall results reveal a main difference between the charged (1a-1d) and uncharged (2a-2e) compounds in the orientation of the hydroxyl group resulting in a different cyclic dimer formation. In both cases the structures are dominated by hydrogen bonding (1a-1d: Osbnd H⋯Cl, Nsbnd H⋯Cl and 2a-2e: Osbnd H⋯N). Furthermore, all crystal structures show π involved interactions though taking only a minor part in the packing of the molecules.

  16. Cell proliferation in Allium cepa L. meristems under 8-hydroxyquinoline, a chelating agent that affects DNA and RNA polymerases.

    Science.gov (United States)

    Ferrero, M L; De la Torre, C

    1986-02-01

    8-Hydroxyquinoline (HQ) chelates Mg2+ and Mn2+ and, secondarily, affects the activities of DNA and RNA polymerases. The in vivo effect of HQ has been estimated in Allium cepa L. meristems growing under new growth kinetics in the presence of this agent. HQ (at both 5 X 10(-5) M and 10(-4) M) depressed incorporation of [3H]uridine much more effectively than that of [3H]-thymidine. Cycle kinetics in meristems behaved as if they were independent of the rates of synthesis or accumulation of RNA since, under HQ, cycle time was only moderately modified and the new cycle kinetics achieved could be explained by the new rates of [3H]thymidine incorporation. Lengthened S periods were partially compensated for by shortened G2 phases, suggesting that, in these cells, both the growth cycle and its coupling with the DNA-division cycle were not disturbed by a decreased amount of RNA. Finally, the nucleolar cycle during mitosis, but not the interphase nucleolus, was modified under the new rates of RNA synthesis.

  17. Synthesis, molecular structure, theoretical calculation, DNA/protein interaction and cytotoxic activity of manganese(III) complex with 8-hydroxyquinoline.

    Science.gov (United States)

    Thamilarasan, V; Sengottuvelan, N; Sudha, A; Srinivasan, P; Siva, A

    2015-01-01

    Manganese(III) complex (1) [Mn(8-hq)3] (where 8-hq=8-hydroxyquinoline) has been synthesized and characterized by elemental, spectral (UV-vis, FT-IR) and thermal analysis. The structure of complex (1) has been determined by single crystal X-ray diffraction studies and the configuration around manganese(III) ion was elongated octahedral coordination geometry. Density functional theory calculations were performed for ligand and its complex. Binding studies of ligand and complex 1 with calf thymus DNA (CT-DNA) was investigated by absorption, fluorescence, circular dichroic (CD) spectroscopy and viscosity measurements. Absorption spectral studies revealed that ligand and complex 1 binds to DNA groove and its intrinsic binding strength has been found to be 2.57×10(4) and 2.91×10(4)M(-1). A molecular docking study confirm that the complex 1 is a minor groove binder and was stabilized through hydrogen bonding interactions. Complex 1 exhibits a good binding propensity to bovine serum albumin (BSA) protein. The in vitro cytotoxicity study of complex 1 on breast cancer cell line (MCF-7) indicate that it has the potential to act as effective anticancer drug, with IC50 values of 3.25μM. The ligand and its complex have been screened for antimicrobial activities and the complex showed better antimicrobial activity than the free ligand.

  18. Ion Exchange Study of Some New Copolymer Resins Derived from 8-Hydroxyquinoline-5-sulphonic Acid, Biuret and Formaldehyde

    Directory of Open Access Journals (Sweden)

    P. A. Dhakite

    2011-01-01

    Full Text Available Copolymer resins (8-HQSABF were synthesized by the condensation of 8-hydroxyquinoline-5-sulphonic acid and biuret with formaldehyde in the presence of hydrochloric acid as catalyst, proved to be selective chelation ion exchange copolymer resins for certain metals. Chelation ion exchange properties to these polymers were studied for Cu2+, Cd2+, Co2+ and Zn2+ ions. A batch equilibrium method was employed in the study of the selectivity of the distribution of a given metal ions between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in a media of various ions strengths. The polymer showed a higher selectivity for Cu2+ ions than for Cd2+, Co2+ and Zn2+ ions. Hence on the basis of above studies these copolymer may be used as semiconductors, surface coating, ion-exchangers, materials for rechargeable battery cell in various electronic industries, plastic materials, elastomers and in boiler plants

  19. Spintronic detection of interfacial magnetic switching in a paramagnetic thin film of tris(8-hydroxyquinoline)iron(III)

    Science.gov (United States)

    Sun, Dali; Kareis, Christopher M.; van Schooten, Kipp J.; Jiang, Wei; Siegel, Gene; Kavand, Marzieh; Davidson, Royce A.; Shum, William W.; Zhang, Chuang; Liu, Haoliang; Tiwari, Ashutosh; Boehme, Christoph; Liu, Feng; Stephens, Peter W.; Miller, Joel S.; Vardeny, Z. Valy

    2017-02-01

    Organic semiconductors find increasing importance in spin transport devices due to the modulation and control of their properties through chemical synthetic versatility. The organic materials have been used as interlayers between two ferromagnet (FM) electrodes in organic spin valves, as well as for magnetic spin manipulation of metal-organic complexes at the molecular level. In the latter, the substrate-induced magnetic switching in a paramagnetic molecule has been evoked extensively but studied by delicate surface spectroscopies. Here we present evidence of the substantial magnetic switching in a thin film of the paramagnetic molecule, tris(8-hydroxyquinoline)iron(III) (Fe q3 ) deposited on a FM substrate, using the magnetoresistance response of electrical spin-injection in an organic spin valve structure, as well as the inverse-spin-Hall effect induced by state-of-art pulsed microwave spin-pumping. We show that interfacial spin control at the molecular level may lead to a macroscopic organic spin transport device, thus bridging the gap between organic spintronics and molecular spintronics.

  20. Novel tacrine-8-hydroxyquinoline hybrids as multifunctional agents for the treatment of Alzheimer's disease, with neuroprotective, cholinergic, antioxidant, and copper-complexing properties.

    Science.gov (United States)

    Fernández-Bachiller, María Isabel; Pérez, Concepción; González-Muñoz, Gema C; Conde, Santiago; López, Manuela G; Villarroya, Mercedes; García, Antonio G; Rodríguez-Franco, María Isabel

    2010-07-01

    Tacrine and PBT2 (an 8-hydroxyquinoline derivative) are well-known drugs that inhibit cholinesterases and decrease beta-amyloid (Abeta) levels by complexation of redox-active metals, respectively. In this work, novel tacrine-8-hydroxyquinoline hybrids have been designed, synthesized, and evaluated as potential multifunctional drugs for the treatment of Alzheimer's disease. At nano- and subnanomolar concentrations they inhibit human acetyl- and butyrylcholinesterase (AChE and BuChE), being more potent than tacrine. They also displace propidium iodide from the peripheral anionic site of AChE and thus could be able to inhibit Abeta aggregation promoted by AChE. They show better antioxidant properties than Trolox, the aromatic portion of vitamin E responsible for radical capture, and display neuroprotective properties against mitochondrial free radicals. In addition, they selectively complex Cu(II), show low cell toxicity, and could be able to penetrate the CNS, according to an in vitro blood-brain barrier model.

  1. 8-Hydroxyquinoline Schiff-base compounds as antioxidants and modulators of copper-mediated Aβ peptide aggregation.

    Science.gov (United States)

    Gomes, Luiza M F; Vieira, Rafael P; Jones, Michael R; Wang, Michael C P; Dyrager, Christine; Souza-Fagundes, Elaine M; Da Silva, Jeferson G; Storr, Tim; Beraldo, Heloisa

    2014-10-01

    One of the hallmarks of Alzheimer's disease (AD) in the brain are amyloid-β (Aβ) plaques, and metal ions such as copper(II) and zinc(II) have been shown to play a role in the aggregation and toxicity of the Aβ peptide, the major constituent of these extracellular aggregates. Metal binding agents can promote the disaggregation of Aβ plaques, and have shown promise as AD therapeutics. Herein, we describe the syntheses and characterization of an acetohydrazone (8-H2QH), a thiosemicarbazone (8-H2QT), and a semicarbazone (8-H2QS) derived from 8-hydroxyquinoline. The three compounds are shown to be neutral at pH7.4, and are potent antioxidants as measured by a Trolox Equivalent Antioxidant Capacity (TEAC) assay. The ligands form complexes with Cu(II), 8-H2QT in a 1:1 metal:ligand ratio, and 8-H2QH and 8-H2QS in a 1:2 metal:ligand ratio. A preliminary aggregation inhibition assay using the Aβ1-40 peptide showed that 8-H2QS and 8-H2QH inhibit peptide aggregation in the presence of Cu(II). Native gel electrophoresis/Western blot and TEM images were obtained to give a more detailed picture of the extent and pathways of Aβ aggregation using the more neurotoxic Aβ1-42 in the presence and absence of Cu(II), 8-H2QH, 8-H2QS and the drug candidate PBT2. An increase in the formation of oligomeric species is evident in the presence of Cu(II). However, in the presence of ligands and Cu(II), the results match those for the peptide alone, suggesting that the ligands function by sequestering Cu(II) and limiting oligomer formation in this assay.

  2. Development of an optical fibre reflectance sensor for p-aminophenol detection based on immobilised bis-8-hydroxyquinoline.

    Science.gov (United States)

    Filik, Hayati; Hayvali, Mustafa; Kiliç, Emine; Apak, Reşat; Aksu, Duygu; Yanaz, Zeynep; Cengel, Tayfun

    2008-10-19

    2,2'-(1,4-Phenylenedivinylene)bis-8-hydroxyquinoline (PBHQ), a highly sensitive reagent used for the colorimetric determination of p-aminophenol (PAP), was successfully immobilised on XAD-7 and coupled with optical fibres to investigate a sensor-based approach for determining p-aminophenol. The solid-state sensor is based on the reaction of PAP with PBHQ in presence of an oxidant to produce an indophenol dye. The reflectance measurements were carried out at a wavelength of 647 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the analyte. The linear dynamic range of PAP was found within the concentration range of 0.1-2.18 mg l(-1) with its LOD of 0.02 mg l(-1). The sensor response from different probes (n=7) gave a R.S.D. of 4.4% at 1.09 mg l(-1) PAP concentration. The response time of the optical one-shot sensor was 5 min for a stable solution. As this PAP sensor is irreversible, a fresh sensor has to be used for each measurement. All the experimental parameters were optimized for the determination of PAP. Using the optical sensing probe, PAP in pharmaceutical wastewater and paracetamol was determined. The effect of potential interferences such as inorganic and organic compounds was also evaluated. Potential on-site determination of PAP with such sensors can indirectly aid detection of organo-phosphorus nerve agents and pesticides in the field by inhibition of acetylcholine esterase-catalyzed hydrolysis of p-aminophenyl acetate to p-aminophenol.

  3. Combined optical gain and degradation measurements in DCM2 doped Tris-(8-hydroxyquinoline)aluminum thin-films

    Science.gov (United States)

    Čehovski, Marko; Döring, Sebastian; Rabe, Torsten; Caspary, Reinhard; Kowalsky, Wolfgang

    2016-04-01

    Organic laser sources offer the opportunity to integrate flexible and widely tunable lasers in polymer waveguide circuits, e.g. for Lab-on-Foil applications. Therefore, it is necessary to understand gain and degradation processes for long-term operation. In this paper we address the challenge of life-time (degradation) measurements of photoluminescence (PL) and optical gain in thin-film lasers. The well known guest-host system of aluminum-chelate Alq3 (Tris-(8-hydroxyquinoline)aluminum) as host material and the laser dye DCM2 (4-(Dicyanomethylene)-2- methyl-6-julolidyl-9-enyl-4H-pyran) as guest material is employed as laser active material. Sample layers have been built up by co-evaporation in an ultrahigh (UHV) vacuum chamber. 200nm thick films of Alq3:DCM2 with different doping concentrations have been processed onto glass and thermally oxidized silicon substrates. The gain measurements have been performed by the variable stripe length (VSL) method. This measurement technique allows to determine the thin-film waveguide gain and loss, respectively. For the measurements the samples were excited with UV irradiation (ƛ = 355nm) under nitrogen atmosphere by a passively Q-switched laser source. PL degradation measurements with regard to the optical gain have been done at laser threshold (approximately 3 μJ/cm2), five times above laser threshold and 10 times above laser threshold. A t50-PL lifetime of > 107 pulses could be measured at a maximum excitation energy density of 32 μJ/cm2. This allows for a detailed analysis of the gain degradation mechanism and therefore of the stimulated cross section. Depending on the DCM2 doping concentration C the stimulated cross section was reduced by 35 %. Nevertheless, the results emphasizes the necessity of the investigation of degradation processes in organic laser sources for long-term applications.

  4. Antioxidation and DNA-binding properties of binuclear lanthanide(III) complexes with a Schiff base ligand derived from 8-hydroxyquinoline-7-carboxaldehyde and benzoylhydrazine.

    Science.gov (United States)

    Liu, Yongchun; Zhang, Kejun; Wu, Yun; Zhao, Junying; Liu, Jianning

    2012-08-01

    8-Hydroxyquinoline-7-carboxaldehyde (8-HQ-7-CA), Schiff-base ligand 8-hydroxyquinoline-7-carboxaldehyde benzoylhydrazone, and binuclear complexes [LnL(NO(3))(H(2)O)(2)](2) were prepared from the ligand and equivalent molar amounts of Ln(NO(3))·6H(2)O (Ln=La(3+), Nd(3+), Sm(3+), Eu(3+), Gd(3+), Dy(3+), Ho(3+), Er(3+), Yb(3+), resp.). Ligand acts as dibasic tetradentates, binding to Ln(III) through the phenolate O-atom, N-atom of quinolinato unit, and C=N and -O-C=N- groups of the benzoylhydrazine side chain. Dimerization of this monomeric unit occurs through the phenolate O-atoms leading to a central four-membered (LnO)(2) ring. Ligand and all of the Ln(III) complexes can strongly bind to CT-DNA through intercalation with the binding constants at 10(5)-10(6) M(-1). Moreover, ligand and all of the Ln(III) complexes have strong abilities of scavenging effects for hydroxyl (HO·) radicals. Both the antioxidation and DNA-binding properties of Ln(III) complexes are much better than that of ligand.

  5. Solid Phase Extraction of Inorganic Mercury Using 5-Phenylazo-8-hydroxyquinoline and Determination by Cold Vapor Atomic Fluorescence Spectroscopy in Natural Water Samples

    Science.gov (United States)

    Daye, Mirna; Halwani, Jalal; Hamzeh, Mariam

    2013-01-01

    8-Hydroxyquinoline (8-HQ) was chosen as a powerful ligand for Hg solid phase extraction. Among several chelating resins based on 8-HQ, 5-phenylazo-8-hydroxyquinoline (5Ph8HQ) is used for mercury extraction in which the adsorption dynamics were fully studied. It has been shown that Hg(II) is totally absorbed by 5Ph8HQ within the first 30 minutes of contact time with t1/2 5 minutes, following Langmuir adsorption model. At pH 4, the affinity of mercury is unchallenged by other metals except, for Cu(II), which have shown higher Kd value. With these latter characteristics, 5Ph8HQ was examined for the preconcentration of trace levels of Hg(II). The developed method showed quantitative recoveries of Hg(II) with LOD = 0.21 pg mL−1 and RSD = 3–6% using cold vapor atomic fluorescence spectroscopy (CV-AFS) with a preconcentration factor greater than 250. PMID:24459417

  6. Solid Phase Extraction of Inorganic Mercury Using 5-Phenylazo-8-hydroxyquinoline and Determination by Cold Vapor Atomic Fluorescence Spectroscopy in Natural Water Samples

    Directory of Open Access Journals (Sweden)

    Mirna Daye

    2013-01-01

    Full Text Available 8-Hydroxyquinoline (8-HQ was chosen as a powerful ligand for Hg solid phase extraction. Among several chelating resins based on 8-HQ, 5-phenylazo-8-hydroxyquinoline (5Ph8HQ is used for mercury extraction in which the adsorption dynamics were fully studied. It has been shown that Hg(II is totally absorbed by 5Ph8HQ within the first 30 minutes of contact time with t1/2 5 minutes, following Langmuir adsorption model. At pH 4, the affinity of mercury is unchallenged by other metals except, for Cu(II, which have shown higher Kd value. With these latter characteristics, 5Ph8HQ was examined for the preconcentration of trace levels of Hg(II. The developed method showed quantitative recoveries of Hg(II with LOD = 0.21 pg mL−1 and RSD = 3–6% using cold vapor atomic fluorescence spectroscopy (CV-AFS with a preconcentration factor greater than 250.

  7. Critical evaluation of equilibrium constants involving 8-hydroxyquinoline and its metal chelates critical evaluation of equilibrium constants in solution : part b : equilibrium constants of liquid-liquid distribution systems

    CERN Document Server

    Stary, J

    1979-01-01

    Critical Evaluation of Equilibrium Constants Involving 8-Hydroxyquinoline and Its Metal Chelates presents and evaluates the published data on the solubility, dissociation, and liquid-liquid distribution of oxine and its metal chelates to recommend the most reliable numerical data. This book explores the dissociation constants of oxine in aqueous solutions.Organized into four chapters, this book begins with an overview of the characteristics of 8-hydroxyquinoline (oxine). This text then examines the total solubility of oxine in aqueous solution at different pH values. Other chapters consider th

  8. A study on the spectroscopic, energy band, and optoelectronic properties of α,ω-dihexylsexithiophene/tris(8-hydroxyquinolinate) gallium blends; DH6T/Gaq3 composite system

    Science.gov (United States)

    Muhammad, Fahmi F.; Yahya, Mohd Yazid; Ketuly, Kamal Aziz; Muhammad, Abdulkader Jaleel; Sulaiman, Khaulah

    2016-12-01

    In this work the optical response, spectroscopic behaviour, and optoelectronic properties of solution and solid state composite systems based on α,ω-dihexylsexithiophene/tris(8-hydroxyquinolinate) gallium (DH6T/Gaq3) are studied upon the incorporation of different molar percentages of Gaq3. UV-vis, PL, FTIR spectrophotometers and SEM technique were utilized to perform the investigations. The results showed a reduced energy band (Eg) (from 2.33 eV to 1.83 eV) and a broadened absorption spectrum for the blend system when 29.8% molar of Gaq3 was incorporated. These were attributed to the enhanced intermolecular interactions that are brought about by the increased strength of π - π overlap between the molecular moieties. A mathematical formula was developed to interpret the non-monotonic change occurred in Eg, while numerical calculations have been made to assign the type and nature of the electronic transitions governing the spectroscopic behaviour of the system. The results were elaborated and comprehensively discussed in terms of the exciton generation, energy band theory, molecular interactions, and spatial geometry.

  9. Synthesis, spectral, thermal and antibacterial investigations of mixed ligand complexes of thorium(IV) derived from 8-hydroxyquinoline and some amino acids.

    Science.gov (United States)

    Patil, Sunil S; Thakur, Ganesh A; Shaikh, Manzoor M

    2012-01-01

    Mixed ligand Th(IV) complexes of the type [M(Q)(L)(NO3)2] x 2 H2O have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N- and/or O- donor amino acids (HL) such as L-lysine, L-aspartic acid and L-cysteine as secondary ligands. The metal complexes have been characterized on the basis of elemental analysis, electrical conductance, room temperature magnetic susceptibility measurements,spectral and thermal studies. The electrical conductance studies of the complexes in DMF in 10(-3) M concentration indicate their non-electrolytic nature. Room temperature magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intra-ligand and charge transfer transitions, respectively. Bonding of the metal ion through N- and O- donor atoms of the ligands revealed by IR studies and the chemical environment of the protons is also confirmed by NMR studies. The thermal analysis data of the complexes indicate the presence of crystallized water molecules. The agar cup and tube dilution method have been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus, C. diphtheriae, S. typhi and E. coli.

  10. Synthesis, Spectral, Thermal Analysis, Biological Activity and Kinetic Studies of Copper(II)-Pyridine-2,5-dicarboxylate Complexes with 2-Aminomethylpyridine and 8-Hydroxyquinoline.

    Science.gov (United States)

    Colak, Alper Tolga; Colak, Ferdağ; Atar, Necip; Olgun, Asım

    2010-03-01

    In this work we report the synthesis of two novel square-planar copper(II) complexes, namely, (2-aminomethylpyridinium-pyridinedicarboxylato)copper(II) dihydrate, [Cu(pydc)(2-amp)] • 2H2O (1) and (8-hydroxyquinolinum-pyridinedicarboxylato)copper(II) hydrate, [Cu(pydc)(8-HQ)] • H2O (2) (2-amp = 2-aminomethylpyridine, 8-HQ = 8-hydroxyquinoline, H2pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid) and present the first preliminary study on kinetics and biological activities of copper complexes. The synthesized complexes have been characterized by elemental, spectroscopic (FT-IR, UV and mass spectra), thermal analysis, magnetic and conductivity measurements techniques. Kinetic parameters were obtained for each stage of thermal degradation of the complexes using Coats-Redfern and Horowitz-Metzger methods. Antimicrobial activities of two complexes and two ligands were evaluated using agar diffusion method. Antimicrobial activity of complex 2 was determined with the agar dilution methods. The results were compared with two well known antibiotics, namely, tetracycline and nystatin.

  11. Luminescence, magnetocaloric effect and single-molecule magnet behavior in lanthanide complexes based on a tridentate ligand derived from 8-hydroxyquinoline.

    Science.gov (United States)

    Shen, Hai-Yun; Wang, Wen-Min; Bi, Yan-Xia; Gao, Hong-Ling; Liu, Shuang; Cui, Jian-Zhong

    2015-11-21

    A new family of lanthanide complexes, [Ln2(hfac)4L2] (Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Lu (7); hfac = hexafluoroacetylacetonate, HL = 2-(2′-benzothiazole)-8-hydroxyquinoline), was synthesized and characterized using single-crystal X-ray diffraction, elemental analysis (EA), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and UV-vis spectra. X-ray crystallographic analyses reveal that 1–7 are isomorphous and crystallize in the monoclinic space group C2/c. In these dinuclear complexes, each LnШ ion is eight-coordinated with two bidentate hfac and two μ-phenol bridging L ligands. The TGA results show that the complexes have relatively high thermal stabilities. Complexes 1 and 3 show the characteristic transitions of the corresponding lanthanide ions with ligand-related emission peaks. Meanwhile, complexes 4 and 7 exhibit ligand-centered fluorescence at room temperature. Magnetic measurements were carried out on complexes 2–6. The magnetic study reveals that 2 displays a magnetocaloric effect, with a maximum −ΔSm value of 16.89 J K−1 kg−1 at 2 K for ΔH = 8 T. Dynamic magnetic studies reveal single-molecule magnet (SMM) behavior for complex 4. Fitting the dynamic magnetic data to the Arrhenius law gives an energy barrier ΔE/kB = 50.33 K and pre-exponential factor τ0 = 1.05 × 10(-8)s.

  12. Paramagnetic relaxation enhancement of membrane proteins by incorporation of the metal-chelating unnatural amino acid 2-amino-3-(8-hydroxyquinolin-3-yl)propanoic acid (HQA)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Ho; Wang, Vivian S.; Radoicic, Jasmina; Angelis, Anna A. De; Berkamp, Sabrina; Opella, Stanley J., E-mail: sopella@ucsd.edu [University of California, San Diego, Department of Chemistry and Biochemistry (United States)

    2015-04-15

    The use of paramagnetic constraints in protein NMR is an active area of research because of the benefits of long-range distance measurements (>10 Å). One of the main issues in successful execution is the incorporation of a paramagnetic metal ion into diamagnetic proteins. The most common metal ion tags are relatively long aliphatic chains attached to the side chain of a selected cysteine residue with a chelating group at the end where it can undergo substantial internal motions, decreasing the accuracy of the method. An attractive alternative approach is to incorporate an unnatural amino acid that binds metal ions at a specific site on the protein using the methods of molecular biology. Here we describe the successful incorporation of the unnatural amino acid 2-amino-3-(8-hydroxyquinolin-3-yl)propanoic acid (HQA) into two different membrane proteins by heterologous expression in E. coli. Fluorescence and NMR experiments demonstrate complete replacement of the natural amino acid with HQA and stable metal chelation by the mutated proteins. Evidence of site-specific intra- and inter-molecular PREs by NMR in micelle solutions sets the stage for the use of HQA incorporation in solid-state NMR structure determinations of membrane proteins in phospholipid bilayers.

  13. Determination of Some Trace Metals in Environmental Samples by Flame AAS Following Solid Phase Extraction with Amberlite XAD-2000 Resin after Complexing with 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    DURAN Celal; SENTURK H.Basri; GUNDOGDU Ali; BULUT V.Numan; EICi Latif; SOYLAK Mustafa; TUFEKCI,Mehmet; UYGUR Yaprak

    2007-01-01

    A procedure for preconcentration of Mn(Ⅱ), Fe(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Cd(Ⅱ), Zn(Ⅱ), Pb(Ⅱ) and Ni(Ⅱ) based on retention of their complexes with 8-hydroxyquinoline (HQ) on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume,concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn2+ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L 1 (n=20, blank+3s). The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.

  14. High-performance supercapacitor based on nitrogen-doped porous carbon derived from zinc(II)-bis(8-hydroxyquinoline) coordination polymer.

    Science.gov (United States)

    Chen, Xiang Ying; Xie, Dong Hua; Chen, Chong; Liu, Jian Wei

    2013-03-01

    Nitrogen-doped porous carbon electrodes with remarkable specific capacitance have been fabricated by the rational carbonization of zinc(II)-bis(8-hydroxyquinoline) (abbr. Znq(2)) coordination polymer, and heating treatment with CO(NH(2))(2). The experimental results demonstrate that the mass ratio of carbon precursor and CO(NH(2))(2) plays a key role in the formation of porous carbon with various nitrogen content as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge-discharge measurements show that the capacitive performance has been remarkably improved by doping with nitrogen. The specific capacitance of 219.2 F g(-1) is achieved at the current density of 1 A g(-1) with nitrogen-doped porous carbon, increasing up to ca. 56.8% compared to that with pristine porous carbon. The nitrogen-doped porous carbon electrode exhibits enhance capacitance retention as ca. 45.2% at 20 A g(-1) as well as cycling stability (ca. 7.6% loss after 3000 cycles). The present carbonization method as well as the nitrogen-doping method for porous carbon from coordination polymer can enrich the strategies for the production of carbon-based electrodes materials in the application of electrochemical capacitors.

  15. Synthesis, Structure and Third-order Non-linear Optical Properties of Tungsten Dioxo Complex with 8-Hydroxyquinoline Ligand WO2(C9H6NO)2

    Institute of Scientific and Technical Information of China (English)

    LI Yong; LU Jing; XU Ji-qing; CUI Xiao-bing; SUN Ying-hua; LI Ke-chang; YANG Qing-xin; PAN Ling-yun; BIE Hai-ying

    2004-01-01

    Tungsten dioxo complex WO2(C9H6NO)2 was obtained via the low temperature solid-state reaction of(NH4)2WS4, 8-hydroxyquinoline(8-hq) and(CH3)4NI, and it was characterized by means of elemental analyses, IR spectroscopy and X-ray diffraction analysis. The crystal of the title compound belongs to monoclinic, space group C2/c, with the crystal cell parameters: a=1.3316(3) nm, b=0.94444(19) nm, c=1.3485(3) nm, β=109.66(3)°, V=1.5970(6) nm3, Z=6. The title compound possesses a supramolecular structure formed through hydrogen bonds and π-π stacking interactions. The third-order non-linear optical(NLO) properties of the title compound were also investigated. The third-order non-linear absorption coefficient α2 and refractive index n2 are 0.85×10-11 m/W-1 and -1.5×10-19 m2/W, respectively. The third-order non-linear susceptibility χ(3) is 3.03×10-13 esu for 3.8×10-5 mol/L sample concentration.

  16. Maximising metal ions flux across a microdialysis membrane by incorporating poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline and ethylenediaminetetraacetic acid in the perfusion liquid

    Energy Technology Data Exchange (ETDEWEB)

    Mogopodi, Dikabo [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana); Torto, Nelson [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana)]. E-mail: torton@mopipi.ub.bw

    2005-04-08

    This paper presents a study of quiescent microdialysis sampling of Cr{sup 3+}, Cu{sup 2+}, Ni{sup 2+} and Pb{sup 2+} involving the incorporation of poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline (8-HQ) and ethylenediaminetetraacetic acid (EDTA), in the perfusion liquid as an approach to maximise metal analyte flux across the microdialysis membrane. These chelating agents were individually optimised with respect to microdialysis recovery and subsequently combined in the perfusion liquid. A combination of 20% (w/v) poly-L-histidine, 0.032% (w/v) poly-L-aspartic acid and 1 mM 8-HQ achieved microdialysis recovery up to 90%. Since 1 mM EDTA achieved recoveries greater than 80% for all metals understudy, EDTA was not combined with any of the chelating agents. Under the optimal conditions of maximum metal ion flux across the microdialysis membrane, metal ions from natural and wastewater were sampled and analysed with an electrothermal atomic absorption spectrometer equipped with a Zeeman background corrector. Results showed higher concentrations of detected metal ions after microdialysis sampling compared to direct detection without sample clean-up. Incorporation of chelating agents in the microdialysis perfusion liquid enhanced metal ions recovery in real samples and achieved enrichment factors of up to 42. The study demonstrated that combining chelating agents is a good approach towards maximising metal flux across the dialysis membrane. Given that recoveries between 80 and 90% were achieved under quiescent microdialysis sampling conditions, these findings are an important development for in vivo diagnostic sampling of metal ions.

  17. Effects of thermal annealing on the optical, spectroscopic, and structural properties of tris (8-hydroxyquinolinate) gallium films grown on quartz substrates

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Fahmi Fariq, E-mail: fahmi982@gmail.com [Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Physics, Faculty of Science and Engineering, University of Koya, Koya, Kurdistan Region (Iraq); Sulaiman, Khaulah [Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2011-10-03

    Highlights: {yields} Achieving a broad absorption band for Gaq3 covering the whole UV and some parts of visible spectra. {yields} Increasing photoluminescence emission to five times stronger than that of pristine film. {yields} Conformational changes towards the formation of crystalline {alpha}-Gaq3 polymorph. {yields} Determination of glass transition temperature for Gaq3 (T{sub g} 182 deg. C) and Alq3 (T{sub g} = 173 deg. C). {yields} Improving and understanding the physical properties of Gaq3 film by means of thermal treatment. - Abstract: In this study we report the optical, spectroscopic, and structural properties of vacuum deposited tris (8-hydroxyquinolinate) gallium film upon thermal annealing in the temperature range from 85 deg. C to 255 deg. C under a flowing nitrogen gas for 10 min. The optical UV-vis-NIR and luminescence spectroscopy measurements were performed to estimate the absorption bands, optical energy gap (E{sub g}), and photoluminescence (PL) of the films. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques were used to probe the spectroscopic and structural nature of the films. We show that, by annealing the films from 85 deg. C to 235 deg. C, it is possible to achieve an enhanced absorption and increased photoluminescence to five times stronger than that of the pristine film. The PL quenching at 255 deg. C was attributed to the presence of plainer chains allow easy going for excitons to a long distance due to the crystalline region formation of {alpha}-Gaq3 polymorph. The reduction in E{sub g} and infrared absorption bands upon annealing were referred to the enhancement in {pi}-{pi} interchain interaction and conformational changes by re-arrangement of the Gaq3 quinolinate ligands, respectively. Stokes shift for the films were observed and calculated. From the differential scanning calorimetry, DSC measurements, higher glass transition temperature was observed for Gaq3 (T{sub g} = 182 deg. C) compared to

  18. Synthesis and DNA-binding of La(III) complex with methacrylic acid and 8-hydroxyquinoline%甲基丙烯酸-8-羟基喹啉-镧配合物的合成及与DNA的作用

    Institute of Scientific and Technical Information of China (English)

    李小芳; 冯小强; 张宏伟; 杨声

    2014-01-01

    合成了配合物La(C4H6O2)2(hq)(C4H6O2=甲基丙烯酸,hq=8-羟基喹啉),通过元素分析、摩尔电导、红外光谱、紫外光谱和热重分析手段对产物进行表征。此外,采用紫外吸收光谱、荧光光谱,研究了配合物与鲱鱼精DNA之间的相互作用。结果显示配合物与鲱鱼精DNA作用的结合常数K=7.59×103L·mol-1,配合物与DNA的作用摩尔比为1∶1,作用模式为嵌插作用。%A ternary complex of La(Ш)with methacrylic acid and 8-hydroxyquinoline(La(C4H6O2)2(hq),C4H6O2=methacrylic acid,hq=8-hydroxyquinoline) was synthesized and characterized by elemental analysis,molar conductivity,IR spectrum,ultraviolet spectrum and differential thermal gravimetric analysis methods. In addition, the interaction between ternary complex and herring sperm DNA have been investigated by absorption spectroscopy and fluorescent spectroscopy. The results showed that the binding constant k of complex with herring sperm DNA was7. 59×103L·mol-1,and the molar ratio of 1∶1. Their interaction mode is due to insertion.

  19. Determining WO3 Content in Tungsten Concentrate by 8-Hydroxyquinoline Gravimetric Method%8-羟基喹啉重量法测定钨精矿中WO3的含量

    Institute of Scientific and Technical Information of China (English)

    吴伟明; 徐晶; 梁晓鹏; 柴敏平; 程明焱; 蒋小岗

    2012-01-01

    This article reviews the advantages and disadvantages of the common gravimetric methods for the content determination of tungsten. The conditions of decomposition and precipitation of the 8-hydroxyquinoline gravimetric method to determine WO3 content in tungsten concentrate were studied by stating the best conditions of color reaction. The experimental results show that the sample decomposition is fast and complete, which shows the method is accurate, convenient and efficient.%对钨精矿中钨含量测定的常用重量法进行了综合评述;对8-羟基喹啉重量法中硫-磷混酸分解试样条件、沉淀条件选择及干扰元素影响的消除、最佳显色条件等进行实验探讨.结果表明,试样分解快速完全、结果精密度高、方法可行有效.

  20. Evaluation of immobilized metal-ion affinity chromatography and electrospray ionization tandem mass spectrometry for recovery and identification of copper(II-binding ligands in seawater using the model ligand 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Richard L Nixon

    2016-11-01

    Full Text Available Complexation by organic ligands dominates the speciation of iron (Fe, copper (Cu, and other bioactive trace metals in seawater, controlling their bioavailability and distribution in the marine environment. Several classes of high-affinity Fe-binding ligands (siderophores have been identified in seawater but the chemical structures of marine Cu-complexing ligands remain unknown. Immobilized metal-ion affinity chromatography (IMAC allows Cu ligands to be isolated from bulk dissolved organic matter (DOM in seawater and separated into fractions which can be characterized independently using electrochemical and spectroscopic techniques. Attempts have been made to combine IMAC with electrospray ionization mass spectrometry (ESI-MS to characterize marine Cu ligands, but results have proven inconclusive due to the lack of tandem mass spectrometry (MS/MS data to confirm ligand recovery. We used 8-hydroxyquinoline (8-HQ, a well-characterized model ligand that forms strong 1:2 metal:ligand complexes with Cu2+ at pH 8 (log β2 = 18.3, to evaluate Cu(II-IMAC and ESI-MS/MS for recovery and identification of copper(II-complexing ligands in seawater. One-litre samples of 0.45µm-filtered surface seawater were spiked with 8-HQ at low concentrations (up to 100 nM and fractionated by IMAC. Fractions eluted with acidified artificial seawater were desalted and re-suspended in methanol via solid-phase extraction (SPE to obtain extracts suitable for ESI-MS analysis. Recovery of 8-HQ by Cu(II-IMAC was confirmed unambiguously by MS/MS and found to average 81% based upon accurate quantitation via multiple reaction monitoring (MRM. Cu(II-IMAC fractionation of unspiked seawater using multiple UV detection wavelengths suggests an optimal fraction size of 2 mL for isolating and analyzing Cu ligands with similar properties.

  1. On-Line pre-concentration of Cr(III) and Mn(II) in FI-FAAS: A critical study involving interference effects and analytical use of an immobilized 8-hydroxyquinoline minicolumn

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, C.G.; Pino, F.E.; Campos, V.H. [Depto. de Analisis Instrumental, Facultad de Farmacia, Universidad de Concepcion, P.O. Box 237, Concepcion (Chile); Nobrega, J.A. [Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13565-905, Sao Carlos, SP (Brazil)

    2002-09-01

    A flow injection system with a pre-concentration minicolumn based on a chelating resin was coupled to a flame atomic absorption spectrometer. The focus of this work was the investigation of interference effects and the analytical applicability of the azo-immobilized 8-hydroxyquinoline on controlled-pore glass for the determination of Cr and Mn in mussel and non-fat milk powder. All studied concomitants affected the retention of Cr(III). These effects are probably related to the formation of hydroxo-complexes at the optimum pH range 9.0-10. The positive effect caused by Ca(II) was exploited to increase the retention of Cr(III) species and to improve the slope by 70%. The interferences on Mn(II) retention were less severe. The quantification of Cr and Mn was performed by standard additions. The proposed methodology was validated by analysis of three certified reference materials of mussels (Cr and Mn) and non-fat milk powder (Mn) with a mean relative percent error of <6.5% and mean relative standard deviation of <13%. Chromium and Mn were determined in typical Chilean mussels samples, and Mn was determined in non-fat milk powder samples. Results agreed at the 95% confidence level with those obtained by electrothermal atomic absorption spectrometry (ETAAS) using graphite furnace atomization. The method detection limits for a 30 s pre-concentration time were 0.9 and 1.1 {mu}g L{sup -1} for Mn, and 2.2 and 2.5 {mu}g L{sup -1} for Cr in acid digested solutions of mussel and non-fat milk, respectively. The methodology is simple, fast (sampling frequency 60-72 h{sup -1}), reliable, of low cost, and can be applied to the determination of traces of Cr ({>=}0.18 {mu}g g{sup -1}) and Mn ({>=}0.6 {mu}g g{sup -1}) in mussel samples, and Mn ({>=}0.37 {mu}g g{sup -1}) in non-fat milk powder. (orig.)

  2. Aspects of Ti(IV), Sr(II) and Pb(II) bis (8-hydroxyquinolinates) related to the precipitation conditions and to the thermal treatment; Aspectos dos bis-(8-hidroxiquinolinatos) de titanio(IV), estroncio(II) e chumbo(II) referentes as condicoes de precipitacao e de tratamento termico

    Energy Technology Data Exchange (ETDEWEB)

    Guinesi, L.S.; Zorel Junior, H.E.; Ribeiro, C.A.; Crespi, M.S. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    1999-07-01

    Several conditions of preparation of titanium (IV), strontium and bis (8-hydroxyquinolinates) were analyzed such as solvent, pH, temperature, addition of reagent and their influence under physical and chemical aspects of the complexes formed and of the residues of thermal decomposition. Through XRD, it was verified that all the chelates are crystalline but they present different shapes and sizes of particles, as SEM. The results of IR spectroscopy showed metals coordinated through O and N atoms the ligand. Elemental analysis and TG/DTA curves indicates TG/DTA curves indicated the pH influence of synthesis in the stability and thermal behaviour of compounds giving origin tio chelates with different stoichiometries. (author)

  3. Synthesis and Polarized Absorption and Photoluminescence of 5-(4'-Alkoxyl-phenyl)-8-hydroxyquinoline Zn(Ⅱ) Complexes%5-(4'-烷氧基苯基)-8-羟基喹啉锌的合成及其偏振发光性能

    Institute of Scientific and Technical Information of China (English)

    王欣; 骆开均; 蒋世平; 贾娟; 陈艳芳

    2011-01-01

    Three complexes of 5-(4'-alkoxyl-phenyl)-8-hydroxyquinoline Zn(II), (C8OphQ)2Zn, (C8OphQ)2Zn and (C12OphQ)2Zn, were synthesized. Their chemical structures and photophysical properties were characterized by 1H NMR, MS, UV-Vis and photoluminescence (PL) spectra. Differential scanning calorimetry (DSC) and polarizing microscope were used to probe liquid properties of the complexes. The polarized absorption and photoluminescence spectrs of the aligned films of the complexes on the rubbed polyimide film were recorded on a UV-4802S spectrophotometer and Perkin Elmer LS55 fluorometer equipped with a polarizer. It is found that the complexes can be aligned preferably on rubbed polyimide film for their liquid crystal properties. For an aligned film of (C8OphQ)2Zn complex, the maxima of the absorption dichroic ratio at 332 nm and emission dichroic ratio at 500 nm are 2.0 and 2.4 respectively.%本文通过在8-羟基喹啉的5位上引入含不同碳链长度的对烷氧基苯基,合成了一类5-(4’-烷氧基苯基)-8-羟基喹啉锌配合物(C6OphQ)2Zn 、(C8OphQ)2Zn和(C12OphQ)2Zn.通过DSC和偏振显微镜等热力学仪器考察了它们的液晶性,发现长链的5-对烷氧基-苯基-8-羟基喹啉锌均具有液晶性.将它们在聚酰亚胺取向薄膜上进行排列,应用装备有偏振器的紫外分光光度计和荧光分光光度仪测定了薄膜偏振光性质.实验发现,这些具有液晶性质的发光配合物在聚酰哑胺取向薄膜上能够产生有序排列,表现出一定的吸收和发射二色比.其中配合物(C8OphQ)2Zn在332 nm处的最大吸收二色比是2.0,在500 nm处的发射二色比为2.4.

  4. 表面引发接枝聚合法制备接枝微粒PHEMA/SiO2及其8-羟基喹啉功能化转变研究%STUDIES ON PREARATION OF GRAFTED PARTICLES OF PHEMA/SiO2 AND THEIR 8-HYDROXYQUINOLINE-FUNCTIONALIZATION TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    房晓琳; 高保娇; 黄小卫; 张永奇; 顾来沅

    2012-01-01

    Micron-sized silica gel particles were surface-modified with coupling agent y- aminopropyltrimethoxysilane (AMPS) , obtaining the modified particles AMPS-SiO2. A redox initiating system was constituted by the amino groups on the surface of AMPS-SiO2 particles and persulfate in the solution, and the surface-initiated graft-polymerization of 2-hydroethyl methacrylate was performed, resulting in the grafted particles PHEMA/SiO2. Subsequently, a polymer reaction of the grafted PHEMA was carried out,and it was the nucleophilic substitution reaction between the hydroxyl group of the grafted PHEMA and the chloromethyl group of 5-chloromethyl-8-hydroxyquinoline ( CHQ). As a result, the 8-hydroxyquinoline-functionalization transform of the grafted PHEMA was realized,obtaining the functional composite particles HQ-PHEMA/SiO2. The two kinds of particles were characterized by several methods. In this work, the graft-polymerization mechanism for the amino group-persulfate initiation system was mainly investigated, and the mechanism of the substitution reaction between the hydroxyl group of the grafted PHEMA and the chloromethyl group of CHQ was also explored in depth. Finally,the chelating adsorption property of HQ-PHEMA/SiO2 for heavy metal ions was preliminarily examined. The experimental results show that the amino group-persulfate initiation system has very high initiation activity, and it can effectively initiates the graft-polymerization of HEM A on silica gel particles. At room temperature (30t) ,the grafted particles PHEMA/SiO2 with high grafting degree (40 g/ 100 g) can obtained. The substitution reaction between the hydroxyl groups of the grafted PHEMA and CHQ has a reaction mechanism of SN1 ,and using the solvent with strong polarity is advantageous to the reaction. The functional particles HQ-PHEMA/SiO2 possess very strong chelating adsorption ability for heavy metal ions. The functional composite particles are promising and potential in the analysis and separation

  5. Thermochemical Study on Coordination Complex of Neodymium Trichloroacetic Acid with 8-Hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    李强国; 屈松生; 刘义

    2002-01-01

    Two coordinate reactions, NdCl3*6H2O(s) +3CCl3COOH(s)( or TCA) =Nd(TCA)3*3H2O(s) +3HCl(g) +3H2O(l) and Nd(TCA)3*3H2O(s) +2C9H7NO(s)= Nd(TCA)(C9H6NO)2 (s) +2CCl3COOH(s) +3H2O(l), were studied by the classical solution calorimetry at 298.15K. The molar dissolution enthalpies of the reactants and the products in certain solvent (the first reaction in 1 mol*L-1 HCl, the second in a mixed solution consisting of absolute ethyl alcohol, dimethyl sulfoxide and 4 mol*L-1 HCl ) were measured by using an isoperibol calorimeter at 298.15K . From the results and other auxiliary quantities, the standard molar formation enthalpies of [Nd(TCA)3*3H2O,s,298.15K] and [Nd(TCA) (C9H6NO)2 ,s, 298.15K] are determined as ΔfHm°[Nd(TCA)3*3H2O,s,298.15K]= -3053.3 kJ*mol-1 and ΔfHm°[Nd(TCA) (C9H6NO)2 ,s, 298.15K] = -1355.6 kJ*mol-1.

  6. Extraction and spectrophotometric determination of vanadium(V) with 8-hydroxyquinoline.

    Science.gov (United States)

    Kurmaiah, N; Satyanarayana, D; Rao, V P

    1967-04-01

    The extraction and spectrophotometric determination of vanadium (V) with oxine is investigated at higher acidities than described previously. Under these conditions, n-butanol and other alcohols are found to exert a synergic effect on the extraction of vanadium into benzene. In the presence of alcohol only a 6-fold ligand excess is needed for quantitative extraction in a single operation, the acidity of the aqueous medium being 0.05M with respect to sulphuric or phosphoric acid. The interference of iron(III) in the spectrophotometric determination of vanadium is suppressed by the addition of pyrophosphate. Beer's law is obeyed up to 14.0 mug of vanadium/ml and the sensitivity is 0.008 mug of vanadium/cm(2) at 390 mmu. The composition of the extracted species is found to be vanadium:oxine:n-butanol = 1:2:2.

  7. Solid state cathodoluminescence based on tris-(8-hydroxyquinoline) aluminum and its quenching mechanism

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel solid state cathodoluminescence(SSCL) device(the device has a structure of ITO/SiO2/Alq3/SiO2/Al) is fabricated using organic materials as the fluorescent film sandwiched between two SiO2 layers.When alternating current(AC) voltage is applied to this device,uniform emissions are observed.When the voltage is 50 V,a longer wavelength emission(522 nm) is obtained,but the shorter wavelength emission(465 nm) is dominant when the voltage is 76 V.The origins of these emissions are discussed.The interface formed between SiO2 and tris-(8-hydroquinoline) aluminum(Alq3) of SSCL device was investigated by using X-ray photoelectron spectroscopy(XPS).Analyses of the XPS spectra reveal a deep diffusion of the indium into the interface.On the other hand,the interaction between indium and Alq3 occurs at the interface and results in the formation of a carbon-oxygen-metal(In or Al) complex in the contact region.This effect causes a luminescence quenching in the SSCL device.

  8. Preparation and thermal decomposition of copper(II, zinc(II and cadmium(II chelates with 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Crespi Marisa S.

    1999-01-01

    Full Text Available When the compounds are heated in an inert atmosphere it can be verified the consecutive partial sublimation, fusion, partial volatilization and partial thermal decomposition of the anhydrous complexes. When in an oxidating atmosphere the above process is only verified to Cu(II chelates. Anhydrous copper(II complexes present a monoclinic structure in the b form and the volatilized compound in a a form. Zinc(II and cadmium(II hydrated complexes are isomorphous and they present different cell dimensions from those reported previously.

  9. The structure of the blue luminescent delta-phase of tris(8-hydroxyquinoline)aluminium(III) (Alq3).

    Science.gov (United States)

    Cölle, Michael; Dinnebier, Robert E; Brütting, Wolfgang

    2002-12-07

    The existence of the facial isomer in the delta-phase of Alq3 is proven by X-ray structural analysis, revealing that both the different molecular structure and the weaker overlap of the pi-orbitals of hydroxyquinoline ligands belonging to neighboring Alq3 molecules as compared to other phases (alpha, beta) are likely to be the origin of the significantly different optical properties of delta-Alq3.

  10. Atomistic simulation on charge mobility of amorphous tris(8-hydroxyquinoline) aluminum (Alq3): origin of Poole-Frenkel-type behavior.

    Science.gov (United States)

    Nagata, Yuki; Lennartz, Christian

    2008-07-21

    The atomistic simulation of charge transfer process for an amorphous Alq(3) system is reported. By employing electrostatic potential charges, we calculate site energies and find that the standard deviation of site energy distribution is about twice as large as predicted in previous research. The charge mobility is calculated via the Miller-Abrahams formalism and the master equation approach. We find that the wide site energy distribution governs Poole-Frenkel-type behavior of charge mobility against electric field, while the spatially correlated site energy is not a dominant mechanism of Poole-Frenkel behavior in the range from 2x10(5) to 1.4x10(6) V/cm. Also we reveal that randomly meshed connectivities are, in principle, required to account for the Poole-Frenkel mechanism. Charge carriers find a zigzag pathway at low electric field, while they find a straight pathway along electric field when a high electric field is applied. In the space-charge-limited current scheme, the charge-carrier density increases with electric field strength so that the nonlinear behavior of charge mobility is enhanced through the strong charge-carrier density dependence of charge mobility.

  11. COMPARISON OF SILICA IMMOBILIZED POLY-L-CYSTEINE AND 8-HYDROXYQUINOLINE FOR TRACE METAL CHELATION AND PRECONCENTRATION. (R826694C651)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  12. Water-Soluble 8-Hydroxyquinoline Conjugate of Amino-Glucose As Receptor for La(3+) in HEPES Buffer, on Whatman Cellulose Paper and in Living Cells.

    Science.gov (United States)

    Areti, Sivaiah; Bandaru, Sateesh; Teotia, Rohit; Rao, Chebrolu P

    2015-12-15

    A water-soluble glucopyranosyl conjugate, L, has been synthesized and characterized by different analytical and spectral techniques. The L has been demonstrated to have switch-on fluorescence enhancement of ∼75 fold in the presence of La(3+) among the nine lanthanide ions studied in the HEPES buffer at pH 7.4. A minimum detection limit of 140 nM (16 ± 2 ppb) was shown by L for La(3+) in the buffer at physiological pH. The utility of L has been demonstrated by showing its sensitivity toward La(3+) on Whatman filter paper strips. The reversible and reusable action of L has been demonstrated by monitoring the fluorescence changes as a function of the addition of La(3+) followed by F(-) and HPO4(2-) ions. The complexation of L by La(3+) was shown by absorption spectra wherein isosbestic behavior was observed. The Job's plot suggests a 2:1 complex between L and La(3+), and the same was supported by ESI-MS. The control molecular study revealed the necessity of hydroxy quinoline and the amine group for La(3+) ion binding and the glyco-moiety to bring water solubility and biocompatibility. The structural features of the [2L+La(3+)] complex were established by DFT computational calculations. The chemo-ensemble, [2L+La(3+)], is shown responsible for providing intracellular fluorescence imaging in HepG2 cells.

  13. The urinary antibiotic 5-nitro-8-hydroxyquinoline (Nitroxoline) reduces the formation and induces the dispersal of Pseudomonas aeruginosa biofilms by chelation of iron and zinc.

    Science.gov (United States)

    Sobke, A; Klinger, M; Hermann, B; Sachse, S; Nietzsche, S; Makarewicz, O; Keller, P M; Pfister, W; Straube, E

    2012-11-01

    Since cations have been reported as essential regulators of biofilm, we investigated the potential of the broad-spectrum antimicrobial and cation-chelator nitroxoline as an antibiofilm agent. Biofilm mass synthesis was reduced by up to 80% at sub-MIC nitroxoline concentrations in Pseudomonas aeruginosa, and structures formed were reticulate rather than compact. In preformed biofilms, viable cell counts were reduced by 4 logs at therapeutic concentrations. Complexation of iron and zinc was demonstrated to underlie nitroxoline's potent antibiofilm activity.

  14. 含8-羟基喹啉侧基聚酯的合成、结构表征及荧光性能%The synthesis,characterization and fluorescence property of polyesters with 8-hydroxyquinoline side groups

    Institute of Scientific and Technical Information of China (English)

    于世钧; 马百庆; 安金成; 鲁岩; 吴思雨

    2015-01-01

    以5‐硝基间苯二甲酸、5‐氯甲基‐8‐羟基喹啉盐酸盐等为主要原料,经多步反应合成了2种新型含8‐羟基喹啉侧基聚酯P5和P6.利用IR、UV‐Vis、1 H NMR、GPC和荧光光谱对相关化合物结构和性能进行表征.P5的重均分子量M w 、数均分子量M n和相对分子质量分布指数PDI为4416、3025 g/mol和1.46.P6的重均分子量Mw 、数均分子量Mn和相对分子质量分布指数PDI为7661、5040 g/mol和1.52.P5和P6的紫外光谱表明,二者的吸收峰位于266、328 nm处,分别归属于苯环的π‐π倡跃迁吸收峰和喹啉环的π‐π倡跃迁吸收峰.溶解性测试表明,P5和P6易溶于DMAc、DMF、DMSO和NMP ,部分溶于THF和CHCl3.P5和P6的DMF溶液(5×10-5 mol/L)以362 nm波长光激发,分别在432、433 nm处出现最大发射峰,发射紫色荧光.%Two novel polyesters with 8‐hydroxyquinoline side group (P5 ,P6)was synthesized by multi‐step reaction with 5‐nitro isophthalic acid ,5‐chloromethyl‐8‐hydroxyquinoline hydrochloride as raw material .The structure and properties of related compounds were characterized by IR ,UV‐Vis ,1 H NMR ,GPC and fluorescence spectra .The Mw ,Mn and PDI of P5 were 4416 ,3052 g/mol and 1 .46 . The Mw ,Mn and PDI of P6 were 7661 ,5040 g/mol and 1 .52 .The absorption peaks of P5 ,P6 ap‐peared at 266 and 328 nm ,attributed to π‐π* transition absorption peak of the benzene ring and quin‐oline ring ,respectively .Solubility test showed that the P5 and P6 can be dissolved in DMAc ,NMP , DMF and DMSO ,partly be dissolved in THF and CHCl3 .Fluorescence emission peaks of P5 and P6 in DMF solution (5 × 10-5 mol/L) appeared at 432 and 433 nm ,they emit purple light .

  15. 苯并三唑和8-羟基喹啉对铜的缓蚀协同作用%Synergistic Effects of Benzotriazole and 8-Hydroxyquinoline Combined Inhibitors on Copper Corrosion

    Institute of Scientific and Technical Information of China (English)

    张大全; 高立新; 周国定; 陆柱

    2002-01-01

    通过电化学极化曲线和电化学阻抗谱研究了苯并三唑(BTA)和8-羟基喹啉(HQ)对铜的缓蚀协同作用,BTA和HQ复配使用后提高了电极的膜电阻,降低了电极的膜电容,增强了对铜腐蚀的抑制作用.通过MM2分子力学程序和PPP-SCF量子化学方法优化计算了BTA和HQ的分子结构参数,分析讨论了它们之间的缓蚀协同效应.

  16. Corrosion Inhibition of Benzotriazole and 8-Hydroxyquinoline for Copper in 3% NaCl Solution%苯并三氮唑和8-羟基喹啉对铜缓蚀作用的研究

    Institute of Scientific and Technical Information of China (English)

    张大全; 高立新

    2002-01-01

    通过采用失重法、电化学极化曲线和电化学阻抗谱研究了3%NaCl溶液中苯并三氮唑(BTA)和8-羟基喹啉(HQ)的缓蚀协同作用.BTA和HQ复配使用后增强了对铜的阳极极化过程的抑制作用,提高了电极的膜电阻,降低了电极的膜电容.通过PPP-SCF量子化学方法优化分析了BTA和HQ的分子结构及其缓蚀协同效应.

  17. Fenton-like Degradation of Phenol in Water with 8-Hydroxyquinoline Iron and Copper Complex%8-羟基喹啉铁铜配合物类Fenton降解水中苯酚

    Institute of Scientific and Technical Information of China (English)

    孙宏; 张泽; 何蓉

    2016-01-01

    为克服Fenton氧化体系只能在酸性条件下使用且产生大量铁泥的缺陷,制备了8-羟基喹啉铁铜配合物(FeQ,FeCuQ)用于催化降解水中的苯酚.通过傅里叶变换红外光谱(FT IR)和紫外可见光谱(UV-Vis)对产物进行结构表征.采用静态实验,在室温(20℃)和初始pH为7条件下,考察了催化剂用量,H2O2浓度,反应时间,催化剂的稳定性等影响因素.对FeQ和FeCuQ进行了降解动力学初步分析.实验表明,FeQ和FeCuQ对苯酚氧化具有良好的催化活性.

  18. Complexation and coordination selectivities of the tetradentate ligand 7-[(2-hydroxy-5-sulfophenyl) azo]-8-hydroxyquinoline-5-sulfonic acid with Fe(II), Ni(II), Zn(II), Cd(II) and VO(IV)

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hu; Kai, Fumiaki; Hirohata, Masaaki; Nakamura, Masaaki; Matsuzaki, Susumu; Komori, Kenji; Tsunematsu, Yuriko [Kumamoto Univ. (Japan)

    1993-12-31

    The new title tetradentate ligand (SPAHQS), containing both phenylazo and 8-quinolinol fragments, was prepared. Proton-dissociation processes of the ligand and complexing equilibria with Fe(II), Ni(II), Zn(II), Cd(II), and VO(IV) were analyzed spectrophotometrically. Coordination modes of SPAHQS with these metal ions have been investigated by means of polarography and Raman spectroscopy in aqueous solution. It was established that the coordination selectivity of SPAHQS for such metal ions is mainly dependent on steric factors in the chelate ring formed, not on HSAB properties. 18 refs., 6 figs., 2 tabs.

  19. 活性碳纤维耦合喹啉铁的pH-tolerant性能研究%pH-tolerant performance of activated carbon fibers coupled with 8-hydroxyquinoline ferric

    Institute of Scientific and Technical Information of China (English)

    白志飞; 李代文; 姚玉元; 吕汪洋; 黄三庆; 陈文兴

    2015-01-01

    The application of Fenton reaction is restricted to a narrow pH range (2‐3 5.) ,which has long been a technological bottleneck .Therefore ,the development of a pH‐tolerant Fenton‐like catalyst is an active and chal‐lenging research front in the field of environmental catalysis .In this work ,the pH‐tolerant performance of the novel Fenton‐like catalytic fibers (QuFe@ ACFs) based on activated carbon fibers (ACFs) coupled with 8‐hydroxyquinoline ferric (QuFe) was evaluated by a simple impregnation method .The UV‐Vis spectroscopy measurements showed that the reactive brilliant red M‐3BE (RR M‐3BE) was completely degraded in 32 min . Probe compound O‐phenylenediamine combined with electron paramagnetic resonance (EPR) spectroscopy and UV‐Vis spectroscopy were employed to demonstrate the catalytic stability of QuFe@ ACFs ,and the experimen‐tal results showed that QuFe@ ACFs exhibited excellent catalytic ability and recycle utilization performance across a wide pH range from 3 to 9 ,brought remarkable pH‐tolerant performance .To sum up ,the QuFe@ACFs prepared by an extremely simple impregnation method ,breaks the technological bottleneck for Fenton treatment ,providing new ideas for preparing novel pH‐tolerant Fenton‐like catalysts with excellent catalytic ac‐tivity .%pH值适应范围窄一直是制约芬顿反应发展的技术瓶颈,因此,开发pH‐tolerant类芬顿催化剂成为环境催化领域的研究热点和难点。采用活性碳纤维(ACFs)耦合喹啉铁(QuFe)制得一种新型pH‐tolerant类芬顿催化纤维(QuFe@ ACFs),该催化纤维在中性条件下可以活化双氧水有效降解活性艳红 M‐3B E。采用自由基捕获剂邻苯二胺,结合电子顺磁共振波谱、紫外‐可见光谱等对催化纤维的重复稳定性进行了重点考察。结果显示,QuFe@ ACFs在pH值为3~9范围内均具有良好的催化性能和重复使用性,表现出了优异的pH‐tolerant性能。QuFe@ ACFs制备方法简单,巧妙解决了制约传统芬顿反应发展的技术瓶颈,为制备新一代高活性pH‐tolerant芬顿催化剂提供了新思路。

  20. 新型8-羟基喹啉铁配合物的合成及其对半胱氨酸和高半胱氨酸的识别性能%Synthesis of a Novel 8-Hydroxyquinoline -Iron Complex and Its Recognition Performance on Cysteine and Homocysteine

    Institute of Scientific and Technical Information of China (English)

    秦明林; 张灯青; 金武松

    2011-01-01

    A novel FeQ3 complex [ HQ = 8-hydroxy-7-(4-tolyldiazenyl) quinoline-5-sulfonic acid ] was designed and synthesized by displacement reaction. The structure was characterized by 1H NMR,13C NMR and elemental analysis. Selectivity visual acuity recognition of FeQ3 on cysteine and homocysteine were achieved by UV-Vis and change of solution colour.%利用取代反应的原理,设计并合成了一种新型的8-羟基喹啉配合物[FeQ(HQ=8-羟基-7-(4-甲苯二氮烯基)喹啉-5-磺酸],其结构经H NMR,C NMR和元素分析表征.利用UV-Vis和溶液颜色的变化,实现了FeQ对半胱氨酸和高半胱氨酸的选择性裸眼识别.

  1. 八羟基喹啉铜(II)配合物的DNA结合和切割活性及与牛血清白蛋白相互作用%DNA binding,DNA cleavage and BSA interaction of a bis-8-hydroxyquinoline copper(II) complex

    Institute of Scientific and Technical Information of China (English)

    陈战芬; 张书萍; 张健

    2015-01-01

    利用紫外吸收光谱、荧光光谱、圆二色光谱(CD )和琼脂糖凝胶电泳等手段研究了八羟基喹啉铜(II )配合物Cu[8‐OHQ]2与DNA和蛋白质的相互作用.实验结果表明,在生理条件下,Cu[8‐OHQ]2能通过插入方式较强的与CT‐DNA结合,诱导DNA构象的改变.其本征结合常数 Kb为11.5(±00.1)×105 L/mol ,表观结合常数 Kapp为42.1×106 L/mol .再者,琼脂糖凝胶电泳实验表明,在生理条件和抗坏血酸(Vc)存在情况下, Cu[8‐OHQ]2能有效地将超螺旋pBR322质粒DNA切割成缺刻和线性,甚至降解为小的片断.机理研究表明扩散的・OH ,H2 O2和1 O2都不是在切割过程中起作用的活性氧物种(ROS);copper‐oxo中间体可能是此切割过程中主要的活性氧物种.另外,Cu[8‐OHQ]2也能以适中的结合力与牛血清白蛋白(BSA)结合而猝灭BSA内源荧光,猝灭机理为静态猝灭.所有这些结果表明Cu[8‐OHQ]2具有作为潜在化疗试剂的生物活性.%The interactions between DNA/protein and the bis‐8‐hydroxyquinoline copper (II) complex , Cu[8‐OHQ]2 ,were investigated under physiological conditions using UV‐vis absorption ,fluorescence , circular dichroism (CD) ,and agarose gel electrophoresis .The experimental results suggest Cu[8‐OHQ]2 could strongly bind to calf thymus DNA (CT‐DNA) through an intercalative mode and induce a remarka‐ble conformational variation of DNA .The intrinsic binding constant Kb of Cu[8‐OHQ]2 to DNA is 1 1.5 ( ± 0 0.1) × 105 L/mol and the apparent binding constant Kapp is 4 2.1 × 106 L/mol .Furthermore ,agar‐ose gel electrophoresis revealed ,in the presence of ascorbic acid (Vc) under nearly physiological condi‐tions ,Cu[8‐OHQ]2 could efficiently cleave the supercoiled pBR322 plasmid DNA into its nicked and line‐ar forms ,even degrade into undetectable minor fragments .Mechanism studies demonstrated diffusible・OH ,H2 O2 and 1 O2 are not the effective reactive oxygen species (ROS) in the cleavage process media‐ted by the complex and the copper‐oxo species might be responsible for the cleavage .Additionally ,Cu[8‐OHQ]2 could also bind to bovine serum albumin (BSA) with a medium affinity and quench the intrinsic fluorescence of BSA through a single static quenching mechanism .All these results suggest that Cu[8‐OHQ]2 exhibits biological action as a potential chemotherapy agent .

  2. HQS柱前衍生HPLC法高选择性测定痕量钯及其在矿样分析中的应用%HPLC Method for High Selective Determination of Trace Palladium by Using 8-Hydroxyquinoline-5-sulfonic Acid as a Pre-Column Derivative Rea gent and Its Analytical Application in Minerals

    Institute of Scientific and Technical Information of China (English)

    杨左军; 张华山; 程介克

    2000-01-01

    采用8-羟基喹啉-5-磺酸(HQS)作柱前衍生试剂,不含对离子试剂,在ODS柱上以甲醇-水(38∶62V/V,含有10mm ol/L pH5.6乙酸-乙酸钠缓冲溶液)作为流动相,4.7min内高选择性测定了痕量Pd?.此方法共存离子允许量很大,具有很高的选择性 ,且流动相在同类试剂中最简单,当信噪比为3时,检出限为2.1ng/m L.方法用于直接测定矿样中痕量钯,结果与标准参考值相符.

  3. 自组装银膜增强8-羟基喹啉铝(Alq3)光致发光的实验和理论研究%Exp erimental and theoretical study of tris-(8-hydroxyquinoline) aluminum (Alq3) photoluminescence enhanced by self-assembled silver films

    Institute of Scientific and Technical Information of China (English)

    叶松; 王向贤; 侯宜栋; 张志友; 杜惊雷

    2014-01-01

    Alq3 photoluminescences (PL) enhanced by self-assembled silver films are investigated experimentally and theoret-ically. The experimental results show that both the apparent enhancement factor (AEF) and the emission enhancement factor (EEF) of Alq3 PL increase with the increase of density of average 70 nm diameter silver nanoparticles on the substrate. The maxima of AEF and EEF are about 3.2 and 13, respectively. Based on the optical antenna theory, the theoretical maxima of both quantum efficiency enhancement factor and EEF of Alq3 PL are about 1.4 and 15, respectively. By comparing of the experimental results with the theoretical results, we can conclude that the near-field enhancement of silver nanoparticles makes a major contribution to Alq3 PL emission enhancement, and the emission enhancement is dependent on the Alq3-silver nanoparticle distance and the area coverage ratio of silver nanoparticles to substrate.%实验和理论研究了不同自组装密度的银纳米颗粒膜对8-羟基喹啉铝(Alq3)光致发光的影响.结果表明:Alq3光致发光的表观增强和发射增强因子与银纳米颗粒膜密度呈正相关关系,最大值约为3.2和13;理论计算表明银纳米颗粒膜对Alq3光致发光的量子效率和发射的最大增强因子约为1.4和15.对比实验和理论结果,金属纳米颗粒膜的近场场强增强是导致Alq3光致发光发射强度增强的主要因素,且Alq3光致发光效率与Alq3相对银纳米颗粒的分布和“热点”区域面积覆盖率有关.

  4. Longevity of cut inflorescence shoots of high kamasija (Camassia quamash (Pursh Greene depending on postharvest treatment

    Directory of Open Access Journals (Sweden)

    Maria Paulina Ulczycka

    2013-09-01

    Full Text Available The research was carried out to determine the effect of conditioning of cut flowering shoots of the Camassia quamash in 8-hydroxyquinoline sulphate on postharvest longevity. The inflorescence shoots were conditioned for 24 h in water solutions of 8-hydroxyquinoline sulphate at concentration of 200 mg·dm-3 and then kept in water or gibberellic acid solutions at concentration of 50 or 100 mg·dm-3. The inflorescent shoots not conditioned and kept in water showed the longest postharvest longevity. 8-hydroxyquinoline sulphate and gibberellic acid solutions shortened their longevity. The shortest fresh weight loss of Camassia quamash then was kept in gibberellic acid solutions at concentration of 100 mg·dm-3. The smallest change of the inflorescence shoots length of Camassia quamash was observed after application of gibberellic acid solutions at concentration of 50 mg·dm-3.

  5. 8-Hydroxy-2-methylquinolinium tetrachlorido(pyridine-2-carboxylato-κ2N,Ostannate(IV

    Directory of Open Access Journals (Sweden)

    Ezzatollah Najafi

    2011-02-01

    Full Text Available In the reaction of pyridine-2-carboxylic acid and stannic chloride in the presence of 2-methyl-8-hydroxyquinoline, the 2-methyl-8-hydroxyquinoline is protonated, yielding the title salt, (C10H10NO[SnCl4(C6H4NO2]. The SnIV atom in the anion is N,O-chelated by a pyridine-2-carboxylate in a cis-SnNOCl4 octahedral geometry. The cation is linked to the anion by an O—H...O hydrogen bond.

  6. Electrospun mats from styrene/maleic anhydride copolymers: modification with amines and assessment of antimicrobial activity.

    Science.gov (United States)

    Ignatova, Milena; Stoilova, Olya; Manolova, Nevena; Markova, Nadya; Rashkov, Iliya

    2010-08-11

    New antimicrobial microfibrous electrospun mats from styrene/maleic anhydride copolymers were prepared. Two approaches were applied: (i) grafting of poly(propylene glycol) monoamine (Jeffamine® M-600) on the mats followed by formation of complex with iodine; (ii) modification of the mats with amines of 8-hydroxyquinoline or biguanide type with antimicrobial activity. Microbiological screening against S. aureus, E. coli and C. albicans revealed that both the formation of complex with iodine and the covalent attachment of 5-amino-8-hydroxyquinoline or of chlorhexidine impart high antimicrobial activity to the mats. In addition, S. aureus bacteria did not adhere to modified mats.

  7. Efficient Synthesis of 2-(8-Quinolinoxy)-4H-imidazolin-4-ones

    Institute of Scientific and Technical Information of China (English)

    DING Ming-wu; SHU Ya-li; LIU Zhao-jie

    2003-01-01

    The title compounds 2-(8-quinolinoxy)-4H-imidazolin-4-ones(4) were synthesized by means of base catalytic reactions of 8-hydroxyquinoline with each of carbodiimides 2, which were obtained via aza-Wittig reactions of iminophosphoranes 1 with the corresponding aromatic isocyanates.

  8. X-ray dose detector based on color changing of light-emitting polymer–metal complex hybrid material.

    OpenAIRE

    2012-01-01

    We report on the design, fabrication and performance of a poly (2-methoxy-5(2_-ethylhexyloxy)- p-phenylenevinylene)/tris-(8-hydroxyquinoline)aluminum (MEH-PPV/Alq3) X-ray dose detector for improving safety for cancer patients shortly before radiation therapy. The detector consists of an inexpen-sive (

  9. Improved Performance of Organic Light-Emitting Diodes with MgF2 as the Anode Buffer Layer

    Institute of Scientific and Technical Information of China (English)

    XIE Jing; ZHANG De-Qiang; WANG Li-Duo; DUAN Lian; QIAO Juan; QIU Yong

    2006-01-01

    @@ Organic light-emitting diodes (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3) are improved by using a thin MgF2 buffer layer sandwiched between the indium tin oxide (ITO) anode and hole transporting layer (HTL) of NPB.

  10. A Simplified Experimental Scheme for the Study of Mitosis.

    Science.gov (United States)

    Gill, John

    1980-01-01

    A procedure is described for providing preparations of dividing cells from root apical meristems, requiring only inexpensive equipment and minimal experimental skill, and using 8-Hydroxyquinoline and Toluidene-blue as a chromosome stain. The method has been sucessfully tested in schools and yields permanent preparations of adequate quality for…

  11. Effect of antimicrobial compounds on cut Gerbera flowers: Poor relation between stem bending and numbers of bacteria in the vase water

    NARCIS (Netherlands)

    Witte, van de Y.; Harkema, H.; Doorn, van W.G.

    2014-01-01

    Gerbera flowers (Gerbera jamesonii) often show stem bending. In four cultivars (Tamara, Liesbeth, Cora, and Mickey), we tested the effects on bending of antimicrobial compounds (chlorine bleach, a slow release chlorine compound, 8-hydroxyquinoline citrate [HQC], silver nitrate, carvacrol and thymol)

  12. A matrix-focused structure-activity and binding site flexibility study of quinolinol inhibitors of botulinum neurotoxin serotype A.

    Science.gov (United States)

    Harrell, William A; Vieira, Rebecca C; Ensel, Susan M; Montgomery, Vicki; Guernieri, Rebecca; Eccard, Vanessa S; Campbell, Yvette; Roxas-Duncan, Virginia; Cardellina, John H; Webb, Robert P; Smith, Leonard A

    2017-02-01

    Our initial discovery of 8-hydroxyquinoline inhibitors of BoNT/A and separation/testing of enantiomers of one of the more active leads indicated considerable flexibility in the binding site. We designed a limited study to investigate this flexibility and probe structure-activity relationships; utilizing the Betti reaction, a 36 compound matrix of quinolinol BoNT/A LC inhibitors was developed using three 8-hydroxyquinolines, three heteroaromatic amines, and four substituted benzaldehydes. This study has revealed some of the most effective quinolinol-based BoNT/A inhibitors to date, with 7 compounds displaying IC50 values ⩽1μM and 11 effective at ⩽2μM in an ex vivo assay.

  13. Unimolecular half-adders and half-subtractors based on acid-base reaction

    Institute of Scientific and Technical Information of China (English)

    Wei JIANG; Hengyi ZHANG; Yu LIU

    2009-01-01

    According to the structural analysis of reported mole-cular processors with acids and bases as inputs, we proposed a general method for constructing molecular half-adders and/or half-subtractors based on acid-base reaction. The method is preliminarily supported by four molecular processors (8-hydroxyquinoline, 4-hydroxypyridine, 4-aminophenol and 5-amino-1-naphthol) capable of the elementary addition and/or subtraction algebraic operations. Noticeably, 8-hydroxyquinoline can mimic the functions of three logic devices, i.e. half-adder, half-subtractor and digital comparator, by the use of superposition and reconfi-guration. The method described in this paper may be useful not only for designing new unimolecular arithmetical processors with the same inputs and outputs as standard devices for the construction of future molecular computers, but it can also help us disclose the simplest molecules and biomolecules with computational properties concealed around us.

  14. Membrane filtration of nickel(II) on cellulose acetate filters for its preconcentration, separation, and flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Soylak, Mustafa [Chemistry Dept., Faculty of Science Arts, University of Erciyes, Kayseri (Turkey); Unsal, Yunus Emre; Aydin, Ayse [Fen Bilimleri Enstitusu, University of Erciyes, Kayseri (Turkey); Kizil, Nebiye [Saglik Bilimleri Enstitusu, University of Erciyes, Kayseri (Turkey)

    2010-01-15

    An enrichment method for trace amounts of Ni(II), as 8-hydroxyquinoline chelates, has been established on a cellulose acetate membrane filter. Ni(II)-8-hydroxyquinoline chelates adsorbed on a membrane filter were eluted using 5 mL of 1 M HNO{sub 3}. The eluent nickel concentration was determined by a flame atomic absorption spectrometer. The influence of some analytical parameters, including pH, amount of reagent, sample volume, etc., on recovery was investigated. The interference of co-existent ions was studied. The nickel detection limit was 4.87 {mu}g/L. The method was applied to real samples for the determination of nickel(II) ions. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  15. Photoluminescence of Electrospun Poly-Methyl-Methacrylate:Alq3 Composite Fibres

    Institute of Scientific and Technical Information of China (English)

    TONG Ke-Qin; XU Chun-Xian; WANG Qiong; GU Bao-Xiang; ZHENG Ke; YE Li-Hua; LI Xin-Song

    2008-01-01

    @@ Tris(8-hydroxyquinoline) aluminium doped poly-methyl-methactylate (PMMA:AIq3) composite nanofibres are fabricated by electrospinning.The morphology of fibres is characterized by scanning electron microscopy.The photoluminescenee of a series of the nanofibres with various contents of Alq3 to PMMA is investigated.UV-visible absorption and the PL spectra analysis are employed to analyse the interaction between the polymer and the luminescent molecule.

  16. Synthesis and Optical Characterization of Mixed Ligands Beryllium Complexes for Display Device Applications

    Directory of Open Access Journals (Sweden)

    Vandna Nishal

    2015-01-01

    Full Text Available Synthesis and photoluminescent behaviour of mixed ligand based beryllium complexes with 2-(2-hydroxyphenylbenzoxazole (HPB and 5-chloro-8-hydroxyquinoline (Clq or 5,7-dichloro-8-hydroxyquinoline (Cl2q or 2-methyl-8-hydroxyquinoline (Meq or 8-hydroxyquinoline (q are reported in this work. These complexes, that is, [BeHPB(Clq], [BeHPB(Cl2q], [BeHPB(Meq], and [BeHPB(q], were prepared and their structures were confirmed by elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and thermal analysis. The beryllium complexes exhibited good thermal stability up to ~300°C temperature. The photophysical properties of beryllium complexes were studied using ultraviolet-visible absorption and photoluminescence emission spectroscopy. The complexes showed absorption peaks due to π-π∗ and n-π∗ electronic transitions. The complexes emitted greenish blue light with peak wavelength at 496 nm, 510 nm, 490 nm, and 505 nm, respectively, consisting of high intensity. Color tuning was observed with changing the substituents in quinoline ring ligand in metal complexes. The emitted light had Commission Internationale d’Eclairage color coordinates values at x=0.15 and y=0.43 for [BeHPB(Clq], x=0.21 and y=0.56 for [BeHPB(Cl2q], x=0.14 and y=0.38 for [BeHPB(Meq], x=0.17 and y=0.41 for [BeHPB(q]. Theoretical calculations using DFT/B3LYP/6-31G(d,p method were performed to reveal the three-dimensional geometries and the frontier molecular orbital energy levels of these synthesized metal complexes.

  17. Highly efficient oxidation of alcohols using Oxone(R) as oxidant catalyzed by ruthenium complex under mild reaction conditions

    Institute of Scientific and Technical Information of China (English)

    Zi Qiang Lei; Jian Qiang Wang; Peng Hua Yan

    2008-01-01

    Aromatic and alkyl alcohols were oxidized to the corresponding aldehydes or ketones at room temperature with high conversion and selectivity using Oxone (2KHSO5·KHSO4·K2SO4) as oxidant catalyzed by ruthenium complex Quin-Ru-Quin (where Quin = 8-hydroxyquinoline). The reaction time is very short and the preparation of complex is simple. 2008 Zi Qiang Lei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  18. Effect of surface modification of microfiltration membrane on capture of toxic heavy metal ions.

    Science.gov (United States)

    Madaeni, Sayed Siavash; Heidary, Farhad

    2012-01-01

    A novel complexing membrane containing 8-hydroxyquinoline groups was used for the removal of heavy metal ions (Cd2+ and Ni2+) from aqueous solution. The functionalized membranes were characterized by FTIR-ATR, SEM and EDAX for the presence of functional groups, the physical structure of the membranes and the analysis of the particles deposited on the membrane, respectively. The influence of 8-hydroxyquinoline concentration, feed concentration, pH and temperature of the solution on capture capability was studied. The modified membrane showed a higher affinity to Cd2+ cations than to Ni2+. The metal ion rejection was increased with an increase in concentration of 8-hydroxyquinoline from 0.5 to 2.0 wt%. However at a ligand concentration higher than 2.0 wt%, no significant change was observed in the metal rejection. The experimental results revealed that the metal rejection was decreased with an increase in metal ion concentration in the feed. Moreover the rejection depended on feed pH and is higher for elevated pH. By changing the temperature in the range of 23-28 degrees C, no considerable effect on metal rejection was observed. However, a higher temperature resulted in a decline in metal rejection. For filtration of a mixture of the two metal ions, the retention was similar to that of the single cations, i.e. Cd > Ni but with smaller absolute rejections.

  19. [Investigation of enhancing effect for hydride generation-atomic fluorescence of transition metal elements].

    Science.gov (United States)

    Sun, Han-Wen; Suo, Ran

    2008-11-01

    A mechanism of hydride generation based on disassembly reaction of hydrogen-transferred interim state [M(BH4)m]* was developed by investigating the effect of reaction medium acidity on hydride generation. The effects of Co2+ and Ni2+, phenanthroline and 8-hydroxyquinoline on hydride generation-atomic fluorescence signals of Zn, Cd, Cu and Ni were studied, respectively, and their enhancing mechnism was discussed. The enhancing effect Co2+ and Ni2+ on the fluorescence signals of Zn and Cd was due to the increase in transmission efficiency of hydride of Zn and Cd. There was a synergic enhancing effect between phenanthroline or 8-hydroxyquinoline and Co2+ on the fluorescence signals of Zn and Cd, however no synergic enhancing effect between phenanthroline and 8-hydroxyquinoline on the fluorescence signals of Zn and Cd. The simulative action of cationic surfactant, anion surfactant and non-ionic surfactant surfactant to hydride generation was investigated. It is shown that both cationic surfactant and non-ionic surfactant have obvious enhancing effect on the fluorescence signals of analytes because of the decrease in surface tension of reaction solution. The release characteristics of hydride from the absorption solution containing surfactant was ulteriorly examined by using graphite furnace atomic absorption spectrometry, and the mechanism of enhancing effect of surfactant on hydride generation and transmission was proposed.

  20. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    Science.gov (United States)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  1. On prediction of OH stretching frequencies in intramolecularly hydrogen bonded systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Spanget-Larsen, Jens

    2012-01-01

    OH stretching frequencies are investigated for a series of non-tautomerizing systems with intramolecular hydrogen bonds. Effective OH stretching wavenumbers are predicted by the application of empirical correlation procedures based on the results of B3LYP/6-31G(d) theoretical calculations......-hydroxyquinoline N-oxide. The spectrum of the former displays a broad, composite band between 3500 and 2500 cm–1 which can be assigned to overlapping monomer and dimer contributions. In the latter case, the results support a reassignment of the OH stretching band of 8-hydroxyquinoline N-oxide; the reassignment...

  2. Synthesis of Er-complexes for photonic applications

    Science.gov (United States)

    Sofer, Zdenek; Třešňáková, Pavlína; Špirková, Jarmila; Rubáš, Stanislav; Kalábová, Martina

    2007-05-01

    We present a new approach of introducing erbium ions onto thin surface layers of silica glass substrates based on soaking of solution of erbium complexes. Different types of Er3+ complexes with 2,2‧-dipyridyle, 1,10-phenantroline, 8-hydroxyquinoline and ethylendiamine ligands and nitrate, thiocyanate and acetate anions were prepared. Composition of the complexes was determined by elementary analysis and by FT-IR spectroscopy. Decomposition temperature was measured by thermogravimetric analysis. Erbium doped surface layers exhibit strong photoluminescence with maximum on 1533 nm and full width at half maximum above 50 nm.

  3. Xenobiotics enhance laccase activity in alkali-tolerant γ-proteobacterium JB.

    Science.gov (United States)

    Singh, Gursharan; Batish, Mona; Sharma, Prince; Capalash, Neena

    2009-01-01

    Various genotoxic textile dyes, xenobiotics, substrates (10 µM) and agrochemicals (100 µg/ml) were tested for enhancement of alkalophilic laccase activity in γ-proteobacterium JB. Neutral Red, Indigo Carmine, Naphthol Base Bordears and Sulphast Ruby dyes increased the activity by 3.7, 2.7, 2.6 and 2.3 fold respectively. Xenobiotics/substrates like p-toluidine, 8-hydroxyquinoline and anthracine increased it by 3.4, 2.8 and 2.3 fold respectively. Atrazine and trycyclozole pesticides enhanced the activity by 1.95 and 1.5 fold respectively.

  4. Thin copolymer-cased light-emitting display made with fluorine-foped tin oxide substrates

    OpenAIRE

    Lessmann Rudolf; Hümmelgen Ivo Alexandre

    2004-01-01

    Seven-segment displays are used to show numerical quantities in electronic equipment, being present in most of the low-end electronics. In this work we describe a novel organic light emitting display made with poly(1,10 decanedioxy 2 methoxy - 1,2 phenylene - 1,2 ethenylene - 3,6 dimethoxy - 1,4 phenylene - 1,2 ethenylene 3 methoxy - 1,4 - phenylene) (OPPVDBC), tris(8-hydroxyquinoline)aluminum salt (Alq3) and a hole injection layer (PEDOT:PSS: poly(3,4 - ethylenedioxythiophene) : poly(styrene...

  5. Characterization of electronic structure of aluminum (III) bis(2-methyl-8-quninolinato)-4-phenylphenolate (BAlq) for phosphorescent organic light emitting devices

    Science.gov (United States)

    Chu, Ta-Ya; Wu, Yao-Shan; Chen, Jenn-Fang; Chen, Chin H.

    2005-03-01

    The structure of the triplet host material, aluminum (III) bis(2-methyl-8-quninolinato)-4-phenylphenolate (BAlq), has been optimized by density functional theory (DFT) with B3LYP methods to study the electronic distribution of its HOMO and LUMO energy states. Calculated triplet bandgap energy of BAlq is shown to be consistent with the experimental data. By analyzing the partial density states (PDOS) of these ligands contributing to the total density of states (TDOS), it is concluded that the HOMO and LUMO orbitals of BAlq are mainly localized on the 4-phenylphenol and 2-methyl-8-hydroxyquinoline ligands, respectively.

  6. (Metal-Organic Framework)-Polyaniline sandwich structure composites as novel hybrid electrode materials for high-performance supercapacitor

    Science.gov (United States)

    Guo, ShuaiNan; Zhu, Yong; Yan, YunYun; Min, YuLin; Fan, JinChen; Xu, QunJie; Yun, Hong

    2016-06-01

    Carbonized Zn-(Metal-Organic Framework)MOF- polyaniline composites for high performance of supercapacitor have been developed from zinc acetate, 8-Hydroxyquinoline, and aniline via a simple process. The as-synthesized product has been characterized by X-ray powder diffraction (XRD), Scanning electron microscopy(SEM), Fourier transform infrared spectra (FT-IR), Transmission electron microscope (TEM). The electrochemical properties of carbonized Zn-MOF/polyaniline electrode were investigated by current charge-discharge and cyclic voltammetry. The specific capacitance of MOF/PANI has been approach to be as high as 477 F g-1 at a current density of 1 A g-1.

  7. Preparation and Electrochemical Properties of 3-Phenyl-6-aryl-1,2,4-triazolo[3,4-b][1,3,4]-thiadiazoles

    Institute of Scientific and Technical Information of China (English)

    CHEN Miao; XIAO Tai; LI Hui-xue; LIU Xiang

    2004-01-01

    @@ Introduction Since Tang[1] firstly reported the electroluminescence of 8-hydroxyquinoline aluminium, much attention has been paid to the organic compound as electro-luminescent material. Especially, electron transport materials play an important role in organic light-emitting diode(OLED). 2-(4-Biphenyl)-5-(t-butylphenyl)-1,3,4-oxadiazole(PBD), as a kind of popular electron injection/transport materials, can improve remarkably the injection balance of electrons and holes. As a result, it can amend the properties of OLED[2,3].

  8. Organic Light-Emitting Devices with a LiF Hole Blocking Layer

    Institute of Scientific and Technical Information of China (English)

    LIAN Jia-Rong; YUAN Yong-Bo; ZHOU Xiang

    2007-01-01

    We introduce a thin LiF layer into tris-8-hydroxyquinoline aluminium (Alq3) based bilayer organic light-emittingdevices to block hole transport. By varying the thickness and position of this LiF layer in Alq3, we obtain an electroluminescent efficiency increase by a factor of two with respect to the control devices without a LiF blocking layer. By using a 10nm dye doped Alq3 sensor layer, we prove that LiF can block holes and excitons effectively.Experimental results suggest that the thin LiF layer may be a good hole and exciton blocking layer.

  9. Organic Electroluminescent Device Based on TPP%基于TPP的有机电致发光器件

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A kind of pyrazoline derivative 1,3-bis(phenyl)-5-(2-phenanthrene)-2-pyrazoline(TPp) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/Al (150 nm) and ITO /TPP (50 nm)/lithium tera-(8-hydroxy-uinolinato)boron(LiBq4 (50 nm)/Alq3 (5 nm)/Al (150 nm) were fabricated, they showed good electroluminescent(EL) performance and TPP was proved to be a good hole transporting material.

  10. Organic Electroluminescent Device Based on TPP%基于TPP的有机电致发光器件

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A kind of pyrazoline derivative 1,3-bis(phenyl)-5-(2-phenanthrene)-2-pyrazoline(TPp) was synthesized in order to obtain stable film and applied to organic electroluminecsent diode as hole transporting material. Two devices with structures as indium-tin-oxide(ITO) TPP (50 nm)/tris-(8-hydroxyquinoline) aluminum(Alq3) (50 nm)/Al (150 nm) and ITO /TPP (50 nm)/lithium tera-(8-hydroxy-uinolinato)boron(LiBq4 (50 nm)/Alq3 (5 nm)/Al (150 nm) were fabricated, they showed good electroluminescent(EL) performance and TPP was proved to be a good hole transporting material.

  11. Determination of trace amounts of molybdenum in plant tissue by solvent extraction-atomic-absorption and direct-current plasma emission spectrometry.

    Science.gov (United States)

    Lajunen, L H; Kubin, A

    1986-03-01

    Methods are presented for determination of molybdenum in plant tissue by flame and graphite-furnace atomic-absorption spectrometry and direct-current argon-plasma emission spectrometry. The samples are digested in HNO(3)-H(2)SO(4)-HC1O(4) mixture, and Mo is separated and concentrated by chelation and extraction. Three organic solvents (methyl isobutyl ketone, di-isobutyl ketone and isoamyl alcohol) and two ligands (8-hydroxyquinoline and toluene-3,4-dithiol) were studied. The procedure were tested on pine needle and birch leaf samples.

  12. Separation and preconcentration of aluminum in parenteral solutions and bottled mineral water using different analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Tasneem G., E-mail: tgkazi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Khan, Sumaira, E-mail: skhanzai@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jameel A., E-mail: jab_mughal@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kolachi, Nida F., E-mail: nidafatima6@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan I., E-mail: hassanimranafridi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kandhro, Ghulam A.; Kumar, Sham [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Q., E-mail: aqshah07@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2009-12-30

    A new method is reported for the separation of aluminum ions [Al(III)] from interfering elements in parenteral and pharmaceutical solutions (PS) and bottled mineral water (BMW) samples, through solid-phase extraction with 2-methyl-8-hydroxyquinoline (quinaldine) adsorbed onto activated silica gel. While the enrichment step of separated Al(III) was carried out by cloud point extraction (CPE) using 8-hydroxyquinoline as complexing reagent, the resulted complex was entrapped in a non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114). The enriched Al(III) in sample solutions were determined by spectrofluorometry (SPF) at {lambda}{sub excitation} 370 nm and {lambda}{sub emission} 510 nm, and flame atomic absorption spectrometry (FAAS) for comparative purpose. The variables affecting the complexation and extraction steps were studied and optimized. The validity of methodology was checked with certified reference material of water and standard addition method. The enrichment factor and detection limit of Al(III) for the preconcentration of 50 ml of PS and BMW were found to be 100 and 0.25 {mu}g/L, respectively. The proposed method has been applied for the determination of trace amount of Al(III) in PS and BMW samples with satisfactory results. In PS the levels of Al(III) are above than permissible limit (25 {mu}g/L).

  13. Preparation and characterization of a novel strong-fluorescent hydrotalcite-like compound (Al-HTLc)

    Institute of Scientific and Technical Information of China (English)

    ZHANG WenGong; CHEN Hong

    2008-01-01

    A novel strong-fluorescent hydrotalcite-like compound (Al-HTLc) was synthesized by coprecipitation. In the sample, the content of aluminum(ill) in the layers was decreased to a proper value. The Al3+ ions coordinated with 8-hydroxyquinolines (8-HQ) which were dispersed into the anions in the interlayer region. The sample was characterized by XRD, XPS, FT-IR, TG-DSC, UV-Vis, and fluorescence spec-troscopy; its composition and structure were also determined. The results indicate that the sample can emit fluorescence (487 nm) with a strong fluorescence intensity (4.9×105(a.u.)). The fluorescent lifetime and fluorescence quantum yield of Al-HTLc were measured to be 21.24 ns and 67%, respectively, higher than those of pure 8-hydroxyquinoline aluminum (Alq3). The result of TG-DSC measurement clearly shows the enhanced thermal stability of Al-HTLc compared with that of MgAl-LDH and pure Alq3.Al-HTLc may be used as a novel luminescent functional material.

  14. Preparation and characterization of a novel strong-fluorescent hydrotalcite-like compound (Al-HTLc)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel strong-fluorescent hydrotalcite-like compound (Al-HTLc) was synthesized by coprecipitation. In the sample, the content of aluminum(III) in the layers was decreased to a proper value. The Al3+ ions coordinated with 8-hydroxyquinolines (8-HQ) which were dispersed into the anions in the interlayer region. The sample was characterized by XRD, XPS, FT-IR, TG-DSC, UV-Vis, and fluorescence spec- troscopy; its composition and structure were also determined. The results indicate that the sample can emit fluorescence (487 nm) with a strong fluorescence intensity (4.9×105 (a.u.)). The fluorescent lifetime and fluorescence quantum yield of Al-HTLc were measured to be 21.24 ns and 67%, respectively, higher than those of pure 8-hydroxyquinoline aluminum (Alq3). The result of TG-DSC measurement clearly shows the enhanced thermal stability of Al-HTLc compared with that of MgAl-LDH and pure Alq3. Al-HTLc may be used as a novel luminescent functional material.

  15. Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base

    Science.gov (United States)

    Devi, Jai; Batra, Nisha

    2015-01-01

    Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline have been synthesized and characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV-VIS, NMR, mass and ESR). On the basis of these characterizations, it was revealed that Schiff base ligands existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen and deprotonated hydroxyl oxygen and heterocyclic nitrogen base 8-hydroxyquinoline existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring with octahedral or distorted octahedral geometry around metal ion. All the compounds have been tested in vitro against various pathogenic Gram positive bacteria, Gram negative bacteria and fungi using different concentrations (25, 50, 100, 200 μg/mL) of ligands and their complexes. Comparative study of antimicrobial activity of ligands, and their mixed complexes indicated that complexes exhibit enhanced activity as compared to free ligands and copper(II) Cu(LIV)(Q)ṡH2O complex was found to be most potent antimicrobial agent.

  16. Determination of Trace Amounts of Nickel (Ⅱ) by Graphite Furnace Atomic Absorption Spectrometry Coupled with Cloud Point Extraction

    Institute of Scientific and Technical Information of China (English)

    SHAH Syed Mazhar; WANG Hao-nan; SU Xing-guang

    2011-01-01

    A new method based on the cloud point extraction(CPE) for separation and preconcentration of nickel(Ⅱ)and its subsequent determination by graphite furnace atomic absorption spectrometry(GFAAS) was proposed,8-hydroxyquinoline and Triton X-100 were usedl as the ligand and surfactant respectively. Nickel(Ⅱ) can form a hydrophobic complex with 8-hydroxyquinoline, the complex can be extracted into the small volume surfactant rich phase at the cloud point temperature(CPT) for GFAAS determination. The factors affecting the cloud point extraction,such as pH, ligand concentration, surfactant concentration, and the incubation time were optimized. Under the optimal conditions, a detection limit of 12 ng/L and a relative standard deviation(RSD) of 2.9% were obtained for Ni(Ⅱ) determination. The enrichment factor was found to be 25. The proposed method was successfully applied to the determination of nickel(Ⅱ) in certified reference material and different types of water samples and the recovery was in a range of 95% 103%.

  17. Graphite furnace atomic absorption spectrometric detection of vanadium in water and food samples after solid phase extraction on multiwalled carbon nanotubes.

    Science.gov (United States)

    Wadhwa, Sham Kumar; Tuzen, Mustafa; Gul Kazi, Tasneem; Soylak, Mustafa

    2013-11-15

    Vanadium(V) ions as 8-hydroxyquinoline chelates were loaded on multiwalled carbon nanotubes (MWNTs) in a mini chromatographic column. Vanadium was determined by graphite furnace atomic absorption spectrometry (GFAAS). Various analytical parameters including pH of the working solutions, amounts of 8-hydroxyquinoline, eluent type, sample volume, and flow rates were investigated. The effects of matrix ions and some transition metals were also studied. The column can be reused 250 times without any loss in its sorption properties. The preconcentration factor was found as 100. Detection limit (3 s) and limit of quantification (10 s) for the vanadium in the optimal conditions were observed to be 0.012 µg L(-1) and 0.040 μg L(-1), respectively. The capacity of adsorption was 9.6 mg g(-1). Relative standard deviation (RSD) was found to be 5%. The validation of the method was confirmed by using NIST SRM 1515 Apple leaves, NIST SRM 1570a Spinach leaves and GBW 07605 Tea certified reference materials. The procedure was applied to the determination of vanadium in tap water and bottled drinking water samples. The procedure was also successfully applied to microwave digested food samples including black tea, coffee, tomato, cabbage, zucchini, apple and chicken samples.

  18. Effect of 8-hydroxy-, 8-mercapto- and 5-chloro-7-iodo-8-hydroxy-quinoline on the uptake and distribution of nickel in mice

    Energy Technology Data Exchange (ETDEWEB)

    Borg-Neczak, K.; Tjaelve, H. (Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala Biomedical Centre, Uppsala (Sweden))

    1994-01-01

    Oral administration of Ni[sup 2+] together with 8-hydroxyquinoline (8-OH-quinoline), 8-mercaptoquinoline (8-SH-quinoline) or 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol) resulted in increased tissue levels of the metal in several tissues of mice in comparison with animals given the Ni[sup 2+] alone. Ni[sup 2+] forms lipophilic complexes with these compounds and it can be assumed that this will facilitate the uptake of Ni[sup 2+] over the walls of the gastrointestinal tract. Our results showed that 8-SH-quinoline, in contrast to 8-OH-quinoline and clioquinol, induces a markedly changed distribution pattern of the Ni[sup 2+] in the body, with uptake of the metal in tissues such as the central nervous system, pigmented tissues, the pancreatic islets and the thyroid. It is probable that the Ni[sup 2+] -complex with 8-SH-quinoline is stable enough to persist for a time period in the tissues and that the obtained pattern partly reflects the distribution of the complexed metal. In contrast, following the absorption from the gastrointestinal tract there may be a dissociation of the complexes between Ni[sup 2+] and 8-OH-quinoline or clioquinol, resulting in increased metal levels in various tissues, but with similar distribution as when the Ni[sup 2+] is given alone. (au) (21 refs.).

  19. Equilibrium Speciation of Select Lanthanides in the Presence of Acidic Ligands in Homo- and Heterogeneous Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Troy A [Univ. of Nevada, Las Vegas, NV (United States)

    2011-08-01

    This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd3+), sodium (Na+), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd3+ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probed through vapor pressure osmometry, visible and Fourier Transform Infrared (FTIR) spectroscopy, 22Na and 13C labeled lactate radiotracer distribution measurements, Karl Fischer titrations, and equilibrium pH measurements. Distribution of Nd3+, Na+, lactate, and equilibrium pH were modeled using the SXLSQI software to obtain logKNd and logKNa extraction constants under selected conditions. Results showed that high Nd3+ loading of the HDEHP led to Nd3+ speciation that departs from the ion exchange mechanism and includes formation of highly aggregated, polynuclear [NdLactate(DEHP)2]x; (with x > 1). By substituting lanthanum (La3+) for Nd3+ in this system, NMR scoping experiments using 23Na, 31P nuclei and 13C labeled lactate were performed. Results indicated that this technique is sensitive to changes in system speciation, and that further experiments are warranted. In a homogeneous system representing the TALSPEAK aqueous phase, Lactate protonation behavior at various temperatures was characterized using a combination of potentiometric titration and modeling with the Hyperquad computer program. The temperature dependent deprotonation behavior of lactate showed little change with temperature at 2.0 M NaCl ionic strength. Cloud point extraction is a non-traditional separation technique that starts with a homogeneous

  20. Separation process for lanthanides based on solvation properties of non ionic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Draye, M.; Favre-Reguillon, A.; Foos, J.; Cote, G

    2004-07-01

    In the present study, cloud-point extraction is used with a lipophilic chelating agent (8-hydroxyquinoline) to extract and separate lanthanum (III) and gadolinium (III) from an aqueous solution. The methodology used is based on the formation of lanthanide (III) organic complexes that are soluble in a micellar phase of non-ionic surfactant. The lanthanide (III) complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. The cloud-point temperature, the structure of the lipophilic part of the nonionic surfactant and the chelating agent - metal molar ratio are identified as factors determining the extraction efficiency and selectivity. With Triton X-114, high selectivity and decontamination factor for Gd(III) is observed indicating that micelle mediated extraction involving cloud-point extraction is promising for the specific separation of actinide ions from nuclear waste solution. (authors)

  1. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium and nickel in drinking and wastewater samples.

    Science.gov (United States)

    Naeemullah; Kazi, Tasneem G; Shah, Faheem; Afridi, Hassan I; Baig, Jameel Ahmed; Soomro, Abdul Sattar

    2013-01-01

    A simple method for the preconcentration of cadmium (Cd) and nickel (Ni) in drinking and wastewater samples was developed. Cloud point extraction has been used for the preconcentration of both metals, after formation of complexes with 8-hydroxyquinoline (8-HQ) and extraction with the surfactant octylphenoxypolyethoxyethanol (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Cd and Ni contents were measured by flame atomic absorption spectrometry. The experimental variables, such as pH, amounts of reagents (8-HQ and Triton X-114), temperature, incubation time, and sample volume, were optimized. After optimization of the complexation and extraction conditions, enhancement factors of 80 and 61, with LOD values of 0.22 and 0.52 microg/L, were obtained for Cd and Ni, respectively. The proposed method was applied satisfactorily for the determination of both elements in drinking and wastewater samples.

  2. Linewidth Narrowing and Intensity Enhancement of Wavelength Tunable MOLEDs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Microcavity structure consisting of distributed Bragg reflector and metal aluminum mirror is designed. Using tris (8-hydroxyquinoline) aluminum as electron-transport layer and emissive layer, and N, N′-bis (3-methylphenyl)-N, N′-diphenylbenzidine as a hole-transport layer, microcavity organic light-emitting diodes(MOLEDs) are fabricated. Compared to the electroluminescence spectra of non-cavity OLEDs, the linewidth of the MOLEDs is compressed from 75 nm to 7 nm, and the peak intensity enhances by a factor of about 3. When the effective length of the microcavity is modified, resonance wavelength can be selectively scanned over a very wide range of wavelengths that cover almost 140 nm.

  3. In Situ Formation of Steroidal Supramolecular Gels Designed for Drug Release

    Directory of Open Access Journals (Sweden)

    Hana Bunzen

    2013-03-01

    Full Text Available In this work, a steroidal gelator containing an imine bond was synthesized, and its gelation behavior as well as a sensitivity of its gels towards acids was investigated. It was shown that the gels were acid-responsive, and that the gelator molecules could be prepared either by a conventional synthesis or directly in situ during the gel forming process. The gels prepared by both methods were studied and it was found that they had very similar macro- and microscopic properties. Furthermore, the possibility to use the gels as carriers for aromatic drugs such as 5-chloro-8-hydroxyquinoline, pyrazinecarboxamide, and antipyrine was investigated and the prepared two-component gels were studied with regard to their potential applications in drug delivery, particularly in a pH-controlled drug release.

  4. Significant relaxation of residual negative carrier in polar Alq3 film directly detected by high-sensitivity photoemission

    Science.gov (United States)

    Kinjo, Hiroumi; Lim, Hyunsoo; Sato, Tomoya; Noguchi, Yutaka; Nakayama, Yasuo; Ishii, Hisao

    2016-02-01

    Tris(8-hydroxyquinoline)aluminum (Alq3) has been widely applied as a good electron-injecting layer (EIL) in organic light-emitting diodes. High-sensitivity photoemission measurement revealed a clear photoemission by visible light, although its ionization energy is 5.7 eV. This unusual photoemission is ascribed to Alq3 anions captured by positive polarization charges. The observed electron detachment energy of the anion was about 1 eV larger than the electron affinity reported by inverse photoemission. This difference suggests that the injected electron in the Alq3 layer is energetically relaxed, leading to the reduction in injection barrier. This nature is one of the reasons why Alq3 worked well as the EIL.

  5. 钴/氮杂环催化剂体系对庚烯氢酯基化反应的影响%Effect of Cobalt/N-heterocyclic Catalyst Systems on Hydroesterification of 1-Heptene

    Institute of Scientific and Technical Information of China (English)

    陈静; 傅宏祥; 童进

    2001-01-01

    The cobalt/pyridine catalyzed hydroesterification of olefine has been investigated in detail. In this paper a catalyst system of a nitrogen-containing heterocyclic compound having an enolic hydroxy group on the carbon atom adjacent to the ring forming nitrogen atom with a cobalt carbonyl compound was studied in carbonylation of 1-heptene. Under the reaction conditions of T=100 ℃ and p=5.0 MPa for 6 h, it is obvious that the nitrogen-ring compound has accelerative effect on the hydroesterification of 1-heptene . Among the N-ring bases studied, hydroxy group-containing N-ring compound has been found to be most effective, but the conversion of 1-heptene decreased with the increase of the concentration of the N-compounds . The effectiveness of N-containing heterocyclic compound in increasing the conversion of heptene decreases in the order: 2-hydroxypyridine > 3-hydroxypyridine > quinoline> 8-hydroxyquinoline 3,5-lutidine > pyridine.

  6. Analytical control and thermal behaviour study of Pb Ti O{sub 3} and Sr Ti O{sub 3} precursor powders by chemical precipitation; Controle analitico e estudo do comportamento termico de pos precursores de PbTiO{sub 3} e SrTiO{sub 3} via precipitacao quimica

    Energy Technology Data Exchange (ETDEWEB)

    Zorel Junior, H.E.; Torres, C.; Crespi, M.S.; Ribeiro, C.A. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    1997-12-31

    Different studies have been carried out to obtain precursors powders of pure and homogeneous ceramic materials aiming better properties of final product. In this work was investigated influences of temperature and addition rate of reagents in the precipitation of Pb Ti O{sub 3} and Sr Ti O{sub 3} precursors powders, using the ligand 8-hydroxyquinoline. Powders were characterized through X Ray Diffractometry, Infrared Absorption Spectroscopy, Atomic Absorption Spectroscopy, Thermogravimetry and Differential Thermal Analysis. It was observed that the beginning of the formation of crystalline phase correspondent to Pb Ti O{sub 3} occurs before the final thermal decomposition of precursor powder. At 900 deg C it was observed only peaks of tetragonal Pb Ti O{sub 3} phase while cubic Sr Ti O{sub 3} phase was observed only up to 1000 deg C. Results show differences in the precursor powder depending on atmosphere and heat hate used on the calcination. (author) 4 refs., 9 figs.

  7. 山东莱州发现三倍体薤白%Discovery of Triploid Allium macrostemon Bunge in Laizhou City of Shandong Province

    Institute of Scientific and Technical Information of China (English)

    王爱云; 王艳化; 任晓莉; 张琳丰

    2009-01-01

    [Objective] The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province. [Method] The root tip of A.macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [Result] Allium macrostemon Bunge in Laizhou City introduced in this study was triploid; its somatic chromosome number was 24 and karyotype formula was K(2n)=3x=24m(2SAT)+1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells. [Conclusion] This introduction of triploid A.macrostemon found in China was the first time.

  8. Crystal structure of bis{μ-(E-2-[(2-oxidophenyliminomethyl]quinolin-8-olato-κ4O,N,N′,O′}bis[dibutyltin(IV

    Directory of Open Access Journals (Sweden)

    Camacho-Camacho Carlos

    2017-01-01

    Full Text Available Condensation of 8-hydroxyquinoline-2-carbaldehyde with 2-aminophenol gave the (E-2-[(2-hydroxyphenyliminomethyl]quinolin-8-ol derivative that reacted with di-n-butyltin oxide with release of H2O to yield the chelate title complex, [Sn2(C4H94(C16H10N2O22]. The compound crystallizes in the triclinic space group P-1, with two independent centrosymmetric dimers in the unit cell. Each features a typical pincer-type structure where the dianionic ligand is tetradentate, coordinating to the central tin atom through both phenolate oxygen atoms, as well as through the quinoline and imine N atoms. Each metal atom adopts a distorted pentagonal–bipyramidal SnC2N2O3 coordination arising from the N,N′,O,O′-tetradentate deprotonated Schiff base, one bridging phenolate O atom of the neighbouring ligand and two butyl groups in the axial sites.

  9. Characterisation of molecular thin films grown by organic molecular beam deposition

    CERN Document Server

    Bayliss, S M

    2000-01-01

    This work concerns the growth and characterisation of molecular thin films in an ultra high vacuum regime by organic molecular beam deposition (OMBD). Films of three different molecular materials are grown, namely free base phthalocyanine (H sub 2 Pc), perylene 3,4,9,10-tetracarboxylic dianhydride (PTCDA) and aluminium tris-8-hydroxyquinoline (Alq sub 3). The relationship between the growth parameters such as film thickness, growth rate, and substrate temperature during and after growth, and the structural, optical and morphological properties of the film are investigated. These investigations are carried out using various ex-situ techniques. X-ray diffraction, Raman spectroscopy and electronic absorption spectroscopy are used to probe the bulk film characteristics, whilst Nomarski microscopy and atomic force microscopy are used to study the surface morphology. Three different levels of influence of the growth parameters on the film properties are observed. In the case of H sub 2 Pc, two crystal phases are fo...

  10. Enhancement of third-order nonlinear optical susceptibility of Alqsub>3sub> in polar aprotic solvents.

    Science.gov (United States)

    Derkowska-Zielinska, Beata

    2017-02-01

    The influence of solvent polarity on nonlinear optical properties of tris-(8-hydroxyquinoline)-aluminum (Alqsub>3sub>) was investigated by the degenerate four-wave mixing method at the 532 nm. It was obtained that the effective values of the third-order nonlinear optical susceptibility (χeff⟨3⟩) and the second-order hyperpolarizability (γsub>effsub>) of Alqsub>3sub> depend on the solvent polarity. Additionally, it was found that Alqsub>3sub> dissolved in dimethyl sulfoxide has the highest values of χeff⟨3⟩ and γsub>effsub>. Furthermore, two Stegeman's figures of merit were also calculated. The obtained results suggest that Alqsub>3sub> is also promising material for application in all-optical signal processing devices.

  11. Arsenic species analysis in porewaters and sediments using hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    LIAO Meng-xia; DENG Tian-long

    2006-01-01

    It was observed that the atomic fluorescence emission due to As(Ⅴ) could has a 10% to 40% of fluorescence emission signal during the determination of As(Ⅲ) in the mixture of As(Ⅲ) and As(Ⅴ). Besides, interferes from heavy metals such as Pb(Ⅱ),Cu(Ⅱ) can cause severe increase of the signals as compared to the insignificant effects caused by Cd(Ⅱ), Zn(Ⅱ), Mn(Ⅱ) and Fe(Ⅲ). On the basis of further studies, the masking agent of 8-hydroxyquinoline was used as an efficient agent to eliminate interference of As(Ⅴ)emission and the heavy metal of Cu2+ and Pb2+ in the measurements of arsenic species. After a series standard additions and CRM researches, a sensitive and interference-free analytical procedure was developed for the speciation of arsenic in samples ofporewaters and sediments in Poyang Lake, China.

  12. Structural characterization and biological evaluation of a clioquinol-ruthenium complex with copper-independent antileukaemic activity.

    Science.gov (United States)

    Gobec, Martina; Kljun, Jakob; Sosič, Izidor; Mlinarič-Raščan, Irena; Uršič, Matija; Gobec, Stanislav; Turel, Iztok

    2014-06-28

    In this study, we present the synthesis, biological characterization, and first crystal structure of an organometallic-clioquinol complex. Combining ruthenium with the established apoptotic agent and 8-hydroxyquinoline derivative, clioquinol, resulted in a complex that induces caspase-dependent cell death in leukaemia cells. This activity is copper independent and is improved compared to the parent compound, clioquinol. The study of the mode of action reveals that this clioquinol-ruthenium complex does not intercalate between DNA base pairs. Additionally, this clioquinol-ruthenium complex shows proteasome-independent inhibition of the NFκB signalling pathway, with no effects on cell-cycle distribution. These data suggest a mechanism of action that involves a target profile that is different from that for clioquinol alone.

  13. Time-resolved spin-dependent processes in magnetic field effects in organic semiconductors

    Science.gov (United States)

    Peng, Qiming; Li, Xianjie; Li, Feng

    2012-12-01

    We investigated the time-resolved magnetic field effects (MFEs) in tri-(8-hydroxyquinoline)-aluminum (Alq3) based organic light-emitting diodes (OLEDs) through the transient electroluminescence (EL) method. The values of magneto-electroluminescence (MEL) decrease with the time, and the decreasing slope is proportional to the driving voltage. Specifically, negative MELs are seen when the driving voltage is high enough (V > 11 V). We propose a model to elucidate the spin-dependent processes and theoretically simulate the time-resolved MELs. In particular, this dynamic analysis of time-resolved MELs reveals that the intersystem crossing between singlet and triplet electron-hole pairs and the triplet-triplet annihilation are responsible for the time-resolved MELs at the beginning and enduring periods of the pulse, respectively.

  14. Effect of the physical and the chemical structures of Ni nanocrystals on the nonvolatile memory characteristics for small-molecule nonvolatile memorycells embedded with Ni nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Woo-Sik; Park, Jea-Gun [Hanyang University, Seoul (Korea, Republic of)

    2011-06-15

    We determined the effects of the evaporation rate of the Ni layer and the presence of in-situ O{sub 2} plasma oxidation on the physical and the chemical structures of Ni nanocrystals embedded in small molecule (Alq{sub 3}: aluminum tris(8-hydroxyquinoline)) memorycells. The Ni nanocrystals produced by an evaporation rate of 0.1 A/s for the Ni layer with in-situ O{sub 2} plasma oxidation were well isolated from one another by a NiO tunneling barrier. The small-molecule memorycell embedded with isolated Ni nanocrystals surrounded by a NiO tunneling barrier demonstrated a memory margin (I{sub on}/I{sub off} ratio) of {approx}1 x 10{sup 3}, a retention time of more than 10{sup 5} sec, and an endurance of more than 2 x 10{sup 2} erase-and- program cycles.

  15. Organic bistable memory devices based on MoO3 nanoparticle embedded Alq3 structures

    Science.gov (United States)

    Abhijith, T.; Kumar, T. V. Arun; Reddy, V. S.

    2017-03-01

    Organic bistable memory devices were fabricated by embedding a thin layer of molybdenum trioxide (MoO3) between two tris-(8-hydroxyquinoline)aluminum (Alq3) layers. The device exhibited excellent switching characteristics with an ON/OFF current ratio of 1.15 × 103 at a read voltage of 1 V. The device showed repeatable write–erase capability and good stability in both the conductance states. These conductance states are non-volatile in nature and can be obtained by applying appropriate voltage pulses. The effect of MoO3 layer thickness and its location in the Alq3 matrix on characteristics of the memory device was investigated. The field emission scanning electron microscopy (FE-SEM) images of the MoO3 layer revealed the presence of isolated nanoparticles. Based on the experimental results, a mechanism has been proposed for explaining the conductance switching of fabricated devices.

  16. Dispersive liquid-liquid microextraction (DLLME combined with graphite furnace atomic absorption spectrometry (GFAAS for determination of trace Cu and Zn in water Samples

    Directory of Open Access Journals (Sweden)

    Ghorbani A.

    2014-07-01

    Full Text Available Dispersive liquid-liquid microextraction (DLLME combined with graphite furnace atomic absorption spectrometry (GFAAS was proposed for the determination of trace amounts of Copper and Zinc ions using 8-hydroxyquinoline (8-HQ as chelating agent. Several factors influencing the microextraction efficiency of Cu and Zn and their subsequent determinations, such as pH, extraction and disperser solvent type and their volume, concentration of the chelating agent and extraction time were studied, and the optimized experimental conditions were established. After extraction, the enrichment factors were 25 and 26 for Cu and Zn, respectively. The detection limits of the method were 0.025 and 0.0033 μg/L for Cu and Zn, and the relative standard deviations (R.S.D for five determinations of 1 ng/ml Cu and Zn were 8.51% and 7.41%, respectively.

  17. n-type ZnS used as electron transport material in organic light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    Du Peng; Zhang Xi-Qing; Sun Xue-Bai; Yao Zhi-Gang; Wang Yong-Sheng

    2006-01-01

    This paper reports on the n-type ZnS used as electron transport layer for the organic light-emitting diodes(OLEDs). The naphthyl-substituted benzidine derivative (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3)are used as the hole transport layer and the emitting layer respectively. The insertion of the n-type ZnS layer enhances the electron injection in the OLEDs. The study was carried out on OLEDs of structures: indium-tin-oxide (ITO)/NPB/Alq3/ZnS/LiF/AL, ITO/NPB/Alqa/LiF/AL and ITO/NPB/Alq3/AL. The luminance and efficiency of the device containing this electron transport layer are increased significantly over those obtained from conventional devices due to better carrier balance.

  18. Paramagnetic defect centres in crystalline Alq{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Grecu, M N [National Institute for Materials Physics, POB MG-7, 077125 Magurele-Bucharest (Romania); Mirea, A [Experimental Physics II, Bayreuth University, 95440 Bayreuth (Germany); Ghica, C [National Institute for Materials Physics, POB MG-7, 077125 Magurele-Bucharest (Romania); Coelle, M [Philips Research, Laboratories, NL-5656 AA Eindhoven (Netherlands); Schwoerer, M [Experimental Physics II, Bayreuth University, 95440 Bayreuth (Germany)

    2005-10-05

    X- and Q-band electron paramagnetic resonance (EPR) investigation of different crystalline Alq{sub 3} (tris(8-hydroxyquinoline)aluminium (III)) fractions formed by a train sublimation method are reported. Several paramagnetic defect centres corresponding to 1/2, 1, and 3/2 spin are observed at room temperature. Their intensity is dependent on the temperature, nature of the crystalline phase, and preparation conditions. Spectra simulation and analysis based on the spin Hamiltonian appropriate to a high spin system (S{>=}1) suggest the existence of randomly oriented triplets and quartets in annealed Alq{sub 3} fractions. The crystalline Alq{sub 3} phases responsible for the EPR powder spectra have been identified by transmission electron microscopy measurements performed on these sample fractions.

  19. All-polymer organic semiconductor laser chips: Parallel fabrication and encapsulation

    DEFF Research Database (Denmark)

    Vannahme, Christoph; Klinkhammer, Sönke; Christiansen, Mads Brøkner;

    2010-01-01

    Organic semiconductor lasers are of particular interest as tunable visible laser light sources. For bringing those to market encapsulation is needed to ensure practicable lifetimes. Additionally, fabrication technologies suitable for mass production must be used. We introduce all-polymer chips...... tris(8- hydroxyquinoline) aluminum (Alq3) doped with the laser dye 4-dicyanomethylene-2- methyl-6-(p-dimethylaminostyril)-4H-pyrane (DCM) are hermetically sealed by thermally bonding a polymer lid. The organic thin film is placed in a basin within the substrate and is not in direct contact to the lid...... comprising encapsulated distributed feedback organic semiconductor lasers. Several chips are fabricated in parallel by thermal nanoimprint of the feedback grating on 4? wafer scale out of poly(methyl methacrylate) (PMMA) and cyclic olefin copolymer (COC). The lasers consisting of the organic semiconductor...

  20. Electronic structure of planar-quasicycled organic molecules with intramolecular hydrogen bond

    Directory of Open Access Journals (Sweden)

    ALEXEI N. PANKRATOV

    2007-03-01

    Full Text Available By means of the HF/6-311G(d,p method, the electronic structure of the series of organic molecules, among which are malonaldehyde, acetylacetone, thiomalonaldehyde,’the derivatives of aniline 2-XC6H4NH2, phenol 2-XC6H4OH, benzenethiol 2-XC6H4SH (X = CHO, COOH, COO-, NO, NO2, OH, OCH3, SH, SCH3, F, Cl, Br, 8-hydroxyquinoline, 8-mercaptoquinoline, tropolone, has been studied. The intramolecular hydrogen bond (IHB has been established to lead to a local electron redistribution in quasicycle, and primarily to the electron density transfer between the direct IHB participants – from the hydrogen atom toward the proton-aceptor atom. On forming the IHB of the S–H···O type, the electron density in general decreases on the sulphohydryl hydrogen atom and increases on the sulphur atom.

  1. Luminescent Enhancement of Heterostructure Organic Light-Emitting Devices Based on Aluminum Quinolines

    Institute of Scientific and Technical Information of China (English)

    Jun-Sheng Yu; Lu Li; Ya-Dong Jiang; Xing-Qiao Ji; Tao Wang

    2007-01-01

    High performance organic light-emitting devices (OLEDs) have been investigated by using fluorescent bis (2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(BAlq) as an emissive layer on the performance of multicolor devices consisting of N, N'-bis-(1-naphthyl)-N,N'diphenyI-l,l'-biphenyI-4,4'-diamine (NPB) as hole transport layer. The results show that the performance of heterostructure blue light-emitting device composed of 8-hydroxyquinoline aluminum (Alq3) as an electron transport layer has been dramatically enhanced. In the case of high performance heterostructure devices, the electroluminescent spectra has been perceived to vary strongly with the thickness of the organic layers due to the different recombination region, which indicates that various color devices composed of identical components could be implemented by changing the film thickness of different functional layers.

  2. 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...... surfactants, leading to marked increases in fluorescence intensity. However, significant differences are seen in the behavior of the two metal ions. With aluminium, a stable [Al(8-QS)3]3- anion is formed, and interacts, predominantly through electrostatic interactions, with the surfactant, without disrupting...... the metal ion coordination sphere. In contrast, with Zn(II), there is a competition between the metal ion and surfactants in the interaction with 8-HQS, although the [Zn(8-QS)2(H2O)2]2- species is stable at appropriate pH and surfactant concentration. The studies are extended to systems with the conjugated...

  3. Metal ions, Alzheimer's disease and chelation therapy.

    Science.gov (United States)

    Budimir, Ana

    2011-03-01

    In the last few years, various studies have been providing evidence that metal ions are critically involved in the pathogenesis of major neurological diseases (Alzheimer, Parkinson). Metal ion chelators have been suggested as potential therapies for diseases involving metal ion imbalance. Neurodegeneration is an excellent target for exploiting the metal chelator approach to therapeutics. In contrast to the direct chelation approach in metal ion overload disorders, in neurodegeneration the goal seems to be a better and subtle modulation of metal ion homeostasis, aimed at restoring ionic balance. Thus, moderate chelators able to coordinate deleterious metals without disturbing metal homeostasis are needed. To date, several chelating agents have been investigated for their potential to treat neurodegeneration, and a series of 8-hydroxyquinoline analogues showed the greatest potential for the treatment of neurodegenerative diseases.

  4. Electroluminescence and negative differential resistance studies of TPD:PBD:Alq3 blend organic-light-emitting diodes

    Indian Academy of Sciences (India)

    M A Mohd Sarjidan; S H Basri; N K Za’aba; M S Zaini; W H Abd Majid

    2015-02-01

    Ternary system of single-layer organic-light-emitting diodes (OLEDs) were fabricated containing tris(8-hydroxyquinoline) aluminium (Alq3) blended with N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine and 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole small molecules. Electroluminescence properties were investigated with respect to blend systems. Significant improvement in turn-on voltage and luminance intensity was observed by employing the blends technique. Negative differential resistance (NDR) characteristics observed at a low voltage region in blended OLED is related to the generation of guest hopping site and phonon scattering phenomenon. However, luminescence of the devices is not altered by the NDR effect.

  5. One-step Double-layer Thermal Evaporation Method for Organic Light Emitting Diodes

    Science.gov (United States)

    Kee, Y. Y.; Yong, T. K.; Ong, D. S.; Tou, T. Y.

    2011-03-01

    A new one-step double-layer thermal evaporation method was used to fabricate organic light emitting diodes (OLEDs) with device structure of: ITO (anode)/N,N_-diphenyl-N,N_-bis(3-methylphenyl)-1,1_-diphenyl-4,4_-diamine (TPD) /tris-(8-hydroxyquinoline)aluminum(3) (Alq3)/Al (cathode). These OLEDs were fabricated in cleanroom on the ITO-coated glass with a sheet resistivity of 20Ω/sq and an optical transmittance of 90%. The I-V and brightness characteristic showed that the new method could produce better performance achieving lower turn-on voltage (-2V), higher peak current efficiency (+29%) and higher brightness (+36%).

  6. Bio-recognitive photonics of a DNA-guided organic semiconductor.

    Science.gov (United States)

    Back, Seung Hyuk; Park, Jin Hyuk; Cui, Chunzhi; Ahn, Dong June

    2016-01-01

    Incorporation of duplex DNA with higher molecular weights has attracted attention for a new opportunity towards a better organic light-emitting diode (OLED) capability. However, biological recognition by OLED materials is yet to be addressed. In this study, specific oligomeric DNA-DNA recognition is successfully achieved by tri (8-hydroxyquinoline) aluminium (Alq3), an organic semiconductor. Alq3 rods crystallized with guidance from single-strand DNA molecules show, strikingly, a unique distribution of the DNA molecules with a shape of an 'inverted' hourglass. The crystal's luminescent intensity is enhanced by 1.6-fold upon recognition of the perfect-matched target DNA sequence, but not in the case of a single-base mismatched one. The DNA-DNA recognition forming double-helix structure is identified to occur only in the rod's outer periphery. This study opens up new opportunities of Alq3, one of the most widely used OLED materials, enabling biological recognition.

  7. Cathodoluminescence and electroluminescence from multi-layered organic structures induced by field electron emission from carbon nanotubes

    Science.gov (United States)

    Kuznetzov, Alexander A.; Zakhidov, Alexander A.; Ovalle, Raquel; Nanjundaswami, Rashmi; Williams, Christopher; Zhang, Mei; Lee, Sergey B.; Ferraris, John; Zakhidov, Anvar A.

    2005-10-01

    We report the observation of cathodoluminescence (CL) of organic multilayers of tris-(8-hydroxyquinoline) aluminium (Alq3) and 2- (4biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) deposited on ITO-coated glass, with and without hole transport layer and compare it with electroluminescence (EL) from similar devices. Excitation of the CL of such multilayer organic anodes was accomplished by low energy electrons field emitted by single walled carbon nanotube cathodes. The dependence of CL spectrum and intensity on voltage (V), current (I), type of transport layer and the cathode-anode geometry has been studied. We propose carbon nanotubes as efficient cathodes for stable CL emission from multi-layer anodes at small cathode-anode separations. The role of hole-transport layer is also discussed.

  8. Fabrication of Green Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    高德青; 黄春辉; 奎热西; 刘凤琴

    2002-01-01

    A gadolinium ternary complex, tris(1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone) (2, 2′-dipyridyl) gadolinium Gd(PMIP)3(Bipy) was synthesized and used as a light emitting material in the organic electroluminescent devices. The devices exhibited the green electroluminescent (EL) emission peaking at 513 nm, originating from the Gd(PMIP)3(Bipy). By improving the configuration, the device with a structure of ITO/poly(N-vinylcarbazole) (PVK) (40 nm)/Gd(PMIP)3(Bipy) (40 nm)/tris (8-hydroxyquinoline) aluminum (ALQ) (40 nm)/Mg∶Ag(200 nm)/Ag(100 nm) showed higher performance and a maximum luminance of 340 cd*m-2 at 18 V.

  9. Simulation of mixed-host emitting layer based organic light emitting diodes

    Science.gov (United States)

    Riku, C.; Kee, Y. Y.; Ong, T. S.; Yap, S. S.; Tou, T. Y.

    2015-04-01

    `SimOLED' simulator is used in this work to investigate the efficiency of the mixed-host organic light emitting devices (MH-OLEDs). Tris-(8-hydroxyquinoline) aluminum(3) (Alq3) and N,N-diphenyl-N,N-Bis(3-methylphenyl)-1,1-diphenyl-4,4-diamine (TPD) are used as the electron transport layer (ETL) material and hole transport layer (HTL) material respectively, and the indium-doped tin oxide (ITO) and aluminum (Al) as anode and cathode. Three MH-OLEDs, A, B and C with the same structure of ITO / HTM (15 nm) / Mixed host (70 nm) / ETM (10 nm) /Al, are stimulated with ratios TPD:Alq3 of 3:5, 5:5, and 5:3 respectively. The Poole-Frenkel model for electron and hole mobilities is employed to compute the current density-applied voltage-luminance characteristics, distribution of the electric field, carrier concentrations and recombination rate.

  10. Studies on cluster, salt and molecular complex of zinc-quinolinate

    Indian Academy of Sciences (India)

    Prithiviraj Khakhlary; Jubaraj B Baruah

    2015-02-01

    Reactions of zinc halides with 8-hydroxyquinoline (hydroxQ) in equimolar ratio were carried out in different solvents. Respective solvates of tetranuclear clusters, namely [Zn4(oxyQ)6X2].(solvent)2, (when X=Cl, Solvent=dimethylformamide (1), dimethylacetamide (2) and dimethysulphoxide (3); X = Br, solvent = dimethylformamide (4), oxyQ=quinolinate anion) were obtained. Bond parameters of these isostructural clusteres 1–4 are compared from their single crystal structures. Anhydrous form of the cluster have porous packing and is thermally stable below 250° C. Surface area of the clusters 1 and 4 are 8.933 and 6.172 m2/g, respectively. Complexes 1 and 4 can be reversibly hydrated, which is reflected in colour changes. The reaction of zinc chloride with 8-hydroxyquinoline in equimolar ratio followed by crystallization from water gave salt (HhydroxQ)2 [ZnCl4] (5) and a similar reaction followed by crystallization from 3-methylpyridine (3mepy) resulted in the molecular complex [Zn(oxyQ)2(3mepy)]. [Zn(oxyQ)2(3mepy)2].3H2O (6). Complex 5 is formed from a hydrolytic equilibrium of water with zinc chloride yielding tetrachloro zinc anion and zinc hydroxide. Taking advantage of this reaction, a composite material of ZnO@complex 5 exhibiting dual fluorescence at 450 and 575 nm on excitation at 390 nm was prepared. Fluorescence emission properties of all the complexes in solid state are compared with fluorescence emission of the ligand

  11. Synthesis, characterization, thermal behaviour and single crystal X-ray analysis of two new insensitive high energy density materials [8-hydroxyquinolinium 5-(2,4,6-trinitrophenyl)barbiturate (I) and 8-hydroxyquinolinium 5-(5-chloro-2,4-dinitrophenyl)-1,3-dimethyl barbiturate (II)

    Science.gov (United States)

    Manickkam, V.; Devi, P. Poornima; Kalaivani, D.

    2014-12-01

    Barbiturates I and II have been synthesized as maroon red and red orange coloured solids by mixing the ethanolic solutions of 2-chloro-1,3,5-trinitrobenzene ( TNCB), pyrimidine-2,4,6(1 H,3 H,5 H)-trione [barbituric acid ( BA)] and 8-hydroxyquinoline and 1,3-dichloro-4,6-dinitrobenzene ( DCDNB), 1,3-dimethylpyrimidine-2,4,6(1 H,3 H,5 H)-trione(1,3-dimethylbarbituric acid) and 8-hydroxyquinoline respectively. The structures of these two barbiturates have been predicted from the spectral studies (UV-VIS, IR, 1H NMR, 13C NMR, mass) and elemental analysis. Qualitative tests have been carried out to infer the presence of nitrogen and nitro groups and also chlorine atom in barbiturate II. Slow evaporation of ethanol-dimethylsulphoxide/ethanol solutions of barbiturate I/barbiturate II at 293 K yielded good for X-Ray diffraction crystals. Single crystal X-ray diffraction studies of the crystals further confirm the putative structures of the barbiturates. The asymmetric unit of the barbiturate I comprises of 8-hydroxyquinolinium cation, 5-(2,4,6-trinitrophenyl) barbiturate anion and a molecule of dimethylsulphoxide (DMSO), which is used as a recrystallizing solvent. It crystallizes in the triclinic system with space group (centrosymmetric). Barbiturate II crystallizes in the orthorhombic system with space group P212121 (non-centrosymmetric). Barbiturates I and II are stable towards an impact sensitivity test, when a weight of 2 kg mass hammer is dropped from a height of 160 cm of the instrument. TGA/ DTA analyses at four different heating rates (5, 10, 20, and 40 K/min) imply that they undergo exothermic decomposition (˜85%) in three different stages between 273 and 873 K. Activation energies for these decomposition processes have been calculated by employing Kissinger and Ozawa plots. Impact sensitivity test and activation energies have revealed that the titled barbiturates are insensitive high energy density materials ( IHEDMS).

  12. Molecular mechanics approach for design and conformational studies of macrocyclic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Rohini,; Akbar, Rifat; Kanungo, B. K., E-mail: b.kanungo@gmail.com [Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal-148106 (India)

    2015-08-28

    Computational Chemistry has revolutionized way of viewing molecules at the quantum mechanical scale by allowing simulating various chemical scenarios that are not possible to study in a laboratory. The remarkable applications of computational chemistry have promoted to design and test of the effectiveness of various methods for searching the conformational space of highly flexible molecules. In this context, we conducted a series of optimization and conformational searches on macrocyclic based ligands, 9N3Me5Ox, (1,4,7-tris(5-methyl-8-hydroxyquinoline)-1,4,7-triazacyclononane) and 12N3Me5Ox, (1,5,9-tris(5-methyl-8-hydroxyquinoline)-1,5,9-triazacyclododecane) and studied their selectivity and coordination behavior with some lanthanide metal ions in molecular mechanics and semiempirical methods. The methods include both systematic and random conformational searches for dihedral angles, torsion angles and Cartesian coordinates. Structural studies were carried out by using geometry optimization, coordination scans and electronic properties were evaluated. The results clearly show that chair-boat conformational isomer of 9N3Me5Ox ligand is more stable due to lower eclipsing ethane interaction and form stronger adduct complexes with lanthanide metal ion. This is because of the fact that, in a central unit of 9N3 of the ligand form six endo type bonds out of nine. The rest of bonds have trans conformation. In contrast, for the adduct of 12N3Me5Ox, two C-C bonds have on eclipsed conformation, and others have synclinal and antiperiplanar confirmations. The distortion of the two eclipsed conformations may affect the yields and the stability of the complexes.

  13. Manutenção da qualidade de rosas cortadas cv. Vega em soluções conservantes Keeping quality of cut roses cv. Vega in holding solutions

    Directory of Open Access Journals (Sweden)

    Júlia de Pietro

    2012-03-01

    Full Text Available A rosa é considerada uma das flores de corte mais tradicionais e requisitadas no mercado mundial. Entretanto, após o corte, essas flores tornam-se altamente perecíveis devido à elevada atividade metabólica que conduz aos processos de senescência. Assim, o experimento foi realizado para verificar o efeito do uso de soluções conservantes na fisiologia pós-colheita de rosas vermelhas cortadas cultivar Vega. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial composto por dois fatores: sete tratamentos pós-colheita e quatro datas de avaliação. As flores permaneceram nas seguintes soluções de manutenção: 1 Água destilada; 2 8-hidroxiquinolina (200 mg L-1; 3 8-hidroxiquinolina (200 mg L-1 + Sacarose (20 mg L-1; 4 Ácido cítrico (75 mg L-1; 5 Ácido cítrico (75 mg L-1 + Sacarose (20 mg L-1; 6 6-benziladenina (60 mg L-1; 7 6 benziladenina (60 mg L-1 + Sacarose (20 mg L-1. Foram realizadas análises qualitativas e fisiológicas ao longo do período de avaliação. O tratamento com 8-hidroxiquinolina e ácido cítrico revelaram-se mais promissores para manter a qualidade e prolongar a vida de vaso das flores, o que foi evidenciado pela menor perda de massa fresca, atividade respiratória e conteúdo relativo de água; melhor manutenção do conteúdo de carboidratos solúveis e redutores, antocianina e coloração.The rose is considered one of the most traditional and required cut flowers in the world market. However, after cutting, these flowers become highly perishable, because the high metabolic activity leads to senescence processes. The experiment was accomplished to verify the effect of holding solutions on the postharvest physiology of cut red roses, cv. Vega. A randomized design in a factorial scheme composed by two factors was used: seven postharvest treatments and four evaluation dates. The flowers remained in the following holding solutions: 1 Distilled water; 2 8-hydroxyquinoline citrate (200 mg L-1; 3 8

  14. Cathode Formed by Thermal Evaporation of Ba:Al Alloy and Estimations of Barrier Height in an Organic LED

    Institute of Scientific and Technical Information of China (English)

    DING Lei; ZHANG Fang-Hui

    2011-01-01

    @@ It is demonstrated that barium and aluminum alloy synthesized by melting in a glass tube under low vac- uum is applicable for organic laser emitting diodes (LEDs) as a thin film cathode.The alloy film obtained by the thermal evaporation of pre-synthesized alloy is used in a single-boat organic LED device with the struc- ture: indium tin oxide (ITO)/4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(NPB)/tris-(8-hydroxyquinoline) aluminum(Alq) /barium:aluminum alloy.The experimental results show that devices with this alloy film cathode exhibit better current densityovoltage-luminance characteristics than those with a conventional pure AI cathode, and more weight of barium in aluminum leads to better performance of the devices.Characteristics of cur- rent density versus voltage for the electron-only devices are fitted by the Richardson-Schottky emission model, indicating that the electron injection barrier has a decrease of about 0.3 eV by this alloy cathode.%It is demonstrated that barium and aluminum alloy synthesized by melting in a glass tube under low vacuum is applicable for organic laser emitting diodes (LEDs) as a thin Rim cathode. The alloy Him obtained by the thermal evaporation of pre-synthesized alloy is used in a single-boat organic LED device with the structure: indium tin oxide (ITO)/4,4'-bis[N-(l-naphthyl)-N-phenylamino]biphenyl(NPB)/tris-(8-hydroxyquinoline) aluminum(Alq3)/barium:aluminum alloy. The experimental results show that devices with this alloy film cathode exhibit better current density-voltage-luminance characteristics than those with a conventional pure Al cathode, and more weight of barium in aluminum leads to better performance of the devices. Characteristics of current density versus voltage for the electron-only devices are fitted by the Richardson-Schottky emission model, indicating that the electron injection barrier has a decrease of about 0.3 eV by this alloy cathode.

  15. 木薯嫩叶染色体的制片方法%Chromosome Observation Method for Cassava Tender Leaves

    Institute of Scientific and Technical Information of China (English)

    凡杰; 安飞飞; 郑峰

    2012-01-01

    采用改良苯酚品红压片法,对华南124多倍体木薯品种的嫩叶染色体标本制备方法进行了探讨,比较了0.002mol·L-1的8-羟基喹啉3种温度3种时间的预处理效果、不同的解离方法以及取样部位对制片效果的影响。结果表明,于上午9:00.10:00摘取1.5~2cm长的嫩叶,用0.002mol·L“的8-羟基喹啉于4℃下预处理4h,再置于1mol·L-1盐酸溶液中,于25℃下解离1h,挑取嫩叶中部叶肉用改良苯酚品红染色,然后进行压片观察,能获得分散良好、清晰的染色体图像。%Modified phenol fuchsin squashing method was used to prepare chromosome specimens of tender leaves of polypoidy cassava SC 124. The tender leaves were pretreated with 0. 002 mol ·L-1 8 -hydroxyquinoline at three different temperatures for different time by using different solution methods and sampled from different parts of the plant. The tender leaves collected 1.5 -2 cm long in the morning at 9:00 am - 10:00 am were pretreated with 0. 002 mol · L-1 the 8 -hydroxyquinoline at 4 C for 4 h, and then put in 1 mol · L-1hydrochloric acid solution at 25 C for 1 h for maceration, and the mesophyll in the central part of the tender leaves were stained with modified phenol suchsin and then squashed for observatio n. This method produced a well dispersed, clear chromosome image.

  16. [A Fluorescent Chemical Sensor Based on MgAl-8-HQ LDH Composite Particle for the Selective Detection of Fe3+].

    Science.gov (United States)

    Yang, Lei; Yao, Qi; Yuan, Xue-hua; Yang, Yan-ling

    2015-03-01

    In order to achieve the highly selective and Simple detection for ferric ion, strong-fluorescent 8-hydroxyquinoline (8-HQ) Mg-Al layered double hydroxide(Mg(χ)Al-8-HQ LDH) was designed and prepared by 8-HQ's intercalation and ready coordination based on adjustment of Al3+ on Mg-Al layered double hydroxides (MgAl LDH) laminates. Meanwhile its structure and property were characterized by IR, XRD, UV-Vis and fluorescent spectrometer. IR analysis showed coordinate bonds of C-O-Al and C-N-Al between 8-HQ and Al3+ were generated. XRD revealed that 8-HQ had already inserted in MgAl LDH laminates, and it made (003) diffraction peaks move to low 2θ angle direction, and the diffraction peak intensity was enhanced with the molar ratio of Mg and Al increasing. Because the coordination reaction between 8-HQ and Al3+ in MgAl LDH laminates took place, it induced the absorption peak of 8-HQ at 314 nm disappeared, at the same time the transition absorption peak at 376 nm between metal ions and ligands appeared. As demonstrated by fluorescence spectroscopic analysis, fluorescence intensity of Mg(χ)Al-8-HQ LDH increased with the content of Al3+ reducing, when the molar ratio of Magnesium and Aluminium ion is 4 : 1, its fluorescence intensity enhanced more significantly than 8-hydroxyquinoline aluminum. Through the research on the influence of metal ions on the fluorescence spectra of Mg4 Al-8-HQ LDH particle, it was found that the particle to metal ions exhibited significant selection and difference, especially with high selectivity for Fe3+ ion. The effect of [Fe3+] on the color and fluorescence intensity of Mg4Al-8-HQ LDH particle solution was further studied, and the results showed that the solution varied from light yellow to dark green with the content of Fe3+ in 10(-6) to 10(-2) mol x L(-1) increasing, so it can implement colorimetric sensing for Fe3+ in the above range. And at the same time its fluorescence intensity significantly decreased, and its fluorescence could be

  17. A rare earth alloy as a synthetic reagent: contrasting homo metallic rare earth and hetero bimetallic outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Deacon, G.B.; Forsyth, C.M.; Junk, P.C.; Leary, S.G. [Monash Univ., School of Chemistry, Clayton (Australia)

    2006-04-15

    Reaction of LaNi{sub 5} with 2,2'-dipyridyl-amine (HNpy{sub 2}) at 170 C under vacuum gave crystals of dimeric [La(Npy{sub 2}){sub 3}]{sub 2} as a previously unknown eight-coordinate isomer (1a) (two {mu}-{eta}{sup 2}:{eta}{sup 2} and two terminal chelating (Namide,Npy) Npy{sub 2} ligands), which reverts to the known ten coordinate isomer (1b) on recrystallization from THF/PhMe, thereby establishing linkage isomerism of a [Ln(Npy{sub 2}){sub 3}]{sub 2} complex for the first time. Reaction of 8-hydroxyquinoline (HOQ) with excess LaNi{sub 5} alloy at 190 C resulted in extraction of both metals and the formation of hetero-bimetallic [Ni{sub 2}La(OQ){sub 7}] (2). The trinuclear complex has two terminal, fac-octahedral nickel(II) sites, each bound to three chelating 8-quinolinolate anions which bridge through the oxygen atoms to the lanthanum(III) centre. The eight-coordinate lanthanum environment is completed by a chelating OQ ligand. (authors)

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

    Directory of Open Access Journals (Sweden)

    Sachin R. Joshi

    2014-09-01

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

  19. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Naeemullah; Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Khan, Sumaira; Arian, Sadaf Sadia; Brahman, Kapil Dev

    2012-01-01

    Cloud point extraction (CPE) has been used for the preconcentration and simultaneous determination of cobalt (Co) and lead (Pb) in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine) as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114), temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS). The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e) was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample. PMID:23227429

  20. Improvement of the cloud point extraction of uranyl ions by the addition of ionic liquids.

    Science.gov (United States)

    Gao, Song; Sun, Taoxiang; Chen, Qingde; Shen, Xinghai

    2013-12-15

    The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

  1. Cloud point extraction-flame atomic absorption spectrometry method for preconcentration and determination of trace cadmium in water samples.

    Science.gov (United States)

    Ning, Jinyan; Jiao, Yang; Zhao, Jiao; Meng, Lifen; Yang, Yaling

    2014-01-01

    A method based on cloud point extraction (CPE) separation/preconcentration of trace cadmium (Cd) as a prior step to its determination by flame atomic absorption spectrometry has been developed. Cadmium reacted with 8-hydroxyquinoline to form hydrophobic chelates, which were extracted into the micelles of nonionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) in an alkaline medium. Octanol was used to depress the cloud point of Genapol X-080 in the extraction process. The chemical variables that affect the CPE, such as pH of complexation reaction, amount of chelating agent, Genapol X-080 and octanol were evaluated and optimized. Under optimized conditions, linearity was obeyed in the range of 10-500 μg/L, with the correlation coefficient of 0.9993. For 5 mL of sample solution, the enhancement factor was about 20. The limit of detection and limit of quantification of the method were 0.21 and 0.63 μg/L, respectively. The relative standard deviations (n = 6) was 3.2% for a solution containing 100 μg/L of Cd. The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. Recoveries of spiked samples varied in the range of 94.1-103.8%.

  2. Cloud point extraction with/without chelating agent on-line coupled with inductively coupled plasma optical emission spectrometry for the determination of trace rare earth elements in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Li Yingjie [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu Bin, E-mail: binhu@whu.edu.cn [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2010-02-15

    The on-line incorporation of cloud point extraction (CPE) with/without 8-hydroxyquinoline (8-Ox) as chelating agent into flow injection analysis associated with inductively coupled plasma optical emission spectrometry (ICP-OES) for determining trace rare earth elements (REEs) is presented and evaluated. The significant parameters affecting on-line cloud point extraction of REEs such as sample pH, flow rate, 8-Ox concentration, Triton X-114 concentration were systematically studied. Under the optimized conditions, with the consumption of 3.0 mL sample solution, the limits of detection (3{sigma}) were ranged from 41.4 pg mL{sup -1} (Yb) to 448 pg mL{sup -1} (Gd) with relative standard deviations (RSDs) of 1.0% (Eu)-5.9% (Sm) for on-line CPE-ICP-OES with 8-Ox as chelating agent, and 69.0 pg mL{sup -1} (Sc) to 509.5 pg mL{sup -1} (Sm) with RSDs of 2.9% (Yb)-7.5% (Ho) for on-line CPE-ICP-OES without 8-Ox as chelating agent, respectively. The sample throughput of 17 samples h{sup -1} was obtained for both systems. The developed methods of on-line CPE-ICP-OES were validated by the analysis of certified reference material (GBW07605, tea leaves) and real biological samples of pig liver, Auricularia auricula and mushroom.

  3. Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry.

    Science.gov (United States)

    Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng; Chen, Jianrong

    2012-11-15

    A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH=7.0, Triton X-114=0.05% (w/v), 8-HQ=2.0×10(-4) mol L(-1), HNO3=0.8 mol L(-1)), the detection limits for Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 μg L(-1), respectively. Relative standard deviation (RSD) values for 10 replicates at 100 μg L(-1) were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion in water samples.

  4. Organic Light Emitting Diodes with p-Si Anodes and Semitransparent Ce/Au Cathodes

    Institute of Scientific and Technical Information of China (English)

    SUN Zhiguo; JIANG Guangzhi

    2011-01-01

    The Ce (x nm)/Au (15 nm) stacked layers were used as semitransparent cathodes in the top-emission organic light emitting devices (TOLEDs) fabricated on a p-type silicon anodes and substrate, where x varies from 4 to 16. The consequence of the Ce layer thickness on transmittance and the device performance were studied when the organic layers NPB (60 nm)/ALQ (60 nm) were kept unchanged, where NPB was N, N,n'-bis-(l-naphthl)-diphenyl-l, 1 '-biphenyl-4, 4'-diamine, and AlQ is tris-(8-hydroxyquinoline) aluminum. The cathode of Ce (11 nm)/Au (15 nm) has a transparency of 46%, and the TOLED with it achieves the highest luminescence efficiencies: a current efficiency of 0.91 cd/A at 13.7 V and a peak power efficiency of 0.28 lm/W at 9 V. The tum-on voltage is 3.0 V. The Ce/Au cathode is both chemically and electrically stable.

  5. Lifetime improvement mechanism in organic light-emitting diodes with mixed materials at a heterojunction interface

    Science.gov (United States)

    Minagawa, Masahiro; Takahashi, Noriko

    2016-02-01

    To investigate the lifetime improvement mechanism caused by mixing at the heterojunction interface, organic light-emitting diodes (OLEDs) with stacked and mixed 4,4‧-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (α-NPD)/tris(8-hydroxyquinoline)aluminum (Alq3) interfaces were fabricated, and changes in their displacement current due to continuous operation were measured. A decrease in accumulated holes at the α-NPD/Alq3 interface was observed in the stacked configuration devices over longer operations. These results indicate that the injected hole density was reduced during continuous operation, implying that the carrier balance became uneven in the emission region. However, few accumulated holes and changes in the displacement current due to continuous operation were observed in the devices having the mixed layer. Therefore, it was deduced that the number of holes concentrated between the α-NPD and Alq3 layers was decreased by mixing at the heterojunction interface, and that the change in the number of holes was smaller during continuous operation, resulting in less degradation.

  6. Influence of Preparation Conditions on Electrical Properties of the Al/Alq3/Si Diode Structures

    Directory of Open Access Journals (Sweden)

    Irina ČERNIUKĖ

    2013-12-01

    Full Text Available Hybrid organic-inorganic diode structures, Al/Alq3/n-Si and Al/Alq3/p-Si based on thin films of tris(8-hydroxyquinoline aluminum (Alq3 have been investigated. The Alq3 films were evaporated in vacuum and spin coated onto patterned areas of crystalline n- and p-type Si substrates with chemically removed native SiO2 layer. Current-voltage characteristics of the diode structures demonstrated improved rectification property compared to similar Al/n-Si and Al/p-Si device structures. Increased barrier height values (0.90 eV ÷ 1.1 eV and 0.77 eV ÷ 0.91 eV for the Al/Alq3/n-Si and Al/Alq3/p-Si device structures, respectively certified presence of an interface dipole induced by the organic interlayer. Non-ideal behavior of forward current-voltage characteristics has been explained assuming non-uniformity of barrier height, presence of interface states, and influence of the organic film on diode series resistance and space charge limited current. DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2733

  7. Effect of different processing methods for the hole transporting layer on the performance of double layer organic light-emitting devices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The hole transporting layer (HTL) of organic light-emitting device (OLED) was processed by vacuum deposition and spin coating method, respectively, where N,N'-biphenyl-N, N'-bis(3-methylphenyl)-1, 1'-biphenyl-4,4' -diamine (TPD) and poly (vinylcarbazole) (PVK) acted as the hole-transport materials. Tris-(8-hydroxyquinoline)- aluminum (Alq3) was utilized as both the light-emitting layer and the electron transporting layer. The basic structure of the device cell was: indium-tin-oxide (ITO)/PVK: TPD/Alq3/Mg:Ag. The electroluminescent (EL) characteristics of devices were characterized. The results showed that the peak of EL spectra was located at 530 nm, which conformed to the characterizing spectrum of Alq3.Compared with using vacuum deposition method, the green emission with a maximum luminance up to 26135 cd/m2 could be achieved at a drive voltage of 15 V by selecting proper solvent using spin-coating technique, and its maximum luminance efficiency was 2.56 lm/W at a drive voltage of 5.5 V.

  8. A New Conducting Polymer Electrode for Organic Electroluminescence Devices

    Institute of Scientific and Technical Information of China (English)

    QU Shu; PENG Jing-Cui

    2008-01-01

    @@ Conducting polymer polydimethylsiloxane (PDMS) is studied for the high performance electrode of organic electroluminescence devices. A method to prepare the electrode consisting of a SiC thin film and PDMS is investigated. By using ultra thin SiC films with different thicknesses, the organic electroluminescenee devices are obtained in an ultra vacuum system with the model device PDMS/SiC/PPV/Alq3, where PPV is poly para-phenylene vinylene and Alq3 is tris(8-hydroxyquinoline) aluminium. The capacitance-voltage (C-V), capacitance-frequency (C-F), current-voltage (I- V), radiation intensity-voltage (R- V) and luminance efficiency-voltage (E-V) measurements are systematically studied to investigate the conductivity, Fermi align-ment and devices properties in organic semiconductors. Scanning Kelvin probe measurement shows that the work function of PDMS/SiC anode with a 2.5-nm SiC over layer can be increased by as much as 0.28eV, compared to the conventional ITO anode. The result is attributed to the charge transfer effect and ohmic contacts at the interface.

  9. Effect of BCP ultrathin layer on the performance of organic light-emitting devices

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; YU Jun-sheng; LI Lu; TANG Xiao-qing; JIANG Ya-dong

    2008-01-01

    Based on conventional double layer device, triple layer organic light-emitting diodes (OLEDs) with two heterostructures of indium-tin oxide (ITO)/N,N'-diphenyl-N,N'-his(1-naphthyl)(1,1'-biphenyl)-4,4'-diamine(NPB)/2,9 -dimethyl-4,7 -diphenyl-1,10-phenanthroline (BCP)/8-Hydroxyquinoline aluminum (Alq3)/Mg:Ag using vacuum deposition method have been fabricated. The influence of different film thickness of BCP layer on the performance of OLEDs has been investigated. The results showed that when the thickness of the BCP layer film gradually varied from 0.1 nm to 4.0 nm, the electrolumines-cence (EL) spectra of the OLEDs shifted from green to greenish-blue to blue, and the BCP layer acted as the recombination region of charge carriers related to EL spectrum, enhancing the brightness and power efficiency. The power efficiency of OLEDs reached as high as 7.3 lm/W.

  10. NÚMERO CROMOSSÔMICO DE Lippia gracilis Schauer (VERBENACEAE OCORRENTES NO ESTADO DO RIO GRANDE DO NORTE, BRASIL

    Directory of Open Access Journals (Sweden)

    LUIS EDUARDO DE SOUSA SOARES

    2011-01-01

    Full Text Available The genus Lippia (Verbenaceae comprises about 200 species of pantropical distribution. Lippia gracilis Schauer, popularly known as the mountain balm, is an aromatic plant, native of northeastern Brazil, used in folk medicine as an antiseptic and to treat dermatitis. Although cytogenetic serve as a tool in taxonomy rate, cytogenetical studies of genus Lippia are restricted. Given the above, the present study aimed to determine, at the first time, the chromosome number of copies of L. gracilis, and thereby contribute to a better taxonomic understanding of this genus. In this sense root tips collected from newly planted specimens were pretreated with a solution of 2mM 8-hydroxyquinoline for 4 hours, fixed in Carnoy 3:1 (ethanol: acetic acid for 24 hours and stored in the same fixative for later analysis. The roots were hydrolyzed in 5N HCl for 20 minutes and the slides, prepared by squashing in acetic acid (45% and stained with 2% Giemsa. The best metaphases were photographed and pointed to the chromosome number 2n = 24. Moreover, were observed metacentric and submetacentric chromosomes. Because there are several chromosome numbers in the genus, from n=10 to n=30, and as the same is little known cytogenetically, f more comprehensive cytogenetic studies are necessary, involving a larger number of species, so these data may help to clarify taxonomic inconsistencies in the family Verbenaceae.

  11. Photophysical properties of Alq3 thin films

    Science.gov (United States)

    Zawadzka, A.; Płóciennik, P.; Strzelecki, J.; Łukasiak, Z.; Sahraoui, B.

    2013-11-01

    This work contains investigation results of the photophysical properties of aluminum (III) tris(8-hydroxyquinoline) thin films. The Alq3 thin films were successfully fabricated by Physical Vapor Deposition technique. The films were grown on transparent: (quartz and glass) and semiconductor (n-type silica) substrates kept at room temperature during the deposition process. Selected films were annealed after fabrication in ambient atmosphere for 12 h at the temperature equal to 100 °C and 150 °C. Morphology of the films was investigated by AFM technique. Photophysical properties were characterized via photoluminescence, transmission, second and third harmonic generation measurements. The thin films exhibit high structural quality regardless of the annealing process, but the stability of the film can be improved by using an appropriate temperature during the annealing process. Photoluminescence of Alq3 films obtained in air were efficient and stable. The measurements of transmission, SHG and THG spectra allowed us to determine optical constant of the films. We find that the photophysical properties were strictly connected with the morphology and the annealing process significantly changes the structural properties of the films.

  12. Transfer of Copper from an Amyloid to a Natural Copper-Carrier Peptide with a Specific Mediating Ligand.

    Science.gov (United States)

    Nguyen, Michel; Bijani, Christian; Martins, Nathalie; Meunier, Bernard; Robert, Anne

    2015-11-16

    The oxidative stress that arises from the catalytic reduction of dioxygen by Cu(II/I)-loaded amyloids is the major pathway for neuron death that occurs in Alzheimer's disease. In this work, we show that bis-8(aminoquinoline) ligands, copper(II) specific chelators, are able to catalytically extract Cu(II) from Cu-Aβ1-16 and then completely release Cu(I) in the presence of glutathione to provide a Cu(I)-glutathione complex, a biological intermediate that is able to deliver copper to apo forms of copper-protein complexes. These data demonstrate that bis-8(aminoquinolines) can perform the transfer of copper ions from the pathological Cu-amyloid complexes to regular copper-protein complexes. These copper-specific ligands assist GSH to recycle Cu(I) in an AD brain and consequently slow down oxidative damage that is due to copper dysregulation in Alzheimer's disease. Under the same conditions, we have shown that the copper complex of PBT2, a mono(8-hydroxyquinoline) previously used as a drug candidate, does not efficiently release copper in the presence of GSH. In addition, we report that GSH itself was unable to fully abstract copper ions from Cu-β-amyloid complexes.

  13. Comparison of organic light emitting diodes with different mixed layer structures

    Energy Technology Data Exchange (ETDEWEB)

    Kee, Y.Y.; Siew, W.O. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya (Malaysia); Yap, S.S. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya (Malaysia); Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Tou, T.Y., E-mail: tytou@mmu.edu.my [Faculty of Engineering, Multimedia University, 63100 Cyberjaya (Malaysia)

    2014-11-03

    A mixed-source thermal evaporation method was used to fabricate organic light emitting diodes (OLEDs) with uniformly mixed (UM), continuously graded mixed (CGM) and step-wise graded, mixed (SGM) light-emitting layers. N,N′-Bis(3-methylphenyl)-N,N′-diphenylbenzidine and Tris-(8-hydroxyquinoline)aluminum were used, respectively, as the hole- and electron-transport materials. As compared to the conventional, heterojunction OLED, the maximum brightness of UM-, CGM- and SGM-OLEDs without charge injection layers were improved by 2.2, 3.8 and 2.1 times, respectively, while the maximum power efficiencies improved by 1.5, 3.2 and 1.9 times. These improvements were discussed in terms of more distributed recombination zone and removal of interfacial barrier. - Highlights: • Fabrication of OLEDs using a mixed-source evaporation technique • Three different types of mixed-host OLEDs with better brightness • Improved electroluminescence and power efficiencies as compared to conventional OLED.

  14. Preparation of gallium-68 radiopharmaceuticals for positron tomography. Progress report, November 1, 1977-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1980-06-01

    Although the germanium-68 ..-->.. gallium-68 generator is probably the only source of positron-emitting radionuclides that could enable the widespread application of positron tomography, the commercially available /sup 68/Ga//sup 68/Ge generator system suffers from several major disadvantages. The most important of these is that the generator is eluted with EDTA, which forms a very strong chelate with gallium. In order to produce radiopharmaceuticals other than /sup 68/Ga-EDTA, it is first necessary to break the stable EDTA complex and remove all traces of EDTA. This procedure adds several steps and a significant amount of time to procedures for preparing /sup 68/Ga-radiopharmaceuticals. We have developed a new generator using a solvent extraction system which will produce /sup 68/Ga-oxine (8-hydroxyquinoline), a weak chelate. Using this agent we have synthesized several /sup 68/Ga-radiopharmaceuticals and tested them in vitro and in vivo. We have also carried out some preliminary studies to compare generator systems which produce /sup 68/Ga in an ionic form. Attempts have been made using polarographic and chromatographic techniques, and in vivo distribution data to investigate the stability of radiogallium complexes with a series of potentially lipophilic complexing agents.

  15. Organic semiconductor/gold interface interactions: from physisorption on planar surfaces to chemical reactions with metal nanoparticles.

    Science.gov (United States)

    Ligorio, Giovanni; Nardi, Marco Vittorio; Christodoulou, Christos; Koch, Norbert

    2015-08-24

    The interaction of gold nanoparticles (AuNPs) with prototypical organic semiconductors used in optoelectronics, namely, tris(8-hydroxyquinoline)aluminium (Alq3 ) and 4,4-bis[N-(1-naphthyl)-N-phenylamino]diphenyl (α-NPD), is investigated in situ by X-ray photoelectron spectroscopy (XPS). These AuNPs-on-molecule experiments are compared with the reversed molecule-on-Au cases. The molecules-on-Au systems show only weak interactions, and the evolution of the XP spectra is dominated by final-state effects. In contrast, in the AuNPs-on-molecules cases, both initial-state effects and final-state effects occur. Spectral features arising for both molecules and metal indicate charge transfer and the formation of organometallic complexes (initial-state effects). The energy shift in the metal emission underlines the size-induced nanometric nature of the molecule/Au interaction (final-state effects). Consequently, the chemical interaction between metals and organic semiconductors likely depends strongly on the deposition sequence in general.

  16. Developing high mobility emissive organic semiconductors towards integrated optoelectronic devices (Conference Presentation)

    Science.gov (United States)

    Dong, Huanli; Hu, Wenping; Heeger, Alan J.

    2016-09-01

    The achievement of organic semiconductors with both high mobility and strong fluorescence emission remains a challenge. High mobility requires molecules which pack densely and periodically, while serious fluorescence quenching typically occurs when fluorescent materials begin to aggregate (aggregation-induced quenching (AIQ)). Indeed, classical materials with strong fluorescent emission always exhibit low mobility, for example, tris(8-hydroxyquinoline) aluminium (ALQ) and phenylenevinylene-based polymers with mobility only 10-6-10-5 cm2V-1s-1, and benchmark organic semiconductors with high mobility demonstrate very weak emission, for example, rubrene exhibits a quantum yield 1% in crystalline state and pentacene shows very weak fluorescence in the solid state. However, organic semiconductors with high mobility and strong fluorescence are necessary for the achievement of high efficiency organic light-emitting transistors (OLETs) and electrically pumped organic lasers. Therefore, it is necessary for developing high mobility emissive organic/polymeric semiconductors towards a fast mover for the organic optoelectronic integrated devices and circuits.

  17. Studies of the enzymic mechanism of the metabolism of diethyl 4-nitrophenyl phosphorothionate (parathion) by rat liver microsomes

    Science.gov (United States)

    Neal, R. A.

    1967-01-01

    1. The metabolism of parathion by rat liver microsomes is affected by various enzyme inhibitors in a manner quite typical of the `mixed-function oxidase' enzyme systems. 2. With many of these inhibitors (p-chloromercuribenzoate, Cu2+, 8-hydroxyquinoline) the conversion of parathion into diethyl hydrogen phosphorothionate is less inhibited than conversion into diethyl 4-nitrophenyl phosphate (paraoxon). 3. Compounds containing reduced sulphur stimulate the overall metabolism of parathion. However, the conversion of parathion into diethyl hydrogen phosphorothionate is stimulated more than its conversion into paraoxon. 4. The metabolism of parathion to diethyl hydrogen phosphorothionate is also stimulated by EDTA, Ca2+ and Ba2+, but these stimulatory effects are not additive. 5. The electron acceptors FAD, riboflavine, menadione and methylene blue exhibit a concentration-dependent differential inhibition of the metabolism of parathion to diethyl hydrogen phosphorothionate and to paraoxon. 6. The concentration of parathion required for the half-maximal rate of production of diethyl hydrogen phosphorothionate is significantly different from the concentration required for half-maximal rate of production of paraoxon. 7. The results are discussed in terms of either two separate enzyme systems metabolizing parathion to diethyl hydrogen phosphorothionate and to paraoxon or two different binding sites for parathion, which share a common electron-transport pathway. PMID:4964764

  18. Mixed-ligand Al complex-a new approach for more high efficient OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, Petia K., E-mail: petia@clf.bas.bg [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Tomova, Reni L.; Stoycheva-Topalova, Rumiana T. [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Kaloyanova, Stefka S.; Deligeorgiev, Todor G. [Applied Organic Chemistry, Faculty of Chemistry, University of Sofia, Sofia 1164 (Bulgaria)

    2012-02-15

    The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq{sub 2}Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq{sub 3}. Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq{sub 3} The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: Black-Right-Pointing-Pointer A novel electroluminescent Alq{sub 2}Acac complex is presented as material for OLED. Black-Right-Pointing-Pointer Electroluminescent emission of Alq{sub 2}Acac is very similar to that of commercial Alq{sub 3}. Black-Right-Pointing-Pointer Devices with Alq{sub 2}Acac show better characteristics compared to those with Alq{sub 3}.

  19. Nanocrystalline Mixed Ligand Complexes of Cu (II, Ni (II, Co (II with N, O Donor Ligands: Synthesis, Characterization, and Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Kolhe Nitin H

    2016-12-01

    Full Text Available In present investigation nanocrystalline mixed ligand complexes were synthesized using 8-hydroxyquinoline, salicylaldoxime with metals like Cu (II, Ni (II and Co (II. The metal: ligand ratio was found to be 1:1:1. These complexes were characterized using electronic spectra, FTIR spectra, elemental analysis, magnetic susceptibility, thermogravimetric analysis, conductivity measurement, powder X-ray diffraction and Scanning Electron Microscopy with electron dispersive spectroscopic methods. The electronic spectra of complexes suggest that they have square planer geometries. In FTIR analysis characteristic bands of ν (M-N and ν (M-O.The Co (II and Cu (II complexes are paramagnetic in nature and these had square planer geometry. While Ni (II complexes are diamagnetic nature and having square planer geometry. The thermal analysis of complexes was studied in an attempt to assign intermediate compounds. Low molar conductance values indicate non – electrolytic nature of the complexes. The Powder X-ray diffraction study shows formation of nanocrystalline phase as well as the grain size of complexes is less than 10 nm. The EDS study is shows good agreement for formation of mixed ligand metal complexes . Complex: [C16H12CuN2O2], [C14H12N2NiO4 ], [C16H12NiN2O2] and [C16H12CoN2O2] had antimicrobial activity against four bacteria tested. Bacteria were resistant to other five complexes.

  20. Application of solid-phase microextraction to the determination of polycyclic aromatic sulfur heterocycles in Bohai Sea crude oils.

    Science.gov (United States)

    Yang, Baijuan; Hou, Wei; Zhang, Kuiying; Wang, Xiaoru

    2013-08-01

    A simple and rapid solid-phase microextraction approach for the isolation of polycyclic aromatic sulfur heterocycles from the aromatic fraction of crude oil is described. 8-Hydroxyquinoline silica gel impregnated with palladium chloride was used as a sorbent material for extraction. Operational parameters of the extraction solvents have been evaluated and optimized. Benzothiophene, dibenzothiophene, and benzo[b]naphtho[1,2-d]thiophene and their C1-C4 alkyl derivatives were identified and quantified by GC-MS. Under optimum conditions, the limits of detection for benzothiophene, dibenzothiophene, and benzo[b]naphtho[1,2-d]thiophene were 0.277, 0.193, and 0.597 μg/g oil, respectively. The recoveries for the polycyclic aromatic sulfur heterocycles ranged from 81.5 to 92.1%, and the linear dynamic range was from 10 to 1000 ng/mL. The developed methodology was tested in the characterization of crude oil samples collected at the DY, SZ, ZH, and HC petroleum oil fields of the Bohai Sea. The results proved that SPE coupled with GC-MS is a promising tool for the quantitative analysis of polycyclic aromatic sulfur heterocycles in crude oils, especially for oil samples with low concentrations of polycyclic aromatic sulfur heterocycles.

  1. The effect of the hole injection layer on the performance of single layer organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Wenjin, Zeng; Ran, Bi; Hongmei, Zhang, E-mail: iamhmzhang@njupt.edu.cn, E-mail: iamwhuang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210023 (China); Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210023 (China); Wei, Huang, E-mail: iamhmzhang@njupt.edu.cn, E-mail: iamwhuang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210023 (China)

    2014-12-14

    Efficient single-layer organic light-emitting diodes (OLEDs) were reported based on a green fluorescent dye 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7–tetramethyl-1H,5H,11H-(1) benzopyropyrano (6,7-8-I,j)quinolizin-11-one (C545T). Herein, poly(3,4-ethylenedioxy thiophene) poly(styrene sulfonate) were, respectively, applied as the injection layer for comparison. The hole transport properties of the emission layer with different hole injection materials are well investigated via current-voltage measurement. It was clearly found that the hole injection layers (HILs) play an important role in the adjustment of the electron/hole injection to attain transport balance of charge carriers in the single emission layer of OLEDs with electron-transporting host. The layer of tris-(8-hydroxyquinoline) aluminum played a dual role of host and electron-transporting materials within the emission layer. Therefore, appropriate selection of hole injection layer is a key factor to achieve high efficiency OLEDs with single emission layer.

  2. Optically Active Charge Transfer in Hybrids of Alqsub>3sub> Nanoparticles and MoSsub>2sub> Monolayer.

    Science.gov (United States)

    Ghimire, Ganesh; Dhakal, Krisnhna; Neupane, Guru; Jo, Seong Gi; Kim, Hyun; Seo, Changwon; Lee, Young; Joo, Jinsoo; Kim, Jeongyong

    2017-03-20

    Organic/inorganic hybrid structures have been widely studied because of their enhanced physical and chemical properties. Monolayers of transition metal dichalcogenides (1L-TMDs) and organic nanoparticles can provide a hybridization configuration between zero- and two-dimensional systems with the advantages of convenient preparation and strong interface interaction. Here, we present such a hybrid system made by dispersing π-conjugated organic (tris(8-hydroxyquinoline)aluminum(III)) (Alqsub>3sub>) nanoparticles (NPs) on 1L-MoSsub>2sub>. Hybrids of Alqsub>3sub> NP/1L-MoSsub>2sub> exhibited a two-fold increase in the photoluminescence of Alqsub>3sub> NPs on 1L-MoSsub>2sub> and the n-doping effect of 1L-MoSsub>2sub>, and these spectral and electronic modifications were attributed to the charge transfer between Alqsub>3sub> NPs and 1L-MoSsub>2sub>. Our results suggested that a hybrid of organic NPs/1L-TMD can offer a convenient platform to study the interface interactions between organic and inorganic nano objects and to engineer optoelectronic devices with enhanced performance.

  3. The solution structure of the copper clioquinol complex.

    Science.gov (United States)

    Pushie, M Jake; Nienaber, Kurt H; Summers, Kelly L; Cotelesage, Julien J H; Ponomarenko, Olena; Nichol, Helen K; Pickering, Ingrid J; George, Graham N

    2014-04-01

    Clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) recently has shown promising results in the treatment of Alzheimer's disease and in cancer therapy, both of which also are thought to be due to clioquinol's ability as a lipophilic copper chelator. Previously, clioquinol was used as an anti-fungal and anti-protozoal drug that was responsible for an epidemic of subacute myelo-optic neuropathy (SMON) in Japan during the 1960s, probably a myeloneuropathy arising from a clioquinol-induced copper deficiency. Previous X-ray absorption spectroscopy of solutions of copper chelates of clioquinol suggested unusual coordination chemistry. Here we use a combination of electron paramagnetic, UV-visible and X-ray absorption spectroscopies to provide clarification of the chelation chemistry between clioquinol and copper. We find that the solution structures for the copper complexes formed with stoichiometric and excess clioquinol are conventional 8-hydroxyquinolate chelates. Thus, the promise of clioquinol in new treatments for Alzheimer's disease and in cancer therapy is not likely to be due to any novel chelation chemistry, but rather due to other factors including the high lipophilicity of the free ligand and chelate complexes.

  4. Utilization of TiO2 deposited on glass plates for removal of metals from aqueous wastes

    Science.gov (United States)

    Hilmi; Luong; Nguyen

    1999-02-01

    Glass plates coated with TiO2 were used in a photocatalytic process to collect mercury, lead, copper and cadmium from aqueous solutions containing individual metals and mixtures. Stripping voltammetry, verified to achieve 1-10 ppb detection limits, was used to show that individual metals at concentrations of 1000 to 5200 ppb were reduced to undetectable levels in 3 to 55 min. Capillary electrophoresis (CE) with 8-hydroxyquinoline-5-sulfonic acid as complexing agent was used when appropriate, since it could quantitate all four metals under study in one run although it was less sensitive. It was demonstrated that 100 mL solutions containing 10 ppm of each of the four metals could be treated with a 10 cm2 TiO2-coated plate to leave undetectable metal concentrations in one hour. Stripping voltammetry using carbon electrodes coated with mercury films was estimated to generate daily about 1.1 L of aqueous waste containing 0.1 ppm of each metal. The results indicate the feasibility of assembling an apparatus capable of treating the waste generated by stripping voltammetry to render the latter suitable for routine on-site analyses without environmental concern. Data were also obtained to show the effectiveness in treating silver containing solutions, indicating suitability of the photocatalytic process in treating photographic processing wastes.

  5. Validated spectophotometric methods for the assay of cinitapride hydrogen tartrate in pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Satyanarayana K.V.V.

    2013-01-01

    Full Text Available Three simple, selective and rapid spectrophotometric methods have been established for the determination of cinitapride hydrogen tartrate (CHT in pharmaceutical tablets. The proposed methods are based on the diazotization of CHT with sodium nitrite and hydrochloric acid, followed by coupling with resorcinol, 1-benzoylacetone and 8-hydroxyquinoline in alkaline medium for methods A, B and C respectively. The formed azo dyes are measured at 442, 465 and 552 nm for methods A, B and C respectively. The parameters that affect the reaction were carefully optimized. Under optimum conditions, Beer’s law is obeyed over the ranges 2.0-32.0, 1.0-24.0 and 1.0-20.0 μg. mL-1 for methods A, B, and C, respectively. The calculated molar absorptivity values are 1.2853 x104, 1.9624 x104 and 3.92 x104 L.mol-1.cm-1 for methods A, B and C, respectively. The results of the proposed procedures were validated statistically according to ICH guidelines. The proposed methods were successfully applied to the determination of CHT in Cintapro tablets without interference from common excipients encountered.

  6. Efficient Biomimetic Hydroxylation Catalysis with a Bis(pyrazolyl)imidazolylmethane Copper Peroxide Complex.

    Science.gov (United States)

    Wilfer, Claudia; Liebhäuser, Patricia; Hoffmann, Alexander; Erdmann, Hannes; Grossmann, Oleg; Runtsch, Leander; Paffenholz, Eva; Schepper, Rahel; Dick, Regina; Bauer, Matthias; Dürr, Maximilian; Ivanović-Burmazović, Ivana; Herres-Pawlis, Sonja

    2015-12-01

    Bis(pyrazolyl)methane ligands are excellent components of model complexes used to investigate the activity of the enzyme tyrosinase. Combining the N donors 3-tert-butylpyrazole and 1-methylimidazole results in a ligand that is capable of stabilising a (μ-η(2) :η(2) )-dicopper(II) core that resembles the active centre of tyrosinase. UV/Vis spectroscopy shows blueshifted UV bands in comparison to other known peroxo complexes, due to donor competition from different ligand substituents. This effect was investigated with the help of theoretical calculations, including DFT and natural transition orbital analysis. The peroxo complex acts as a catalyst capable of hydroxylating a variety of phenols by using oxygen. Catalytic conversion with the non-biological phenolic substrate 8-hydroxyquinoline resulted in remarkable turnover numbers. In stoichiometric reactions, substrate-binding kinetics was observed and the intrinsic hydroxylation constant, kox , was determined for five phenolates. It was found to be the fastest hydroxylation model system determined so far, reaching almost biological activity. Furthermore, Hammett analysis proved the electrophilic character of the reaction. This sheds light on the subtle role of donor strength and its influence on hydroxylation activity.

  7. Vegetative propagation of the Azorean endemic shrub Viburnum treleasei Gand

    Directory of Open Access Journals (Sweden)

    MÓNICA MOURA

    2009-01-01

    Full Text Available Viburnum treleasei Gand. is a threatened hermaphroditic shrub or small tree endemic to the Azores islands. In this study we aimed at defining a fast, simple and cost-efficient propagation methodology that could be used by non-skilled workers in conservation actionplans. Our objective was also to produce cleaner material for initiation of in vitro cultures and to determine the effects of season, placement of cuttings in the branch, placement of vegetative buds in cuttings and forcing solutions in shoot development. It was possible to produce clean shoots from cuttings using a forcing solution with 8-hydroxyquinoline sulphate (8-HQS, 2% sucrose and no growth regulators addition. Shoot development results obtained with apical and sub-apical cuttings indicate that V. treleasei possessesapical dominance and deep endodormancy. Apical semihardwood cuttings in autumn or airlayered branches in autumn and winter with 2 or 5% (w/w of IBA produced excellent rooting results which will allow reinforcing depleted populations of V. treleasei efficientlyand at reduced costs.

  8. Isolation and selection of fluorescent pseudomonads based on multiple plant growth promotion traits and siderotyping

    Directory of Open Access Journals (Sweden)

    Jayamohan Subramanian

    2014-09-01

    Full Text Available Fluorescent pseudomonads, acclaimed plant associated bacterial group, are well-known plant growth promoting-biocontrol agents in rhizosphere arena. In this study, 144 fluorescent pseudomonad isolates from rhizosphere soil samples were screened with King's medium B supplemented with 8-hydroxyquinoline (8-HQ chelator and comprehensively profiled for plant growth promotion viz., production of indole acetic acid (IAA, siderophore, ammonia, hydrogen cyanide, motility, phosphate solubilization, root growth promotion, and biofilm forming ability, along with two known control strains of pseudomonads. Iron and IAA regulated secondary metabolite siderophore production were investigated quantitatively. All isolates were positive for ammonia production and motility; 46% isolates were positive for hydrogen cyanide, 44% shown positivity for phosphate solubilization, and 40% isolates for siderophore production. Siderotyping showed production of hydroxamate type of siderophores which are known to be more efficient biocontrol agents. All isolates stimulated root growth to varying extent and had potentiality to form biofilms, a critical constituent for survival on different environments. Forty-two isolates of pseudomonads showed antagonistic behavior against the deleterious fungal pathogen Fusarium oxysporum (MTCC1755. Based on the above observations and statistical analysis, 11 isolates were shortlisted for further scrutiny. The study of biogeographic correlation and secondary metabolite profiling in association with plant growth promotion focalizes significant assessment on the behavior and antagonistic action, which probably brings out a competent biocontrol agent in a sustainable eco-friendly dimension.

  9. Light emission in forward and reverse bias operation in OLED with amorphous silicon carbon nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R [Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Av. Tupac Amaru SN, Lima (Peru); Cremona, M [Departamento de Fisica, PontifIcia Universidade Catolica de Rio de Janeiro, PUC-Rio, Cx. Postal 38071, Rio de Janeiro, RJ, CEP 22453-970 (Brazil); Achete, C A, E-mail: rreyes@uni.edu.pe [Departamento de Engenheria Metalurgica e de Materiais, Universidade Federal do Rio de Janeiro, Cx. Postal 68505, Rio de Janeiro, RJ, CEP 21945-970 (Brazil)

    2011-01-01

    Amorphous silicon carbon nitride (a-SiC:N) thin films deposited by magnetron sputtering were used in the structure of an organic light emitting diode (OLED), obtaining an OLED operating in forward and reverse bias mode. The device consist of the heterojunction structure ITO/a-SiC:N/Hole Transport Layer (HTL)/ Electron Transport Layer (ETL)/a-SiC:N/Al. As hole transporting layer was used a thin film of 1-(3-methylphenyl)-1,2,3,4 tetrahydroquinoline - 6 - carboxyaldehyde - 1,1'- diphenylhydrazone (MTCD), while the tris(8-hydroxyquinoline aluminum) (Alq{sub 3}) is used as electron transport and emitting layer. A significant increase in the voltage operation compared to the conventional ITO/MTCD/Alq{sub 3}/Al structure was observed, so the onset of electroluminescence occurs at about 22 V in the forward and reverse bias mode of operation. The electroluminescence spectra is similar in both cases, only slightly shifted 0.14 eV to lower energies in relation to the conventional device.

  10. Molecular electrophosphorescence in (Sm, Gd)-{beta}-diketonate complex blend for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R., E-mail: fisicaplic@hotmail.com [Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, UNI, Av. Tupac Amaru 210, Lima 31, Peru (Peru); Cremona, M. [DIMAT - Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, INMETRO, Duque de Caxias, RJ (Brazil); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, PUC-Rio, C.P. 38071, Rio de Janeiro, RJ, CEP 22453-970 (Brazil); Teotonio, E.E.S. [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, UFPB, C.P. 5093, Joao Pessoa, PB, CEP 5805-970 (Brazil); Brito, H.F. [Instituto de Quimica, Universidade de Sao Paulo, USP, C.P. 26077, Sao Paulo, SP, CEP 05599-970 (Brazil); Malta, O.L. [Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco, Cidade Universitaria, Recife, PE, CEP 50670-901 (Brazil)

    2013-02-15

    In this work the preparation and characterization of the triple-layer organic light-emitting diode (OLED) using a mixture of the samarium and gadolinium {beta}-diketonate complexes [Sm{sub 0.5}Gd{sub 0.5}(TTA){sub 3}(TPPO){sub 2}] as emitting layer is reported. The OLED's devices contain 1-(3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1, 1'-diphenylhydrazone (MTCD) as hole-transporting layer and tris(8-hydroxyquinoline aluminum) (Alq{sub 3}) as electron transporting layer. The electroluminescence spectrum present emission narrow bands from the {sup 4}G{sub 5/2}{yields}{sup 6}H{sub J} transitions (where J=5/2, 7/2 and 9/2) characteristic of the Sm{sup 3+} ion. These sharp lines are overlapped with a broad band attributed to the electrophosphorescence from the T{sub 1}{yields}S{sub 0} transition in the ligand TTA. The intramolecular energy transfer is discussed and applied on the change of the emission color of the organic LEDs at different bias voltages. - Highlights: Black-Right-Pointing-Pointer Samarium and gadolinium complexes. Black-Right-Pointing-Pointer OLED with complex blend (Sm,Gd). Black-Right-Pointing-Pointer Electrophosphorescence emission detection. Black-Right-Pointing-Pointer Application in OLED changing the color emission.

  11. Chelating polymeric beads as potential therapeutics for Wilson's disease.

    Science.gov (United States)

    Mattová, Jana; Poučková, Pavla; Kučka, Jan; Skodová, Michaela; Vetrík, Miroslav; Stěpánek, Petr; Urbánek, Petr; Petřík, Miloš; Nový, Zbyněk; Hrubý, Martin

    2014-10-01

    Wilson's disease is a genetic disorder caused by a malfunction of ATPase 7B that leads to high accumulation of copper in the organism and consequent toxic effects. We propose a gentle therapy to eliminate the excessive copper content with oral administration of insoluble non-resorbable polymer sorbents containing selective chelating groups for copper(II). Polymeric beads with the chelating agents triethylenetetramine, N,N-di(2-pyridylmethyl)amine, and 8-hydroxyquinoline (8HQB) were investigated. In a preliminary copper uptake experiment, we found that 8HQB significantly reduced copper uptake (using copper-64 as a radiotracer) after oral administration in Wistar rats. Furthermore, we measured organ radioactivity in rats to demonstrate that 8HQB radiolabelled with iodine-125 is not absorbed from the gastrointestinal tract after oral administration. Non-resorbability and the blockade of copper uptake were also confirmed with small animal imaging (PET/CT) in mice. In a long-term experiment with Wistar rats fed a diet containing the polymers, we have found that there were no signs of polymer toxicity and the addition of polymers to the diet led to a significant reduction in the copper contents in the kidneys, brains, and livers of the rats. We have shown that polymers containing specific ligands could potentially be novel therapeutics for Wilson's disease.

  12. Microextraction Methods for Preconcentration of Aluminium in Urine Samples

    Directory of Open Access Journals (Sweden)

    Farzad Farajbakhsh, Mohammad Amjadi, Jamshid Manzoori, Mohammad R. Ardalan, Abolghasem Jouyban

    2016-07-01

    Full Text Available Background: Analysis of aluminium (Al in urine samples is required in management of a number of diseases including patients with renal failure. This work aimed to present dispersive liquid-liquid microextraction (DLLME and ultrasound-assisted emulsification microextraction (USAEME methods for the preconcentration of ultra-trace amount of aluminum in human urine prior to its determination by a graphite furnace atomic absorption spectrometry (GFAAS. Methods: The microextraction methods were based on the complex formation of Al3+ with 8-hydroxyquinoline. The effect of various experimental parameters on the efficiencies of the methods and their optimum values were studied. Results: Under the optimal conditions, the limits of detection for USAEME-GFAAS and DLLME-GFAAS were 0.19 and 0.30 ng mL−1, respectively and corresponding relative standard deviations (RSD, n=5 for the determination of 40 ng mL−1 Al3+ were 5.9% and 4.9%. Conclusion: Both methods could be successfully used to the analysis of ultra trace concentrations of Al in urine samples of dialysis patients.

  13. Six Zn(II) and Cd(II) coordination polymers assembled from a similar binuclear building unit: tunable structures and luminescence properties.

    Science.gov (United States)

    Zhang, Liyan; Rong, Lulu; Hu, Guoli; Jin, Suo; Jia, Wei-Guo; Liu, Ji; Yuan, Guozan

    2015-04-21

    Six Zn(ii) and Cd(ii) coordination polymers were constructed by treating a 2-substituted 8-hydroxyquinolinate ligand containing a pyridyl group with zinc or cadmium salts, and characterized by a variety of techniques. Interestingly, based on a similar binuclear Zn(ii) or Cd(ii) building unit, the supramolecular structures of the six coordination polymers () exhibit an unprecedented structural diversification due to the different choices of metal salts. and represent a novel 2D framework containing 1D infinite right- and left-handed helical chains. and are 2D coordination frameworks based on binuclear Cd(ii) building units. For and , the L ligands can bridge binuclear building units forming a 1D infinite chain. Interestingly, the adjacent Cd2O2 planes of the 1D chain in are in parallel with each other, while the dihedral angle between the two Zn2O2 planes in is 83.43°. Photoluminescence properties revealed that the six coordination polymers exhibit redshifted emission maximum compared with the free ligand HL, which can be ascribed to an increased conformational rigidity and the fabrication of coplanar binuclear building units M2L2 in . Coordination polymers also display distinct fluorescence lifetimes and quantum yields because of their different metal centers and supramolecular structures.

  14. Synthesis and investigation of antimicrobial activity and spectrophotometric and dyeing properties of some novel azo disperse dyes based on naphthalimides.

    Science.gov (United States)

    Shaki, Hanieh; Gharanjig, Kamaladin; Khosravi, Alireza

    2015-01-01

    A series of novel disperse dyes containing azo group were synthesized through a diazotization and coupling process. The 4-amino-N-2-aminomethylpyridine-1,8-naphthalimide was diazotized by nitrosylsulphuric acid and coupled with various aromatic amines such as N,N-diethylaniline, N,N-dihydroxyethylaniline, 8-hydroxyquinoline, and 2-methylindole. Chemical structures of the synthesized dyes were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), proton nuclear magnetic resonance ((1) H NMR), carbon nuclear magnetic resonance ((13) C NMR), elemental analysis, and ultraviolet-visible (UV-visible) spectroscopy. The spectrophotometric data of all dyes were evaluated in various solvents with different polarity. Eventually, the dyes were applied on polyamide fabrics in order to investigate their dyeing properties. The fastness properties of the dyed fabrics such as wash, light, and rubbing fastness degrees were measured by standard methods. Moreover, the color gamut of the synthesized dyes was measured on polyamide fabrics. Results indicated that some of the synthesized dyes were able to dye polyamide fabrics with deep shades. They had very good wash and rubbing fastness degrees and moderate-to-good light fastness on polyamide fabrics. The antibacterial and antifungal activities of the synthesized dyes were evaluated in soluble state and on the dyed fabrics. The results indicated that dye 2 containing N,N-dihydroxyethylaniline as coupler had the highest activity against all the bacteria and fungi used.

  15. Ligand substitution reactions of a phenolic quinolyl hydrazone; oxidovanadium (IV complexes

    Directory of Open Access Journals (Sweden)

    Seleem Hussein S

    2011-08-01

    Full Text Available Abstract Background Quinoline ring has therapeutic and biological activities. Quinolyl hydrazones constitute a class of excellent chelating agents. Recently, the physiological and biological activities of quinolyl hydrazones arise from their tendency to form metal chelates with transition metal ions. In this context, we have aimed to study the competency effect of a phenolic quinolyl hydrazone (H2L; primary ligand with some auxiliary ligands (Tmen, Phen or Oxine; secondary ligands towards oxidovanadium (IV ions. Results Mono- and binuclear oxidovanadium (IV - complexes were obtained from the reaction of a phenolic quinolyl hydrazone with oxidovanadium (IV- ion in absence and presence of N,N,N',N'- tetramethylethylenediamine (Tmen, 1,10-phenanthroline (Phen or 8-hydroxyquinoline (Oxine. The phenolic quinolyl hydrazone ligand behaves as monobasic bidentate (NO- donor with O- bridging. All the obtained complexes have the preferable octahedral geometry except the oxinato complex (2 which has a square pyramid geometry with no axial interaction; the only homoleptic complex in this study. Conclusion The ligand exchange (substitution/replacement reactions reflect the strong competency power of the auxiliary aromatic ligands (Phen/Oxine compared to the phenolic quinolyl hydrazone (H2L towards oxidovanadium (IV ion; (complexes 2 and 3. By contrast, in case of the more flexible aliphatic competitor (Tmen, an adduct was obtained (4. The obtained complexes reflect the strength of the ligand field towards the oxidovanadium (IV- ion; Oxine or Phen >> phenolic hydrazone (H2L > Tmen.

  16. Investigation of iron(III) reduction and trace metal interferences in the determination of dissolved iron in seawater using flow injection with luminol chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Ussher, Simon J. [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Milne, Angela [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320 (United States); Landing, William M. [Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320 (United States); Attiq-ur-Rehman, Kakar [Department of Chemistry, University of Balochistan, Quetta (Pakistan); Seguret, Marie J.M.; Holland, Toby [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Achterberg, Eric P. [National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH (United Kingdom); Nabi, Abdul [Department of Chemistry, University of Balochistan, Quetta (Pakistan); Worsfold, Paul J., E-mail: pworsfold@plymouth.ac.uk [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2009-10-12

    A detailed investigation into the performance of two flow injection-chemiluminescence (FI-CL) manifolds (with and without a preconcentration column) for the determination of sub-nanomolar dissolved iron (Fe(II) + Fe(III)), following the reduction of Fe(III) by sulphite, in seawater is described. Kinetic experiments were conducted to examine the efficiency of reduction of inorganic Fe(III) with sulphite under different conditions and a rigorous study of the potential interference caused by other transition metals present in seawater was conducted. Using 100 {mu}M concentrations of sulphite a reduction time of 4 h was sufficient to quantitatively reduce Fe(III) in seawater. Under optimal conditions, cobalt(II) and vanadium(IV)/(III) were the major positive interferences and strategies for their removal are reported. Specifically, cobalt(II) was masked by the addition of dimethylglyoxime to the luminol solution and vanadium(IV) was removed by passing the sample through an 8-hydroxyquinoline column in a low pH carrier stream. Manganese(II) also interfered by suppression of the CL response but this was not significant at typical open ocean concentrations.

  17. Iron-chelating backbone coupled with monoamine oxidase inhibitory moiety as novel pluripotential therapeutic agents for Alzheimer's disease: a tribute to Moussa Youdim.

    Science.gov (United States)

    Weinreb, Orly; Mandel, Silvia; Bar-Am, Orit; Amit, Tamar

    2011-03-01

    It is for these authors a great privilege to dedicate this review article to Moussa Youdim, who is one of the most imperative pharmacologists and pioneer investigators in the search and development of novel therapeutics for neurodegenerative diseases. 40 years ago, Moussa Youdim has started studying brain iron, catecholamine receptor and monoamine oxidase (MAO)-A and -B functions. Although Moussa Youdim succeeded in exploring the novel anti-Parkinsonian, selective MAO-B inhibitor drug, rasagiline (Azilect, Teva Pharmaceutical Co.), he did not stop searching for superior therapeutic approaches for neurodegenerative disorders. To date, Moussa Youdim and his research group are designing and synthesizing pluripotential drug candidates possessing diverse pharmacological properties that can act on multiple targets and pathological features ascribed to Parkinson's disease, Alzheimer's disease (AD) and amyotrophic lateral sclerosis. One such example is the multimodal non-toxic, brain-permeable iron-chelating compound, M30 (5-[N-methyl-N-propargylaminomethyl]-8-hydroxyquinoline), which amalgamates the propargyl moiety of rasagiline with the backbone of the potent iron chelator, VK28. This review discusses the multiple effects of several leading compounds of this series, concerning their neuroprotective/neurorestorative molecular mechanisms in vivo and in vitro, with a special focus on the pathological features ascribed to AD, including antioxidant and iron chelating activities, regulation of amyloid precursor protein and amyloid β peptide expression processing, activation of pro-survival signaling pathways and regulation of cell cycle and neurite outgrowth.

  18. Brain catalase in the streptozotocin-rat model of sporadic Alzheimer's disease treated with the iron chelator-monoamine oxidase inhibitor, M30.

    Science.gov (United States)

    Sofic, E; Salkovic-Petrisic, M; Tahirovic, I; Sapcanin, A; Mandel, S; Youdim, M; Riederer, P

    2015-04-01

    Low intracerebroventricular (icv) doses of streptozotocin (STZ) produce regionally specific brain neurochemical changes in rats that are similar to those found in the brain of patients with sporadic Alzheimer's disease (sAD). Since oxidative stress is thought to be one of the major pathologic processes in sAD, catalase (CAT) activity was estimated in the regional brain tissue of animals treated intracerebroventricularly with STZ and the multitarget iron chelator, antioxidant and MAO-inhibitor M30 [5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline]. Five-day oral pre-treatment of adult male Wistar rats with 10 mg/kg/day M30 dose was followed by a single injection of STZ (1 mg/kg, icv). CAT activity was measured colorimetrically in the hippocampus (HPC), brain stem (BS) and cerebellum (CB) of the control, STZ-, M30- and STZ + M30-treated rats, respectively, 4 weeks after the STZ treatment. STZ-treated rats demonstrated significantly lower CAT activity in all three brain regions in comparison to the controls (p iron chelators such as M30 might also have beneficial effects in this non-transgenic sAD model.

  19. Improving efficiency of organic light-emitting devices by optimizing the LiF interlayer in the hole transport layer

    Institute of Scientific and Technical Information of China (English)

    Jiauo Zhi-Qiang; Wu Xiao-Ming; Hua Yu-Lin; Dong Mu-Sen; Su Yue-Ju; Shen Li-Ying; Yin Shou-Gen

    2011-01-01

    The efficiency of organic light-emitting devices (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-N,l' biphenyl-4,4'-diamine (NPB) (the hole transport layer) and tris(8-hydroxyquinoline) aluminum (Alq3) (both emission and electron transport layers) is improved remarkably by inserting a LiF interlayer into the hole transport layer.This thin LiF interlayer can effectively influence electrical performance and significantly improve the current efficiency of the device.A device with an optimum LiF layer thickness at the optimum position in NPB exhibits a maximum current efficiency of 5.96 cd/A at 215.79 mA/cm2,which is about 86% higher than that of an ordinary device (without a LiF interlayer,3.2 cd/A).An explanation can be put forward that LiF in the NPB layer can block holes and balance the recombination of holes and electrons.The results may provide some valuable references for improving OLED current efficiency.

  20. Iron Chelators and Antioxidants Regenerate Neuritic Tree and Nigrostriatal Fibers of MPP+/MPTP-Lesioned Dopaminergic Neurons.

    Directory of Open Access Journals (Sweden)

    Pabla Aguirre

    Full Text Available Neuronal death in Parkinson's disease (PD is often preceded by axodendritic tree retraction and loss of neuronal functionality. The presence of non-functional but live neurons opens therapeutic possibilities to recover functionality before clinical symptoms develop. Considering that iron accumulation and oxidative damage are conditions commonly found in PD, we tested the possible neuritogenic effects of iron chelators and antioxidant agents. We used three commercial chelators: DFO, deferiprone and 2.2'-dypyridyl, and three 8-hydroxyquinoline-based iron chelators: M30, 7MH and 7DH, and we evaluated their effects in vitro using a mesencephalic cell culture treated with the Parkinsonian toxin MPP+ and in vivo using the MPTP mouse model. All chelators tested promoted the emergence of new tyrosine hydroxylase (TH-positive processes, increased axodendritic tree length and protected cells against lipoperoxidation. Chelator treatment resulted in the generation of processes containing the presynaptic marker synaptophysin. The antioxidants N-acetylcysteine and dymetylthiourea also enhanced axodendritic tree recovery in vitro, an indication that reducing oxidative tone fosters neuritogenesis in MPP+-damaged neurons. Oral administration to mice of the M30 chelator for 14 days after MPTP treatment resulted in increased TH- and GIRK2-positive nigra cells and nigrostriatal fibers. Our results support a role for oral iron chelators as good candidates for the early treatment of PD, at stages of the disease where there is axodendritic tree retraction without neuronal death.

  1. ATOX1 gene silencing increases susceptibility to anticancer therapy based on copper ionophores or chelating drugs.

    Science.gov (United States)

    Barresi, Vincenza; Spampinato, Giorgia; Musso, Nicolò; Trovato Salinaro, Angela; Rizzarelli, Enrico; Condorelli, Daniele Filippo

    2016-03-01

    Copper is a catalytic cofactor required for the normal function of many enzymes involved in fundamental biological processes but highly cytotoxic when in excess. Therefore its homeostasis and distribution is strictly regulated by a network of transporters and intracellular chaperones. ATOX1 (antioxidant protein 1) is a copper chaperone that plays a role in copper homeostasis by binding and transporting cytosolic copper to ATPase proteins in the trans-Golgi network. In the present study the Caco-2 cell line, a colon carcinoma cell line, was used as an in vitro model to evaluate if ATOX1 deficiency could affect sensitivity to experimentally induced copper dyshomeostasis. Silencing of ATOX1 increased toxicity of a short treatment with a high concentration of Cu(2+). Copper ionophores, such as 5-chloro-8-hydroxyquinoline, induced a copper-dependent cell toxicity which was significantly potentiated after ATOX1 silencing. The copper chelator TPEN (N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine) produced a form of cell toxicity that was reversed by the addition of Cu(2+). ATOX1 silencing increased Caco-2 cell sensitivity to TPEN toxicity. Our results suggest the possibility of a therapy with copper-chelating or ionophore drugs in subtypes of tumors showing specific alterations in ATOX1 expression.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-15

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

  3. Strong Photo-Amplification Effects in Flexible Organic Capacitors with Small Molecular Solid-State Electrolyte Layers Sandwiched between Photo-Sensitive Conjugated Polymer Nanolayers

    Science.gov (United States)

    Lee, Hyena; Kim, Jungnam; Kim, Hwajeong; Kim, Youngkyoo

    2016-02-01

    We demonstrate strong photo-amplification effects in flexible organic capacitors which consist of small molecular solid-state electrolyte layers sandwiched between light-sensitive conjugated polymer nanolayers. The small molecular electrolyte layers were prepared from aqueous solutions of tris(8-hydroxyquinoline-5-sulfonic acid) aluminum (ALQSA3), while poly(3-hexylthiophene) (P3HT) was employed as the light-sensitive polymer nanolayer that is spin-coated on the indium-tin oxide (ITO)-coated poly(ethylene terephthalate) (PET) film substrates. The resulting capacitors feature a multilayer device structure of PET/ITO/P3HT/ALQSA3/P3HT/ITO/PET, which were mechanically robust due to good adhesion between the ALQSA3 layers and the P3HT nanolayers. Results showed that the specific capacitance was increased by ca. 3-fold when a white light was illuminated to the flexible organic multilayer capacitors. In particular, the capacity of charge storage was remarkably (ca. 250-fold) enhanced by a white light illumination in the potentiostatic charge/discharge operation, and the photo-amplification functions were well maintained even after bending for 300 times at a bending angle of 180o.

  4. Binary and ternary copper(II) complexes of a tridentate ONS ligand derived from 2-aminochromone-3 carboxaldehyde and thiosemicarbazide: Synthesis, spectral studies and antimicrobial activity

    Science.gov (United States)

    Shebl, Magdy; Ibrahim, M. A.; Khalil, Saied M. E.; Stefan, S. L.; Habib, H.

    2013-11-01

    A tridentate ONS donor ligand, HL, was synthesized by the condensation of 2-aminochromone-3-carboxaldehyde with thiosemicarbazide. The structure of the ligand was elucidated by elemental analyses, IR, 1H and 13C NMR, electronic and mass spectra. Reaction of the ligand with several copper(II) salts, including AcO-, NO3-, SO42-, Cl-, Br- and ClO4- afforded different metal complexes that reflect the non-coordinating or weakly coordinating power of the ClO4- and Br- anions as compared to the strongly coordinating power of AcO-, SO42-, Cl- and NO3- anions. Also, the ligand was allowed to react with Cu(II) ion in the presence of a secondary ligand (L‧) [N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline]. Characterization and structure elucidation of the prepared complexes were achieved by elemental and thermal analyses, IR, electronic, mass and EPR spectra as well as conductivity and magnetic susceptibility measurements. The EPR spin Hamiltonian parameters of some complexes were calculated. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. The ligand and most of its metal complexes showed antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  5. Structural diversity in binuclear complexes of alkaline earth metal ions with 4,6-diacetylresorcinol

    Science.gov (United States)

    Shebl, Magdy; Khalil, Saied M. E.; Taha, A.; Mahdi, M. A. N.

    2012-11-01

    A new series of binuclear and mixed-ligand complexes with the general formula: [M 2(LO)yClz]; where M = Mg(II), Ca(II), Sr(II) and Ba(II); H2L = 4,6-diacetylresorcinol, the secondary ligand L' = acetylacetone (acac), 8-hydroxyquinoline (8-HQ) or 2,2'-bipyridyl (Bipy), n = 0-2, m = 1, 2, x = 0, 1, 2, 4, y = 0, 2, 4, 5 and z = 0-2; have been synthesized. They have been characterized by the analytical and spectral methods (IR, 1H NMR and mass) as well as TGA and molar conductivity measurements. The spectroscopic and conductance data suggested that the H2L ligand behaves as a neutral, monobasic or dibasic tetradentate ligand, depending on the basicity of the secondary ligand, through the two phenolic and two carbonyl groups. Binuclear octahedral geometry has been assigned to all of the prepared complexes in various molar ratios 2:2; 2:2:2; 1:2:1 and 1:2:4 (L:M:L'). Molecular orbital calculations were performed for the ligands and their complexes using Hyperchem 7.52 program on the bases of PM3 level and the results were correlated with the experimental data. The ligand and some of its alkaline metal(II) complexes showed antibacterial activity towards some of Gram-positive and Gram-negative bacteria, yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  6. Experimental and theoretical study of hydroxyquinolines: hydroxyl group position dependent dipole moment and charge-separation in the photoexcited state leading to fluorescence

    Science.gov (United States)

    Singh Mehata, Mohan; Singh, Ajay K.; Sinha, Ravindra Kumar

    2016-12-01

    Optical absorption and fluorescence (FL) spectra of 2-, 6-, 7-, 8-hydroxyquinolines (2-,6-,7- and 8-HQs) have been measured at room temperature in the wide range of solvents of different polarities, dielectric constant and refractive index. The ground state dipole moment (µ g) and excited state dipole moment (µ e) of 2-, 6-, 7- and 8-HQs were obtained using solvatochromic shift (SS) methods and microscopic solvent polarity parameters (MSPP). Change in the dipole moment (Δµ) between the ground and photo-excited states was estimated from SS and MSPP methods. DFT and TDDFT based theoretical calculations were performed for the ground and excited states dipole moments, and for vertical transitions. A significant enhancement in the excited state dipole moment was observed following photo-excitation. The large value of Δµ clearly indicates to the charge-separation in the photo-excited states, which in turn depends on the position of the hydroxyl group in the ring.

  7. Tuning open-circuit voltage in organic solar cells by magnesium modified Alq(3).

    Science.gov (United States)

    Chou, Chi-Ta; Lin, Chien-Hung; Wu, Meng-Hsiu; Cheng, Tzu-Wei; Lee, Jiun-Haw; Liu, Chin-Hsin J; Tai, Yian; Chattopadhyay, Surojit; Wang, Juen-Kai; Chen, Kuei-Hsien; Chen, Li-Chyong

    2011-10-15

    The low molecular weight tris-(8-hydroxyquinoline) aluminum (Alq(3)) has been incorporated with magnesium (Mg) that altered the nature of its opto-electronic characteristics. The lowering of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) in Mg:Alq(3), compared to pure Alq(3), creates a stronger field (exceeding the exciton binding energy) at the donor-acceptor junction to dissociate the photo-generated exciton and also provides a low barrier for electron transport across the device. In an electron-only device (described in the text), a current enhancement in excess of 10(3), with respect to pure Alq(3), could be observed at 10 V applied bias. Optimized Mg:Alq(3) layer, when introduced in the photovoltaic device, improves the power conversion efficiencies significantly to 0.15% compared to the pure Alq(3) device. The improvement in the photovoltaic performance has been attributed to the superior exciton dissociation and carrier transport.

  8. Online determination of copper in aluminum alloy by microchip solvent extraction using isotope dilution ICP-MS method.

    Science.gov (United States)

    Kagawa, Tsuyoshi; Ohno, Masashi; Seki, Tatsuya; Chikama, Katsumi

    2009-09-15

    Isotope dilution mass spectroscopy (IDMS)/ICP-MS combined with microchip solvent extraction was successfully applied for the online determination of copper in an aluminum alloy. The microchip solvent extraction was developed for the separation of Cu from major element, and optimal pH range was wider than that of the batchwise extraction method. The dimensions of the microchip were 30 mm x 70 mm and that of micro-channel on the microchip was 180 microm wide and 40 microm deep. The copper complex with 8-hydroxyquinoline was extracted into o-xylene at pH 5.5 and back extracted with 0.1 mol l(-1) nitric acid at flow rate of 20 microl min(-1). The total extraction efficiency (water/organic solvent/nitric acid) was around 40%. IDMS/ICP-MS was coupled with solvent extraction for precise determination of Cu. The extraction and back-extraction on the microchip took about 1s and the total measurement time for the IDMS/ICP-MS was about 40s/sample. The blank value of this method was 0.1 ng g(-1). The proposed method was used for the determination of Cu in Al standard materials (JSAC 0121-C, The Japan Society for Analytical Chemistry and 7074 Al alloy, Nippon Light Metal Co. Ltd.). The obtained analytical results are in good agreement with the certified values.

  9. A sequential injection system for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples.

    Science.gov (United States)

    Mesquita, Raquel B R; Rangel, António O S S

    2004-08-01

    A sequential injection methodology for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples is proposed. A single manifold is used for the determination of the three analytes, and the same protocol sequence allows the sequential determination of calcium and magnesium (the sum corresponds to the water hardness). The determination of both metals is based on their reaction with cresolphtalein complexone; mutual interference is minimized by using 8-hydroxyquinoline for the determination of calcium and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) for the determination of magnesium. Alkalinity determination is based on a reaction with acetic acid, and corresponding color change of Bromcresol Green. Working ranges of 0.5 - 5 mg dm(-3) for Ca, 0.5 - 10 mg dm(-3) for Mg, and 10 - 100 mg HCO3- dm(-3), for alkalinity have been achieved. The results for water samples were comparable to those of the reference methods and to a certified reference water sample. RSDs lower than 5% were obtained, a low reagent consumption and a reduced volume of effluent have been accomplished. The determination rate for calcium and magnesium is 80 h(-1), corresponding to 40 h(-1) per element, while 65 determinations of alkalinity per hour could be carried out.

  10. Hole transporting material 5, 10, 15-tribenzyl-5H-diindolo[3, 2-a:3′, 2′-c]-carbazole for efficient optoelectronic applications as an active layer

    Institute of Scientific and Technical Information of China (English)

    郑燕琼; William J.Potscavage Jr; 张建华; 魏斌; 黄荣娟

    2015-01-01

    In order to explore the novel application of the transparent hole-transporting material 5,10,15-tribenzyl-5H-diindolo[3,2-a:3′,2′-c]-carbazole (TBDI), in this article TBDI is used as an active layer but not a buffer layer in a pho-todetector (PD), organic light-emitting diode (OLED), and organic photovoltaic cell (OPV) for the first time. Firstly, the absorption and emission spectra of a blend layer comprised of TBDI and electron-transporting material bis-(2-methyl-8-quinolinate) 4-phenylphenolate (BAlq) are investigated. Based on the absorption properties, an organic PD with a peak absorption at 320 nm is fabricated, and a relatively-high detectivity of 2.44×1011 cm·Hz1/2/W under 320-nm illumination is obtained. The TBDI/tris (8-hydroxyquinoline) aluminum (Alq3) OLED device exhibits a comparable external quantum efficiency and current efficiency to a traditional 4, 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD)/Alq3 OLED. A C70-based Schottky junction with 5 wt%-TBDI yields a power conversion efficiency of 5.0%, which is much higher than 1.7%for anα-NPD-based junction in the same configuration. These results suggest that TBDI has some promising properties which are in favor of the hole-transporting in Schottky junctions with low-concentration donor.

  11. NPB厚度对异质结OLED载流子复合区域的调控%Modification Effect of NPB Film Thickness on Charge Carrier Recombination Zone of Heterostructure OLEDs

    Institute of Scientific and Technical Information of China (English)

    李璐; 于军胜; 黎威志; 李伟; 蒋亚东

    2007-01-01

    通过调控p型半导体N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl)benzidine(NPB)层的厚度,制备了结构为ITO/NPB/aluminum(Ⅲ)bis(2-methyl-8-quinolinato)-4-phenylphenolate(BAlq)/ NPB(0~18 nm)/tri-(8-hydroxyquinoline)-aluminum (Alq3)/Mg:Ag的多层有机电致发光器件.分析结果表明,在该类异质结器件中,NPB不仅可以作为空穴传输材料,在适当的厚度范围内,它还可以起到调控载流子复合区域的作用;当NPB厚度在0~18 nm之间变化时,随着其厚度增加器件发光颜色可由蓝色变为绿色.通过器件发光光谱的表征可以得知,器件的载流子复合区域相应地由BAlq层转移至Alq3层.

  12. Titanium complex formation of organic ligands in titania gels.

    Science.gov (United States)

    Nishikiori, Hiromasa; Todoroki, Kenta; Setiawan, Rudi Agus; Teshima, Katsuya; Fujii, Tsuneo; Satozono, Hiroshi

    2015-01-27

    Thin films of organic ligand-dispersing titania gels were prepared from titanium alkoxide sols containing ligand molecules by steam treatment without heating. The formation of the ligand-titanium complex and the photoinduced electron transfer process in the systems were investigated by photoelectrochemical measurements. The complex was formed between the 8-hydroxyquinoline (HQ) and titanium species, such as the titanium ion, on the titania nanoparticle surface through the oxygen and nitrogen atoms of the quinolate. A photocurrent was observed in the electrodes containing the complex due to the electron injection from the LUMO of the complex into the titania conduction band. A bidentate ligand, 2,3-dihydroxynaphthalene (DHN), formed the complex on the titania surface through dehydration between its two hydroxyl groups of DHN and two TiOH groups of the titania. The electron injection from the HOMO of DHN to the titania conduction band was observed during light irradiation. This direct electron injection was more effective than the two-step electron injection.

  13. Determination of molybdenum in plants by vortex-assisted emulsification solidified floating organic drop microextraction and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oviedo, Jenny A.; Fialho, Lucimar L.; Nóbrega, Joaquim A., E-mail: djan@terra.com.br

    2013-08-01

    A fast and sensitive procedure for extraction and preconcentration of molybdenum in plant samples based on solidified floating organic drop microextraction combined with flame atomic absorption spectrometry and discrete nebulization was developed. 8-Hydroxyquinoline (8-HQ) was used as complexing agent. The experimental conditions established were: 0.5% m v{sup −1} of 8-HQ, 60 μL of 1-undecanol as the extractant phase, 2 min vortex extraction time, centrifugation for 2 min at 2000 rpm, 10 min into an ice bath and discrete nebulization by introducing 200 μL of solution. The calibration curve was linear from 0.02 to 4.0 mg L{sup −1} with a limit of detection of 4.9 μg L{sup −1} and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L{sup −1} Mo were 6.0 and 14.5%, respectively. The developed procedure was applied for determining molybdenum in corn samples and accuracy was proved using certified reference materials. - Highlights: ► Molybdenum was determined in plants by flame AAS. ► Flame AAS sensitivity was improved using microextraction and discrete nebulization. ► The developed procedure can be easily implemented in routine analysis. ► Green chemistry principles are followed.

  14. Vortex-assisted ionic liquid microextraction coupled to flame atomic absorption spectrometry for determination of trace levels of cadmium in real samples

    Directory of Open Access Journals (Sweden)

    Mahmoud Chamsaz

    2013-01-01

    Full Text Available A simple and rapid vortex assisted ionic liquid based liquid–liquid microextraction technique (VALLME was proposed for preconcentration of trace levels of cadmium. According to this method, the extraction solvent was dispersed into the aqueous samples by the assistance of vortex agitator. Cadmium preconcentration was mediated by chelation with the 8-hydroxyquinoline (oxine reagent and an IL, 1-octyl-3-methylimidazolium hexafluorophosphate ([Omim][PF6] was chosen as the extraction solvent to extract the hydrophobic complex. Several variables such as sample pH, concentration of oxine, volume of [Omim][PF6] and extraction time were investigated in details and optimum conditions were selected. Under the optimum conditions, the limit of detection (LOD was 2.9 μg L−1 for Cd (ІІ and relative standard deviation (RSD% for five replicate determinations of 125 μg L−1 was 4.1%. The method was successfully applied to the determination of cadmium in tap water, apple and rice samples.

  15. Preservation Effection of Different Preservative on Cut Flower of Gladiolus%不同保鲜液对唐菖蒲切花保鲜的影响

    Institute of Scientific and Technical Information of China (English)

    张秀丽

    2011-01-01

    通过用不同保鲜液对唐菖蒲切花进行保鲜,研究保鲜液对切花的保鲜效果及观赏价值,并探讨CaCl2对唐菖蒲切花保鲜的促进作用,及CaCl2与不同药剂处理结合对唐菖蒲切花保鲜效果的研究.结果表明,处理4:100 mg/L苯甲酸钠+600 mg/L8-羟基喹啉柠檬酸盐+4 g/L蔗糖,无论从保鲜效果、鲜重和切花观赏值来说,其效果都为最佳.%The research aimed to study the different preservative of Cut Flower of Gladiolus and provide reference for the planting and preservative method selection of Cut Flower of Gladiolus. It shows that 100 mg/L Sodium benzoate + 600 mg/L8-Hydroxyquinoline citrate +4g/L Sucrose be the best results.

  16. Tandem organic light-emitting diode with a molybdenum tri-oxide thin film interconnector layer

    Institute of Scientific and Technical Information of China (English)

    Lu Fei-Ping; Wang Qian; Zhou Xiang

    2013-01-01

    A 10-nm-thick molybdenum tri-oxide (MoO3) thin film was used as the interconnector layer in tandem organic lightemitting devices (OLEDs).The tandem OLEDs with two identical emissive units consisting of N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) / tris(8-hydroxyquinoline) aluminum (Alq3) exhibited current efficiency-current density characteristics superior to the conventional single-unit devices.At 20 mA/cm2,the current efficiency of the tandem OLEDs using the interconnector layers of MoO3 thin film was about 4.0 cd/A,which is about twice that of the corresponding conventional single-unit device (1.8 cd/A).The tandem OLED showed a higher power efficiency than the conventional single-unit device for luminance over 1200 cd/m2.The experimental results demonstrated that a MoO3 thin film with a proper thickness can be used as an effective interconnector layer in tandem OLEDs.Such an interconnector layer can be easily fabricated by simple thermal evaporation,greatly simplifying the device processing and fabrication processes required by previously reported interconnector layers.A possible explanation was proposed for the carrier generation of the MoO3 interconnector layer.

  17. Improvement in the Lifetime of Planar Organic Photovoltaic Cells through the Introduction of MoO3 into Their Cathode Buffer Layers

    Directory of Open Access Journals (Sweden)

    Linda Cattin

    2014-03-01

    Full Text Available Recently, MoO3, which is typically used as an anode buffer layer in organic photovoltaic cells (OPVCs, has also been used as a cathode buffer layer (CBL. Here, we check its efficiency as a CBL using a planar heterojunction based on the CuPc/C60 couple. The CBL is a bi-layer tris-(8-hydroxyquinoline aluminum (Alq3/MoO3. We show that the OPVC with MoO3 in its CBL almost immediately exhibits lower efficiency than those using Alq3 alone. Nevertheless, the OPVCs increase their efficiency during the first five to six days of air exposure. We explain this evolution of the efficiency of the OPVCs over time through the variation in the MoO3 work function due to air contamination. By comparison to a classical OPVC using a CBL containing only Alq3, if it is found that the initial efficiency of the latter is higher, this result is no longer the same after one week of exposure to ambient air. Indeed, this result is due to the fact that the lifetime of the cells is significantly increased by the presence of MoO3 in the CBL.

  18. Newer mixed ligand Schiff base complexes from aquo-N-(2‧-hydroxy acetophenone) glycinatocopper(II) as synthon: DFT, antimicrobial activity and molecular docking study

    Science.gov (United States)

    Pramanik, Harun A. R.; Das, Dharitri; Paul, Pradip C.; Mondal, Paritosh; Bhattacharjee, Chira R.

    2014-02-01

    Synthesis of a series of newer mixed ligand copper(II) complexes of aminoacid Schiff base of the type [CuL(X)] (L = N-(2‧-hydroxy acetophenone) glycinate, X = imidazole (im) 2, benzimidazole (benz) 3, pyridine (py) 4, hydrazine (hz) 5,8-hydroxyquinoline (8-hq) 6, pyrrolidine (pyrr) 7, piperidine (pip) 8, and nicotinamide (nic) 9) have been accomplished from the interaction of an aquated Schiff base complex, [CuL(H2O)]·H2O, 1 with some selected neutral nitrogen-donor ligands. The copper(II) Schiff base complex, [CuL(H2O)]·H2O, L = N-(2‧-hydroxy acetophenone) glycinate was synthesized from the reaction of glycine and 2‧ hydroxy acetophenone and copper(II) acetate. The compounds were characterised by elemental analysis, spectral, magnetic and thermal studies. The density functional theory calculations were performed using LANL2DZ and 6-311 G(d, p) basis sets with B3LYP correlation functional to ascertain the stable electronic structure, HOMO-LUMO energy gap, chemical hardness and dipole moment of the mixed ligand complexes. A distorted square planar geometry has been conjectured for the complexes. Antibacterial activities of the ligand and its metal complexes have been tested against selected gram-positive and gram-negative strains and correlated with computational docking scores.

  19. Identification of Xylem Occlusions Occurring in Cut Clematis (Clematis L., fam. Ranunculaceae Juss.) Stems during Their Vase Life

    Science.gov (United States)

    Jedrzejuk, Agata; Rochala, Julia; Zakrzewski, Jacek; Rabiza-Świder, Julita

    2012-01-01

    During the vase life of cut stems obstruction of xylem vessels occurs due to microbial growth, formation of tyloses, deposition of materials in the lumen of xylem vessels and the presence of air emboli in the vascular system. Such obstructions may restrict water uptake and its transport towards upwards thus lowering their ornamental value and longevity of cut flowers. Clematis is a very attractive plant material which may be used as cut flower in floral compositions. Nothing is known about the histochemical or cytological nature of xylem blockages occurring in cut stems of this plant. This study shows that in clematis, tyloses are the main source of occlusions, although bacteria and some amorphic substances may also appear inside the vessels. A preservative composed of 200 mg dm−3 8-HQC (8-hydroxyquinolin citrate) and 2% sucrose arrested bacterial development and the growth of tyloses. This information can be helpful in the development of new treatments to improve keeping qualities of cut clematis stems. PMID:22919351

  20. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2012-01-01

    Full Text Available Cloud point extraction (CPE has been used for the preconcentration and simultaneous determination of cobalt (Co and lead (Pb in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114, temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS. The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

  1. A moderate metal-binding hydrazone meets the criteria for a bioinorganic approach towards Parkinson's disease: Therapeutic potential, blood-brain barrier crossing evaluation and preliminary toxicological studies.

    Science.gov (United States)

    Cukierman, Daphne Schneider; Pinheiro, Ana Beatriz; Castiñeiras-Filho, Sergio L P; da Silva, Anastácia Sá P; Miotto, Marco C; De Falco, Anna; de P Ribeiro, Thales; Maisonette, Silvia; da Cunha, Alessandra L M C; Hauser-Davis, Rachel A; Landeira-Fernandez, J; Aucélio, Ricardo Q; Outeiro, Tiago F; Pereira, Marcos D; Fernández, Claudio O; Rey, Nicolás A

    2017-02-22

    Alzheimer's and Parkinson's diseases share similar amyloidogenic mechanisms, in which metal ions might play an important role. In this last neuropathy, misfolding and aggregation of α-synuclein (α-Syn) are crucial pathological events. A moderate metal-binding compound, namely, 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone (INHHQ), which was previously reported as a potential 'Metal-Protein Attenuating Compound' for Alzheimer's treatment, is well-tolerated by healthy Wistar rats and does not alter their major organ weights, as well as the tissues' reduced glutathione and biometal levels, at a concentration of 200mgkg(-1). INHHQ definitively crosses the blood-brain barrier and can be detected in the brain of rats so late as 24h after intraperitoneal administration. After 48h, brain clearance is complete. INHHQ is able to disrupt, in vitro, anomalous copper-α-Syn interactions, through a mechanism probably involving metal ions sequestering. This compound is non-toxic to H4 (human neuroglioma) cells and partially inhibits intracellular α-Syn oligomerization. INHHQ, thus, shows definite potential as a therapeutic agent against Parkinson's as well.

  2. Microemulsion extraction separation and determination of aluminium species by spectrofluorimetry.

    Science.gov (United States)

    Lu, Jusheng; Tian, Jiuying; Guo, Na; Wang, Yan; Pan, Yichun

    2011-01-30

    A simple and sensitive microemulsion extraction separation method was developed for the speciation of aluminium in tea samples by spectrofluorimetry. With 8-hydroxyquinoline (8-HQ) as the chelating agent and Triton X-100 Winsor II microemulsion as the extractant, separation of aluminium species in different pH solutions was achieved by microemulsion extraction. The formation of microemulsion, the conditions of extraction and determination of aluminium species were studied. The results showed that, the contents of aluminium species in tea leaves and infusions samples, such as total aluminium, total soluble aluminium, total granular aluminium, inorganic aluminium except Al-F, and (Al-F+Al-org), were obtained successfully under the optimal conditions. The limit of detection was 0.23 μg L(-1) in pH 9.5 solution, and 0.59 μg L(-1) in pH 6.0 solution respectively; the precision (RSD) for 11 replicate measurements of 10 μg L(-1) aluminium was 2.1% in pH 9.5 solution, and 2.8% in pH 6.0 solution respectively; the recoveries for the spiked samples were 96.8-103.5%. The proposed method is simple and efficient, which has been applied to the speciation of aluminium in tea samples with satisfactory results.

  3. Phenolics and plant allelopathy.

    Science.gov (United States)

    Li, Zhao-Hui; Wang, Qiang; Ruan, Xiao; Pan, Cun-De; Jiang, De-An

    2010-12-07

    Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  4. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

    Full Text Available Phenolic compounds arise from the shikimic and acetic acid (polyketide metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  5. Device based on the coupling of an organic light-emitting diode with a photoconductive material

    Energy Technology Data Exchange (ETDEWEB)

    El Amrani, A. [Universite de Limoges, Faculte des Sciences et Techniques, CNRS, UMR 6172, Institut de Recherche XLIM, Departement MINACOM, 123 Av Albert Thomas, 87060 Limoges (France); Lucas, B. [Universite de Limoges, Faculte des Sciences et Techniques, CNRS, UMR 6172, Institut de Recherche XLIM, Departement MINACOM, 123 Av Albert Thomas, 87060 Limoges (France)], E-mail: bruno.lucas@unilim.fr; Moliton, A. [Universite de Limoges, Faculte des Sciences et Techniques, CNRS, UMR 6172, Institut de Recherche XLIM, Departement MINACOM, 123 Av Albert Thomas, 87060 Limoges (France)

    2008-02-15

    We have realized a device based on the coupling of an organic light-emitting diode (with tri(8-hydroxyquinoline)aluminium for light emission) as an input unit with a photoconductive material as an output unit. Various photoconductive materials like pentacene, Cu-phtalocyanine and fullerene were investigated under green light illumination with an emission peak at 550 nm. Photocurrent measurements versus light intensity and bias voltage (applied between two 50 {mu}m distant indium-tin oxide bottom electrodes for the current to flow through the materials) were realized at room temperature a photocurrent gain around 4 is obtained when the materials are subjected to a luminance of about 5000 cd/m{sup 2} and for bias voltage of - 50 V. Besides, it was shown that to obtain a device with a fast photocurrent response by switching the light off and on, it is necessary to apply a bias voltage higher than - 200 V in these conditions, the gain is multiplied by a factor of 3.

  6. Lifetime obtained by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chakaroun, M. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France); Antony, R. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)], E-mail: remi.antony@unilim.fr; Taillepierre, P.; Moliton, A. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)

    2007-09-15

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H{sub 2}O and O{sub 2}. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances.

  7. Bias-induced photoluminescence quenching of single colloidal quantum dots embedded in organic semiconductors.

    Science.gov (United States)

    Huang, Hao; Dorn, August; Nair, Gautham P; Bulović, Vladimir; Bawendi, Moungi G

    2007-12-01

    We demonstrate reversible quenching of the photoluminescence from single CdSe/ZnS colloidal quantum dots embedded in thin films of the molecular organic semiconductor N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) in a layered device structure. Our analysis, based on current and charge carrier density, points toward field ionization as the dominant photoluminescence quenching mechanism. Blinking traces from individual quantum dots reveal that the photoluminescence amplitude decreases continuously as a function of increasing forward bias even at the single quantum dot level. In addition, we show that quantum dot photoluminescence is quenched by aluminum tris(8-hydroxyquinoline) (Alq3) in chloroform solutions as well as in thin solid films of Alq3 whereas TPD has little effect. This highlights the importance of chemical compatibility between semiconductor nanocrystals and surrounding organic semiconductors. Our study helps elucidate elementary interactions between quantum dots and organic semiconductors, knowledge needed for designing efficient quantum dot organic optoelectronic devices.

  8. Hydroxyapatite microparticles as feedback-active reservoirs of corrosion inhibitors.

    Science.gov (United States)

    Snihirova, D; Lamaka, S V; Taryba, M; Salak, A N; Kallip, S; Zheludkevich, M L; Ferreira, M G S; Montemor, M F

    2010-11-01

    This work contributes to the development of new feedback-active anticorrosion systems. Inhibitor-doped hydroxyapatite microparticles (HAP) are used as reservoirs, storing corrosion inhibitor to be released on demand. Release of the entrapped inhibitor is triggered by redox reactions associated with the corrosion process. HAP were used as reservoirs for several inhibiting species: cerium(III), lanthanum(III), salicylaldoxime, and 8-hydroxyquinoline. These species are effective corrosion inhibitors for a 2024 aluminum alloy (AA2024), used here as a model metallic substrate. Dissolution of the microparticles and release of the inhibitor are triggered by local acidification resulting from the anodic half-reaction during corrosion of AA2024. Calculated values and experimentally measured local acidification over the aluminum anode (down to pH = 3.65) are presented. The anticorrosion properties of inhibitor-doped HAP were assessed using electrochemical impedance spectroscopy. The microparticles impregnated with the corrosion inhibitors were introduced into a hybrid silica-zirconia sol-gel film, acting as a thin protective coating for AA2024, an alloy used for aeronautical applications. The protective properties of the sol-gel films were improved by the addition of HAP, proving their applicability as submicrometer-sized reservoirs of corrosion inhibitors for active anticorrosion coatings.

  9. Identification of Xylem Occlusions Occurring in Cut Clematis (Clematis L., fam. Ranunculaceae Juss. Stems during Their Vase Life

    Directory of Open Access Journals (Sweden)

    Agata Jedrzejuk

    2012-01-01

    Full Text Available During the vase life of cut stems obstruction of xylem vessels occurs due to microbial growth, formation of tyloses, deposition of materials in the lumen of xylem vessels and the presence of air emboli in the vascular system. Such obstructions may restrict water uptake and its transport towards upwards thus lowering their ornamental value and longevity of cut flowers. Clematis is a very attractive plant material which may be used as cut flower in floral compositions. Nothing is known about the histochemical or cytological nature of xylem blockages occurring in cut stems of this plant. This study shows that in clematis, tyloses are the main source of occlusions, although bacteria and some amorphic substances may also appear inside the vessels. A preservative composed of 200 mg dm−3 8-HQC (8-hydroxyquinolin citrate and 2% sucrose arrested bacterial development and the growth of tyloses. This information can be helpful in the development of new treatments to improve keeping qualities of cut clematis stems.

  10. Synthesis, Characterization and Fluorescence of a One-dimensional Cadmium( Ⅱ ) Compound Involving Covalent and Hydrogen Bonds

    Institute of Scientific and Technical Information of China (English)

    LIAN Fen-Yan; WANG Rui-Hu; HAN Lei; HONG Mao-Chun

    2005-01-01

    The title compound [Cd(Hq)2(Hdpa)2] (Hq = 8-hydroxyquinoline, H2dpa = diphenic acid) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 20.6880(5), b = 14.2584(4), c = 13.4776(4) (A), β = 113.434(2)°, C46H28Cd1N2O10, Mr = 881.10, V = 3647.68(17) (A)3, Z = 4, Dc = 1.604 g/cm3, F(000) = 1784,μ = 0.668 mm-1, the final R = 0.0576 and wR = 0.1157 for 2631 observed reflections with I >2σ(Ⅰ). The centrosymmetric Cd(Ⅱ) ion is six-coordinated in a slightly distorted octahedral geometry.The intermolecular hydrogen bonds extend the mononuclear structure into a one-dimensional supramolecular framework. The fluorescence spectrum of the compound exhibits intense emission at 520 nm when excited at 330 nm in solid state at room temperature.

  11. Study of the antioxidant effects of Eremostachys laciniata rhizome extracts in isolated rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2015-09-01

    Full Text Available Eremostachys laciniata, having rich flavonoid content, is expected to have a considerable antioxidant effect. In this study We used ACMS (Accelerated cytotoxic or protective mechanism screening technique to evaluate the possible antioxidant effect of E. laciniata rhizome against oxidative cell damages induced by different types of oxidative stress such as iron-8-hydroxyquinolin (IQ complex and copper in freshly isolated liver cells. The extracts were prepared with n-hexane, dichloromethane and methanol. Hepatocytes were isolated from male Sprague-Dawley rats by a two-step collagenase perfusion. Cell viability was measured by trypan blue exclusion method. DPPH (2, 2-diphenyl-1-picrylhydrazyl assay was used to evaluate the antioxidant activity. ROS formation was measured by using DCFDA (2, 7-dichlorofluorescin diacetate probe, mitochondrial membrane potential (MMP was assessed by rhodamine 123 fluorescence and lipid peroxidation was determined by thiobarbituric acid reactive substances (TBARS assay. The MET extract was demonstrated to possess a significant radical scavenging activity (RC50%=0.212. Unlike MET extract, the n-hexane and dichloromethane extracts showed toxic effects in cell suspensions. The MET extract significantly decreased cell death and ROS formation induced by IQ complex and copper and demonstrated protective effects against copper-induced mitochondrial membrane potential collapse and lipid peroxidation. The protection induced by MET extract can be attributed to antioxidant characteristics of the phenylethanoids content.

  12. Nanoparticulate Radiolabelled Quinolines Detect Amyloid Plaques in Mouse Models of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Celeste A. Roney

    2009-01-01

    Full Text Available Detecting aggregated amyloid peptides (Aβ plaques presents targets for developing biomarkers of Alzheimer's disease (AD. Polymeric n-butyl-2-cyanoacrylate (PBCA nanoparticles (NPs were encapsulated with radiolabelled amyloid affinity I125-clioquinol (CQ, 5-chloro-7-iodo-8-hydroxyquinoline as in vivo probes. I125-CQ-PBCA NPs crossed the BBB (2.3±0.9 ID/g (P<.05 in the WT mouse (N = 210, compared to I125-CQ (1.0±0.4 ID/g. I125-CQ-PBCA NP brain uptake increased in AD transgenic mice (APP/PS1 versus WT (N = 38; 2.54×105±5.31×104 DLU/mm2; versus 1.98×105±2.22×104 DLU/mm2 and in APP/PS1/Tau. Brain increases were in mice intracranially injected with aggregated Aβ42 peptide (N = 17; 7.19×105±1.25×105 DLU/mm2, versus WT (6.07×105±7.47×104 DLU/mm2. Storage phosphor imaging and histopathological staining of the plaques, Fe2+ and Cu2+, validated results. I125-CQ-PBCA NPs have specificity for Aβ in vitro and in vivo and are promising as in vivo SPECT (I123, or PET (I124 amyloid imaging agents.

  13. A Selective Bioreduction of Toxic Heavy Metal Ions from Aquatic Environment by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    A. M. Rahatgaonkar

    2008-01-01

    Full Text Available The need to remove or recover metal ions from industrial wastewater has been established in financial as well as environmental terms. This need has been proved financially in terms of cost saving through metal reuse or sale and environmentally as heavy metal toxicity can affect organisms throughout the food chain, including humans. Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. Current removal strategies are mainly based on bioreduction of Co++, Ni++, Cu++ and Cd++ to their metallic forms by Saccharomyces cerevisiae in buffered aqueous solution. The rate of biotransformation was significantly influenced by pH of aqueous solution, concentration of biomass and hardness of water. All reaction conditions were optimized and maximum reduction of Co++, Cd++, Ni++ and Cu++ were observed as 80%, 63%, 50%, and 44% respectively. Unreacted Co++, Cd++, Ni++metal ions were extracted by 8-hydroxyquinoline and Cu++ by diethylthio carbamate in CHCl3 at different pH. Furthermore, the concentrations of unreacted metal ions were established spectrophotometrically.

  14. Clioquinol synergistically augments rescue by zinc supplementation in a mouse model of acrodermatitis enteropathica.

    Directory of Open Access Journals (Sweden)

    Jim Geiser

    Full Text Available BACKGROUND: Zinc deficiency due to poor nutrition or genetic mutations in zinc transporters is a global health problem and approaches to providing effective dietary zinc supplementation while avoiding potential toxic side effects are needed. METHODS/PRINCIPAL FINDINGS: Conditional knockout of the intestinal zinc transporter Zip4 (Slc39a4 in mice creates a model of the lethal human genetic disease acrodermatitis enteropathica (AE. This knockout leads to acute zinc deficiency resulting in rapid weight loss, disrupted intestine integrity and eventually lethality, and therefore provides a model system in which to examine novel approaches to zinc supplementation. We examined the efficacy of dietary clioquinol (CQ, a well characterized zinc chelator/ionophore, in rescuing the Zip4 (intest KO phenotype. By 8 days after initiation of the knockout neither dietary CQ nor zinc supplementation in the drinking water was found to be effective at improving this phenotype. In contrast, dietary CQ in conjunction with zinc supplementation was highly effective. Dietary CQ with zinc supplementation rapidly restored intestine stem cell division and differentiation of secretory and the absorptive cells. These changes were accompanied by rapid growth and dramatically increased longevity in the majority of mice, as well as the apparent restoration of the homeostasis of several essential metals in the liver. CONCLUSIONS: These studies suggest that oral CQ (or other 8-hydroxyquinolines coupled with zinc supplementation could provide a facile approach toward treating zinc deficiency in humans by stimulating stem cell proliferation and differentiation of intestinal epithelial cells.

  15. Selectivity of catalytic methods of determination.

    Science.gov (United States)

    Otto, M; Mueller, H; Werner, G

    1978-03-01

    By means of catalytic analytical methods, extremely low levels can be determined at low cost and with a high sensitivity that is equal to that of physical methods of trace analysis. The selectivity of the catalytic determinations, is, however, usually rather lower than that of other methods of trace analysis. The selectivity can sometimes be improved by modification of the indicator reaction through variation of the reagents and their concentrations, or by use of masking reagents or activators, or by combination with a separation method. Modification of the indicator reaction can be exemplified by the selective determination of osmium and ruthenium by their catalysis of the nitrate oxidation of 1-naphthylamine. By variation of the nitrate concentration and the use of 1,10-phenanthroline and 8-hydroxyquinoline as complexing agents it is possible to determine these two elements simultaneously. An especially significant increase in the selectivity is made possible by use of a preliminary separation step. If the ion to be determined is separated by solvent extraction and then catalytically determined directly in the extract, a very specific determination is possible; this technique has been called "extractive catalytic determination". This method has been used for determination of molybdenum (0.5 ng/ml) in sea-water, iron (5 ng/ml) in heavy metal salts, and copper (3 ng/ml) in the presence of numerous elements.

  16. Biofunctional constituent isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues show acaricidal and insecticidal efficacy.

    Science.gov (United States)

    Jeon, Ju-Hyun; Lee, Hoi-Seon

    2014-08-27

    The acaricidal and insecticidal potential of the active constituent isolated from Citrullus colocynthis fruits and its structurally related analogues was evaluated by performing leaf disk, contact toxicity, and fumigant toxicity bioassays against Tetranychus urticae, Sitophilus oryzae, and Sitophilus zeamais adults. The active constituent of C. colocynthis fruits was isolated by chromatographic techniques and was identified as 4-methylquinoline on the basis of spectroscopic analyses. To investigate the structure-activity relationships, 4-methylquinoline and its structural analogues were tested against mites and two insect pests. On the basis of the LC50 values, 7,8-benzoquinoline was the most effective against T. urticae. Quinoline, 8-hydroxyquinoline, 2-methylquinoline, 4-methylquinoline, 6-methylquinoline, 8-methylquinoline, and 7,8-benzoquinoline showed high insecticidal activities against S. oryzae and S. zeamais regardless of the application method. These results indicate that introduction of a functional group into the quinoline skeleton and changing the position of the group have an important influence on the acaricidal and insecticidal activities. Furthermore, 4-methylquinoline isolated from C. colocynthis fruits, along with its structural analogues, could be effective natural pesticides for managing spider mites and stored grain weevils.

  17. Simulation of mixed-host emitting layer based organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Riku, C.; Kee, Y. Y.; Ong, T. S.; Tou, T. Y. [Faculty of Engineering, Multimedia University, 631000 Cyberjaya (Malaysia); Yap, S. S. [Faculty of Engineering, University of Malaya, 50603 Kuala Lampur (Malaysia)

    2015-04-24

    ‘SimOLED’ simulator is used in this work to investigate the efficiency of the mixed-host organic light emitting devices (MH-OLEDs). Tris-(8-hydroxyquinoline) aluminum(3) (Alq{sub 3}) and N,N-diphenyl-N,N-Bis(3-methylphenyl)-1,1-diphenyl-4,4-diamine (TPD) are used as the electron transport layer (ETL) material and hole transport layer (HTL) material respectively, and the indium-doped tin oxide (ITO) and aluminum (Al) as anode and cathode. Three MH-OLEDs, A, B and C with the same structure of ITO / HTM (15 nm) / Mixed host (70 nm) / ETM (10 nm) /Al, are stimulated with ratios TPD:Alq{sub 3} of 3:5, 5:5, and 5:3 respectively. The Poole-Frenkel model for electron and hole mobilities is employed to compute the current density-applied voltage-luminance characteristics, distribution of the electric field, carrier concentrations and recombination rate.

  18. Sharp green electroluminescence from 1H-pyrazolo[3,4-b]quinoline-based light-emitting diodes

    Science.gov (United States)

    Tao, Y. T.; Balasubramaniam, E.; Danel, A.; Jarosz, B.; Tomasik, P.

    2000-09-01

    A multilayer organic light-emitting diode was fabricated using a fluorescent compound {6-N,N-diethylamino-1-methyl-3-phenyl-1H-pyrazolo[3,4-b]quinoline} (PAQ-NEt2) doped into the hole-transporting layer of NPB {4,4'-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl}, with the TPBI {2,2',2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole]} as an electrontransporting material. At 16% PAQ-NEt2 doping concentration, the device gave a sharp, bright, and efficient green electroluminescence (EL) peaked at around 530 nm. The full width at half maximum of the EL is 60 nm, which is 60% of the green emission from typical NPB/AlQ [where AlQ=tris(8-hydroxyquinoline) aluminum] device. For the same concentration, a maximum luminance of 37 000 cd/m2 was obtained at 10.0 V and the maximum power, luminescence, and external quantum efficiencies were obtained 4.2 lm/W, 6.0 cd/A, and 1.6%, respectively, at 5.0 V.

  19. Kinetic Study of Copper(II Simultaneous Extraction/Stripping from Aqueous Solutions by Bulk Liquid Membranes Using Coupled Transport Mechanisms

    Directory of Open Access Journals (Sweden)

    Loreto León

    2016-09-01

    Full Text Available Heavy metals removal/recovery from industrial wastewater has become a prime concern for both economic and environmental reasons. This paper describes a comparative kinetic study of the removal/recovery of copper(II from aqueous solutions by bulk liquid membrane using two types of coupled facilitated transport mechanisms and three carriers of different chemical nature: benzoylacetone, 8-hydroxyquinoline, and tri-n-octylamine. The results are analyzed by means of a kinetic model involving two consecutive irreversible first-order reactions (extraction and stripping. Rate constants and efficiencies of the extraction (k1, EE and the stripping (k2, SE reactions, and maximum fluxes through the membrane, were determined for the three carriers to compare their efficiency in the Cu(II removal/recovery process. Counter-facilitated transport mechanism using benzoylacetone as carrier and protons as counterions led to higher maximum flux and higher extraction and stripping efficiencies due to the higher values of both the extraction and the stripping rate constants. Acceptable linear relationships between EE and k1, and between SE and k2, were found.

  20. 具有高离子识别能力的镉离子表面印迹材料的制备及其离子识别机理的研究%Studies on Preparation of Cd2+ Ion Surface-Imprinted Material with High Ion Recognition Ability and Its Ion Recognition Mechanism

    Institute of Scientific and Technical Information of China (English)

    房晓琳; 高保娇; 黄小卫; 张永奇; 顾来沅

    2013-01-01

    Hydroxyethyl methacrylate (HEMA) was graft-polymerized on micron-sized silica gel particles via surface-initiated graft-polymerization with amino/persulfate redox initiating system, obtaining the grafted particles PHEMA/SiO2 with a high grafting degree. Subsequently, the nucleophilic substitution reaction between the grafted PHEMA and 5-chloromethyl-8-hydroxyquinoline (CHQ) was carried out, and the 8-hydroxyquinoline-functionalization transformation of the grafted particles PHEMA/SiO2 was realized, preparing the functional grafted particles HQ-PHEMA/SiO2. The strong chelating adsorption property of HQ-PHEMA/SiO2 towards Cd2+ ion was deeply investigated. On that basis, the ion imprinting towards the functional grafted macromolecules HQ-PHEMA was conducted with Cd2+ ion as the template ion and di-chloroether as crosslinker by using the novel surface imprinting technique found by our research group, and Cd2+ ion surface-imprinted material IIP-HQP/SiO2 was prepared. The ion recognition and combination characters of IIP-HQP/SiO2 were examined in detailed. The experimental results show that this ion imprinted material has excellent recognition selectivity and combination affinity for the template ion, Cd2+ ion. Relative to Cu2+ and Pb2+ ions as two contrast ions, the selectivity coefficients of IIP-HQP/SiO2 for Cd2+ ion reach up to 25.52 and 22.91, respectively, displaying ultrahigh ion recognition ability.%采用氨基-过硫酸盐氧化还原引发体系,先实现了甲基丙烯酸羟乙酯(HEMA)在微米级硅胶微粒表面的引发接枝聚合,制得高接枝度的接枝微粒PHEMA/SiO2.然后使接枝大分子PHEMA的侧羟基与5-氯-8-羟基喹啉(CHQ)发生亲核取代反应,将8-羟基喹啉(HQ)基团键合在接枝大分子侧链,使接枝大分子PHEMA实现8-羟基喹啉功能化转变,制得表面含有高密度HQ基团的功能接枝微粒HQ-PHEMA/SiO2,考察研究了功能微粒HQ-PHEMA/SiO2对Cd2+离子的强螯合吸附作用.在此基础上,采用本

  1. pH dependent photophysical studies of new europium and terbium complexes of tripodal ligand: Experimental and semiempirical approach

    Energy Technology Data Exchange (ETDEWEB)

    Akbar, Rifat [Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal, Punjab 148106 (India); Baral, Minati [Department of Chemistry, National Institute of Technology Kurukshetra, Haryana 136119 (India); Kanungo, B K, E-mail: b.kanungo@gmail.com [Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal, Punjab 148106 (India)

    2015-11-15

    The photophysical properties of adduct of a novel nonadentate tripodal ligand, 5,5′-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1, 3-diyl)bis(azanediyl)bis(methylene diquinolin-8-ol, (TAME5OX), with Eu{sup 3+} and Tb{sup 3+} metal ions have been probed for photonics applications. The absorption spectroscopy of these complexes show remarkable spectral changes due to characteristic lanthanide transitions, which support the use of TAME5OX as a sensitive optical pH based sensor to detect Ln{sup 3+} metal ions in biological systems. In addition, these complexes have also been shown to exhibit strong green fluorescence allowing simultaneous sensing within the visible region under physiological pH in competitive medium for both Eu{sup 3+} and Tb{sup 3+} ions. The intense fluorescence from these compounds were revealed to intermittently get quenched under acidic as well as basic conditions due to the photoinduced intramolecular electron transfer from excited 8-hydroxyquinoline (8-HQ) moiety to metal ion, just an opposite process. This renders these compounds the OFF–ON–OFF type of pH-dependent fluorescent sensor. The thermodynamic stability and aqueous coordination chemistry of the chelator with the said lanthanide ions have also been probed by potentiometric, UV–visible and fluorescence spectrophotometric method. TAME5OX has been found to form two protonated complexes [Ln(H{sub 5}L)]{sup 5+} and [Ln(H{sub 4}L)]{sup 4+} below pH 2.5 with both metal ions, which consecutively deprotonates through one proton process with rise of pH. The formation constants (log β{sub 11n}) of neutral complexes have been determined to be 33.51 and 32.16 with pLn (pLn=−log[Ln{sup 3+}]) values of 16.14 and 19.48 for Eu{sup 3+} and Tb{sup 3+} ions, respectively, calculated at pH 7.4, indicating TAME5OX is a good lanthanide synthetic chelator. The emission lifetimes of the Eu{sup 3+} and Tb{sup 3+} complexes recorded in D{sub 2}O and H{sub 2}O suggest the presence

  2. Synthesis, characterization, and computational study of complexes containing Pt···H hydrogen bonding interactions.

    Science.gov (United States)

    Baya, Miguel; Belío, Ursula; Martín, Antonio

    2014-01-06

    Complexes [Pt(C6F5)(bzq)L] (bzq = 7,8-benzoquinolinate; L = 8-hydroxyquinoline, hqH (1); 2-methyl-8-hydroxyquinoline, hqH' (2)) have been prepared by replacing the labile acetone ligand in the starting material [Pt(C6F5)(bzq)(Me2CO)]. The (1)H NMR spectra of 1 and 2 show that the signals attributable to the hydroxyl proton of the hqH or hqH' ligands are displaced downfield 2.64 ppm for 1 and 2.74 ppm for 2 with respect to the respective free ligands. Moreover, in both complexes the signals present platinum satellites with J(Pt,H) coupling constant of 67.0 Hz for 1 and 80.6 Hz for 2. All these features are indicative of the existence of Pt···H-O hydrogen bonds in solution for these complexes. The structures of complexes 1 and 2 have been established by an X-ray diffraction study and allow us to confirm the existence of these interactions in the solid state too. Thus, in both cases the hydroxyl hydrogen atom is pointing toward the metal center, and the measured geometric parameters involving this hydrogen are Pt-H = 2.09(4) Å, O-H = 0.94(4) Å, Pt-H-O 162(4)°, for 1, and Pt-H = 2.10(4) Å, O-H = 0.91(4) Å, Pt-H-O 162(4)°, for 2, all of which are fully compatible with a hydrogen bond system. Complexes 1 and 2 and the analogues [Pt(C6F5)3(hqH)](-) (A) and [Pt(C6F5)3(hqH')](-) (B), prepared some time ago in our laboratory and also showing Pt···H-O hydrogen bonds, have been the object of theoretical calculations to obtain better insight into the Pt···H interactions. Their density functional theory (DFT) calculated structures show excellent agreement with the X-ray determined ones (1, 2, and B). Topological analyses of the electron density function (ρ(r)) have been performed on the four complexes according to Bader's Atoms In Molecules theory. These analyses reveal a bond path that relates the platinum atom and the hydroxyl hydrogen atom, as well as the corresponding bond critical points. The values of the Laplacian ∇(2)ρ(r) and local energy density H

  3. Study on Optimization of Jiangxi Yanshan Red Bud Taro Plantlet Chromosome Preparation Technique%江西铅山红芽芋试管苗染色制片技术优化研究

    Institute of Scientific and Technical Information of China (English)

    王艾平; 柯维忠; 林国卫; 吴燕芳; 易雪梅; 叶志康; 黄丽; 余琪; 肖淮宾

    2014-01-01

    以江西铅山红芽芋试管苗为材料,探讨不同取材部位、不同预处理剂、不同酸解离时间和不同改良卡宝品红染色时间对江西铅山红芽芋试管苗染色体制片的影响,以期为江西铅山红芽芋的起源、演化及遗传育种提供一定理论依据。结果表明,切取江西铅山红芽芋试管苗根尖,在室温下用0.1%秋水仙素+0.002mol/L 8-羟基喹啉混合溶液预处理4h ,然后在60℃条件下用1 mol/L盐酸解离15 min ,最后用改良卡宝品红染色5 min ,此时染色体制片效果最佳。%In order to better understand the information about cytology of Jiangxi Yanshan red bud taro ( Colocasia esculenta L .Schott var .cormosus cv .Hongyayu) ,provide information support for genetic breeding of red bud taro .The protocol of different sampling places ,pretreatments solutions ,dissociating time and dying time on chromosome observation from red bud taro plantlets was studied . The results showed that the effect of chromosome preparation was best when the root tips of red bud taro plantlets was cut ,pretreated in a mixture of 0 .1% colchicines and 0 .002mol/L 8-hydroxyquinoline at 25 ℃ for 4h ,dissocated in 1 mol/L HCl at 60 ℃ for 15 min and dyed with modified carbol fuchsin for 5 min .

  4. Syntheses, structures and luminescent properties of Sm (III) and Eu (III) chelates for organic electroluminescent device applications

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Y.J.; Wong, T.K.S.; Yan, Y.K.; Hu, X

    2003-08-25

    Samarium(III) and europium(III) complexes of the {beta}-diketone ligand (2-thienyl)trifluoroacetylacetone (HTTA) and triphenylphosphine oxide (TPPO) were prepared. The complexes, Sm(TTA){sub 2}(TPPO){sub 2}NO{sub 3} (1), Eu(TTA){sub 2}(TPPO){sub 2}NO{sub 3}H{sub 2}O (2), and Eu(TTA){sub 3}(TPPO){sub 2} (3) were characterized. Single crystal X-ray diffraction molecular structures of complexes 1 and 3 are presented and some of the crystal parameters for complex 1 are: space group, P1; a=11.019(4) A, b=11.791(6) A, c=12.535(5) A; {alpha}=102.68(3) deg., {beta}=102.06(3) deg., {gamma}=117.75(3) deg. ; for complex 3: space group, P-1, a=11.1946(9) A, b=12.117(2) A, c=23.535(2) A, {alpha}=80.047(13) deg., {beta}=76.498(7) deg., {gamma}=70.450(9) deg. . Electroluminescent devices were fabricated by vacuum evaporation. Apart from single layer devices, double and triple layer devices with the following structures: ITO/TPD/Complex 2/Al; ITO/TPD/Complex 3/Al; ITO/TPD/Complex 2/Alq/Al were studied, where N,N-bis(3-methylphenyl)-N,N'-diphenyl-benzidine (TPD) was used as a hole transporting layer and tris(8-hydroxyquinolinate)aluminum (Alq) as an electron transporting layer. The results indicate that single layer devices show very low quantum efficiency, while the double layer devices with a hole transporting layer exhibit enhanced efficiency and a well defined EL spectrum. No significant improvement was observed in the triple layer devices with an additional electron transporting layer.

  5. New Opportunities for Lanthanide Luminescence

    Institute of Scientific and Technical Information of China (English)

    Jean-Claude G. Bünzli; Steve Comby; Anne-Sophie Chauvin; Caroline D. B. Vandevyver

    2007-01-01

    Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence: materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris(8-hydroxyquinolinate) displayed a bright green emission suitable for organic light emitting diodes (OLEDs) was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the

  6. Efficient implementation of core-excitation Bethe-Salpeter equation calculations

    Science.gov (United States)

    Gilmore, K.; Vinson, John; Shirley, E. L.; Prendergast, D.; Pemmaraju, C. D.; Kas, J. J.; Vila, F. D.; Rehr, J. J.

    2015-12-01

    We present an efficient implementation of the Bethe-Salpeter equation (BSE) method for obtaining core-level spectra including X-ray absorption (XAS), X-ray emission (XES), and both resonant and non-resonant inelastic X-ray scattering spectra (N/RIXS). Calculations are based on density functional theory (DFT) electronic structures generated either by ABINIT or QuantumESPRESSO, both plane-wave basis, pseudopotential codes. This electronic structure is improved through the inclusion of a GW self energy. The projector augmented wave technique is used to evaluate transition matrix elements between core-level and band states. Final two-particle scattering states are obtained with the NIST core-level BSE solver (NBSE). We have previously reported this implementation, which we refer to as OCEAN (Obtaining Core Excitations from Ab initio electronic structure and NBSE) (Vinson et al., 2011). Here, we present additional efficiencies that enable us to evaluate spectra for systems ten times larger than previously possible; containing up to a few thousand electrons. These improvements include the implementation of optimal basis functions that reduce the cost of the initial DFT calculations, more complete parallelization of the screening calculation and of the action of the BSE Hamiltonian, and various memory reductions. Scaling is demonstrated on supercells of SrTiO3 and example spectra for the organic light emitting molecule Tris-(8-hydroxyquinoline)aluminum (Alq3) are presented. The ability to perform large-scale spectral calculations is particularly advantageous for investigating dilute or non-periodic systems such as doped materials, amorphous systems, or complex nano-structures.

  7. Optoelectronic Properties of Color-Tunable Mixed Ligand-Based Light-Emitting Zinc Complexes

    Science.gov (United States)

    Singh, Devender; Bhagwan, Shri; Saini, Raman Kumar; Tanwar, Vijeta; Nishal, Vandna

    2016-10-01

    A series of mixed ligand-based zinc complexes (Zn1-Zn5); [(8-hydroxyquinolinato)(2-(2-hydroxyphenyl)benzimidazolato)zinc(II)] (Zn1), [(5-chloro-8-hydroxyquinolinato)(2-(2-hydroxyphenyl)benzimidazolato)zinc(II)] (Zn2), [(5,7-dichloro-8-hydroxyquinolinato)(2-(2-hydroxyphenyl)benzimidazolato)zinc(II)] (Zn3), [(2-methyl-8-hydroxyquinolinato)(2-(2-hydroxyphenyl)benzimidazolato)zinc(II)] (Zn4) and [(5,7-dimethyl-8-hydroxyquinolinato)(2-(2-hydroxyphenyl)benzimidazolato)zinc(II)] (Zn5) were synthesized and characterized. The photophysical properties of zinc complexes were examined by ultraviolet-visible absorption and photoluminescence emission spectroscopy. All prepared metal complexes produced intense luminescence on excitation with a UV light source. In this study, the color-tunable characteristics of metal complexes were investigated by introducing the electron-donating and electron-withdrawing groups on the 8-hydroxyquinoline ligand. The emission spectra of metal complexes showed emission wavelength at 500 nm for [ZnHBI(q)], 509 nm for [ZnHBI(Clq)], 504 nm for [Zn(HBI)(Cl2q)], 496 nm for [ZnHBI (Meq)] and 573 nm for [ZnHBI(Me2Q)] materials. A temperature-dependent PL spectrum was used to study the emission profile of zinc complex and observed that variation in the temperature altered the position and the intensity of emission peak. The synthesized metal complex also exhibited good thermal stability (>300°C). Photophysical characteristics of color-tunable light-emitting zinc complexes suggested that these materials could be efficiently used for emissive display device applications.

  8. Effect of osmotic shock on the redox system in plasma membrane of Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    CHENSIXUE; CHICHIONGYEN; 等

    1996-01-01

    The unicellular halotolerant alga Dunaliella salina had the ability to oxidize NADH and reduce Fe(CN)63-.The redox reactions were to some extent stimulated by slight hyperosmotic shock (2.0mol/L→2.6mol/L NaCl),but markably inhibited by abrupt hyperosmotic shock (2.0mol/L→3.5mol/L NaCl) and hypoosmotic shock (2.0mol/L→1.0mol/L NaCl;2.0mol/L→0.67mol/L NaCl).With the adaptation of algal cells to osmotic shock by accumulating or degraging intracellular grycerol,the plasmalemma redox activities were also restored.The O2 uptake stimulated by NADH could be promoted by FA and SHAM.Hypoosmotic shock increases the basal respiration rate of alga cells,but weakened the stimulating effects of NADH,FA and SHAM on O2 uptake.On the other hand,hyperosmotic shock reduced the basal respiration rate,but relatively enhanced the above effects of NADH,FA and SHAM.H+ extrusion of alga cells was inhibited by NADH and stimulated by Fe(CN)63-.Vanadate and DES could inhibit H+ efflux,but had little effect in the presence of NADH and Fe(CN)63-.Both hyperand hypoosmotic shock stimulated H+ extrusion.This effect could be totally inhibited by vanadate and DES,but almost unaffected by 8-hydroxyquinoline.It was suggested that H+-ATPase probably played a more important role in H+ extrusion and osmoregulation under the conditions of osmotic shock.

  9. Rare earth(III) complexes for the development of new magnetic and luminescent probes; Complexes de lanthanides(III) pour le developpement de nouvelles sondes magnetiques et luminescentes

    Energy Technology Data Exchange (ETDEWEB)

    Nonat, A

    2007-10-15

    The simultaneous optimisation of the molecular parameters determining the relaxivity (number of coordinated water molecules, water-exchange, rotation dynamics of the whole complex, electronic relaxation, Gd(III)-proton distance) is essential to prepare efficient contrast agents. The aim of this work is on the one hand to design and study complexes with a high number of bound water molecules and to understand the influence of the coordination sphere on the stability and on the electronic relaxation and on the other hand, to use the ligand as a chromophore for the development of luminescent probes for biomedical imaging. We present the structure, the stability and the relaxivity of Gd(III) complexes of two series of tripodal ligands containing picolinate units based either on the 1,4,7-tri-aza-cyclononane ring or on a tertiary amine. These complexes show high relaxivity in water and in serum and can establish a non covalent interaction with serum albumin. The interpretation of the water proton relaxivity with the help of new relaxometric methods based on an auxiliary probe solute has allowed us to show that both the presence of the picolinate groups and the 1,4,7-tri-aza-cyclononane framework can lead to Gd(III) complexes with favourable electronic relaxation properties. This ligands have also been used for Eu(III) and Tb(III) complexation leading to strong luminescence in visible light. Other complexes derived from 8-hydroxyquinoline unit which display a very high luminescence in infrared are also studied. (author)

  10. Significance of physicochemical forms of storage in microalgae in predicting copper transfer to filter-feeding oysters (Crassostrea gigas).

    Science.gov (United States)

    Amiard-Triquet, Claude; Berthet, Brigitte; Joux, Lamia; Perrein-Ettajani, Hanane

    2006-02-01

    Copper distribution has been examined in two microalgae (Haslea ostrearia, Diatom; Tetraselmis suecica, Prasinophyceae) exposed to Cu at 30 microg/L(-1). Exchangeable copper linked at the cell surface was desorbed using 8-hydroxyquinoline-5-sulfonate as complexing agent. Then, incorporated copper was separated between soluble and insoluble fractions. In addition, algae were resuspended in acid solutions, the pHs of which covered the range existing in the digestive tract of bivalves. Considering that the soluble fraction is the most easily transferred in the food chain and that exchangeable Cu is easily desorbed, the percentages of Cu potentially available in microalgae have been assessed. These percentages have been compared with those retained in oysters Crassostrea gigas fed with contaminated microalgae in previous studies. In H. ostrearia, the potentially available fraction of Cu (90%) was very similar to the percentage retained by oysters (93%) when the bivalves were acclimated to this food for 3 weeks. Only half (21%) of the potentially available Cu of T. suecica (42%) was readily assimilated in oysters after 3 weeks. This is in agreement with the results of the desorption tests at physiological pHs which showed that only 15-25% of Cu was lost, despite solubilization of other constituents of T. suecica as demonstrated by the decrease in their dry weight. Bioavailability determined from metal speciation in food allows a relevant prediction of the trophic transfer in the case of H. ostrearia, but caution is recommended in generalizing this mode of assessment as shown in the case of T. suecica.

  11. X-rays sensing properties of MEH-PPV, Alq₃ and additive components: a new organic dosimeter as a candidate for minimizing the risk of accidents of patients undergoing radiation oncology.

    Science.gov (United States)

    Schimitberger, T; Ferreira, G R; Akcelrud, L C; Saraiva, M F; Bianchi, R F

    2013-01-01

    In this paper, we report our experimental design in searching a smart and easy-to-read dosimeter used to detect 6 MV X-rays for improving patient safety in radiation oncology. The device was based on an organic emissive solutions of poly(2-methoxy-5(2'-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV), aluminum-tris-(8-hydroxyquinoline) (Alq₃) and additive components which were characterized by UV-Vis absorption, photoluminescence and CIE color coordinate diagram. The optical properties of MEH-PPV/Alq₃ solutions have been examined as function of radiation dose over the range of 0-100 Gy. It has shown that MEH-PPV/Alq₃ solutions are specifically sensitive to X-rays, since the effect of radiation on this organic system is strongly correlated with the efficient spectral overlap between Alq₃ emission and the absorption of degraded MEH-PPV, which alters the color and photoemission of MEH-PPV/Alq₃ mixtures from red to yellow, and then to green. The rate of this change is more sensitive when MEH-PPV/Alq₃ is irradiated in the presence of benzoyl peroxide than when in the presence of hindered phenolic stabilizers, respectively, an accelerator and an inhibitor to activate or inhibit free radical formation. This gives rise to optimize the response curve of the dosimeter. It is clear from the experimental results that organic emissive semiconductors have potential to be used as dedicated and low-cost dosimeters to provide an independent check of beam output of a linear accelerator and therefore to give patients the opportunity to have information on the dose prescription or equipment-related problems a few minutes before being exposed to radiation.

  12. 木薯叶片染色体制片技术研究%Technique for Microscopical Slides of Cassava Leaf for Chromosome Observation

    Institute of Scientific and Technical Information of China (English)

    张健; 郭军辉; 陈雄庭; 王颖; 王文泉; 赖杭桂; 吴坤鑫; 倪彦艳; 黄琴

    2012-01-01

    以木薯嫩叶为材料,对其染色体制片技术的取样时间、预处理药剂、固定液、解离方法以及染色剂等方面进行了试验研究.结果表明:取材时间为上午8:30~10:00,用0.1%秋水仙素与0.002 mol/L 8-羟基喹啉混合液室温预处理3h,经固定液(无水酒精∶氯仿∶冰醋酸=6∶3∶1)固定,用1 mol/L盐酸60℃下解离8 min,再用改良苯酚品红染色压片镜检,能取得良好的分裂相效果.%The young leaves of Manihot esculenta Crantz were used to study the effects of sampling time, pretreatment chemical solution, fixed solutions, hydrolysing time and staining on the chromosome observation slides. The results showed that the optimal sampling time of leaves was about 8:30~10:00 a.m. The samples pretreated with a solution of 0.1% colchicine and 0.002 mol/L 8-hydroxyquinoline at room temperature for 3 hours and fixed with the fixative solution(alcohol : chloroform : glacial acetic acid = 6:3:1), and then hydrolysed with 1 mol/L HCI for 8 min at 60 ℃ and stained with modified Carbol fuchsin solution were proved to be nice for the microscopical slides preparation of Cassava Leaf for Chromosome Observation.

  13. Oxygen transport through laccase biocathodes for a membrane-less glucose/O{sub 2} biofuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Brunel, L.; Innocent, C.; Cretin, M.; Rolland, M.; Tingry, S. [Institut Europeen des Membranes, UMR 5635, Place Eugene Bataillon, CC 047, 34293 Montpellier, Cedex 5 (France); Denele, J.; Servat, K.; Kokoh, K.B. [LACCO ' ' Equipe Electrocatalyse' ' UMR 6503 Universite de Poitiers 40 av. du Recteur Pineau 86022 Poitiers (France); Jolivalt, C. [Laboratoire de Synthese Selective Organique et Produits Naturels UMR 7573, ENSCP, 11 rue Pierre et Marie Curie 75231 Paris Cedex (France)

    2007-02-15

    The present study reports the development of operational membrane-less glucose/O{sub 2} biofuel cell based on oxygen contactor. Glucose oxidation was performed by glucose oxidase (GOx) co-immobilized with the mediator 8-hydroxyquinoline-5-sulfonic acid hydrate (HQS) at the anode, whereas oxygen was reduced by laccase co-immobilized with 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS{sup 2-}) at the cathode. Both enzymes and mediators were immobilized within electropolymerized polypyrrole polymers. Nevertheless, this system is limited by the secondary reaction of O{sub 2} electro-reduction at the anode that reduces the electron flow through the anode and thus the output voltage. In order to avoid the loss of current at the anode in glucose/O{sub 2} biofuel cell, we developed a strategy to supply dissolved oxygen separate from the electrolyte. Porous carbon tubes were used as electrodes and modified on the external surface by the couple enzyme/mediator. The inside of the cathode tube was continuously supplied with saturated dioxygen solution diffusing from the inner to the external surface of the porous tube. The assembled biofuel cell was studied under nitrogen at 37 C in phosphate buffer at pH 5.0 and 7.0. The maximum power density reached 27 {mu}W cm{sup -2} at a cell voltage of 0.25 V at pH 5.0 with 10 mM glucose. The power density was twice as high as compared to the same system with oxygen bubbling directly in the cell. (author)

  14. Multi-target directed donepezil-like ligands for Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Mercedes eUnzeta

    2016-05-01

    Full Text Available Alzheimer's disease (AD, the most common form of adult onset dementia, is an age-related neurodegenerative disorder characterized by progressive memory loss, decline in language skills and other cognitive impairments. Although its etiology is not completely known, several factors including deficits of acetylcholine, β-amyloid deposits, τ-protein phosphorylation, oxidative stress and neuroinflammation are considered to play significant roles in the pathophysiology of this disease. For a long time, AD patients have been treated with acetylcholinesterase inhibitors such as donepezil (Aricept® but with limited therapeutic success. This might be due to the complex multifactorial nature of AD, a fact that has prompted the design of new Multi-Target-Directed Ligands (MTDL based on the one molecule, multiple targets paradigm. Thus, in this context, different series of novel multifunctional molecules with antioxidant, anti-amyloid, anti-inflammatory and metal-chelating properties able to interact with multiple enzymes of therapeutic interest in AD pathology including acetylcholinesterase, butyrylcholinesterase and monoamine oxidases A and B have been designed and assessed biologically. This review describes the multiple targets, the design rationale and an in-house MTDL library, bearing the N-benzylpiperidine motif present in donepezil, linked to different heterocyclic ring systems (indole, pyridine or 8-hydroxyquinoline with special emphasis on compound ASS234, an N-propargylindole derivative. The description of the in vitro biological properties of the compounds and discussion of the corresponding structure-activity-relationships allows us to highlight new issues for the identification of more efficient MTDL for use in AD therapy.

  15. Electrochemiluminescence detection of TNT by resonance energy transfer through the formation of a TNT-amine complex.

    Science.gov (United States)

    Qi, Wenjing; Xu, Min; Pang, Lei; Liu, Zhongyuan; Zhang, Wei; Majeed, Saadat; Xu, Guobao

    2014-04-14

    2,4,6-Trinitrotoluene (TNT) is a widely used nitroaromatic explosive with significant detrimental effects on the environment and human health. Its detection is of great importance. In this study, both electrochemiluminescence (ECL)-based detection of TNT through the formation of a TNT-amine complex and the detection of TNT through electrochemiluminescence resonance energy transfer (ECRET) are developed for the first time. 3-Aminopropyltriethoxysilane (APTES)-modified [Ru(phen)3](2+) (phen=1,10-phenanthroline)-doped silica nanoparticles (RuSiNPs) with uniform sizes of (73±3) nm were synthesized. TNT can interact with APTES-modified RuSiNPs through charge transfer from electron-rich amines in the RuSiNPs to the electron-deficient aromatic ring of TNT to form a red TNT-amine complex. The absorption spectrum of this complex overlaps with the ECL spectrum of the APTES-modified RuSiNPs/triethylamine system. As a result, ECL signals of the APTES-modified RuSiNPs/triethylamine system are turned off in the presence of TNT owing to resonance energy transfer from electrochemically excited RuSiNPs to the TNT-amine complex. This ECRET method has been successfully applied for the sensitive determination of TNT with a linear range from 1×10(-9) to 1×10(-6) M with a fast response time within 1 min. The limit of detection is 0.3 nM. The method exhibits good selectivity towards 2,4-dinitrotoluene, p-nitrotoluene, nitrobenzene, phenol, p-quinone, 8-hydroxyquinoline, p-phenylenediamine, K3[Fe(CN)6], Fe(3+), NO3(-), NO2(-), Cr(3+), Fe(2+), Pb(2+), SO3(2-), formaldehyde, oxalate, proline, and glycine.

  16. The effects of ultra-thin cerium fluoride film as the anode buffer layer on the electrical characteristics of organic light emitting diodes

    Science.gov (United States)

    Lu, Hsin-Wei; Tsai, Cheng-Che; Hong, Cheng-Shong; Kao, Po-Ching; Juang, Yung-Der; Chu, Sheng-Yuan

    2016-11-01

    In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF3film as an ultra-thin buffer layer between the indium tin oxide (ITO) electrode and α-naphthylphenylbiphenyldiamine (NPB) hole transport layer, with the structure configuration ITO/CeF3 (0.5, 1, and 1.5 nm)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris(8-hydroxyquinoline) aluminum (Alq3) (60 nm)/lithium fluoride (LiF) (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy results revealed the formation of the UV-ozone treated CeF3 film. The work function increased from 4.8 eV (standard ITO electrode) to 5.22 eV (0.5-nm-thick UV-ozone treated CeF3 film deposited on the ITO electrode). The surface roughness of the UV-ozone treated CeF3 film was smoother than that of the standard ITO electrode. Further, the UV-ozone treated CeF3 film increased both the surface energy and polarity, as determined from contact angle measurements. In addition, admittance spectroscopy measurements showed an increased capacitance and conductance of the OLEDs. Accordingly, the turn-on voltage decreased from 4.2 V to 3.6 V at 1 mA/cm2, the luminance increased from 7588 cd/m2 to 24760 cd/m2, and the current efficiency increased from 3.2 cd/A to 3.8 cd/A when the 0.5-nm-thick UV-ozone treated CeF3 film was inserted into the OLEDs.

  17. Copper Capture in a Thioether-Functionalized Porous Polymer Applied to the Detection of Wilson's Disease.

    Science.gov (United States)

    Lee, Sumin; Barin, Gokhan; Ackerman, Cheri M; Muchenditsi, Abigael; Xu, Jun; Reimer, Jeffrey A; Lutsenko, Svetlana; Long, Jeffrey R; Chang, Christopher J

    2016-06-22

    Copper is an essential nutrient for life, but at the same time, hyperaccumulation of this redox-active metal in biological fluids and tissues is a hallmark of pathologies such as Wilson's and Menkes diseases, various neurodegenerative diseases, and toxic environmental exposure. Diseases characterized by copper hyperaccumulation are currently challenging to identify due to costly diagnostic tools that involve extensive technical workup. Motivated to create simple yet highly selective and sensitive diagnostic tools, we have initiated a program to develop new materials that can enable monitoring of copper levels in biological fluid samples without complex and expensive instrumentation. Herein, we report the design, synthesis, and properties of PAF-1-SMe, a robust three-dimensional porous aromatic framework (PAF) densely functionalized with thioether groups for selective capture and concentration of copper from biofluids as well as aqueous samples. PAF-1-SMe exhibits a high selectivity for copper over other biologically relevant metals, with a saturation capacity reaching over 600 mg/g. Moreover, the combination of PAF-1-SMe as a material for capture and concentration of copper from biological samples with 8-hydroxyquinoline as a colorimetric indicator affords a method for identifying aberrant elevations of copper in urine samples from mice with Wilson's disease and also tracing exogenously added copper in serum. This divide-and-conquer sensing strategy, where functional and robust porous materials serve as molecular recognition elements that can be used to capture and concentrate analytes in conjunction with molecular indicators for signal readouts, establishes a valuable starting point for the use of porous polymeric materials in noninvasive diagnostic applications.

  18. Up-regulation of hypoxia-inducible factor (HIF)-1α and HIF-target genes in cortical neurons by the novel multifunctional iron chelator anti-Alzheimer drug, M30.

    Science.gov (United States)

    Avramovich-Tirosh, Y; Bar-Am, O; Amit, T; Youdim, M B H; Weinreb, O

    2010-06-01

    Based on a multimodal drug design paradigm, we have synthesized a multifunctional non-toxic, brain permeable iron chelator, M30, possessing the neuroprotective propargylamine moiety of the anti-Parkinsonian drug, rasagiline (Azilect) and antioxidant-iron chelator moiety of an 8-hydroxyquinoline derivative of our iron chelator, VK28. M30 was recently found to confer potential neuroprotective effects in vitro and in various preclinical neurodegenerative models and regulate the levels and processing of the Alzheimer's amyloid precursor protein and its toxic amyloidogenic derivative, Abeta. Here, we show that M30 activates the hypoxia-inducible factor (HIF)-1alpha signaling pathway, thus promoting HIF-1alpha mRNA and protein expression levels, as well as increasing transcription of HIF-1alpha-dependent genes, including vascular endothelial growth factor, erythropoietin, enolase-1, p21 and tyrosine hydroxylase in rat primary cortical cells. In addition, M30 also increased the expression levels of the transcripts of brain derived neurotrophic factor (BDNF) and growth-associated protein-43 (GAP-43). Regarding aspects of relevance to Alzheimer's disease (AD), western blotting analysis of glycogen synthase kinase- 3beta (GSK-3beta) signaling pathway revealed that M30 enhanced the levels of phospho-AKT (Ser473) and phospho- GSK-3beta (Ser9) and attenuated Tau phosphorylation. M30 was also shown to protect cultured cortical neurons against Abeta(25-35) toxicity. All these multimodal pharmacological activities of M30 might be beneficial for its potent efficacy in the prevention and treatment of neurodegenerative conditions, such as Parkinson's disease and AD in which oxidative stress and iron-mediated toxicity are involved.

  19. The novel multi-target iron chelator, M30 modulates HIF-1α-related glycolytic genes and insulin signaling pathway in the frontal cortex of APP/PS1 Alzheimer's disease mice.

    Science.gov (United States)

    Mechlovich, Danit; Amit, Tamar; Bar-Am, Orit; Mandel, Silvia; Youdim, Moussa B H; Weinreb, Orly

    2014-02-01

    Increasing evidence suggests that dysregulation of brain insulin/insulin receptor (InsR) and insulin signaling cascade are associated with the pathogenesis of Alzheimer's disease (AD). Our group has designed and synthesized a series of multi-target iron chelating, brain permeable compounds for AD. One leading multi-target compound, M30 possesses the neuroprotective N-propargyl moiety of the anti-Parkinsonian, monoamine oxidase (MAO)-B inhibitor, rasagiline (Azilect®) and the antioxidant-iron chelating moiety of an 8-hydroxyquinoline derivative of the iron chelator, VK28. Positive outcomes for the behavioral/cognitive and neuroprotective effects of M30 were recently obtained in preclinical experimental studies, regarding pathological aspects relevant to ageing and AD. We report that chronic treatment with M30 (1 and 5 mg/kg p.o; three times a week for 9 months) significantly elevated cortical insulin and InsR transcript and protein expression, respectively and increased the phosphorylated form of glycogen synthase kinase-3β in the frontal cortex of amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mice. In addition, M30 treatment upregulated the levels of hypoxia-inducible factor (HIF)-1α and expression of its target genes involved in glycolysis including, aldolase A, enolase-1 and glucose transporter-1 (Glut-1), in the frontal cortex of APP/PS1 mice. Treatment with M30 also lead to an increase in the hepatic protein expression levels of InsR and Glut-1 and lowered the increase in blood glucose levels following glucose tolerance test. The present findings indicate that the multifunctional iron chelating drug, M30 regulates major brain glucose metabolism parameters and thus, might be beneficial for AD, in which impaired neuronal insulin signaling and Glut expression have been implicated.

  20. An organic light-emitting devices of highly efficient white phosphor using an electron/exciton blocker

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Highly efficient white phosphorescent organic light-emitting devices (WOLEDs) was fabricated using an electron/exciton blocker. The device structure is ITO/2T-NATA(25 nm)/NPBX(25-dnm)/CBP:5%Ir(ppy)3:0.5%Rubrene(8 nm)/NPBX(dnm)/DPVBi(30 nm)/TPBi(20 nm)/Alq(10nm)/LiF(1nm)/Al, in which N,N' -bis- (1-naphthyl)- N,N' -dipheny1-1, 1' - bi-phenyl-4,4 ' -diamine (NPBX) functions as a hole transport layer and electron/exciton blocker, 4,4,N,N 'dicarbazolebiphenyl (CB P) is host, 4,4' -bis(2,2 -diphenyl vinyl)-1,1' -biphenyl (DPVB. i) is blue fluorescent dye, 5,6,11,12,-tetraphenylnaphthacene (rubrene) is fluorescent dye, factris (2-phenylpyridine) iridium (Ir(ppy)3) is phosphorescent sensitizer and tris(8-hydroxyquinoline) aluminum (Alq3) is an electron transport layer. The WOLEDs have obtained white light emission by adjusting the thickness of NPBX, when the concentration of Ir(ppy)3 is 5-wt% and rubrene is 0.5-wt%,respectively, the thickness of the doped emissive layer is 8 nm, the WOLEDs show a maximum luminous efficiency is 11.2 cd/A with d of 10 nm at 7 V and a maximum luminance of 28170 cd/m2 at 17 V, the CIE coordinates is (0.37.0.42), which is in white region.

  1. A new dispersive liquid-liquid microextraction using ionic liquid based microemulsion coupled with cloud point extraction for determination of copper in serum and water samples.

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Mariam Shahzadi; Panhwar, Abdul Haleem; Khan, Naeemullah; Baig, Jameel Ahmed; Shah, Faheem

    2016-04-01

    A simple and rapid dispersive liquid-liquid microextraction procedure based on ionic liquid assisted microemulsion (IL-µE-DLLME) combined with cloud point extraction has been developed for preconcentration copper (Cu(2+)) in drinking water and serum samples of adolescent female hepatitits C (HCV) patients. In this method a ternary system was developed to form microemulsion (µE) by phase inversion method (PIM), using ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and nonionic surfactant, TX-100 (as a stabilizer in aqueous media). The Ionic liquid microemulsion (IL-µE) was evaluated through visual assessment, optical light microscope and spectrophotometrically. The Cu(2+) in real water and aqueous acid digested serum samples were complexed with 8-hydroxyquinoline (oxine) and extracted into IL-µE medium. The phase separation of stable IL-µE was carried out by the micellar cloud point extraction approach. The influence of of different parameters such as pH, oxine concentration, centrifugation time and rate were investigated. At optimized experimental conditions, the limit of detection and enhancement factor were found to be 0.132 µg/L and 70 respectively, with relative standard deviation <5%. In order to validate the developed method, certified reference materials (SLRS-4 Riverine water) and human serum (Sero-M10181) were analyzed. The resulting data indicated a non-significant difference in obtained and certified values of Cu(2+). The developed procedure was successfully applied for the preconcentration and determination of trace levels of Cu(2+) in environmental and biological samples.

  2. Neutrophil killing of human umbilical vein endothelial cells is oxygen radical-mediated and enhanced by TNF-. alpha

    Energy Technology Data Exchange (ETDEWEB)

    Dame, M.K.; Varani, J.; Weinberg, J.M.; Ward, P.A. (Univ. of Michigan, Ann Arbor (United States))

    1991-03-11

    Human umbilical vein endothelial cells are sensitive to killing by activated human neutrophils. Killing is inhibited in the presence of catalase and deferoxamine mesylate but not soybean trypsin inhibitor. Reagent hydrogen peroxide can substitute for activated neutrophils in producing endothelial cell injury. These data suggest that lethal injury is due to the production of oxygen radicals by activated neutrophils. In these respects, the human umbilical vein endothelial cells are similar to rat pulmonary artery endothelial cells in that pretreatment with TNF-{alpha} increases sensitivity to injury by activated neutrophils. In part, the increased endothelial cell sensitivity to killing by neutrophils may be due to up-regulation of surface adhesion molecules. However, it was observed that cells passaged more than two times in culture did not demonstrate increased killing after treatment with TNF-{alpha} while up-regulation of neutrophil adhesion could be detected through several additional passages. Although the human umbilical vein endothelial cells are qualitatively similar to rat pulmonary artery endothelial cells in their sensitivity to killing, they are quantitatively much more resistant. What accounts for the relative resistance of the human umbilical vein endothelial cells is not fully understood. In the rat pulmonary artery endothelial cells, killing is known to be dependent on an intraendothelial source of iron. Pre-treatment of the human umbilical vein endothelial cells with 8-hydroxyquinoline-bound iron increased their sensitivity to oxidant injury. These data suggest that the availability of iron within the human umbilical vein endothelial cells may be a limiting factor in sensitivity to oxygen radical-mediated injury.

  3. Synthesis of Ferrite Nickel Nano-particles and Its Role as a p-Dopant in the Improvement of Hole Injection of an Organic Light-Emitting Diode

    Science.gov (United States)

    Noori, Maryam; Jafari, Mohammad Reza; Hosseini, Sayed Mohsen; Shahedi, Zahra

    2017-02-01

    We fabricated an organometallic complex based on zinc ions using zinc complex as a fluorescent in organic light-emitting diodes (OLEDs). Also, the nano-particles of ferrite nickel were produced in a simple aqueous system prepared by mixing Ni (NO3)2, Fe (NO3)3 and deionized water solutions. The synthesized zinc bis (8-hydroxyquinoline) (Znq2) complex and NiFe2O4 nano-particles were characterized by using x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) as well as photoluminescence spectroscopy analysis. Their energy level was also determined by some cyclic voltammetry (CV) measurements. The maximum green photoluminescence was observed at 565 nm. The nano-particles of ferrite nickel were utilized in preparation of OLEDs by blending of the magnetic nano-particles with PEDOT:PSS and Zn-complex solutions. The electrical and optical performance of prepared OLEDs with/without doped nano-particle was studied. The samples were configured into two structures: (1) Indium Tin Oxide (ITO)/ poly(3,4-ethylenedi-oxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/Znq2/(2-4-biphenylyl)-5-phenyl-oxadiazole (PBD)/aluminum (Al) and (2) ITO/PEDOT:PSS:NiFe2O4(NPs)/Znq2/PBD/Al. Obtained results showed that the current density and electroluminescence efficiency were increased and the turn-on voltage decreased (about 3 V) by using nano-particles into a PEDOT:PSS layer (Hole transport layer). Also, the electroluminescence efficiency was decreased by incorporating magnetic nano-particles into a Zn-complex layer (emissive layer). It was found that utilizing NiFe2O4 nano-particles caused an increase of hole-injection layer conductivity effectively and a decrease of the turn-on voltage.

  4. Synthesis, spectroscopic studies, molecular modeling and antimicrobial activity of binuclear Co(II) and Cu(II) complexes of 4,6-diacetylresorcinol

    Science.gov (United States)

    Shebl, Magdy; Khalil, Saied M. E.; Taha, A.; Mahdi, M. A. N.

    2013-09-01

    Reactions of 4,6-diacetylresorcinol with different cobalt(II) and copper(II) salts viz., OAc-, Cl-, NO3- and SO42-, yielded a new series of binuclear metal complexes. Reactions of the ligand with these metal ions in the presence of a secondary ligand (L‧) [O,O-donor; acetylacetone, N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline and N,N,N‧,N‧-tetramethylethylenediamine] in 1:2:2 (L:M:L‧) molar ratio yielded mixed-ligand complexes with different molar ratios. The metal complexes were characterized by elemental and thermal analyses, IR, electronic, ESR and mass spectra as well as conductivity and magnetic susceptibility measurements. The analytical and spectroscopic data suggested that the H2L ligand behaves as a neutral, monobasic or dibasic tetradentate ligand, depending on the type of the anion and secondary ligand used, through the two phenolic and two carbonyl groups. Electronic spectra, magnetic and conductivity measurements showed that all complexes are octahedral with non-electrolytic nature. The profile of ESR spectra of copper(II) complexes suggested the octahedral geometry and the spin Hamiltonian parameters of the complexes were calculated and discussed. Molecular orbital calculations were performed for metal complexes using Hyperchem 7.52 program on the bases of PM3 level and the results correlated with the experimental data. The free ligand and some of its metal complexes showed antimicrobial activity towards some of Gram-positive and Gram-negative bacteria, yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  5. Storage and Preservation of Two Cut-flower Cultivars of Heliconia psittacorum in Hainan Island%两个鹤蕉切花品种的贮藏保鲜技术

    Institute of Scientific and Technical Information of China (English)

    宋希强; 李育容; 罗冠勇; 杨福孙; 徐诗涛

    2009-01-01

    在室内空气相对湿度为80%~85%、温度为18~28℃的条件下,研究'巧舞女'(Choconian Dancer)和'阳光'(Strawberries and Cream)2个鹤蕉(Heliconia psittacorum Linn.)品种的切花贮藏保鲜技术.结果表明:鹤蕉‘巧舞女'预处理以花枝在浓度为1 mmoI/L的STS中浸泡10min的效果最佳,贮藏寿命较对照的延长了6.5 d;瓶插处理以处理组合3 g,L蔗糖+400 mCL 8-HQ(8-Hydroxyquinoline)+2 mg/L 6-BA的保鲜效果最佳,瓶插寿命较对照的延长了7 d.鹤蕉‘阳光'预处理以1 mmol/L SiX3浸泡8 min的贮藏效果最佳,贮藏寿命比对照的延长了4.5 d;瓶插处理以处理组合2g/L,蔗糖+200mg/L 8-HQ+2mg/L 6-BA的保鲜效果最好,瓶插寿命较对照的延长了5 d.说明鹤蕉品种间的贮藏和瓶插寿命存在一定的差异.

  6. An interplay between infrared multiphoton dissociation Fourier-transform ion cyclotron resonance mass spectrometry and density functional theory computations in the characterization of a tripodal quinolin-8-olate Gd(III) complex.

    Science.gov (United States)

    De Bonis, Margherita; Bianco, Giuliana; Amati, Mario; Belviso, Sandra; Cataldi, Tommaso R I; Lelj, Francesco

    2013-04-01

    A new hexadentate, tripodal 8-hydroxyquinoline based ligand (QH3) and its gadolinium(III) tris-chelated (GdQ) complex with hemicage structure was investigated by using high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FTICRMS). The protonated adduct of the free ligand and its hemicage tripodal Gd(III) complex, [GdQ + H](+), were first observed in experiments of electrospray ionization (ESI) with a linear ion trap (LTQ) mass spectrometer and further investigated by using high resolution FTICRMS. Gas-phase dissociation of the protonated Gd(III) complex, by infrared multiphoton dissociation (IRMPD) FTICR MS, demonstrated a fragmentation pattern with six main product cluster ions labeled as [Fn](+) (n = 1 up to 6). These product ions suggest the elimination of 7-amino-alkyl or 7-alkyl chains of the hemicage moiety. High resolution MS conditions allowed the elucidation of the fragmentation pattern and product ion structures along with the determination, among the isotopic pattern of Gd, of the chemical compositions of closely related species, which differ in terms of hydrogen content. Among the Gd six naturally stable isotopes, (158)Gd is the most abundant, and its peak within each cluster was used as a reference for distinguishing each product ions. Computational DFT investigations were applied to give support to some hypothesis of fragmentation pathways, which could not have been easily justified on the basis of the experimental work. Furthermore, computational studies suggested the coordination geometry of the protonated parent complex and the five- and four-coordinated complexes, which derive from its fragmentation. Furthermore, experimental and computational evidences were collected about the octet spin state of the parent compound.

  7. Effect of 5-chloro-7-iodo-8-hydroxy-quinoline (clioquinol) on the uptake and distribution of nickel, zinc and mercury in mice

    Energy Technology Data Exchange (ETDEWEB)

    Tjaelve, H. (Department of Pharmacology and Toxicology, the Swedish University of Agricultural Sciences, Uppsala); Staahl, K. (Department of Toxicology, University of Uppsala, Sweden)

    1984-01-01

    5-Chloro-7-iodo-8-hydroxy-quinoline (clioquinol) was found to induce a very marked increase in the concentration of /sup 63/Ni/sup 2 +/ in various tissues of mice when given orally together with the metal, compared with oral administrations of /sup 63/Ni/sup 2 +/ only. Markedly increased tissue concentrations, although less expressed than for the /sup 63/Ni/sup 2 +/, were also observed for /sup 65/Zn/sup 2 +/. Clioquinol increased the tissue levels of /sup 203/Hg/sup 2 +/ to a lesser extent. When clioquinol was given intraperitoneally and /sup 63/Ni/sup 2 +/ was given intravenously there were also very markedly increased tissue levels of the metal, compared with intravenous injections of /sup 63/Ni/sup 2 +/ only. It was also shown that the urinary excretion of /sup 63/Ni/sup 2 +/ was greatly increased in mice given the metal orally together with clioquinol, compared with mice given the /sup 63/Ni/sup 2 +/ only. Clioquinol and other 8-hydroxyquinolines form lipophilic chelates with metallic cations and the observed effects on the tissue-disposition of the metals are probably due to a facilitated penetration through the cellular membranes. Determinations of the chloroform:water partition coefficients showed the highest lipophilicity for the nickel-clioquinol-complex followed in decreasing order by the complexes with zinc and mercury. These data suggest that the ability of the clioquinol to affect the uptake of the metals in the cells may be related to the relative lipophilicity of the metal-clioquinol-complexes.

  8. Low temperature tunneling magnetoresistance on (La,Sr)MnO3/Co junctions with organic spacer layers

    Science.gov (United States)

    Vinzelberg, H.; Schumann, J.; Elefant, D.; Gangineni, R. B.; Thomas, J.; Büchner, B.

    2008-05-01

    This paper concerns with giant magnetoresistance (MR) effects in organic spin valves, which are realized as layered (La,Sr)MnO3 (LSMO)-based junctions with tris-(8, hydroxyquinoline) aluminum (Alq3)-spacer and ferromagnetic top layers. The experimental work was focused on the understanding of the transport behavior in this type of magnetic switching elements. The device preparation was carried out in an ultrahigh vacuum chamber equipped with a mask changer by evaporation and sputtering on SrTiO3 substrates with LSMO stripes deposited by pulsed laser technique. The field and temperature dependences of the MR of the prepared elements are studied. Spin-valve effects at 4.2K have been observed in a broad resistance interval from 50Ω to MΩ range, however, without systematic dependence on spacer layer thickness and device area. In some samples, the MR changes sign as a function of the bias voltage. The observed similarity in the bias voltages dependences of the MR in comparison with conventional magnetic tunnel junctions with oxide barriers suggests a description of the found effects within the classical tunneling concept. This assumption is also confirmed by a similar switching behavior observed on ferromagnetically contacted carbon nanotube devices. The proposed model implies the realization of the transport via local Co chains embedded in the Alq3 layer and spin dependent tunneling over barriers at the interface Co grains/Alq3/LSMO. The existence of conducting Co chains within the organics is supported by transmission electron microscopic/electron energy loss spectroscopic studies on cross-sectional samples from analogous layer stacks.

  9. Synthesis of vanadium complexes and butadiene polymerization catalyzed by the complexes%钒配合物的合成及其催化丁二烯聚合

    Institute of Scientific and Technical Information of China (English)

    黄贵秋; 陈敏娥; 熊拯

    2012-01-01

    采用N-亚硝基苯胲铵、二乙基二硫代氨基甲酸钠合三水和8-羟基喹啉三种萃取剂,萃取合成了三个双配位基配体钒配合物,将其用于催化丁二烯聚合获得聚丁二烯产品.用元素分析及红外光谱分析测定了钒配合物的结构,用凝胶渗透色谱、红外光谱及核磁共振波谱分析了聚合产物结构.所得聚丁二烯的数均分子量为(0.96~1.36)×104,相对分子质量分布为3.5~4.3,1,2-结构单元的摩尔分数高于60%,且构型为间同立构和无规结构.%Three vanadium complexes were synthesized via extraction with cupferron, sodium diethyl dithiocarbamate and 8-hydroxyquinoline as extraction reagents. The resultant vanadium complex with bifunctional ligand was successfully applied in catalyzing butadiene polymerization through which the corresponding polymer was acquired. The structure of the vanadium complexes was tested by elemental analyses and infrared spectroscopy (IR). The structure of the resultant polybutadiene was analysized with gel permeation chromatography (GPC), IR, nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR). The polybutadiene possessed number average molecular mass of (0.96-1.36)xl04 and relative molecular mass distribution of 3.5-4.3. The molar content of 1,2-configuration unit, in either syndiotactie or atactic microstructure, was higher than 60% of the polybutadiene.

  10. Site-directed mutagenesis reveals new and essential elements for iron-coordination of the sulfur oxygenasereductase from the acidothermophilic Acidianus teng-chongensis

    Institute of Scientific and Technical Information of China (English)

    CHEN ZhiWei; JIANG ChengYing; LIU ShuangJiang

    2009-01-01

    Previous study on refolding of sulfur oxygenase reductase (SOR) inclusion bodies from recombinant Escherichia coli showed that iron was critical to the activity of the SOR from Acidianus ambivalens. In this study, enzymatic assays showed that 2,2'-Dipyridyl, Tiron and 8-hydroxyquinoline, which are spe-cific for chelating ferrous or ferric ions, strongly inhibited the activity of SOR from A. tengchongensis, suggesting that iron atom is essential for SOR activity. Alignment of several functionally identified SORs and SOR-like sequences from genome database revealed a conserved, putative iron binding motif, H86-X3-H90-Xn-E114-Xn-E129 (numbering according to the Acidianus tengchongensis SOR sequence). Three mutants of SOR were generated by site-directed mutagenesis of H86, H90 and E129 into phenyla-lanine or alanine residue in this study. Circular dichroism spectrum determination indicated that there was no change of the secondary structures of mutant SORs, H86F, H90F and E129A, but all mutants were completely inactive. Through determination of iron contents we found that SOR mutants of H86F, H90F and E129A completely or partially lost iron, while mutants of C31S, C101S, and C104S (generated in a pre-vious study) did not. This result indicated that H86, H90 and E129 but not C31, C101, and C104 were involved in binding to iron atom. Based on this and previous studies, it is proposed that the conserved motifs, C31-Xn-C101-X2-C104 and H86-X3-H90-X23-E114-X14-(E/D)129, are respectively for sulfur and molecular oxygen binding and activation. These two conserved motifs are essential elements for the SOR activity.

  11. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid

    Science.gov (United States)

    Faheim, Abeer A.; Abdou, Safaa N.; Abd El-Wahab, Zeinab H.

    2013-03-01

    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H2L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, 1H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H2L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  12. 不结球白菜根尖体细胞染色体制片及其二倍体和四倍体有丝分裂过程观察%Chromosome preparation of somatic cell in root-tip of non-heading Chinese cabbage ( Brassica campestris ssp.chinensis ) and observation of mitosis process of its diploid and tetraploid

    Institute of Scientific and Technical Information of China (English)

    郑金双; 张蜀宁; 孙成振; 王雅美

    2011-01-01

    以不结球白菜(Brassica campestris ssp.chinensis Makino)根尖为材料,对染色体制片过程中根长(小于0.5 cm、0.5 ~ 1.0 cm、1.0~2.0 cm及大于2.0 cm)、预处理方法、预处理剂种类(2 mmol·L-1 8-羟基喹啉、2 mmol·L-1 8-羟基喹啉与质量浓度0.2g·L-1秋水仙素等体积混合液、质量浓度0.2g·L-1秋水仙素、饱和对二氯苯、质量浓度20或40 mg·L-1放线菌酮、质量浓度40mg·L-1放线菌酮与2 mmol·L-1 8-羟基喹啉等体积混合液)及预处理时间(1.0~3.5 h)进行了比较和筛选;在此基础上,对二倍体和四倍体不结球白菜根尖体细胞有丝分裂过程进行观察.结果表明:根长度对分裂相的数量有显著影响;根长1.0~2.0 cm,分裂相相对较多,占细胞总数的64.75%.冰冻预处理22 ~ 23 h,能获得一定量的分裂相.采用不同的预处理剂及预处理时间,分裂相的数量及染色体形态有明显差异;用质量浓度40 mg·L-1放线菌酮溶液处理3.5h,分裂相数量最多,但易导致染色体加倍;用质量浓度20mg·L-1放线菌酮预处理3.5h,染色体长且着丝点及随体清晰,且分裂相较多,占细胞总数的53.65%.因而,根长度以1.0 ~2.0 cm为宜,适宜的预处理方法为用质量浓度20 mg·L-1放线菌酮浸泡2.0~3.0 h.二倍体及四倍体不结球白菜根尖体细胞有丝分裂过程基本相似,在有丝分裂的间期、前期、中期、后期和末期染色体的行为基本一致,但在四倍体的有丝分裂过程中会出现多价体、染色体桥、落后染色体、染色体异常分离及内源有丝分裂等异常现象.%Using root-tip of non-heading Chinese cabbage (Brassica campestris ssp. Chinensis Makino) as experimental material, root length (shorter than 0.5 cm, 0.5-1.0 cm, 1.0-2.0 cm and longer than 2.0 cm) , pretreatment method, pretreatment agent types (2 mmol · L-1 8-hydroxyquinoline, equivalent volume mixed solution of 2 mmol · L-1 8-hydroxyquinoline and 0. 2 g

  13. On Cloud Point Extraction of Cd2+and Co2+with TritonX-100%TritonX-100对废水中Cd2+、Co2+的浊点萃取研究

    Institute of Scientific and Technical Information of China (English)

    黄海霞; 谭雪晴

    2015-01-01

    以TritonX-100为萃取剂,8-羟基喹啉为络合剂,对废水中Cd2+、Co2+进行浊点萃取,考察了萃取剂的用量、络合剂用量、pH值、平衡时间、平衡温度、离心时间、离心速度等影响萃取效果的因素,得到了浊点萃取的最佳条件,在最佳条件下,Cd2+的最大萃取率为93%,Co2+的最大萃取率为88%。结果表明,此体系对 Cd2+和Co2+的萃取率都比较高,而且对Cd2+的萃取效果比对Co2+的萃取效果较好,用此法处理含Cd2+和Co2+的废水,方法可行。%An experiment was made to remove trace amounts of Cd2+ and Co2+ from waste water by cloud point extraction using TritonX-100 as the extraction agent,8 -hydroxyquinoline as the complexion agent,and NaOH-KH2 PO3 as the buffer solution. The effects of the amount of the extraction agent,the amount of complex-ion,pH value,equilibrium time and temperature,centrifugation time,speed of centrifugation and other factors on the efficiency of cloud point extraction had been systematically examined. Under optimized conditions,the maxi-mum extraction rate of Cd2+ and Co2+ reached to 93% and 88% respectively. The results showed that the system had high extraction ability for Cd2+ and Co2+,but the extraction efficiency to Cd2+ was a little higher than to Co2+. Therefore,the method was practicable to treat waste water containing Cd2+ and Co2+.

  14. Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Chen, Jianrong, E-mail: cjr@zjnu.cn [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A dual-cloud point extraction (d-CPE) procedure was firstly developed for simultaneous pre-concentration and separation of trace metal ions combining with ICP-OES. Black-Right-Pointing-Pointer The developed d-CPE can significantly eliminate the surfactant of Triton X-114 and successfully extend to the determination of water samples with good performance. Black-Right-Pointing-Pointer The designed method is simple, high efficient, low cost, and in accordance with the green chemistry concept. - Abstract: A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH = 7.0, Triton X-114 = 0.05% (w/v), 8-HQ = 2.0 Multiplication-Sign 10{sup -4} mol L{sup -1}, HNO{sub 3} = 0.8 mol L{sup -1}), the detection limits for Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 {mu}g L{sup -1}, respectively. Relative standard deviation (RSD) values for 10 replicates at 100 {mu}g L{sup -1} were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, and Cu{sup 2+} ion in water samples.

  15. Fresh-keeping effect of hydroquinone to cut-flower cultivars of Dianthus caryophyllus 'Master'%对苯二酚对香石竹切花品种“马斯特”的保鲜效应

    Institute of Scientific and Technical Information of China (English)

    王荣华; 郑兴峰; 徐小林; 王红燕

    2012-01-01

    By taking 8-hydroxyquinoline citrate, sucrose as the basic liquid and adding hydroquinone of different concentrations to constitute the antistaling agent, the vase planting test has been conducted. The fresh weight, lift-time and diameter of flower of D. caryophyllus 'Master' were measured, the caudex vessels of the cut flowers were observed with light and scan electron microscopy. The results show that hydroquinone could limit blockage of stem caudex vessels, delay unbalance of water, increase flower diameter, and extend vase life-time of D. caryophyllus; Stem caudex vessel blockage of vase planting D. caryophyllus formed during vase life, and the blockages often were gums or mucilage, and a few of that were rod-shaped bacteria; the xylem vessel blockages is not the only cause to terminate vase life-time of cut flower D. caryophyllus. The most optimum formula of the antistaling agent for D. caryophyllus cut flower is 150 mg/L 8-HQC +2% sucrose+lmmol hydroquinone.%以8-羟基喹啉柠檬酸盐和蔗糖为基础液,添加不同浓度对苯二酚组成保鲜剂,对香石竹切花品种“马斯特”进行瓶插处理.实验测定了切花的鲜重、寿命、花径等指标,同时对切花茎基部导管进行了光镜和电镜观察.结果表明,对苯二酚能延缓香石竹切花茎基部堵塞,延迟水分失衡,增大花径,保持切花鲜艳,延迟切花寿命;香石竹切花茎基部导管在瓶插期间形成堵塞,堵塞物质多为不定型物质如粘液或树胶,少量为定型杆菌;堵塞物质并不是影响香石竹切花寿命的唯一因素;150 mg/L 8-HQC +2%蔗糖+1 mmlo对苯二酚的保鲜剂是香石竹切花保鲜的最优配方.

  16. Influence of small-molecule material on performance of polymer solar cells based on MEH-PPV:PCBM blend

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Dong; Xu Xu-Rong; Xu Zheng; Zhang Fu-Jun; Zhao Su-Ling; Zhang Tian-Hui; Gong Wei; Song Jing-Lu; Kong Chao; Yan Guang

    2010-01-01

    In this work, the influence of a small-molecule material, tris(8-hydroxyquinoline) aluminum (Alq3), on bulk het-erojunction (BHJ) polymer solar cells (PSCs) is investigated in devices based on the blend of poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) and[6,6]-phenyl-C61>-butyric acid methyl ester (PCBM). By dop-ing Alq3 into MEH-PPV:PCBM solution, the number of MEH-PPV excitons can be effectively increased due to the energy transfer from Alq3> to MEH-PPV, which probably induces the increase of photocurrent generated by excitons dissociation. However, the low carrier mobility of Alq3 is detrimental to the efficient charge transport, thereby blocking the charge collection by the respective electrodes. The balance between photon absorption and charge transport in the active layer plays a key role in the performance of PSCs. For the case of 5 wt.% Alq3 doping, the device performance is deteriorated rather than improved as compared with that of the undoped device. On the other hand, we adopt Alq3>as a buffer layer instead of commonly used LiF. All the photovoltaic parameters are improved, yielding an 80% increase in power conversion efficiency (PCE) at the optimum thickness (1 nm) as compared with that of the device without any buffer layer. Even for the 5 wt.% Alq3 doped device, the PCE has a slight enhancement compared with that of the standard device after modification with 1 nm (or 2 nm) thermally evaporated Alq3>. The performance deterioration of Alq3-doped devices can be explained by the low solubility of Alq3, which probably deteriorates the bicontinuous D-A network morphology; while the performance improvement of the devices with Alq3> as a buffer layer is attributed to the increased light harvesting, as well as blocking the hole leakage from MEH-PPV to the aluminum (Al) electrode due to the lower highest occupied molecular orbital (HOMO) level of Alq3 compared with that of MEH-PPV.

  17. Tyrosinase and catechol oxidase activity of copper(I) complexes supported by imidazole-based ligands: structure-reactivity correlations.

    Science.gov (United States)

    Wendt, Franziska; Näther, Christian; Tuczek, Felix

    2016-09-01

    Four new imidazole-based ligands, 4-((1H-imidazol-4-yl)methyl)-2-phenyl-4,5-dihydrooxyzole (L OL 1), 4-((1H-imidazol-4-yl)methyl)-2-(tert-butyl)-4,5-dihydrooxyzole (L OL 2), 4-((1H-imidazol-4-yl)methyl)-2-methyl-4,5-dihydrooxyzole (L OL 3), and N-(2,2-dimethylpropylidene)-2-(1-trityl-1H-imidazol-4-yl-)ethyl amine (L imz 1), have been synthesized. The corresponding copper(I) complexes [Cu(I)(L OL 1)(CH3CN)]PF6 (CuL OL 1), [Cu(I)(L OL 2)(CH3CN)]PF6 (CuL OL 2), [Cu(I)(L OL 3)(CH3CN)]PF6 (CuL OL 3), [Cu(I)(L imz 1)(CH3CN)2]PF6 (CuL imz 1) as well as the Cu(I) complex derived from the known ligand bis(1-methylimidazol-2-yl)methane (BIMZ), [Cu(I)(BIMZ)(CH3CN)]PF6 (CuBIMZ), are screened as catalysts for the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC-H2) to 3,5-di-tert-butylquinone (3,5-DTBQ). The primary reaction product of these oxidations is 3,5-di-tert-butylsemiquinone (3,5-DTBSQ) which slowly converts to 3,5-DTBQ. Saturation kinetic studies reveal a trend of catalytic activity in the order CuL OL 3 ≈ CuL OL 1 > CuBIMZ > CuL OL 2 > CuL imz 1. Additionally, the catalytic activity of the copper(I) complexes towards the oxygenation of monophenols is investigated. As substrates 2,4-di-tert-butylphenol (2,4-DTBP-H), 3-tert-butylphenol (3-TBP-H), 4-methoxyphenol (4-MeOP-H), N-acetyl-L-tyrosine ethyl ester monohydrate (NATEE) and 8-hydroxyquinoline are employed. The oxygenation products are identified and characterized with the help of UV/Vis and NMR spectroscopy, mass spectrometry, and fluorescence measurements. Whereas the copper complexes with ligands containing combinations of imidazole and imine functions or two imidazole units (CuL imz 1 and CuBIMZ) are found to exhibit catalytic tyrosinase activity, the systems with ligands containing oxazoline just mediate a stoichiometric conversion. Correlations between the structures of the complexes and their reactivities are discussed.

  18. Experimental and theoretical approach of photophysical properties of lanthanum(III) and erbium(III) complexes of tris(methoxymethyl)-5-oxine podant

    Science.gov (United States)

    Akbar, Rifat; Baral, Minati; Kanungo, B. K.

    2014-08-01

    With the aim of evaluating the coordination behavior of a novel polydentate tripodal ligand, 5-[[3-[(8-hydroxy-5-quinolyl)methoxy]-2-[(8-hydroxy-5-quinolyl)methoxymethyl]-2-methyl propoxy]methyl]quinolin-8-ol (TMOM5OX), towards La(III) and Er(III) metal ions, the detailed investigations of photophysical properties by theoritical and experimental (potentiometric, UV-visible and fluorescence spectrophotometry) methods were carried out. TMOM5OX has been found to form protonated complex [Ln(H4L)]4+ (Ln = La or Er) below pH 3.8, which consecutively deprotonates through one-proton processes with rise of pH. The formation constants (log β) of neutral complexes have been determined to be 36.42 (LaL) and 35.76, 37.62 (for ErL and ErL2, respectively) and the pLn (pLn = -log[Ln3+]) values of 24.6 and 27.1 for La(III) and Er(III) ions, respectively, calculated at pH 7.4, indicating TMOM5OX is a good lanthanide synthetic chelator. The absorption spectroscopy of these complexes show marked spectral variations due to characteristic lanthanide transitions, which support the use of TMOM5OX as a sensitive optical pH based sensor to detect Ln(III) metal ions in biological systems. In addition, these complexes have also been shown to exhibit strong green fluorescence allowing simultaneous sensing within the visible region under physiological pH in competitive medium for both La(III) and Er(III) ions. The intense fluorescence from these compounds were revealed to intermittently get quenched under acidic and basic conditions due to the photoinduced intramolecular electron transfer from excited 8-hydroxyquinoline (8-HQ) moiety to metal ion, just an opposite process. This renders these compounds the OFF-ON-OFF type of pH-dependent fluorescent sensors. The complexes coordination geometries were optimized using the sparkle/PM6 model and the theoretical spectrophotometric studies were carried out in order to validate the experimental findings, based on ZINDO/S methodology at configuration

  19. 菠萝蜜的染色体制片优化及核型分析%Optimization of Chromosome Mounting Technique and Karyotype Analysis of Jackfruit (Artocarpus heterophyllus Lam.)

    Institute of Scientific and Technical Information of China (English)

    劳世辉; 魏岳荣; 盛鸥; 梁国鲁

    2011-01-01

    应用改良的去壁低渗法研究,比较了不同预处理剂对菠萝蜜染色体制片的效果及其染色体数目和核型.结果表明:以0.002 mo1/L 8-羟基喹啉与0.2%秋水仙素(1∶1)混合液作为预处理剂,预处理3 h效果较好.菠萝蜜的染色体数目为2n=2x=56,为二倍体,主要由中部和近中部着丝点染色体构成,9号染色体上附着1对随体;最长染色体/最短染色体为2.08∶1,臂比大于2的染色体占全组染色体的3.5%,属2A核型,核型公式为2n=2M+50m(2SAT)+4sm.本研究首次发现菠萝蜜可能存在B染色体.%In this paper, the chromosome number and karyotype of jackfruit was studied after detaching the cell wall and treated with low osmotic solution, and the effects of different pretreatments were also investigated.The results showed that the optimum pretreatment chemical was the mixture of 0.2% colchicine and 0.002 mol/L 8-hydroxyquinoline (1:1), with the pretreatment time for 3 hours. The karyotype analysis showed that jackfruit was diploid (2n=2x=56). The ratio of the longest chromosome to the shortest one was 2.08:1, and the arm ration of 3.5% chromosomes was over 2, so that the karyotype formula of jackfruit was 2n=2M+50m (2SAT) +4sm, belonging to 2A karyotype. It is the first report that the B Chromosome may be in jackfruit.

  20. Photo-Crosslinking of Pendent Uracil Units Provides Supramolecular Hole Injection/Transport Conducting Polymers for Highly Efficient Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Hsi-Kang Shih

    2015-04-01

    Full Text Available A new process for modifying a polymeric material for use as a hole injection transport layer in organic light-emitting diodes has been studied, which is through 2π + 2π photodimerization of a DNA-mimetic π-conjugated poly(triphenylamine-carbazole presenting pendent uracil groups (PTC-U under 1 h of UV irradiation. Multilayer florescence OLED (Organic light-emitting diodes device with the PTC-U-1hr as a hole injection/transport layer (ITO (Indium tin oxide/HITL (hole-injection/transport layer (15 nm/N,N'-di(1-naphthyl- N,N'-diphenyl-(1,1'-biphenyl-4,4'-diamine (NPB (15 nm/Tris-(8-hydroxyquinoline aluminum (Alq3 (60 nm/LiF (1 nm/Al (100 nm is fabricated, a remarkable improvement in performance (Qmax (external quantum efficiency = 2.65%, Bmax (maximum brightness = 56,704 cd/m2, and LE (luminance efficiencymax = 8.9 cd/A relative to the control PTC-U (Qmax = 2.40%, Bmax = 40,490 cd/m2, and LEmax = 8.0 cd/A. Multilayer phosphorescence OLED device with the PTC-U-1hr as a hole injection/transport layer (ITO/HITL (15 nm/Ir(ppy3:PVK (40 nm/BCP (10nm/Alq3 (40 nm/LiF (1 nm/Al (100 nm is fabricated by successive spin-coating processes, a remarkable improvement in performance (Qmax = 9.68%, Bmax = 41,466 cd/m2, and LEmax = 36.6 cd/A relative to the control PTC-U (Qmax = 8.35%, Bmax = 34,978 cd/m2, and LEmax = 30.8 cd/A and the commercial product (poly(3,4-ethylenedioxythiophene:polystyrenesulfonate PEDOT:PSS (Qmax = 4.29%, Bmax = 15,678 cd/m2, and LEmax = 16.2 cd/A has been achieved.

  1. Indole-3-acetic acid in plant-pathogen interactions: a key molecule for in planta bacterial virulence and fitness.

    Science.gov (United States)

    Cerboneschi, Matteo; Decorosi, Francesca; Biancalani, Carola; Ortenzi, Maria Vittoria; Macconi, Sofia; Giovannetti, Luciana; Viti, Carlo; Campanella, Beatrice; Onor, Massimo; Bramanti, Emilia; Tegli, Stefania

    The plant pathogenic bacterium Pseudomonas savastanoi, the causal agent of olive and oleander knot disease, uses the so-called "indole-3-acetamide pathway" to convert tryptophan to indole-3-acetic acid (IAA) via a two-step pathway catalyzed by enzymes encoded by the genes in the iaaM/iaaH operon. Moreover, pathovar nerii of P. savastanoi is able to conjugate IAA to lysine to generate the less biologically active compound IAA-Lys via the enzyme IAA-lysine synthase encoded by the iaaL gene. Interestingly, iaaL is now known to be widespread in many Pseudomonas syringae pathovars, even in the absence of the iaaM and iaaH genes for IAA biosynthesis. Here, two knockout mutants, ΔiaaL and ΔiaaM, of strain Psn23 of P. savastanoi pv. nerii were produced. Pathogenicity tests using the host plant Nerium oleander showed that ΔiaaL and ΔiaaM were hypervirulent and hypovirulent, respectively and these features appeared to be related to their differential production of free IAA. Using the Phenotype Microarray approach, the chemical sensitivity of these mutants was shown to be comparable to that of wild-type Psn23. The main exception was 8 hydroxyquinoline, a toxic compound that is naturally present in plant exudates and is used as a biocide, which severely impaired the growth of ΔiaaL and ΔiaaM, as well as growth of the non-pathogenic mutant ΔhrpA, which lacks a functional Type Three Secretion System (TTSS). According to bioinformatics analysis of the Psn23 genome, a gene encoding a putative Multidrug and Toxic compound Extrusion (MATE) transporter, was found upstream of iaaL. Similarly to iaaL and iaaM, its expression appeared to be TTSS-dependent. Moreover, auxin-responsive elements were identified for the first time in the modular promoters of both the iaaL gene and the iaaM/iaaH operon of P. savastanoi, suggesting their IAA-inducible transcription. Gene expression analysis of several genes related to TTSS, IAA metabolism and drug resistance confirmed the presence of a

  2. AS-2, a novel inhibitor of p53-dependent apoptosis, prevents apoptotic mitochondrial dysfunction in a transcription-independent manner and protects mice from a lethal dose of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Akinori, E-mail: morita@tokushima-u.ac.jp [Department of Radiological Science, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Ariyasu, Shinya [Center for Technologies against Cancer, Tokyo University of Science, Chiba 278-8510 (Japan); Wang, Bing [Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Asanuma, Tetsuo; Onoda, Takayoshi [Department of Radiological Science, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Sawa, Akiko [Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510 (Japan); Tanaka, Kaoru [Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Takahashi, Ippei [Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553 (Japan); Togami, Shotaro [Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510 (Japan); Nenoi, Mitsuru [Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Inaba, Toshiya [Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553 (Japan); Aoki, Shin [Center for Technologies against Cancer, Tokyo University of Science, Chiba 278-8510 (Japan); Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510 (Japan)

    2014-08-08

    Highlights: • A bidentate HQ derivative, AS-2, suppresses p53-dependent apoptosis by DNA damage. • AS-2 does not significantly affect nuclear p53 response. • UV-excited blue emission of AS-2 clearly showed its extranuclear localization. • AS-2 prevents mitochondrial dysfunction despite the increase of mitochondrial p53. • AS-2 protects mice from a radiation dose that causes lethal hematopoietic syndrome. - Abstract: In a previous study, we reported that some tetradentate zinc(II) chelators inhibit p53 through the denaturation of its zinc-requiring structure but a chelator, Bispicen, a potent inhibitor of in vitro apoptosis, failed to show any efficient radioprotective effect against irradiated mice because the toxicity of the chelator to mice. The unsuitability of using tetradentate chelators as radioprotectors prompted us to undertake a more extensive search for p53-inhibiting agents that are weaker zinc(II) chelators and therefore less toxic. Here, we show that an 8-hydroxyquinoline (8HQ) derivative, AS-2, suppresses p53-dependent apoptosis through a transcription-independent mechanism. A mechanistic study using cells with different p53 characteristics revealed that the suppressive effect of AS-2 on apoptosis is specifically mediated through p53. In addition, AS-2 was less effective in preventing p53-mediated transcription-dependent events than pifithrin-μ (PFTμ), an inhibitor of transcription-independent apoptosis by p53. Fluorescence visualization of the extranuclear distribution of AS-2 also supports that it is ineffective on the transcription-dependent pathway. Further investigations revealed that AS-2 suppressed mitochondrial apoptotic events, such as the mitochondrial release of intermembrane proteins and the loss of mitochondrial membrane potential, although AS-2 resulted in an increase in the mitochondrial translocation of p53 as opposed to the decrease of cytosolic p53, and did not affect the apoptotic interaction of p53 with Bcl-2. AS-2 also

  3. 常见腌制食品中亚硝酸盐含量的测定%Determination of Nitrite Content in Common Preserved Foods

    Institute of Scientific and Technical Information of China (English)

    彭晓娅; 董祥

    2016-01-01

    采用可见分光光度法,利用亚硝酸根可与中性红试剂、8-羟基喹啉发生重氮反应,然后在氨性溶液中又会生成偶氮染料,反应体系在λ=560nm处有最大吸收峰,测得亚硝酸根的标准吸收曲线方程为A=0.26232C-0.00169,相关系数R=0.99873。此方法测定腌制食品中亚硝酸盐含量均没有超过国家食品中亚硝酸盐含量规定标准(≤20mg/kg),但散装产品较正规包装产品的亚硝酸根含量高,消费者应尽量以新鲜蔬菜为主食,少吃腌菜,特别是散装类型的,注重健康饮食。%By using visible spectrophotometry, the nature could occur diazotization reaction with reagent neutral red, 8-hydroxyquinoline, and then the azo dyes were formed in the ammonia solution. The reaction system had the maximum absorption peak at the wavelength of λ=560 nm, the standard nitrite absorption curve equation wasA=0.262 32C-0.001 69, the correlation coeffcientR was 0.998 73. Using this method to determine the content of nitrite in pickled foods did not exceed the range of Chinese National Food Standard, but the bulk product is higher than the regular packing product's nitrite content. Consumers should try to eat fresh vegetables as the staple food, less sour pickles, especially bulk types, focus on healthy eating.

  4. Effects of Pretreatment with Low Temperature Storage on Preservation of Cut Carnation%预处理结合低温贮藏对康乃馨切花保鲜效果研究

    Institute of Scientific and Technical Information of China (English)

    李小玲; 华智锐; 杨文文

    2012-01-01

    In order to investigate the best approach for preservation of carnation cut flowers,this paper researched post-harvest preservation effect of cut carnation with combination of low temperature storage,addition of sucrose,8-hydroxyquinoline,citric acid,and exogenous hormone 6-BA and 2, 4-D and other substances. The results showed that pretreatment with low-temperature storage of carnation cut flowers increased flower diameter, bud length, branch, fresh weight, and increased CAT activity in the petals. The preservation effect of 5% sucrose+100 mg/L 8-HQ + 200 mg/L CA+100 mg/L 6-BA combination formula with cold storage (2 weeks in 4 癈 refrigerator) was better than that of 5% sucrose+100 mg/L 8-HQ+200 mg/L CA+100 mg/L 2,4-D combined with cold storage method. This showed that pretreatment with low-temperature storage had a good preservation effect on cut flowers of carnations,and exogenous hormone 6-BA was better than 2,4-D.%为探讨康乃馨鲜切花最佳保鲜方法,在低温条件下,通过在保鲜液中添加蔗糖、8-羟基喹啉(8-HQ)、柠檬酸(CA)及外源激素6-BA和2,4-D等,研究康乃馨切花的采后保鲜效果.结果表明,2周4℃的低温保存结合预处理增加了康乃馨切花花径、花蕾长度、花枝鲜质量,提高了花瓣CAT活性,其中,5%蔗糖+100 mg/L 8-HQ+200 mg/L CA+100 mg/L 6-BA配方组合保鲜效果最佳.由此说明,在低温条件下,预处理对康乃馨切花的保鲜和延缓衰老有较好的作用,且添加外源激素6-BA比2,4-D作用更佳.

  5. Charge transport in amorphous organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Lukyanov, Alexander

    2011-03-15

    Organic semiconductors with the unique combination of electronic and mechanical properties may offer cost-effective ways of realizing many electronic applications, e. g. large-area flexible displays, printed integrated circuits and plastic solar cells. In order to facilitate the rational compound design of organic semiconductors, it is essential to understand relevant physical properties e. g. charge transport. This, however, is not straightforward, since physical models operating on different time and length scales need to be combined. First, the material morphology has to be known at an atomistic scale. For this atomistic molecular dynamics simulations can be employed, provided that an atomistic force field is available. Otherwise it has to be developed based on the existing force fields and first principle calculations. However, atomistic simulations are typically limited to the nanometer length- and nanosecond time-scales. To overcome these limitations, systematic coarse-graining techniques can be used. In the first part of this thesis, it is demonstrated how a force field can be parameterized for a typical organic molecule. Then different coarse-graining approaches are introduced together with the analysis of their advantages and problems. When atomistic morphology is available, charge transport can be studied by combining the high-temperature Marcus theory with kinetic Monte Carlo simulations. The approach is applied to the hole transport in amorphous films of tris(8- hydroxyquinoline)aluminium (Alq{sub 3}). First the influence of the force field parameters and the corresponding morphological changes on charge transport is studied. It is shown that the energetic disorder plays an important role for amorphous Alq{sub 3}, defining charge carrier dynamics. Its spatial correlations govern the Poole-Frenkel behavior of the charge carrier mobility. It is found that hole transport is dispersive for system sizes accessible to simulations, meaning that calculated

  6. Effect of LiF on Capacitance of OLEDs%LiF作电子注入缓冲层对有机电致发光器件电容的影响

    Institute of Scientific and Technical Information of China (English)

    李颖弢; 刘肃; 王方聪; 张春林; 岳红菊

    2007-01-01

    Numerical methods have been used to analyze the contribution of LiF layer which is inserted between the cathode and the electron-transporting layer in organic light emitting devices (OLEDs). The LiF as the electron injection buffer layer can improve the performance of the OLEDs, including reducing the cut-in voltage, increasing the current and emitting luminance. This work fabricates two different kinds of devices A and B with structures of Indium Tin Oxide (ITO)/tris-(8-hydroxyquinoline) aluminum (Alq3)/Al and ITO/Alq3/LiF/Al, using the C-V characteristic to analyze the roles of LiF in OLEDs and finding the capacitance of the device A and B is 72 500 pF and 12 500 pF, respectively. At the same time, this paper interprets why LiF could reduce the capacitance and the power consumption of the OLEDs from the correct point of view. It shows that the LiF layer improves the performance of the OLEDs and saves the energy sources, resulting in the change of the capacitance of the devices.%已经有多种方法分析了LiF作为电子注入缓冲层对有机电致发光器件的影响,用LiF/Al双层阴极和发光层Alq3制成的有机电致发光器件(OLED), 可以降低器件的开启电压,提高器件的发光效率、发光亮度.文章主要对OLEDs (A): Al/Alq3/ITO和(B): Al /LiF(1nm)/Alq3/ITO的C-V特性进行了研究,当在阴极和发光层Alq3之间加上1 nm厚的LiF层作为电子注入缓冲层以后,器件的电容由不加LiF时的72 500 pF减小到12 500 pF,由于电容的减小,有效地降低了器件的功耗,进而提高了器件的寿命,节约了能源,进一步改善了器件的性能.

  7. IMPROVING POSTHARVEST VASE-LIFE AND QUALITY OF CUT GERBERA FLOWERS USING NATURAL AND CHEMICAL PRESERVATIVES

    Directory of Open Access Journals (Sweden)

    Mehrdad Jafarpour

    2015-06-01

    Full Text Available Gerbera is one of ten popular cut flowers in the world which occupies the forth place according to the global trends in floriculture. Hence, this study aimed to investigate the effects of chemical, hormonal and essential oil substances in preservative solutions to improve its postharvest qualitative characteristics. Two pulse treatments including distilled water (pulse1 and 4% CaCl2 + 3% sucrose (pulse2 for 24 hour were applied before long-time treatments. Long-time treatments were comprised of (1 Hormonal treatments: 0, 25, 30 mg*l-1 Gibberellic acid, 0, 150, 250 mg*l-1 Benzyl adenine and 0, 100, 200 mg*l-1 5-Sulfosalicylic acid (2 Chemical treatments: 0, 0.4, 0.8 mM Silver thiosulphate, 0, 5, 10 mg*l-1 Nano-silver particles, 0, 4, 6 mM Aminooxy acetic acid and 0, 200 and 400 mg*l-1 8-hydroxyquinoline sulphate (3 Essential oils: Thymus essential oil and Stevia essential oils (0, 0.1 and 0.2 mg*l-1. Data were subjected to analysis of variance based on the factorial experiment model in the layout completely randomized design. Mean comparison was performed using the Duncan’s multiple range test. Parameters of fresh weight, stem bending, capitulum diameter, carotenoid pigments of petal and vase-life longevity were evaluated during 12 days. The highest fresh weight was obtained when cut flowers were held in a solution containing pulse1 + 250 mg*l-1 BA. Among all treatments, 8-HQS treatment showed the best effects on preventing stem bending, increasing capitulum diameter and also on prolonging of vase-life, but nonetheless, the effects of pulse treatments and 8-HQS concentrations were insignificant. To conclude, 200 mg*l-1 8-HQS without pulse treatment has the potential to be used as a commercial preservative solution to improve the keeping quality and vase-life of this important cut flower.

  8. Novel bimodal porous N-(2-aminoethyl)-3-aminopropyltrimethoxysilane-silica monolithic capillary microextraction and its application to the fractionation of aluminum in rainwater and fruit juice by electrothermal vaporization inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Zheng, Fei; Hu, Bin

    2008-01-01

    A novel bimodal porous N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS)-silica monolithic capillary was prepared by sol-gel technology, and used as capillary microextraction (CME) column for aluminum fractionation by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV)-ICP-MS with the use of polytetrafluoroethylene (PTFE) slurry as fluorinating agent. The extraction behaviors of different Al species were studied and it was found that in the pH range of 4-7, labile monomeric Al (free Al 3+, Al-OH and Al-F) could be retained quantitatively on the monolithic capillary, while non-labile monomeric Al (Al-Cit and Al-EDTA) passed through the capillary directly. The labile monomeric Al retained on monolithic capillary was eluted with 10 μL 1 mol L - 1 HCl and the elution was introduced into the ETV for fluorination assisted ETV-ICP-MS determination. The total monomeric Al fraction was also determined by AAPTS-silica monolithic CME-fluorination-assisted electrothermal vaporization (FETV)-ICP-MS after the sample solution was adjusted to pH 8.8. Non-labile monomeric Al was obtained by subtracting labile monomeric Al from the total monomeric Al. Under the optimized conditions, the relative standard deviation (R.S.D) was 6.2% ( C = 1 μg L - 1 , n = 7; sample volume, 5 mL), and the limit of detection was 1.6 ng L - 1 for Al with an enrichment factor of 436 fold and a sampling frequency of 9 h - 1 . The prepared AAPTS-silica monolithic capillary showed an excellent pH tolerance and solvent stability and could be used for more than 250 times without decreasing adsorption efficiency. The developed method was applied to the fraction of Al in rainwater and fruit juice, and the results demonstrated that the established system had advantages over the existing 8-hydroxyquinoline (8-HQ) chelating system for Al fractionation such as wider pH range, higher tolerance of interference and better regeneration.

  9. Ultrahigh density array of vertically aligned small-molecular organic nanowires on arbitrary substrates.

    Science.gov (United States)

    Starko-Bowes, Ryan; Pramanik, Sandipan

    2013-06-18

    In recent years π-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication. A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently π-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important π-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors

  10. On line automated system for the determination of Sb(V), Sb(III), thrimethyl antimony(v) and total antimony in soil employing multisyringe flow injection analysis coupled to HG-AFS.

    Science.gov (United States)

    Silva Junior, Mario M; Portugal, Lindomar A; Serra, Antonio M; Ferrer, Laura; Cerdà, Victor; Ferreira, Sergio L C

    2017-04-01

    This paper proposes the use of a multisyringe flow injection analysis (MSFIA) system for inorganic antimony speciation analysis, trimethyl antimony(V) and determination of total antimony in soil samples using hydride generation atomic fluorescence spectrometry (HG-AFS). Total antimony has been determined after reduction of antimony(V) to antimony(III) using potassium iodide and ascorbic acid. For determination of total inorganic antimony the sample is percolated in a mini-column containing the Dowex 50W-X8 resin for retention of the organic species of antimony. Antimony(III) is quantified in presence of 8-hydroxyquinoline as masking agent for antimony(V) after an extraction step of the organic antimony species using the also same mini-column. The trimethyl antimony(V) content is found by difference between total antimony and total inorganic antimony. By other hand, antimony(V) is quantified by difference between total inorganic antimony and antimony(III). The analytical determinations were performed using sodium tetrahydroborate as reducing agent. The optimization step was performed using two-level full factorial design and Doehlert matrix involving the factors: hydrochloric acid and sodium tetrahydroborate concentrations and sample flow rate. The optimized experimental conditions allow the antimony determination utilizing the external calibration technique with limits of detection and quantification of 0.9 and 3.1ngg(-1), respectively, and a precision expressed as relative standard deviation of 3.2% for an antimony solution of 5.0µgL(-1). The method accuracy was confirmed by analysis of the soil certified reference material furnished from Sigma-Aldrich RTC. Additionally, addition/recovery tests were performed employing synthetic solutions prepared using trimethyl antimony(V), antimony(III), antimony(V) and five soil samples. The antimony extraction step was performed in a closed system using hydrochloric acid, ultrasonic radiation and controlled temperature. The

  11. Optical, electrical, and magnetic field studies of organic materials for light emitting diodes and photovoltaic applications

    Science.gov (United States)

    Basel, Tek Prasad

    We studied optical, electrical, and magnetic field responses of films and devices based on organic semiconductors that are used for organic light emitting diodes (OLEDs) and photovoltaic (OPV) solar cell applications. Our studies show that the hyperfine interaction (HFI)-mediated spin mixing is the key process underlying various magnetic field effects (MFE) and spin transport in aluminum tris(8-hydroxyquinoline)[Alq3]-based OLEDs and organic spin-valve (OSV). Conductivity-detected magnetic resonance in OLEDs and magneto-resistance (MR) in OSVs show substantial isotope dependence. In contrast, isotope-insensitive behavior in the magneto-conductance (MC) of same devices is explained by the collision of spin ½ carriers with triplet polaron pairs. We used steady state optical spectroscopy for studying the energy transfer dynamics in films and OLEDs based on host-guest blends of the fluorescent polymer and phosphorescent molecule. We have also studied the magnetic-field controlled color manipulation in these devices, which provide a strong proof for the `polaron-pair' mechanism underlying the MFE in organic devices. The critical issue that hampers organic spintronics device applications is significant magneto-electroluminescence (MEL) at room temperature (RT). Whereas inorganic spin valves (ISVs) show RT magneto-resistance, MR>80%, however, the devices do not exhibit electroluminescence (EL). In contrast, OLEDs show substantive EL emission, and are particularly attractive because of their flexibility, low cost, and potential for multicolor display. We report a conceptual novel hybrid organic/inorganic spintronics device (h-OLED), where we employ both ISV with large MR at RT, and OLED that has efficient EL emission. We investigated the charge transfer process in an OPV solar cell through optical, electrical, and magnetic field measurements of thin films and devices based on a low bandgap polymer, PTB7 (fluorinated poly-thienothiophene-benzodithiophene). We found that

  12. The effects of ultra-thin cerium fluoride film as the anode buffer layer on the electrical characteristics of organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hsin-Wei [Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan (China); Tsai, Cheng-Che [Department of Electronics Engineering and Computer Science, Tung Fang Design Institute, Kaohsiung, 82941, Taiwan (China); Hong, Cheng-Shong [Department of Electronic Engineering, National Kaohsiung Normal University, Kaohsiung, 824, Taiwan (China); Kao, Po-Ching [Department of Electrophysics, National Chiayi University, Chiayi 60004, Taiwan (China); Juang, Yung-Der [Department of Materials Science, National University of Tainan, Tainan, 70005, Taiwan (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, 70101, Taiwan (China)

    2016-11-01

    Highlights: • OLEDs were enhanced efficiency by depositing CeF{sub 3} buffer layer. • The surface roughness was smoother of the CeF{sub 3} buffer layer. • The surface energy and polarity were increased of the CeF{sub 3} buffer layer. • Admittance spectroscopy showed that increased capacitance. • The carrier injection was enhanced in the space charge region. - Abstract: In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF{sub 3}film as an ultra-thin buffer layer between the indium tin oxide (ITO) electrode and α-naphthylphenylbiphenyldiamine (NPB) hole transport layer, with the structure configuration ITO/CeF{sub 3} (0.5, 1, and 1.5 nm)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris(8-hydroxyquinoline) aluminum (Alq{sub 3}) (60 nm)/lithium fluoride (LiF) (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy results revealed the formation of the UV-ozone treated CeF{sub 3} film. The work function increased from 4.8 eV (standard ITO electrode) to 5.22 eV (0.5-nm-thick UV-ozone treated CeF{sub 3} film deposited on the ITO electrode). The surface roughness of the UV-ozone treated CeF{sub 3} film was smoother than that of the standard ITO electrode. Further, the UV-ozone treated CeF{sub 3} film increased both the surface energy and polarity, as determined from contact angle measurements. In addition, admittance spectroscopy measurements showed an increased capacitance and conductance of the OLEDs. Accordingly, the turn-on voltage decreased from 4.2 V to 3.6 V at 1 mA/cm{sup 2}, the luminance increased from 7588 cd/m{sup 2} to 24760 cd/m{sup 2}, and the current efficiency increased from 3.2 cd/A to 3.8 cd/A when the 0.5-nm-thick UV-ozone treated CeF{sub 3} film was inserted into the OLEDs.

  13. Quinoline-based clioquinol and nitroxoline exhibit anticancer activity inducing FoxM1 inhibition in cholangiocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Chan-on W

    2015-04-01

    , expression of oncogenic FoxM1 was markedly decreased concomitant with downregulation of various FoxM1’s downstream targets including cdc25b, CENP-B, and survivin. In addition, the compounds distinctly impaired HuCCT1 migration as well as inhibited expression of matrix metalloproteinase (MMP-2 and MMP-9.Conclusion: Collectively, this study reports for the first time the anticancer effects of CQ and NQ against CCA cells, and highlights new insights into the mechanism of actions of the quinoline-based compounds to disrupt FoxM1 signaling. Keywords: FoxM1, cholangiocarcinoma, 8-hydroxyquinoline derivatives, clioquinol, nitroxoline, migration

  14. 一串红染色体制片技术优化与计数%Optimization of Chromosome Sectioning and Chromosome Counting of Salvia splendens

    Institute of Scientific and Technical Information of China (English)

    洪培培; 杨建玉; 陈洪伟; 刘克锋; 王红利; 智利婷

    2011-01-01

    The roots of germinating seeds,stem tips and tender leaves of Salvia splendens commercial variety,'Vista Red' were used to study the effect of different plant materials, pretreatment medicaments and pretreatment time on the slide-preparing of the chromosomes by conventional squashing technique, exploring the pretreatment conditions of the experiment. We have also statistics for the chromosomes number of the plant type mutant,wild type and 4 commercial varieties of Salvia splendens by the technique of wall degradation and hypotonic treatment. The results showed that the roots of germinating seeds were pretrea-ted with 0.002 mol/L 8-hydroxyquinoline for 3 - 4 h performed best in the sectioning;30 metaphase cells were observed for each variety. We found that chromosome numbers are 2n=44 in 86. 7% and above cells. There are no differences in the chromosome numbers of the plant type mutant,wild type and 4 commercial varieties of Salvia splendens.%以一串红商品种‘展望红'萌发种子根尖、幼苗茎尖生长点以及嫩叶为实验材料,利用常规压片法比较不同材料、不同预处理液及预处理时间对一串红染色体制片的影响,探索实验预处理条件.然后利用去壁低渗法对一串红4个商品种和一串红株型突变体及其野生型进行染色体计数.实验结果显示:以一串红萌发种子的根尖为实验材料,用0.002 mol/L 8-羟基喹啉预处理3~4 h压片所得染色体效果最好;分别观察6个供试品种(系)分散良好、清晰的30个分裂相细胞,86.7%及以上的细胞染色体数目为2n=44.研究表明,一串红株型突变体与野生型及4个商品种在染色体数目上没有差异.

  15. 甘蔗根尖染色体制片技术研究%Studies on Technique of Chromosome Squashing of Root-tip in Sugarcane

    Institute of Scientific and Technical Information of China (English)

    林秀琴; 蔡青; 陆鑫; 应雄美; 毛钧; 苏火生

    2011-01-01

    甘蔗是异源多倍体植物,染色体数目多、体积小,染色体制片困难,导致细胞遗传学研究进展缓慢.以分裂旺盛的甘蔗根尖为材料,对不同采样时间、预处理方法、解离时间、染色方法等各技术环节进行实验研究.结果表明:在冬季气温较低的条件下,于15:00进行采样,饱和对二氯苯与0.002 mol/L 8-羟基喹啉等体积混合液室温预处理4~4.5 h,1 mol/L HCl与45%乙酸等体积混合液于60℃水浴锅解离8min后,用改良苯酚卡宝品红进行涂片滴染,所获得的染色体制片效果最好.%Sugarcane belongs to the allopolyploid plant which contains large number of chromosome with small size. The cytological research on sugarcane may hence be influenced by its difficulties to obtain chromosome products successful. In this paper, the root-tips of sugarcane were used to study the effects of the sampling time, the pretreatment chemical solution, hydrolysing time and staining on the chromosome squashing. The results showed that the optimal sampling time of roots was 15:00 pm under the lower temperature condition in winter. Among the four pretreatment of chemical solutions, the solution mixed with equal volume of saturated p-dichlorobenzene and 0.002 mol/L 8-hydroxyquinoline, was pretreated at room temperature for 4-4.5 h got best result. Root tips were then hydrolysed with the solution mixed by equal volume of 1 mol/L HC1 and 45% acetic acid, for 8 min at 60℃, and stained with modified Carbol fuchsin solution. With this method a very good effect of chromosome squashing could be obtained.

  16. Synthesis, characterization and standard molar enthalpy of formation of La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO)

    Energy Technology Data Exchange (ETDEWEB)

    Li Qiangguo [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China)]. E-mail: liqiangguo@163.com; Li Xu [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Huang Yi [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Xiao Shengxiong [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Yang Dejun [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Ye Lijuan [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Wei Deliang [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); Liu Yi [Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan 423000 (China); College of Chemistry and Molecular Science, Wuhan University, Wuhan 430062 (China)

    2006-02-15

    The product from reaction of lanthanum chloride seven-hydrate with salicylic acid and 8-hydroxyquinoline, La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO), was characterized by IR, elemental analysis, molar conductance, and thermogravimetric analysis. The standard molar enthalpies of solution of [LaCl{sub 3}.7H{sub 2}O (s)], [2C{sub 7}H{sub 6}O{sub 3} (s)], [C{sub 9}H{sub 7}NO (s)] and [La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s)] in a mixed solvent of absolute ethyl alcohol, dimethyl formamide (DMF) and perchloric acid were determined by calorimetry to be {delta}{sub s}H{sub m}{sup {theta}}[LaCl{sub 3}.7H{sub 2}O (s), 298.15K]=-96.45+/-0.18kJmol{sup -1}, {delta}{sub s}H{sub m}{sup {theta}}[2C{sub 7}H{sub 6}O{sub 3} (s), 298.15K]=14.99+/-0.17kJmol{sup -1}, {delta}{sub s}H{sub m}{sup {theta}}[C{sub 9}H{sub 7}NO (s), 298.15K]=-3.86+/-0.06kJmol{sup -1} and {delta}{sub s}H{sub m}{sup {theta}}[La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s), 298.15K]=-117.78+/-0.11kJmol{sup -1}. The enthalpy change of the reaction(1)LaCl{sub 3}.7H{sub 2}O(s)+2C{sub 7}H{sub 6}O{sub 3}(s)+C{sub 9}H{sub 7}NO(s)=La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO= )(s)+3HCl(g)+7H{sub 2}O(l)was determined to be {delta}{sub r}H{sub m}{sup {theta}}=91.57+/-0.34kJmol{sup -1}. From data in the literature, through Hess' law, the standard molar enthalpy of formation of La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 7}NO) (s) was estimated to be {delta}{sub f}H{sub m}{sup {theta}}[La(C{sub 7}H{sub 5}O{sub 3}){sub 2}.(C{sub 9}H{sub 6}NO) (s), 298.15K]=- 2076.5+/-3.9kJmo0011l{sup -}.

  17. Caracterização cariológica de palmeiras do gênero Butia (Arecaceae Karyological characterization of Butia (Arecaceae palm trees

    Directory of Open Access Journals (Sweden)

    Lauís Brisolara Corrêa

    2009-12-01

    early count. Fruits from natural populations were collected; the seeds were extracted and put to germinate. The aim of this paper was to analyze the chromosomical features between and into five species of this genus. Nine specimens of B. capitata, three of B. eriospatha, three of B. odorata, two of B. paraguayensis and two of B. yatay were analyzed. Root tips from seedlings were pretreated in 0.002M 8-hydroxyquinoline or icy water (0ºC or 1% colchicine, fixed in ethanol and acetic acid (3:1 and then stained in 2% Giemsa. All species showed the same chromosome number, 2n = 2x = 32, and the same chromosome morphology: 14 metacentric, 12 submetacentric and 6 acrocentric chromosomes. Karyotypes of all species are symetric, with two pairs of sattelite, one pair of metacentric and one pair of acrocentric chromosomes.

  18. EL ÁCIDO a-NAFTALENACÉTICO PROLONGA LA VIDA EN LA POSCOSECHA DE ROSAS DE CORTE a-NAPHTALEN ACETIC ACID PROLONGS VASE LIFE OF CUT ROSES

    Directory of Open Access Journals (Sweden)

    Pedro Alberto Bolívar Chávez

    2005-12-01

    200 mgL-1 of 8-hydroxyquinoline citrate (8-HQC solution plus 800 mgL-1 of aluminium sulphate (Al2(SO43 plus 2% sucrose (C12H22O11 and (5 calcium hypoclorite (Ca(ClO2 2 %. The post-harvest handling consisted of hydration, pulsing, storing and transport simulation. The longest vase life was obtained with ANA treatments (ANA plus Florissima, 10,3 days; ANA plus Florissima plus calcium, 9,3 days; and ANA plus Florissima plus 1-MCP, 8.3 days; and the shortest vase life was obtained with the 8-HQC plus Al2(SO43 plus sucrose treatment. The interaction of ANA plus Florissima reduced bent-neck significantly and increased water consumption as compared to the other treatments. There was a synergestic effect between ANA and CaO, which decreased the senescent process.

  19. Photometric flow injection determination of phosphate on a PDMS microchip using an optical detection system assembled with an organic light emitting diode and an organic photodiode.

    Science.gov (United States)

    Liu, Rong; Ishimatsu, Ryoichi; Yahiro, Masayuki; Adachi, Chihaya; Nakano, Koji; Imato, Toshihiko

    2015-01-01

    A compact photometric detector was constructed from an organic light emitting diode (OLED) based on a europium complex, europium(diben-zoylmethanato)3(bathophenanthroline) (Eu(DBM)3bath), as the light source and an organic photodiode (OPD) fabricated from a hetero-junction of two layers of copper phthalocyanine (CuPc)/fullerene (C60) as the photo-detector on a microchip prepared from poly(dimethylsiloxan) (PDMS) and was applied to the determination of phosphate. The OLED and the OPD were fabricated by a vapor deposition method on an indium tin oxide (ITO) coated glass substrate with the following layered structure; Glass (0.7 mm)/ITO (110 nm)/4,4'-bis[N-(1-naphthyl)-N-phenyl amino]-biphenyl (α-NPD) (30 nm)/4,4'-di(N-carbazolyl)biphenyl (CBP): Eu(3+) (8 wt%, 30 nm)/bathocuproine (BCP) (30 nm)/aluminum tris(8-hydroxyquinoline) (Alq3) (25 nm)/magnesium and silver (MgAg) (100 nm)/Ag (10nm) and Glass (0.7 mm)/ITO (110 nm)/CuPc (35 nm)/C60 (50 nm)/BCP (10 nm)/Ag (50 nm), respectively. The OLED based on the europium complex emitted a sharp light at the wavelength of 612 nm with a full width at half maximum (FWHM) of 8 nm. The performance of the photometric detector assembled was evaluated based on measurements of the absorbance of different concentrations of malachite green (MG) solutions for a batch system with 1cm long path length. The molar absorptive coefficient of the MG solution, calculated from the photocurrent of the OPD, was in good agreement with the value reported in the literature. A microchip with two inlets and one outlet U-shaped channel was prepared by a conventional photolithograph method. The OLED and the OPD were configured so as to face each other through the PDMS microchip in parallel in order to align the light axis of the OLED and the OPD with the flow cell (optical path length of 5mm), which was located at the end of outlet. For the determination of phosphate, an ion-association reaction between MG and a molybdenum-phosphate complex was utilized

  20. ITO-free organic light-emitting diodes with MoO{sub 3}/Al/MoO{sub 3} as semitransparent anode fabricated using thermal deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hsin-Wei; Huang, Ching-Wen [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Kao, Po-Ching [Department of Electrophysics, National Chiayi University, Chiayi 60004, Taiwan (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2015-08-30

    Highlights: • In this paper, the structure of the proposed devices is substrate (glass; polyethersulfone (PES))/anode (MoO{sub 3}/Al/MoO{sub 3}; MoO{sub 3}/Al)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris (8-hydroxyquinoline) aluminum (Alq3) (60 nm)/LiF (1 nm)/Al (150 nm). • The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO{sub 3}) and metal (Al) layers. • The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. • The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m{sup 2} and 3.18 cd/A, respectively. • The bending effects on PES substrate by depositing metal oxidation (MoO{sub 3}) and metal (Al) layers were also investigated. • MoO{sub 3} covering the Al layer modifies the surface of the electrode and enhances the durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode. - Abstract: In this paper, semitransparent electrodes with the structure substrate/MoO{sub 3}/Al/MoO{sub 3} (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO{sub 3}) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m{sup 2} and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO{sub 3

  1. Spectrophotometric Determination of Lead in Food with Meso-4-(3-5-Dibromo-4-hydroxyphenyl) Porphyrin [ T(DBHP) P ]%Meso-四-(3-5-二溴4-羟基苯)卟啉分光光度法测食品中铅含量

    Institute of Scientific and Technical Information of China (English)

    陈莉; 彭惠琦

    2011-01-01

    Reaction of Meso-4-(3-5-Dibromo-4-hydroxyphenyl) porphyrin [T(DBHP)P] and the lead in the foods,and the impact of heating time, pH, dosage of the surfactants and reagent on the formation and stability of the complex are studied,and the best reaction conditions are determined. With the presence of 8-hydroxyquinoline, lead can create 1: 2 orange compounds with T(DBHP)P. Which has strong absorption of 479 nm. When the lead content is in the range of 0 ~ 12 (xg/mL,the measured curve is linear. The results showed that the method used is simple,safe,more environmental friendly with higher sensitivity and better selectivity. There is no need to separate the interfering ions in the sample. Simply by adding a masking agent, the calcium and iron effects can be eliminated. The spectrophotometer measures absorbance and the standard curve to calculate the lead content. This method can be used to measure the lead in foods with ease.%以食品为对象,研究了铅与Meso-四-(3-5-二溴-4-羟基苯)卟啉[T(DBHP)P]的配合反应,并对于溶液pH值、加热时间、表面活性剂用量、显色剂用量等对配合物的生成及稳定性的影响进行了探究,确定反应的最佳条件.经试验,当8-羟基喹啉存在时,铅在碱性条件下可与T(DBHP)P反应生成1:2的橙黄色化合物.该化合物在479 nm处有较强的吸收,当铅含量在0~12 μg/mL时,测得的曲线呈线性关系,服从比尔定律,重复性较好.经分光光度计测出其吸光度,绘制标准工作曲线,计算出铅的含量.结果表明:本实验所采用方法简便快速、安全,对环境污染小,且灵敏度较高,选择性较好,样品不需要分离出干扰离子,只需加入掩蔽剂即可消除钙离子和铁离子的影响.将该方法用于测定食品中铅的含量,取得了较满意的效果.

  2. Secado y almacenamiento de semillas de mandarino 'Cleopatra' Drying and storage of 'Cleopatra' mandarin seeds

    Directory of Open Access Journals (Sweden)

    Angel Villegas-Monter

    2005-01-01

    Full Text Available Los objetivos del trabajo fueron evaluar el efecto del tratamiento con productos químicos y contenido de humedad en la conservación de semillas de mandarino 'Cleopatra' (Citrus reshni Hort ex Tan. Semillas con 14,7% de humedad tratadas con cuatro funguicidas y 8-hidroxiquinoleina, fueron almacenadas a 4±2°C durante un año, al igual que tres lotes de semillas con 5,0%, 14,7% y 26,8% de humedad, tratadas con y sin 8-hidroxiquinoleina. Se evaluó la germinación y emergencia al inicio del experimento, a los seis y 12 meses de almacenamiento. En la prueba con productos químicos, el almacenamiento de semillas con 14,7% de humedad sólo fue viable hasta los seis meses, con mayores porcentajes de germinación y emergencia (59,3% y 54,0%, respectivamente, mientras que, en las semillas sin tratamiento químico fue de 33,3% y 27,3%, respectivamente. En relación con el contenido de humedad de las semillas, a los seis meses de almacenamiento se obtuvo mayor emergencia de plántulas (63,6% y 58,0% en semillas con 26,8% y 5%, mientras que a los 12 meses, las semillas con 5%, de humedad tuvieron 75,6% de emergencia.The objetives of this work were to evaluate the effect of the treatment with chemical products and the humidity content for conservation of seeds of 'Cleopatra' mandarin (Citrus reshni Hort ex Tan. Seeds with 14.7% of moisture content were treated with four fungicides and 8-hydroxyquinoline and stored at 4±2°C for one year. Three groups of seeds with 5.0, 14.7% and 26.8% of moisture content were stored as above. Germination and emergence were evaluated at the beginning of the two experiments, at six and twelve months of storage. In the test with chemical products, storage of seeds with 14.7% of moisture content was possible only for six months, with higher percentages of germination and emergence (59.3% and 54.0%, respectively, while in seeds without chemical treatment percentages of germination and emergence were about 33.3% and 27

  3. Manutenção da qualidade e aumento da longevidade floral de crisântemo cv. White polaris Keeping quality and prolonging the postharvest longevity of spray chrysanthemum cv. White polaris

    Directory of Open Access Journals (Sweden)

    Victor Julio Flórez-Roncancio

    1996-01-01

    changes associated with individual flowers. The flowers were held during 24 hours (pulsing treatment period at 25 ± 2°C and 60 to 90% of air relative humidity under continuous cool white fluorescent light at 1.5 KLx. At the end of the treatment, the flowers were transferred to distilled water, under daily 10 hours of continuous fluorescent light and at the same laboratory conditions already described. At the first experiment, it was tested the efficiency of 8-hydroxyquinoline (8-HQ and thiabendazole (TBZ, as germicides, in three concentrations each one. Furthermore, two growth regulators were applied in order to keep the green color and the turgidity of leaves: gibberellic acid (GA3, 6-benzylaminopurine (6-BA and a mix of them. At the second experiment, in order to extend the vase-life by inhibition of ethylene production, it was tested the effect of silver nitrate (AgNO3, anionic silver thiosulphate complex (STS and cobalt chloride (CoCl2 into pulsing solutions in three concentrations each one. The results of experiments showed that pulsing treatment with distilled water + 0.52 mol/m³ citric acid + 58.43 mol/m³ sucrose + 0.69 mol/m³ 8-HQ + 2.9 or 4.4 mol/m³ AgNO3, combined with foliar treatment of 0.058 mol/m³ GA3, improved the foliar quality and extended the flower vase life.

  4. 六出花切花瓶插生理和保鲜效应研究%Study on Vase-physiological and Fresh-keeping Effect of Cut-flower Alstroemeria

    Institute of Scientific and Technical Information of China (English)

    张瑜瑜; 李晶; 吴旭; 姚丽媛; 华金珠

    2013-01-01

    the preservation experiment of cut flower A lstroemeria ,the mixture of 8-hydroxyquinoline citrate(200 mg・L-1 )and sucrose solution(5% )could produce the best preservation effect . The preservative solution could prolong the life of cut flower 9 days more than CK ;3 days delayed to bloom stage ;fresh weight increased 24 g more than CK at the 21th day after vasing ;Moisture balance was 1 .9 g higher than CK .Anthocyanin content was 0 .568 5 than CK at the 21th day after vasing ;In the aspect of the change of cell membrane permeability ,conductivity was 73 .4% ,which was 22 .8% less than CK ,maximum value of solu-ble sugar content was 0 .249 g・kg-1 higher than CK and the content of vitamin C was 5 .072 59 mg・kg-1 higher than CK ,at the 21th day after vasing .

  5. 基于面式-三(2-(4-三氟甲基苯基)吡啶)合铱配合物为发光中心的高效绿光有机电致发光器件%Efficient Green Organic Light-Emitting Diodes with fac-Tris(2-(4-trifluoromethylphenyi)pyridine)iridium Complex as Emitter

    Institute of Scientific and Technical Information of China (English)

    滕明瑜; 王铖铖; 荆一铭; 郑佑轩; 林晨

    2013-01-01

    with 6% dopant concentration exhibits a maximum power efficiency of 27.29 cd·A-1 at 1 981 cd·m-2,a maximum brightness of 33 071 cd·m-2 at 9.6 V.The electron mobility of Ir(ffmppy)3 is 4.24× 10-6 cm2· (V·s)-1 under electric field of 1 300 (V· cm-1)1/2 via transient electroluminescence (TEL) method,which is close to that of Alq3 (tri(8-hydroxyquinoline)aluminum) emitter.CCDC:887658.

  6. 不对称三苯胺-锌酞菁的合成及性能研究%Synthesis and Study of Properties for Asymmetric Triphenylamine-Zinc Phthalocyanine

    Institute of Scientific and Technical Information of China (English)

    毛利军; 谭青龙; 辛冠琼; 韩明亮; 张学俊

    2012-01-01

    以对氨基酚、对硝基氯苯、8-羟基喹啉、4-硝基邻苯二甲腈以及醋酸锌为主要原料,合成了不对称2(3)-[二(对硝基苯基)氨基苯氧基]-9(10),16(17),23(24)-三(8-喹啉氧)锌酞菁(TQPc).用核磁、红外、元素分析等表征TQPc以及前驱化合物结构,TQPc的电子吸收光谱表现出了强烈的π-π*跃迁现象.利用紫外光谱研究了其N,N-二甲基甲酰胺(DMF)和CH2Cl2溶液的吸收光谱性质,结果表明在DMF中主要以单体的形式存在,浓度在0.223×10-5~2.587×10-5 mol/L时,TQPc在CH2Cl2溶液中有二聚体的存在,经计算得到平衡常数为0.24×105 L/mol.用循环伏安法研究了TQPc的氧化还原行为,结合差分伏安数据计算了能级结构,LUMO(-1.04 V vs SCE)和HOMO (0.78 V vs SCE)与纳米TiO2导带能级匹配,可作为性能较好的电荷传输材料用于染料敏化太阳能电池.%Triphenylamine-zinc phthalocyanine (TQPc) that contains a bulky triphenylamine group and three 8-oxy-quinoline groups has been found to exhibit preferable performance. The first example of TQPc has been synthesized. Its zinc complexes of the well-known electron transport material displays enhanced electron-accepting ability relative to free- metallophthalocya-nines, and can also be used as chemical sensors, liquid crystals, photodynamic therapy, data storage and non-linear optics. The triphenylamine-zinc phthalocyanine is synthesized by statistical condensation. The main chemicals are aminophenol, p-chloronitrobenzene, 8-hydroxyquinoline, 4-nitrophthalonitrile and zinc acetate. The fragment 4,4'-dinitro-4"-hydroxy-triphenylamine is synthesized by the reacting from aminophenol with p-chloronitrobenzene at the catalysis of anhydrous potassium carbonate. The gross yield is 27.5%, and its purity is 96.6%. In comparison with other methods, there are some advantages in this method: the materials are cheap and easily available, and the product can be used as a substituent for phthalocyanine. All