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Sample records for 8-quinolinol

  1. Comportamento térmico do 8-quinolinol e seus nitro-derivados Thermal behavior of the 8-quinolinol and their nitro-derivatives

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    Henrique E. Zorel Jr.

    2001-10-01

    Full Text Available The compounds 5-nitro-8-quinolinol and 5,7-dinitro-8-quinolinol were obtained by nitration of the chelant 8-quinolinol. The compounds were characterized through EA, MNR, XRD, IR, TG, DTA and DSC. It was verified through thermal analysis that the compounds show consecutive processes of sublimation, fusion and vaporization. During the vaporization process, partial thermal decomposition was observed, with formation of carbonaceous residues. Considering a slower heating rate, the sublimation is the prevalent process to the nitro-derivatives while the vaporization is the main process to 8-quinolinol. The thermal stability follows the decreasing order from 5,7-dinitro-8-quinolinol to 5-nitro-8-quinolinol to 8-quinolinol.

  2. Catalytic currents of hydrogen in solutions of molybdenum complexes of 8-quinolinol

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    Toropova, V.F.; Polyakov, Yu.N.; Bondar' , I.I.

    1987-11-20

    In the electroreduction of Mo(VI) at a dropping mercury electrode in the presence of 8-quinolinol in 2 x 10/sup -3/ M HCl in the potential range from -1.1 to -1.15 V a catalytic wave of hydrogen is observed. The catalytic current attains a maximum value in the pH range 2.4-2.8 and depends linearly on the Mo(VI) concentration in the range 10/sup -7/-2 x 10/sup -8/ M. The catalytic effect is determined by the protonation of the complex of Mo(V) with 8-quinolinol adsorbed on the electrode. An important part in the catalytic process is played by the adsorption of the Mo(V) complex, which causes a considerable rise in the catalytic current in comparison with the diffusion current.

  3. Synthesis of 7-Nitro-8-quinolinol%7-硝基-8-羟基喹啉的合成

    Institute of Scientific and Technical Information of China (English)

    李鹏; 王帆; 林紫云; 马辰; 黄海洪

    2011-01-01

    7-Nitro-8-quinolinol in overall yield of 69% with more than 99% purity was synthesized from 8-quinolinol by a two-step reaction of nitration and desulfonation. The structure was confirmed by 1H NMR, 13C NMR and HR-MS.%以8-羟基喹啉为原料,经硝化和脱磺酸基保护两步反应合成了7-硝基-8-羟基喹啉,总收率69%,纯度高于99%.其结构经1H NMR,13C NMR和HR-MS确证.

  4. Synthesis, Characterization and Antimicrobial Activity of Metal Chelates of 5-[1(H-Benzotriazole methylene]-8-quinolinol

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    H. S. Patel

    2009-01-01

    Full Text Available 5-Chloromethyl-8-quinolinol was condensed stoichiometrically with benzotriazole in presence of potassium carbonate. The resulting 5-[1(H-benzo triazole methylene]-8-quinolinol (BTMQ was characterized by elemental analysis and spectral studies. The transition metal chelates viz. Cu2+, Ni2+, Co3+, Mn2+ and Zn2+ of BTMQ were prepared and characterized by metal-ligand (M:L ratio, IR and reflectance spectral studies and magnetic properties. The antifungal activity of BTMQ and its metal chelates was screened against various fungi. The results show that all these samples are good antifungal agents.

  5. Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

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    Wappel, Julia

    2016-01-28

    A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru–O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations.

  6. Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

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    Wappel, Julia; Fischer, Roland C; Cavallo, Luigi; Slugovc, Christian

    2016-01-01

    Summary A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru–O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations. PMID:26877818

  7. A rapid and simple 8-quinolinol-based fluorescent stain of phosphoproteins in polyacrylamide gel after electrophoresis.

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    Wang, Xu; Hwang, Sun-Young; Cong, Wei-Tao; Jin, Li-Tai; Choi, Jung-Kap

    2015-10-01

    In order to obtain an easy and rapid protocol to visualize phosphoproteins in SDS-PAGE, a fluorescent detection method named 8-Quinolinol (8-Q) stain is described. 8-Q can form ternary complexes in the gel matrix contributed by the affinity of aluminum ion (Al(3+) ) to the phosphate groups on the proteins and the metal chelating property of 8-Quinolinol, exhibiting strong fluorescence in ultraviolet light. It can visualize as little as 4∼8 ng of α-casein and β-casein, 16∼32 ng of ovalbumin and κ-casein which is more sensitive than Stains-All but less sensitive than Pro-Q Diamond. The protocol of 8-Q requires only 70 min in 0.75 mm mini-size or 1.0 mm large-size gels with five changes of solutions without destaining step; Pro-Q takes at least 250 min with 11 changes of solutions. In addition, the new method was confirmed by the study of dephosphorylation and LC-MS/MS, respectively. The approach to visualize phosphoprotein utilizing 8-Q could be an alternative to simplify the analytical operations for phosphoproteomics research. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthesis, Spectroscopy and Antibacterial Activity of Supermolecular Compounds of Organotitanium Substituted Heteropolytungstates Containing 8-Quinolinol%Synthesis, Spectroscopy and Antibacterial Activity of Supermolecular Compounds of Organotitanium Substituted Heteropolytungstates Containing8-Quinolinol

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    FENG Chang-gen; XIONG Yu-di; LIU Xia

    2011-01-01

    Parent compounds of cyclopentadienyltitanium substituted heteropolytungstates with Keggin structure, An[(CpTi)XW11O39]· xH2O (A=Me4N, K; X=P, Si, Co; Cp=η5-C5H5) were synthesized in aqueous phase. By allowing parent heteropoly compounds to react with protonated 8-quinolinol, the title supermolecular compounds (C9H8NO)mAn[(CpTi)XW11O39]· xH2O (A=Me4N, H; X=P, Si, Co) were synthesized. The title compounds were characterized by means of elementary analysis, IR, UV, 1 H NMR,XRD and TC-DSC. The results indicate that the title compounds are new heteropoly compounds, and there is a charge transfer interaction between the organic cation and heteropoly anion. The results obtained from thermal analysis show that QCpTiPW, QCpTiSiW and QCpTiCoW begin to decompose at 212.4, 194. 2 and 171.2℃, respectively. The results obtained from antibacterial test reveal that QCpTiSiW has the best antibacterial activity, and the MIC values of QCpTiSiW against Escherichia coli and Staphylococcus aurous are 64. 0 and 0. 500 μg · mL-1 , respectively.

  9. Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

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    Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

    2005-01-30

    The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

  10. Preconcentration and determination of Ce, La and Pr by x-ray fluorescence analysis, using amberlite XAD resins loaded with 8-quinolinol and 2-(2-(5 chloropyridylazo)-5-dimethylamino)-phenol

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    Masi, A.N.; Olsina, R.A. (National Univ. of San Luis (Argentina). Dept. of Analytical Chemistry)

    1993-06-01

    8-Quinolinol (oxine) and 2-(2-(5 chloropyridylazo)-5-dimethylamino)-phenol (5ClDMPAP) were immobilized on the non ionic sorbents Amberlite XAD-4 and XAD-7. These loaded resins were used for the preconcentration of Ce, La and Pr. High preconcentration factors were obtained in each case. After the retention of these rare earths, the resins were measured as thin films by X-ray fluorescence spectrometry. Up to 50 ppm of REEs can be retained on these thin films. (Author).

  11. Iron(III and copper(II complexes bearing 8-quinolinol with amino-acids mixed ligands: Synthesis, characterization and antibacterial investigation

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    Saliu A. Amolegbe

    2015-09-01

    Full Text Available Four d-orbital metal complexes with mixed ligands derived from 8-hydroxyquinoline (HQ and amino acids (AA: l-alanine and methionine have been synthesized through a mild reflux in alkaline solution and characterized by elemental analyses, infrared, electronic transition, and temperature dependant magnetic susceptibility. The IR spectroscopy revealed that iron and copper ions coordinated through carbonyl (CO, hydroxyl group (OH of the amino acids, N-pyridine ring of hydroxyquinoline. The elemental analysis measurement with other obtained data suggested an octahedral geometry for the iron(III complexes and tetrahedral geometry for the copper(II complexes. From the molar magnetic susceptibility measurement, the iron(III system (S = 5/2 d5 (non-degenerate 6A1 with χmT = 0.38 cm3 Kmol−1 showed an antiferromagnetic while Cu2+ ions system (S = ½ (2T2g has χmT = 4.77 cm3 Kmol−1 described as paramagnetic behaviour. In vitro antimicrobial investigations of the metal complexes against standard bacteria species gave significant inhibition with, copper complex showing highest inhibitions against Pseudomonas aeruginosa (ATCC27853 of 43 mm at 10 μg/ml signalling its potential as pharmaceutical or chemotherapeutic agents.

  12. Synthesis, Characterization and Catalytic Performance of Copper( Ⅱ )-8-quinolinol Functionalized SBA-15%8-羟基喹啉铜(Ⅱ)功能化SBA-15的制备、表征及催化性质

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    王虹苏; 黄家辉; 徐臣; 徐玲; 宋科; 徐海燕; 王竹倩; 阚秋斌

    2007-01-01

    利用3-氨丙基功能化的介孔SBA-15(APS-SBA-15)作为载体, 通过C-N共价键将8-羟基喹啉铜(Ⅱ)固定到APS-SBA-15孔道中, 制备了8-羟基喹啉铜(Ⅱ)功能化的SBA-15催化剂[Cu(Ⅱ)-Q-APS-SBA-15], 并将其用于以质量分数30%的过氧化氢为氧化剂的苯酚羟化反应中. 结果表明, Cu(Ⅱ)-Q-APS-SBA-15呈现出较高的苯酚转化率和苯二酚选择性.

  13. Synthesis, Characterization and Antimicrobial Activity of Metal Chelates of 5-[4-Chloro phenyl(1, 3, 4thiadiazol-2-ylamino methylene]-8-hydroxy quinoline

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    Divyesh K. Patel

    2009-01-01

    Full Text Available 5-Chloromethyl-8-quinolinol was condensed stoichiometrically with 5-(4-chlorophenyl-(1,3,4 thiadiazol-2-ylamine in the presence of sodium bicarbonate. The resulting 5-[4-chlorophenyl-(1,3,4thiadiazol-2-ylamino methylene]-8-quinolinol (CTAQ was characterized by elemental analysis and spectral studies. The transition metal chelates viz. Cu2+, Ni2+, Co2+, Mn2+ and Zn2+ of CTAQ were prepared and characterized by metal-ligand (M:L ratio, IR and reflectance spectroscopies and magnetic properties. The antifungal activity of CTAQ and its metal chelates was screened against various fungi. The results show that all these samples are good antifungal agents.

  14. Study of Novel Oligomeric Azo Dyes

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    Patel J. R.

    2012-08-01

    Full Text Available Diazotization of p-anisidine and coupling with 3-amino-phenol-Formaldehyde (APF resin give oligomaric azo dye TAPF, based on 3-amino-phenol-Formaldehyde (APF polymer. The TAPF was then treated with 5-chloro methyl-8-quinolinol hydrochloride in the presence of a THF in alkaline medium (pH 9-10 at room temperature for 7 hrs. The resultant oligomaric ligand designated as azo polyphenol-formaldehyde-5-chloromethyl-8-quinolinol (AAPFQ was characterized by elemental analysis, IR spectral studies, and thermogravimetry. The polymeric metal chelates of AAPFQ with Cu2+, Zn2+, Mn2+, Ni2+, Fe3+ and Co2+ metal ions were prepared and characterised by metal:ligand ratio, IR and reflectance studies, magnetic properties and thermogravimetry. The AAPFQ sample was also screened for its chelating and ion-exchanging properties. Batch equilibration method has been adopted for evolution of ion-exchange properties.

  15. ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au3+

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Organic chelating reagent influences upon the redox adsorption of activated carbon fibertowards Au3- were systematically investigated. The experimental results indicated that the presenceof organic chelating reagent on activated carbon fiber strongly affects adsorption capacity ofactivated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three timesby the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended onthe pH value of adsorption and temperature.

  16. 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)

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    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.

  17. Selective Precipitation of Thorium lodate from a Tartaric Acid-Hydrogen Peroxide Medium Application to Rapid Spectrophotometric Determination of Thorium in Silicate Rocks and in Ores

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    Grimaldi, F.S.

    1957-01-01

    This paper presents a selective iodate separation of thorium from nitric acid medium containing d-tartaric acid and hydrogen peroxide. The catalytic decomposition of hydrogen peroxide is prevented by the use of 8quinolinol. A few micrograms of thorium are separated sufficiently clean from 30 mg. of such oxides as cerium, zirconium, titanium, niobium, tantalum, scandium, or iron with one iodate precipitation to allow an accurate determination of thorium with the thoronmesotartaric acid spectrophotometric method. The method is successful for the determination of 0.001% or more of thorium dioxide in silicate rocks and for 0.01% or more in black sand, monazite, thorite, thorianite, eschynite, euxenite, and zircon.

  18. Synthesis and Spectroscopic Properties of a Series of New tetra-Substituted Metal Phthalocyanines

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    YU Hai-ling; YANG Jin; FU Qiang; MA Ji-cheng; LI Wei-li

    2008-01-01

    A new class of metal phthalocyanines(MPcs)containing four 8-quinolinol(8-QH) derivative moieties were successfully synthesized and characterized by mass spectroscopy,IR, UV-Vis and element analysis,the results of which were consistent with the proposed structures.All of them can dissolve in common organic solvents.such as dichloromethane,chloroform,and acetone.The effect of metal ion on the absorption of Q band was studied with UV-Vis spectra.The fluorescent properties for those complexes were also investigated.

  19. Structural dynamics of nitrosylruthenium isomeric complexes studied with steady-state and transient pump-probe infrared spectroscopies

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    Zhao, Yan; Yang, Fan; Wang, Jianru; Yu, Pengyun; Pan, Huifen; Wang, Hongfei; Wang, Jianping

    2016-09-01

    The characteristic nitrosyl stretching (NO) in the region of 1800-1900 cm- 1 was used to study the geometric and ligand effect on two nitrosylruthenium complexes, namely [Ru(OAc)(2QN)2NO] (QN = 2-chloro-8-quinolinol (H2cqn) or QN = 2-methyl-8-quinolinol (H2mqn)). The NO stretching frequency (νNO) was found in the following order: νcis-1 (2cqn) > νcis-2 (2cqn) > νcis-1 (2mqn) > νtrans (2mqn). The results exhibited a spectral sensitivity of the NO mode to both charge distribution and ligand arrangement, which was supported by ab initio computations and natural bond orbital (NBO) analyses. Further, the vibrational population of the vibrationally excited NO stretching mode was found to relax on the order of 7-10 ps, showing less than 30% variation from one isomer to another, which were explained on the basis of NO local structures and solute-solvent interactions in these isomeric nitrosylruthenium complexes.

  20. Supramolecular synthon pattern in solid clioquinol and cloxiquine (APIs of antibacterial, antifungal, antiaging and antituberculosis drugs) studied by ³⁵Cl NQR, ¹H-¹⁷O and ¹H-¹⁴N NQDR and DFT/QTAIM.

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    Latosińska, Jolanta Natalia; Latosińska, Magdalena; Tomczak, Marzena Agnieszka; Seliger, Janez; Zagar, Veselko

    2011-07-01

    The quinolinol derivatives clioquinol (5-chloro-7-iodo-8-quinolinol, Quinoform) and cloxiquine (5-chloro-8-quinolinol) were studied experimentally in the solid state via ³⁵Cl NQR, ¹H-¹⁷O and ¹H-¹⁴N NQDR spectroscopies, and theoretically by density functional theory (DFT). The supramolecular synthon pattern of O-H···N hydrogen bonds linking dimers and π-π stacking interactions were described within the QTAIM (quantum theory of atoms in molecules) /DFT (density functional theory) formalism. Both proton donor and acceptor sites in O-H···N bonds were characterized using ¹H-¹⁷O and ¹H-¹⁴N NQDR spectroscopies and QTAIM. The possibility of the existence of O-H···H-O dihydrogen bonds was excluded. The weak intermolecular interactions in the crystals of clioquinol and cloxiquine were detected and examined. The results obtained in this work suggest that considerable differences in the NQR parameters for the planar and twisted supramolecular synthons permit differentiation between specific polymorphic forms, and indicate that the more planar supramolecular synthons are accompanied by a greater number of weaker hydrogen bonds linking them and stronger π···π stacking interactions.

  1. Covalent heterogenization of discrete bis(8-quinolinolato)dioxomolybdenum(VI) and dioxotungsten(VI) complexes by a metal-template/metal-exchange method: Cyclooctene epoxidation catalysts with enhanced performances

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    Yang, Ying; Chattopadhyay, Soma; Shibata, Tomohiro; Ren, Yang; Lee, Sungsik; Kan, Qiubin

    2014-10-01

    A metal-template/metal-exchange method was used to imprint covalently attached bis(8- quinolinolato)dioxomolybdenum(VI) and dioxotungsten(VI) complexes onto large surface-area, mesoporous SBA-15 silica to obtain discrete MoO2 VIT and WO2 VIT catalysts bearing different metal loadings, respectively. Homogeneous counterparts, MoO2 VIN and WO2 VIN, as well as randomly ligandgrafted heterogeneous analogues, MoO2 VIG and WO2 VIG, were also prepared for comparison. X-ray absorption fine structure (XAFS), pair distribution function (PDF) and UV–vis data demonstrate that MoO2 VIT and WO2 VIT adopt a more solution-like bis(8-quinolinol) coordination environment than MoO2 VIG and WO2 VIG, respectively. Correspondingly, the templated MoVI and WVI catalysts show superior performances to their randomly grafted counterparts and neat analogues in the epoxidation of cyclooctene. It is found that the representative MoO2 VIT-10% catalyst can be recycled up to five times without significant loss of reactivity, and heterogeneity test confirms the high stability of MoO2 VIT-10% catalyst against leaching of active species into solution. The homogeneity of the discrete bis(8-quinolinol) metal spheres templated on SBA-15 should be responsible for the superior performances.

  2. Synthesis, Characterisation, Spectral and Microbial Studies of Transition Metal Complexes of the Drug, Secnidazole

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    Aradhana Verma

    2010-01-01

    Full Text Available 5-Chloromethyl-8-quinolinol hydrochloride was condensed with 1-(2-methyl-5-nitro-1H-imidazol-1-ylpropan-2-ol in presence of potassium carbonate. The resulting 5-((1-(2-methyl-5-nitro-1H-imidazol-1-ylpropan-2-yloxymethylquinolin-8-ol was characterized by elemental analysis and spectral studies. The transition metal chelates of the same were prepared with Cu2+, Ni2+, Co2+, Mn2+ and Zn2+ and characterized by IR and electronic spectral studies and magnetic properties. The antimicrobial activity of ligand and its metal chelates were screened against various gram positive and gram negative organisms. The results show that all these samples are more or less active agents against various organisms.

  3. Selective spectrofluorimetric determination of zinc in biological samples by Flow Injection Analysis (FIA)

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    Fernandez, P.; Perez Conde, C.; Gutierrez, A.; Camara, C. (Universidad Complutense, Madrid (Spain). Dept. de Quimica Analitica)

    1992-03-01

    The automatization of a spectrofluorimetric method for the determination of zinc at trace level is described. It is based on the formation of the fluorescent complex Zn(II)-5,7-dibromo-8-quinolinol (Zn(II)-DBQ) followed by extraction into diethylether using flow injection analysis. The optimum fluorescent emission is reached in hexamethylenetetramine (H{sub 2}MTA{sup +}/HMTA) buffer pH 6.0. A membrane phase separator was used. The calibration graph is linear up to 1.5 {mu}g/ml of Zn(II). The proposed method (detection limit 3 ng/ml) is very selective and has been successfully applied to determine Zn(II) in biological samples, tap waters and various food items. (orig.).

  4. Nonaqueous catalytic fluorometric trace determination of vanadium based on the pyronine B-hydrogen peroxide reaction and flow injection after cloud point extraction.

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    Paleologos, E K; Koupparis, M A; Karayannis, M I; Veltsistas, P G

    2001-09-15

    The catalytic effect of vanadium on the pyronine B-H2O2 system is examined. Enhancement of the catalytic reaction rate along with the efficiency and selectivity against vanadium is achieved in a formic acid environment in the presence of a nonionic surfactant (Triton X-114). Elimination of drastic interference caused by inorganic acids and aqueous matrix along with a 50-fold preconcentration of vanadium are facilitated through cloud point extraction of its neutral complex with 8-quinolinol in an acidic solution. Subsequent flow injection analysis (FIA) with fluorometric detection renders the proposed method ideal for selective and cost-effective determination of as little as 0.020 microng L(-1) vanadium in environmental, biological, and food substrates. The preconcentration step can be applied simultaneously to multiple samples, allowing for massive preparation prior to analysis, compensating, thus, for the time-consuming procedure.

  5. Tetra­kis(8-quinolinolato-κ2 N,O)hafnium(IV) dimethyl­formamide solvate monohydrate

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    Viljoen, Johannes A.; Visser, Hendrik G.; Roodt, Andreas

    2010-01-01

    In the title compound, [Hf(C9H6NO)]·C3H7NO·H2O, the hafnium(IV) atom is coordinated by four 8-quinolinolate (Ox) ligands, forming a slightly distorted square-anti­prismatic coordination polyhedron. The crystal packing is controlled by O—H⋯O and C—H⋯O hydrogen-bonding inter­actions and π–π inter­actions between quinoline ligands of neighbouring mol­ecules. The inter­planar distances vary between 3.150 (1) and 3.251 (2) Å, while centroid–centroid distances vary from 3.589 (1) to 4.1531 (1) Å. PMID:21579072

  6. Tetrakis(8-quinolinolato-κ2N,Ohafnium(IV dimethylformamide solvate monohydrate

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    Johannes A. Viljoen

    2010-05-01

    Full Text Available In the title compound, [Hf(C9H6NO]·C3H7NO·H2O, the hafnium(IV atom is coordinated by four 8-quinolinolate (Ox ligands, forming a slightly distorted square-antiprismatic coordination polyhedron. The crystal packing is controlled by O—H...O and C—H...O hydrogen-bonding interactions and π–π interactions between quinoline ligands of neighbouring molecules. The interplanar distances vary between 3.150 (1 and 3.251 (2 Å, while centroid–centroid distances vary from 3.589 (1 to 4.1531 (1 Å.

  7. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

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    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  8. Preparation and Catalytic Properties of Polymer-Bound Schiff Base Ternary Complexes

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    HAO Cheng-jun; WANG Rong-min; HE Yu-feng; WANG Yun-pu; XIA Chun-gu

    2004-01-01

    The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L (L = Phen, Bipy and 8HQ)-] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phenanthroline(phen), 2,2′-bipyridyl(bipy) and 8-quinolinol(8HQ). The polymer-bound Schiff base ternary manganese complexes were characterized by means of infrared spectrometry and ICPAES. The catalytic activities of the complexes have been studied in the aerobic epoxidation of long-chain linear a[iphatic olefins. It is shown that 1-octene or 1-decene can be directly oxidized by molecular oxygen when catalyzed by PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ), and 1,2-epoxy alkane can be afforded in these reactions.

  9. Flame AAS determination of lead in water with flow-injection preconcentration and speciation using functionalized cellulose sorbent.

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    Naghmush, A M; Pyrzyńska, K; Trojanowicz, M

    1995-06-01

    The on-line solid phase extraction of trace amount of lead in flow-injection system with flame AAS detection was investigated using cellulose sorbents with phosphonic acid and carboxymethyl groups, C(18) sorbent non-modified and modified with Pyrocatechol Violet or 8-quinolinol, commercial chelating sorbents Chelex 100 and Spheron Oxin 1000, non-polar sorbent Amberlite XAD-2 modified with Pyrocatechol Violet and several cation-exchange resins. The best dynamic characteristics of retention were observed for functionalized cellulose sorbents. For Cellex P assumed as optimum sorbent, elution with a separate fractions of nitric acid and ethanol allows the differentiation between tetraalkyllead and sum of inorganic lead and organolead species of smaller number of alkyl groups. The detection limit for the determination of inorganic Pb(II) was estimated as 0.17 microg/l. at preconcentration from 50 ml sample at a flow rate of 7 ml/min.

  10. Realization of Red-Organic-Light Emitting Diode by Introducing the Double Emitting Zone

    Institute of Scientific and Technical Information of China (English)

    姜文龙; 侯晶莹; 赵毅; 刘式墉

    2003-01-01

    A saturated red-organic-light emitting diode (OLED) has been realized by doping an emitting material both in the hole-transporting layer (HTL) and the electron-transporting layer (ETL) to form double emitting zone. The red dopant, 4-(Dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyraan (DCJTB), was doped into the N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) layer and the tris (8-quinolinolate)aluminium (Alq3) layer, both of which act as the emitting layers. The optimal device, with a structure of ITO/CuPc/NPB/NPB:DCJTB/Alqa:DCJTB/Alqa/LiF/Al, showed good chromaticity coordinates (x = 0.63,y = 0.36) at 8 V. Uniquely, the current efficiency of the device was relatively independent of the drive voltage in a wide range from 8 V to 20 V. That may be helpful to ameliorate the lifetime of the organic electroluminescent devices and to adjust the grey-scale for the future full-colour display panel.

  11. 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)

  12. Tetrakis(5,7-dimethylquinolin-8-olato-κ2N,Ohafnium(IV dimethylformamide disolvate

    Directory of Open Access Journals (Sweden)

    Andreas Roodt

    2011-10-01

    Full Text Available In the title compound, [Hf(C11H10NO4]·2C3H7NO, the HfIV atom is coordinated by four N,O-donating bidentate 5,7-dimethyl-8-quinolinolate (Ox− ligands arranged to give a distorted square-antiprismatic coordination polyhedron. The average Hf—O and Hf—N distances are 2.098 and 2.298 Å, respectively, and the average O—Hf—N bite angle is 70.2°. The crystal packing is controlled by π–π interactions between Ox− ligands of neighbouring molecules, giving rise to a three-dimensional supramolecular grid network. The interplanar distances vary from 3.441 (1 to 3.509 (1 Å, while the centroid–centroid distances vary from 3.688 (2 to 3.759 (12 Å. A non-classical C—H...O hydrogen bond is observed between the complex and one of the solvate molecules.

  13. Pollutant-induced modulation in conformation and β-lactamase activity of human serum albumin.

    Directory of Open Access Journals (Sweden)

    Ejaz Ahmad

    Full Text Available Structural changes in human serum albumin (HSA induced by the pollutants 1-naphthol, 2-naphthol and 8-quinolinol were analyzed by circular dichroism, fluorescence spectroscopy and dynamic light scattering. The alteration in protein conformational stability was determined by helical content induction (from 55 to 75% upon protein-pollutant interactions. Domain plasticity is responsible for the temperature-mediated unfolding of HSA. These findings were compared to HSA-hydrolase activity. We found that though HSA is a monomeric protein, it shows heterotropic allostericity for β-lactamase activity in the presence of pollutants, which act as K- and V-type non-essential activators. Pollutants cause conformational changes and catalytic modifications of the protein (increase in β-lactamase activity from 100 to 200%. HSA-pollutant interactions mediate other protein-ligand interactions, such as HSA-nitrocefin. Therefore, this protein can exist in different conformations with different catalytic properties depending on activator binding. This is the first report to demonstrate the catalytic allostericity of HSA through a mechanistic approach. We also show a correlation with non-microbial drug resistance as HSA is capable of self-hydrolysis of β-lactam drugs, which is further potentiated by pollutants due to conformational changes in HSA.

  14. A water-in-oil emulsion containing Kelex-100 for the speciation analysis of trace heavy metals in water

    Energy Technology Data Exchange (ETDEWEB)

    Matsumiya, Hiroaki [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)]. E-mail: h-matsu@numse.nagoya-u.ac.jp; Ohkouchi, Ryohei [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Hiraide, Masataka [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2006-01-25

    A water-in-oil (w/o) emulsion containing Kelex-100 (7-dodecenyl-8-quinolinol) and Span-80 (sorbitan monooleate, non-ionic surfactant) was ultrasonically prepared from 1.0 mol l{sup -1} hydrochloric acid and a (1 + 3) mixture of toluene and n-heptane. The resulting emulsion was gradually injected into water sample and dispersed as numerous tiny globules (0.01-0.1 mm in diameter). Dissolved inorganic species (free metal species) of heavy metals (e.g., Fe, Co, Cu, Cd, and Pb) were selectively transported through the oil layer into the internal aqueous phase of the emulsion, leaving other species, such as humic complexes and suspended particles (larger than 1 {mu}m), in the sample solution. After collecting the dispersed emulsion globules, they were demulsified and the heavy metals in the segregated aqueous phase were determined by graphite-furnace atomic absorption spectrometry. The emulsion-based separation method allowed the selective collection of free metal species with a high concentration factor of 100, whereas the conventional solvent extraction did not offer such discrimination. This unique property of the emulsion method was successfully applied to the selective determination of free species of heavy metals in fresh water samples.

  15. Small-molecule quinolinol inhibitor identified provides protection against BoNT/A in mice.

    Directory of Open Access Journals (Sweden)

    Padma Singh

    Full Text Available Botulinum neurotoxins (BoNTs, etiological agents of the life threatening neuroparalytic disease botulism, are the most toxic substances currently known. The potential for the use as bioweapon makes the development of small-molecule inhibitor against these deadly toxins is a top priority. Currently, there are no approved pharmacological treatments for BoNT intoxication. Although an effective vaccine/immunotherapy is available for immuno-prophylaxis but this cannot reverse the effects of toxin inside neurons. A small-molecule pharmacological intervention, especially one that would be effective against the light chain protease, would be highly desirable. Similarity search was carried out from ChemBridge and NSC libraries to the hit (7-(phenyl(8-quinolinylaminomethyl-8-quinolinol; NSC 84096 to mine its analogs. Several hits obtained were screened for in silico inhibition using AutoDock 4.1 and 19 new molecules selected based on binding energy and Ki. Among these, eleven quinolinol derivatives potently inhibited in vitro endopeptidase activity of botulinum neurotoxin type A light chain (rBoNT/A-LC on synaptosomes isolated from rat brain which simulate the in vivo system. Five of these inhibitor molecules exhibited IC(50 values ranging from 3.0 nM to 10.0 µM. NSC 84087 is the most potent inhibitor reported so far, found to be a promising lead for therapeutic development, as it exhibits no toxicity, and is able to protect animals from pre and post challenge of botulinum neurotoxin type A (BoNT/A.

  16. A Novel Method Applied in Determination and Assessment of Trace Amount of Lead and Cadmium in Rice from Four Provinces, China

    Science.gov (United States)

    Li, Shan; Wang, Mei; Yang, Bingyi; Zhong, Yizhou; Feng, Le

    2014-01-01

    Heavy metal contamination of soils or water can lead to excessive lead (Pb) and cadmium (Cd) levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS). The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9.0 and 40°C. Analytes were quantitatively extracted to a surfactant-rich phase (Triton X-45) after centrifugation and analyzed by GFAAS. The effects of experimental conditions, including pH, concentration of reagents, and equilibration time and temperature, on cloud point extraction were optimized efficiently using Plackett–Burman and Box–Behnken experimental designs. Under the optimum conditions, good linearity was observed in the concentration ranges of 0.5–5 µg/L for Pb and 0.05–0.50 µg/L for Cd. The limits of detection were 0.043 µg/L for Pb with a concentration factor of 24.2 in a 10 mL sample and 0.018 µg/L for Cd with a concentration factor of 18.4 in a 10 mL sample. Twenty rice samples from four provinces were analyzed successfully, and the mean levels of Pb and Cd in the rice were all below their maximum allowable concentrations in China. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb and Cd mean daily intake through rice consumption were 0.84 µg/kg bw/day and 0.40 µg/kg bw/day, which were lower than the tolerable daily intakes. PMID:25251454

  17. A novel method applied in determination and assessment of trace amount of lead and cadmium in rice from four provinces, China.

    Directory of Open Access Journals (Sweden)

    Shan Li

    Full Text Available Heavy metal contamination of soils or water can lead to excessive lead (Pb and cadmium (Cd levels in rice. As cumulative poisons, consumption of Pb and Cd in contaminated rice may cause many toxic effects in humans. In the present study, Pb and Cd levels in rice samples from Hubei, Jiangxi, Heilongjiang, and Guangdong provinces in China were analyzed by cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS. The heavy metals in the rice samples were reacted with 8-quinolinol to form a complex at pH 9.0 and 40°C. Analytes were quantitatively extracted to a surfactant-rich phase (Triton X-45 after centrifugation and analyzed by GFAAS. The effects of experimental conditions, including pH, concentration of reagents, and equilibration time and temperature, on cloud point extraction were optimized efficiently using Plackett-Burman and Box-Behnken experimental designs. Under the optimum conditions, good linearity was observed in the concentration ranges of 0.5-5 µg/L for Pb and 0.05-0.50 µg/L for Cd. The limits of detection were 0.043 µg/L for Pb with a concentration factor of 24.2 in a 10 mL sample and 0.018 µg/L for Cd with a concentration factor of 18.4 in a 10 mL sample. Twenty rice samples from four provinces were analyzed successfully, and the mean levels of Pb and Cd in the rice were all below their maximum allowable concentrations in China. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb and Cd mean daily intake through rice consumption were 0.84 µg/kg bw/day and 0.40 µg/kg bw/day, which were lower than the tolerable daily intakes.

  18. 纯化9,10-二萘蒽对OLED器件光电性能的影响%Purity Effects on the Electroluminescent Performance of 9,10-Di(2-naphthyl)anthracene

    Institute of Scientific and Technical Information of China (English)

    李瑛; 王文根; 邵明; 王秀如; 汤昊; 孙润光

    2006-01-01

    合成了高稳定性蓝光主体材料9,10-二萘蒽(ADN),研究材料纯化对合成材料光电性能的影响.为进一步分析材料经升华提纯对有机电致发光器件性能的影响,以提纯前后ADN为发光层,以NPB 为空穴传输层,分别制作双层器件Ⅰ(提纯前)和器件Ⅱ(提纯后),器件结构为ITO(100 nm)/NPB(40 nm)/ADN(30 nm)/Alq3(20 nm)/LiF (1 nm) /Al (100 nm), 结果表明提纯后材料PL(Photoluminescence)光谱蓝移了2 nm,半峰全宽54.2 nm,与提纯前一致;杂质影响载流子注入效率和迁移率,对器件光电性能有显著影响,纯化前后器件最大电流效率由1.5 cd/A上升至2.5 cd/A;器件Ⅱ色纯度有较大提高,CIE色坐标由器件Ⅰ(0.15,0.10)移至(0.15, 0.06).实验结果表明材料提纯是优化器件性能的有效手段之一.%Organic light-emitting diode (OLED) has attracted considerable attention due to their unique image quality and market potentials in display application. For the full-color display applications, it is essential to deliver the primary RGB emitters with high luminous efficiency, saturated color chromaticity, among which 9, 10-Di (2-naphthyl) anthracene (ADN) is one of the stable and pure blue emitters. However, little attention has been paid to the influences of ADNs purification on the electroluminescent(EL) performance.Synthesis and purification of ADN were studied. The photoluminescence (PL) and electroluminescence (EL) spectra of ADN synthesized and purified are investigated, respectively. The PL spectrum of ADN purified exhibits an emitting peak at 434 nm with a full-width at half-maxium (FWHM) of 54.2 nm, while the rough material without purification is red shifted to 436 nm with the same FWHM of 54.2 nm. Organic light-emitting diodes (OLEDs) with a structure of indium tin oxide (ITO) (100 nm)/N,N′-biphenyl-N,N′-bis-(1-naphenyl)-[1,1′- biphenyl]-4,4′-diamine (NPB)(40 nm)/ADN(30 nm)/tris(8-quinolinolate)aluminum(Alq3)(20 nm)/LiF(1 nm)/Al(100