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Sample records for 8-hydroxyquinoline

  1. Adsorption Kinetic of 8-Hydroxyquinoline on Malachite

    Oprea, Gabriela; Angela MICHNEA; Cristina MIHALI

    2007-01-01

    Influence of temperature and collector concentration on its adsorption rate on mineral surface was studied as regarding to the 8-hydroxyquinoline/malachite system. Theoretical equations as well as experimental data may be useful to estimate the adsorption rate and kinetics connected to the conditioning stage in mineral flotation in order to optimise the selectivity and the recovery of the desired mineral.

  2. Adsorption Kinetic of 8-Hydroxyquinoline on Malachite

    Gabriela OPREA

    2007-01-01

    Full Text Available Influence of temperature and collector concentration on its adsorption rate on mineral surface was studied as regarding to the 8-hydroxyquinoline/malachite system. Theoretical equations as well as experimental data may be useful to estimate the adsorption rate and kinetics connected to the conditioning stage in mineral flotation in order to optimise the selectivity and the recovery of the desired mineral.

  3. Radioassay process using an indium-8-hydroxyquinoline

    There is disclosed an in vivo radioassay process in which a radioactive chelate of indium and an 8-hydroxyquinoline is introduced into a warmblooded animal having an inflammatory reaction in an area in which the chelate would not accumulate to the same extent if the inflammation were not present. The chelate gathers in the inflamed area, for instance, in a body abscess and its location is determined by radio surveying the body by an external imaging technique. (author)

  4. Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface

    The evolution of the interface electronic structure of a sandwich structure involving aluminum oxide and tris(8-hydroxyquinoline) aluminum (Alq), i.e. (Alq/AlOx/Alq), has been investigated with photoemission spectroscopy. Strong chemical reactions have been observed due to aluminum deposition onto the Alq substrate. The subsequent oxygen exposure releases some of the Alq molecules from the interaction with aluminum. Finally, the deposition of the top Alq layer leads to an asymmetry in the electronic energy level alignment with respect to the AlOx interlayer

  5. Substoichiometric determination of lanthanum by using EDTA and 8-hydroxyquinoline

    The substoichiometric separation of lanthanum was studied on the system EDTA - lanthanum - 8-hydroxyquinoline. The optimum conditions for the substoichiometric separation of lanthanum were calculated theoretically and the results were examined experimentally. By using the two chelating agents, EDTA and 8-hydroxyquinoline, lanthanum could be separated substoichiometrically with good accuracy and precision. This method was applied to the determination of lanthanum by activation analysis, and found to be available for the determination of trace amount of lanthanum. (author)

  6. Synthesis and electroluminescent property of dinuclear aluminum 8-hydroxyquinoline complex

    A new structural dinuclear aluminum 8-hydroxyquinoline complex (DAlq3) with two aluminum chelate-center was designed and synthesized. It was assessed as light-emitting material in organic light-emitting device (OLED). The green light emission was observed in films and OLEDs. DAlq3 has better electron mobility and also shows a higher electroluminescence (EL) efficiency than that of aluminum 8-hydroxyquinoline (Alq3).

  7. SYNTHESIS OF 8-HYDROXYQUINOLINE CHALCONES: TRANS CONFIGURATION, INTRAMOLECULAR HYDROGEN BONDS, BROMINATION, AND ANTIFUNGAL ACTIVITY

    ALONSO J MARRUGO-GONZÁLEZ; VALERIE D ORLOV; ROBERTO FERNANDEZ-MAESTRE

    2012-01-01

    Nine (8-Hydroxyquinolin-5-yl)-arylpropenones were synthesized and their structures demonstrated by IR and NMRspectroscopy. These molecules showed transconfiguration and strong intramolecular hydrogen bonding; in the IR spectra of 5-formyl-8-hydroxyquinoline, 5-acetyl-8-hydroxyquinoline, 1-(8-hydroxyquinolin-5-yl)-3-phenylprop-2-en-1-one and 3-(8-hydroxyquinolin-5-yl)-1-phenylprop-2-en-1-one in CHCl3, besides the known intermolecular hydrogen band (~3180 cm-1), we identified the intramolecular...

  8. 8-Hydroxyquinoline and its Derivatives: Synthesis and Applications

    Saleh N Al - Busafi

    2014-01-01

    Studies of structural, chemical and synthetic aspects of 8 -hydroxyquinoline (8-HQ) and its derivatives are reviewed. A special emphasis is given to applications of recently developed 8- HQ derivatives in various fields such as OLEDs, chemosensors, medicinal drugs, and insecticidal agents.

  9. 8-Hydroxyquinoline and its Derivatives: Synthesis and Applications

    Saleh N Al - Busafi

    2014-03-01

    Full Text Available Studies of structural, chemical and synthetic aspects of 8 -hydroxyquinoline (8-HQ and its derivatives are reviewed. A special emphasis is given to applications of recently developed 8- HQ derivatives in various fields such as OLEDs, chemosensors, medicinal drugs, and insecticidal agents.

  10. Studies on the extraction of lanthanide complexes with 8-hydroxyquinoline

    The values of the acid dissociation constants of 8-hydroxyquinoline (HOx and H2Ox+) in water-ethanol solutions and its distribution constants (ρHOx and ρH2Ox+Cl4-) between chloroform and water-ethanol solutions were established at different concentrations of ethanol. The solvent extraction of Pr(III) and Gd(III) by 8-hydroxyquinoline in chloroform from water-ethanol phase has been studied as a function of pH* of the polar phase, and the concentration of HOx or ethanol in the organic phase. It was stated that the presence of ethanol in the polar phase evokes a synergistic effects. The extraction equilibrium constants (Kex), pH0.5* and separation factor SGd-pr have been evaluated. (author). 18 refs, 3 figs, 4 tabs

  11. Labeling of human platelets with [111In] 8-hydroxyquinoline

    We have evaluated the factors influencing the labeling of human platelets in the presence of autologous plasma. The labeling efficiency was found to be dependent on a) the time and temperature of incubation, b) the platelet concentration, c) the concentration of citrate ions (in ACD anticoagulant), and d) the concentration of 8-hydroxyquinoline in the suspending medium. Contrary to what was expected, unsaturated transferrin was found not to interfere with the transfer of In-111 from the [111In] 8-hydroxyquinoline complex to the platelets. Based on the findings of this study, a protocol was established by which human platelets can be labeled with In-111 in plasma with a labeling efficiency of 55.5 +- 9.3 (mean +- 1 s.d.) percent

  12. Pulse radiolysis study of one electron oxidation of 8-hydroxyquinoline

    Reactions of OH radicals and other one electron oxidants with 8-hydroxyquinoline (8-HQ) have been investigated. Rate constants for these reactions have been determined. OH radical was found to undergo addition reaction whereas N3 and SO4- radicals bring about one electron oxidation. O2 was found to react with the OH-adduct of 8-HQ to give peroxy radicals. (author). 1 ref., 2 figs

  13. Improvement in the environmental stability of tris(8-hydroxyquinoline) aluminum by substitution of sulphonic acid in 8-hydroxyquinoline ligand

    Djurišić, AB; Chan, WK; Roy, VAL; Kwong, CY; Pode, RB; Rao, TKG

    2004-01-01

    Tris (8-hydroxyquinoline) aluminum (Alq 3) is a commonly used electron transporting and/or light emitting material in organic light emitting diodes (OLEDs). However, it is well known that Alq 3 is very sensitive to atmosphere exposure and that photoluminescence of Alq 3 films decreases with the time of atmosphere exposure. Degradation is also a serious problem in Alq 3 based OLEDs. Several degradation mechanisms have been identified in these devices, including formation of unstable cationic s...

  14. Luminescence characterisation of aluminium and erbium tris (8-hydroxyquinoline)

    This thesis presents the results of a study of the photoluminescence and electroluminescence in aluminium and erbium tris(8-hydroxyquinoline). It is shown that the luminescence of aluminium tris(8-hydroxyquinoline) (AlQ) originates from three distinct energy levels each of which has its own characteristic emission spectrum. The transfer of energy between each of the levels as a function of temperature has been empirically modelled using a rate equation approach. The emission from one of these levels is due to the radiative recombination of singlet excitons. The emission from the other two levels is thought to be due to radiative recombination of triplet excitons. The study of the luminescence of erbium tris(8-hydroxyquinoline) (ErQ) shows that it is possible to get energy transfer from the ligands of the molecule into the erbium ion. Characteristic emission is then obtained from the erbium ion at 1.5 μm along with emission originating from the ligands. As with AlQ there is evidence of distinct levels being responsible for the ligand emission in ErQ. Stark splitting of the luminescence due to the local electric field surrounding the Er3+ ion is also presented. These results imply that like AlQ there are two isomers of the ErQ molecule, but following sublimation one of these isomers is much more abundant than the other. Given that AlQ based OLEDs have been fabricated on p type silicon, the possibility of producing a silicon compatible 1.5 μm source using this material is also discussed along with the potential applications of such a device. (author)

  15. Oxo-rhenium(V) complexes with 8-hydroxyquinoline derivatives

    Compounds of the types ReOCl2(L)(PPh3) and ReOCl(L)2 were prepared by reacting ReOCl3(PPh3)2 with 8-hydroxyquinoline (HL) and its 2-methyl, 2-chloro, 5-chloro, 5-nitro, 5,7-dichloro, 5,7-dibromo, and 5,7-diiodo derivatives. With the bulky 2-phenyl-8-hydroxyquinoline, only ReOCl2(L)(PPh3) could be isolated, whereas the still bulkier 2-tert-butyl derivative did not react. For ReOCl2(L)(PPh3), the coordination of the quinoline oxygen trans to the Re=O bond and the cis-dichloro arrangement in the equatorial plane were established from crystallographic studies on the 2-chloro and the 5,7-dibromo complexes. From the combined data for these various derivatives, the 1H NMR signals could be fully assigned. With both series of compounds, a complex d-d absorption pattern is observed in the visible spectra, corresponding to the excitation of a d electron from the interaxial d orbital in the equatorial plane to the empty dxz and dyz orbitals, which are inequivalent in these low-symmetry systems. Deconvolution revealed the presence of two very weak low-energy components (∼10 000 and ∼12 000 cm-1), which are assigned to the two expected singlet-triplet transitions, whereas two stronger bands at higher energy (∼14 000 and ∼17 000 cm-1) originate from the two singlet-singlet transitions. These bands are not substantially displaced by substitution on the 8-hydroxyquinoline rings. (author)

  16. DFT studies and vibrational spectra of isoquinoline and 8-hydroxyquinoline

    Krishnakumar, V.; Ramasamy, R.

    2005-02-01

    The geometry, frequency and intensity of the vibrational bands of isoquinoline (IQ) and 8-hydroxyquinoline (8-HQ) were obtained by the density functional theory (DFT) calculations with the B3LYP functional and 6-31 G* basis set. The vibrational spectral data obtained from the solid phase mid and far FT-IR and FT-Raman spectra of IQ and 8-HQ are assigned based on the results of the normal coordinate calculations. The observed and the calculated spectra are found to be in good agreement.

  17. Investigating the Activity Spectrum for Ring-Substituted 8-Hydroxyquinolines

    Aidan Coffey

    2010-01-01

    Full Text Available In this study, a series of fourteen ring-substituted 8-hydroxyquinoline derivatives were prepared. The synthesis procedures are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains. Several compounds showed biological activity comparable with or higher than the standards isoniazid or fluconazole. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed.

  18. Studies on the extraction of lanthanide complexes with 8-hydroxyquinoline

    The solvent extraction of Sm(III) and Eu(III) by 8-hydroxyquinoline (HOx) in chloroform from aqueous and polar aqueous-methanol phase has been studied as a function of pH(pHx) and the concentration of HOx or methanol in the organic phase. The extraction equilibrium constants (Kex,1 and Kex,2), two phase stability constants (β3x) for the Sm(Ox)3 and Eu(Ox)3 complexes, pH0.5, pH0.5x and separation factor SEu-Sm have been evaluated. (author). 22 refs, 5 figs, 2 tabs

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

    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.

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

    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 1H NMR spectroscopes and the molecular structure of a representative complex, [Sm2(Me-HQ)4(NO3)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 4G5/2→6HJ 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. • The prepared complexes were used for fabrication of

  1. Microdetermination of thorium using 5, 7-diiodo-8-hydroxyquinoline

    An extractive spectrophotometric method for the trace determination of thorium is developed employing 5, 7-diiodo-8-hydroxyquinoline (in acetone) as complexing agent for the metal ion in aqueous medium. The yellow colored complex produced is quantitatively extracted into chloroform with absorption maximum at 409 nm. The method obeys Beer's law in the range 0.0-12.0 μg Th ml-1 having molar absorbitivity and Sandell's sensitivity values of 0.9 x 104 1 mol-1 cm-1 and 0.0256 μg Th cm-2 respectively. The ratio of metal to ligand in the extracted species is determined as 1:2. The method is free from the interference of a large number of diverse ions. Using the proposed procedure, the analysis of various samples has been carried out satisfactorily. (author)

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

    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. Distribution of alkaline earth elements between aqueous solutions and polymer sorbents impregnated by 8-hydroxyquinoline

    Interphase distribution of alkaline-earth element (AEE) microimpurities between solutions of alkali metal chlorides and macroporous copolymer of styrene with divinylbenzene impregnated by 8-hydroxyquinoline is investigated. The effect of phase composition on AEE and 8-hydroxyquinoline distribution coefficient is considered. Advantages of the mixture sorption with impregnated sorbent as compared with liquid extraction for thorough purification of salt solution are shown

  4. Determination of uranium and thorium complexes of 5-chloro-7-amino-8-hydroxyquinoline

    5-Chloro-7-amino-8-hydroxyquinoline which is a 8-hydroxyquinoline derivative was synthesized and its thorium and uranium complexes have been determined. 5-Chloro-7-nitro-8-hydroxyquinoline was prepared by nitration reaction of 5-chloro-8-hydroxyquinoline in aqueous solution of nitric acid. Then 5-chloro-7-amino-8-hydroxyquinoline was synthesized by reduction with sodium dithionite. Proton-ligand stability constants of 5-chloro-7-amino-8-hydroxuquinoline and stability constants of thorium and uranium complexes forming this ligand were determined by using the Irving-Rossotti method computing the Calvin-Bjerrum pH-titration data. As a results, thorium complexes were found more stable than uranium complexes. (author). 14 refs., 4 figs., 5 tabs

  5. Optical and ESR studies of Tris(8-hydroxyquinoline)aluminum

    Tris(8-hydroxyquinoline)aluminum (AlQ) powder has been characterized using photoluminescence and electron spin resonance (ESR). The broad asymmetric excitation band is centered at ∼425 nm, while the emission band centered at ∼505 nm is similar to those reported in films. A significant ESR signal with a linewidth of 10 G and g-value of 2.0038 has been observed in as synthesized AlQ powder at room temperature. The signal at same position is present in AlQ powder as-received from Aldrich, as synthesized AlQ powder, and AlQ powder purified by vacuum sublimation. The appearance of the ESR signal is attributed to organic free radicals. Moreover, exposure of AlQ powder to humid air enhances the ESR signal intensity which increases linearly with exposure duration. This is in agreement with recently proposed degradation mechanism in AlQ based organic light emitting diodes, where degradation was attributed to unstable cationic AlQ species. The discovery of natural free radicals in freshly synthesized AlQ may be useful to prevent the degradation of AlQ and other analogous compounds in organic light emitting diodes (OLEDs)

  6. Study of tungsten (V) dimer complexes with 5-7 dihalogeno-8-hydroxyquinoline

    We report the synthesis of oxo and sulfido bridged tungsten (V) complexes with 5.7 dichloro-8-hydroxyquinoline, 5.7 dibromo-8-hydroxyquinoline and 5.7 diiodo-8-hydroxyquinoline as ligands. These complexes were identified by the infrared and electronic spectra, magnetic susceptibility measurements and analytical data and assigned the following formulae: W2O3(LL)4,W2O4(LL)2, W2O2S2(LL)2 and W2O3S(LL)2. The very low values of the magnetic moment, suggest an intramolecular metal-metal interactions. 14 refs

  7. Diagnostic compositions containing a chelate of radioactive indium and 8-hydroxyquinoline

    There are disclosed aqueous, radioassaying solutions of a chelate of radioactive indium and an 8-hydroxyquinoline, having an essential absence of an organic solvent, e.g., alcohol or chloroform. The solutions are useful in radioassaying warmblooded animals. (author)

  8. Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

    Zayed, Mohie E. M.; Reda M. El-Shishtawy; Elroby, Shaaban A.; Obaid, Abdullah.Y.; Al-amshany, Zahra M.

    2015-01-01

    The synthesis and characterization of different ether and ester derivatives of 8-hydroxyquinoline have been made. UV-visible and fluorescence spectra of these compounds have revealed spectral dependence on both solvent and O-substituent. The fluorescence intensity of ether derivatives revealed higher intensity for 8-octyloxyquinoline compared with 8-methoxyquinoline, whereas those of ester derivatives had less fluorescence than 8-hydroxyquinoline. Theoretical calculations based on Time-depen...

  9. Stability of complexes of lanthanide trivalent ions with 8-hydroxyquinoline and its derivatives

    Linear dependence between acid dissociation (pKa) constants of 8-hydroxyquinoline and its derivatives and Hammett parameters determining contributions of induction and resonance effects of substituents is detected. It is found that correlation coefficients of earlier proposed equation determining the common change of stability in the rare earth series (Ln) from La to Lu, and also contributions of spin S and orbital L angle moments of Ln3+ to complex stability, relate linearly with Hammett constants of substituents in 8-hydroxyquinoline derivatives

  10. DNA-Binding Interaction Studies of Microwave Assisted Synthesized Sulfonamide Substituted 8-Hydroxyquinoline Derivatives

    Dixit, Ritu B.; Patel, Tarosh S.; Vanparia, Satish F.; Kunjadiya, Anju P.; Keharia, Harish R.; Dixit, Bharat C.

    2011-01-01

    Sulfonamide substituted 8-hydroxyquinoline derivatives were prepared using a microwave synthesizer. The interaction of sulfonamide substituted 8-hydroxyquinoline derivatives and their transition metal complexes with Plasmid (pUC 19) DNA and Calf Thymus DNA were investigated by UV spectroscopic studies and gel electrophoresis measurements. The interaction between ligand/metal complexes and DNA was carried out by increasing the concentration of DNA from 0 to 12 μl in UV spectroscopic study, whi...

  11. Distribution of alkaline earth elements between aqueous solutions and polymeric sorbent impregnated with 8-hydroxyquinoline

    The interphase distribution of microimpurities of alkaline earth elements (AEE) between solutions of alkali metal chlorides and a macroporous styrene-divinyl-benzene copolymer impregnated with 8-hydroxyquinoline was studied. The influence of the phase composition on the distribution coefficients of AEE and 8-hydroxyquinoline was examined. The advantages of sorption of the impurities by an impregnated sorbent over liquid extraction for thorough purification of salt solutions were shown

  12. Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline)

    Omar, Walaa A.E.

    2013-01-01

    Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorph...

  13. Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline

    Walaa A.E. Omar

    2013-11-01

    Full Text Available Aluminium tris(4-morpholinyl-8-hydroxyquinoline has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline. Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives.

  14. Synthesis and fluorescent properties of 2-styryl-6,7-difluoro-8- hydroxyquinoline and its Zn(II) complex

    Nosova, E. V.; Stupina, T. V.; Lipunova, G. N.; Charushin, V. N.

    2013-01-01

    A synthetic approach to 2-methyl-6,7-difluoro-8-hydroxyquinoline, a key intermediate, has been developed. 6,7-Difluoro derivative of 2-styryl substituted 8-hydroxyquinoline and its Zn(II) complex have been obtained. Effects of fluorine atoms in the benzene ring on photophysical properties of 2-styryl-8-hydroxyquinolines and their Zn(II) complexes have been studied. © 2013 Elsevier B.V.

  15. Polydentate chelants on base of 8-hydroxyquinoline and possibilities of their analytical application

    Binary and heteroligand complex compounds of rare-earth elements have been studied, in which one of the ligands is a polydentate chelating agent, namely, a derivative of 8-hydroxyquinoline, such as 8-hydroxyquinaldoxime, 8-hydroxyquinaldazine, 2- (N-(o-hydroxyphenyl)-formimidoyl]-8-hydroxyquinoline. The most marked differences in the distribution coefficients of elements of the cerium and yttrium subgroups are observed in the case of extraction of rare-earth elements with a chloroform solution of 2-[N-(0-hydroxyphenyl)-formimidoyl]-8-hydroxyquinoline in the presence of Cupferron or benzoylphenylhydroxy amine. The possibility of analytical application of the systems under consideration is shown with a mixture of praseodymium with erbium taken as an example

  16. Hydrogen catalytic currents in solutions of molybdenum complexes with 8-hydroxyquinoline

    To clarify the possibility of manifestation of catalytic effect of Mo(6) complex with 8-hydroxyquinoline in electrochemical hydrogen evolution the polarographic behaviour of the given complex is studied. During Mo(6) electroreduction on a mercury-dropping electrode in the presence of 8-hydroxyquinoline at the background of 2x10-3 M HCl in the range of potentials -1.1--1.15 V the catalytic wave of hydrogen is observed. Catalytic current reaches the maximum value in pH range 2.4-2.8 and it is in a linear dependence on Mo(6) concentration in the concentration range 10-7-2x10-8 mol/l. Catalytic effect is caused by protonation of Mo(6) complex with 8-hydroxyquinoline, adsorbed on the electrode. Adsorption of Mo(6) complex plays the most important role in the catalytic process, which promotes considerable excess of catalytic current as compared with diffusional one

  17. Studies of some mixed-ligand derivatives of hydroxo (aqua) bis- (acetoacetylarylamido) lanthanum (III) with 8-hydroxyquinoline/ 8-hydroxyquinoline-4-(phenyl) sulphonamides

    Some new mixed-ligand complexes of lanthanum(III) of the composition [La(A-A)2(L-L)], where (A-A)H = acetoacetanilide, o-acetoaceto-toluidide or o-acetoacetanisidide and (L-L)H = 8-hydroxyquinoline or 8-hydroxyquinoline-4-(phenyl) sulphonamide. These mixed-ligand chelates have been obtained by the interaction of hydroxo (aqua) bis (acetoacetanilido)-, hydroxo (aqua) bis (o-acetoa-cetotoluidido)-, and hydroxo (aqua) bis (o-aceto-acetanisidido)-lanthanum (III) with the said ligands. The metal chelates so obtained have been characterized by elemental analyses, electrical conductances, magnetic measurements, electronic and infrared spectral studies. An octahedral structure has been proposed for these complexes. (author)

  18. 5-Carboxy-8-hydroxyquinoline is a Broad Spectrum 2-Oxoglutarate Oxygenase Inhibitor which Causes Iron Translocation

    Hopkinson, Richard J.; Tumber, Anthony; Yapp, Clarence; Chowdhury, Rasheduzzaman; Aik, WeiShen; Che, Ka Hing; Li, Xuan Shirley; Kristensen, Jan B. L.; King, Oliver N.F.; Chan, Mun Chiang; Yeoh, Kar Kheng; Choi, Hwanho; Walport, Louise J.; Thinnes, Cyrille C.; Bush, Jacob T

    2013-01-01

    2-Oxoglutarate and iron dependent oxygenases are therapeutic targets for human diseases. Using a representative 2OG oxygenase panel, we compare the inhibitory activities of 5-carboxy-8-hydroxyquinoline (IOX1) and 4-carboxy-8-hydroxyquinoline (4C8HQ) with that of two other commonly used 2OG oxygenase inhibitors, N-oxalylglycine (NOG) and 2,4-pyridinedicarboxylic acid (2,4-PDCA). The results reveal that IOX1 has a broad spectrum of activity, as demonstrated by the inhibition of transcription fa...

  19. Azo compounds on base of N-oxide of 8-hydroxyquinoline - new class of organic reagents

    Azo derivatives of N-oxide of 8-hydroxyquinoline have been synthesized and studied for the first time as organic reagents. The spectrophotometric characteristics of these reagents have been defined. Color reactions of the reagents with Ni, Cd, Fe(2), Zr(4) and Ti(4) have been studied. Most complexes of azo compounds based on N-oxide of 8-hydroxyquinoline with metal ions are readily soluble in oxygen-containing organic solvents, which is indicative of their being suitable for use in extraction-photometric determination of elements

  20. Spectrophotometric Determination of Zinc Using 7-(4-Nitrophenylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

    Korn Maria das Graças Andrade; Ferreira Adriana Costa; Teixeira Leonardo Sena Gomes; Costa Antonio Celso Spínola

    1999-01-01

    A sensitive and selective spectrophotometric method is proposed for the rapid determination of zinc(II) using an 8-hydroxyquinoline derivative, 7-(4-nitrophenylazo)-8-hydroxyquinoline-5-sulfonic acid (p-NIAZOXS), as a new spectrophotometric reagent. The reaction between the p-NIAZOXS and zinc(II) is instantaneous at pH 9.2 (borax buffer) and the absorbance remains stable for over 24 h. The method allows the determination of zinc over the range of 0.05-1.0 mug mL-1 with a molar absorptivity of...

  1. Reasoned opinion on the modification of the existing MRL for 8-hydroxyquinoline in tomatoes

    European Food Safety Authority

    2013-01-01

    In accordance with Article 6 of Regulation (EC) No 396/2005, Spain, hereafter referred to as the evaluating Member State (EMS), received an application from the company Probelte to modify the existing MRL for the active substance 8-hydroxyquinoline in tomatoes. In order to accommodate for the intended indoor use of 8-hydroxyquinoline, Spain proposed to raise the existing MRL in tomatoes to 0.1 mg/kg. Spain drafted an evaluation report in accordance with Article 8 of Regulation (EC) No 396/200...

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

    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.

  3. Elucidating the role of hyperfine interactions on organic magnetoresistance using deuterated aluminium tris(8-hydroxyquinoline)

    Rolfe, N. J.; Heeney, M.; Wyatt, P. B.; Drew, A.J.; Kreouzis, T.; Gillin, W P

    2009-01-01

    Measurements of the effect of a magnetic field on the light output and current through an organic light emitting diode made with deuterated aluminium tris(8-hydroxyquinoline) have shown that hyperfine coupling with protons is not the cause of the intrinsic organic magnetoresistance. We suggest that interactions with unpaired electrons in the device may be responsible.

  4. Reasoned opinion on the modification of the existing MRL for 8-hydroxyquinoline in tomatoes

    European Food Safety Authority

    2013-05-01

    Full Text Available In accordance with Article 6 of Regulation (EC No 396/2005, Spain, hereafter referred to as the evaluating Member State (EMS, received an application from the company Probelte to modify the existing MRL for the active substance 8-hydroxyquinoline in tomatoes. In order to accommodate for the intended indoor use of 8-hydroxyquinoline, Spain proposed to raise the existing MRL in tomatoes to 0.1 mg/kg. Spain drafted an evaluation report in accordance with Article 8 of Regulation (EC No 396/2005, which was submitted to the European Commission and forwarded to EFSA. According to EFSA, the submitted data are sufficient to derive a MRL proposal of 0.1 mg/kg for 8-hydroxyquinoline in tomatoes which reflects the analytical LOQ of the method used to analyse residue trial samples. Based on the risk assessment results, EFSA concludes that the intended indoor use of 8-hydroxyquinoline on tomatoes will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a public health risk.

  5. Thermodynamics of the extraction of Co2+ by htenoyltrifluoroacetone, 8-hydroxyquinoline and phenanthroline

    The extraction of Co2+ from aqueous 0.1M acetate buffer by thenoyltrifluoroacetone (HTTA) and 8-hydroxyquinoline (HQ) and by a mixture of HTTA + phen and HQ + phen in benzene has been studied at various temperatures allowing for elucidation of the thermodynamics of extraction in the cases investigated. (author) 5 refs.; 5 figs.; 2 tabs

  6. Effect of γ-radiation on the IR spectra of lanthanide 8-hydroxyquinoline complexes

    IR absorption spectra of eight lanthanide elements chelated with 8-hydroxyquinoline were measured before and after gamma irradiation with different doses (25-850 MR). It was found that the rate of decrease K of M-O and C-O absorption bands depend on the chelated cation. A mechanism based on the target theory is proposed. (author)

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

    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.

  8. Ring-substituted 8-hydroxyquinoline-2-carboxanilides as potential antimycobacterial agents

    Kos, J.; Zadražilová, I.; Nevin, E.; Soral, M.; Gonec, T.; Kollár, P.; Oravec, Michal; Coffey, A.; O'Mahony, J.; Liptaj, T.; Kralova, K.; Jampílek, J.

    2015-01-01

    Roč. 23, č. 15 (2015), s. 4188-4196. ISSN 0968-0896 Institutional support: RVO:67179843 Keywords : 8-Hydroxyquinolines * in vitro antimycobacterial activity * in vitro cytotoxicity * MTT assay * Structure–activity relationships Subject RIV: EH - Ecology, Behaviour Impact factor: 2.793, year: 2014

  9. Synthesis and characterisation of 8-hydroxyquinoline-bovine serum albumin conjugates as metal ion chelating proteins

    A derivative of 8-hydroxyquinoline (8-quinolinol, oxine) with a linking bridge containing a carboxylic group was covalently coupled to bovine serum albumin by the N-hydroxysuccinimide method to obtain stable monomeric conjugates with oxine to protein mole ratios up to 37. These conjugates were characterised spectrophotometrically and their complexation properties were confirmed by spectral analysis with and without the addition of Al(III), Cd(II), Co(II), Cu(II), Hg(II), Mn(II), Ni(II), Pb(II), V(IV), U(VI) and Zn(II) ions added. The maximum number of ions bound by these chelating proteins was determined spectrophotometrically by titration with metal ions at pH 6.0. The conjugates with a substitution ratio (moles of 8-hydroxyquinoline bound/mole of albumin) less than about 8 showed 1:1 binding with metal ions, while conjugates with higher substitution ratios were able to complex with 2:1 ratio of 8-hydroxyquinoline to metal ion. Association and dissociation kinetics of complexation with copper(II) ions showed a complex mechanism. The spectral and binding properties of these metal ion-binding proteins confirm that the coupling of the 8-hydroxyquinoline derivative to bovine serum albumin gives stable, water soluble, macromolecular chelating agents that retain the complexing ability of the original ligand. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Theoretical Studies on the Ground State and Excited State of 2,4'- (Ethylene)-bis-8-hydroxyquinoline

    Hui-xue Li; Su-juan Pan; Xiao-feng Wang; Tai Xiao

    2008-01-01

    2,7'-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ion- ization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramolecular reor- ganization energy of tris(2,7'-(ethylene)-bis-8-hydroxyquinoline)-aluminum implies its electron transporting property is worse than tris(8-hydroxyquinoline)-aluminurn. The predicted maximum emission wavelength is red-shifted compared with tris(8-hydroxyquinoline)-aluminum.

  11. Theoretical Studies on the Ground State and Excited State of 2,7'-(Ethylene)-bis-8-hydroxyquinoline

    Li, Hui-xue; Pan, Su-juan; Wang, Xiao-feng; Xiao, Tai

    2008-06-01

    2,7'-(Ethylene)-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ionization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramolecular reorganization energy of tris(2,7'-(ethylene)-bis-8-hydroxyquinoline)-aluminum implies its electron transporting property is worse than tris(8-hydroxyquinoline)-aluminum. The predicted maximum emission wavelength is red-shifted compared with tris(8-hydroxyquinoline)-aluminum.

  12. Synthesis, antimicrobial, and antiviral activities of some new 5-sulphonamido-8-hydroxyquinoline derivatives.

    Kassem, Emad M; El-Sawy, Eslam R; Abd-Alla, Howaida I; Mandour, Adel H; Abdel-Mogeed, Dina; El-Safty, Mounir M

    2012-06-01

    A series of fused pyranopyrazole and pyranoimidazole, namely 5-(3,6-diamino-4-aryl-5-carbonitrile-pyrano(2,3-c)pyrazol-2-yl)sulphonyl-8-hydroxyquinolines (5a-e), 5-(6-amino-4-aryl-5-carbonitrile-pyrano(2,3-c)pyrazol-3-yl)sulphonamido-8-hydroxyquinolines (6a-e), 5-(2-thioxo-4-aryl-5-carbonitrile-6-amino-pyrano(2,3-d)imidazol-2-yl)sulphonyl-8-hydroxyquinolines (10a-e), and 5-(2-oxo-4-aryl-5-carbonitrile-6-amino-pyrano(2,3-d)imidazol-2-yl) sulphonyl-8-hydroxyquinolines (11a-e), have been prepared via condensation of some arylidine malononitriles with 5-sulphonamido-8-hydroxyquinoline derivatives 3, 4, 8 and 9. All the synthesized compounds were screened for their antimicrobial activities, and most of the tested compounds showed potent inhibition growth activity towards Escherichia coli, Pseudomonas aeruginosa (Gramnegative bacteria). Furthermore, six selected compounds were tested for their antiviral activity against avian paramyxovirus type1 (APMV-1) and laryngotracheitis virus (LTV), and the results showed that a concentration range of 3-4 μg per mL of compounds 2, 3, and 4 showed marked viral inhibitory activity for APMV-1 of 5000 tissue culture infected dose fifty (TCID(50)) and LTV of 500 TCID(50) in Vero cell cultures based on their cytopathic effect. Chicken embryo experiments show that compounds 2, 3, and 4 possess high antiviral activity in vitro with an inhibitory concentration fifty (IC(50)) range of 3-4 μg per egg against avian APMV-1 and LTV and their toxic concentration fifty (CC(50)) of 200-300 μg per egg. PMID:22870804

  13. Terahertz absorption spectra of 8-hydroxyquinoline and its some metal complexes

    Liu, Guifeng; Ma, Shihua; Zhao, Hongwei; Ji, Te; Zhang, Zengyan; Wang, Wenfeng

    2009-11-01

    The room temperature terahertz (THz) absorption spectra of 8-hydroxyquinoline (8HQ) and tris(8-hydroxyquinolino)aluminum, bis-(8-hydroxyquinolinato)zinc and copper 8-hydroxyquinoline were clearly measured from 0.3 to 1.8 THz. 8HQ has absorption peaks which occur at 1.02, 1.48, and 1.77 THz. Density functional theory (DFT) was used to predict the vibration frequencies of 8HQ in the frequency range 0-10 THz. Metal complexes have various absorption peaks in the THz region, which may be related to different metal ions and used to distinguish them. These results show that THz-TDS are sensitive tools for characterization of metal complexes.

  14. Extraction of carrier-free 144Ce with acetylacetone and 8-hydroxyquinoline

    The extraction of carrier-free 144Ce with 3.25 to 0.65 M solutions of acetylacetone in carbon tetrachloride and with 1.0 to 0.01 M solutions of 8-hydroxyquinoline in chloroform at a constant as well as variable pH was investigated. On the basis of the analysis of distribution curves it may be presumed that in both extraction systems the oxidation of cerium(III) to cerium(IV) microamounts takes place. The distribution curves of extraction and reextraction in the systems with 8-hydroxyquinoline show a considerable complexity. In the extraction system with acetylacetone constants were found which satisfactorily express the distribution of 144Ce in this system. (author)

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

    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.

  16. Magnetic susceptibility of Alq3 powder, pure and Al-doped 8-hydroxyquinoline

    Single-crystal nanowires several microns long and 100-200 nm in diameter were grown by physical vapour deposition from mixed Alq3/γ-Al2O3 powder. The crystals are orthorhombic Al-doped 8-hydroxyquinoline. The molar susceptibility is -3x10-9 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 4x10-4 per formula unit. Pure 8-hydroxyquinoline and aluminium (Alq3) 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 m2 kg-1, which is attributed to metallic iron nanoclusters in the organic material.

  17. Magnetic susceptibility of Alq 3 powder, pure and Al-doped 8-hydroxyquinoline

    Burke, Franklyn; Abid, Mohamed; Stamenov, Plamen; Coey, J. M. D.

    2010-05-01

    Single-crystal nanowires several microns long and 100-200 nm in diameter were grown by physical vapour deposition from mixed Alq 3/γ-Al 2O 3 powder. The crystals are orthorhombic Al-doped 8-hydroxyquinoline. The molar susceptibility is -3×10 -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 4×10 -4 per formula unit. Pure 8-hydroxyquinoline and aluminium (Alq 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 2 kg -1, which is attributed to metallic iron nanoclusters in the organic material.

  18. Extraction spectrophotometric method for the determination of trace thorium using 8-hydroxyquinoline and ethyl violet

    A new highly sensitive colour system for thorium is developed. An association complex of thorium ion is formed with 8-hydroxyquinoline and ethyl violet having absorption maximum at 607 nm. The complex can be extracted into 10 ml of a mixture of benzene and MIBK (3:1) in 1 min. Its apparent ε value is 7.5 x 105 l·mol-1·cm-1 at 607 nm. Optimum conditions for the extraction have been found to be 3.5 x 10-3 mol/l sulfuric acid, 0.020 mol/l 8-hydroxyquinoline and 0.018% ethyl violet. Berr's law is obeyed for 0-4.5 μg of thorium per 10 ml. The colour of the extract is stable in 110 minutes at room temperature. The effects of 32 foreign ions and 4 complex reagents on the determination are discussed

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

    8-Hydroxyquinoline (8-HQ) was attached to mesoporous silica by sulfonamide bond formation between 8-hydroxyquinoline-5-sulfonyl chloride (8-HQ-SO2Cl) 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.

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

    Badiei, Alireza, E-mail: abadiei@khayam.ut.ac.ir [School of Chemistry, College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Goldooz, Hassan [Department of Chemistry, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ziarani, Ghodsi Mohammadi [Department of Chemistry, Faculty of Science, Alzahra University, Tehran (Iran, Islamic Republic of)

    2011-03-15

    8-Hydroxyquinoline (8-HQ) was attached to mesoporous silica by sulfonamide bond formation between 8-hydroxyquinoline-5-sulfonyl chloride (8-HQ-SO{sub 2}Cl) 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.

  1. Spectroscopic studies of fluorescent complexes of tyrosine 8-hydroxyquinoline and tyrosine-8-hydroxyquinaldine in aqueous phase

    A new method has been developed by preparing complexes involving condensation of tyrosine with 8-hydroxyquinoline (Oxine) and 8-hydroxyquinaldine (Quinaldine) respectively, producing fluorescent products. The products obtained have been investigated for identification and quantitative estimation using different spectroscopic techniques including fluorescence activity of newly synthesized products. 8-hydroxyquinaldine and 8-hydroxyquinoline (Oxine) condensed with tyrosine separately produced water soluble fluorescent complexes. The complexes have been investigated for identification and quantitative estimation of amino acids. Identification of amino acids in nano mole or below than nano mole has become possible by present fluorometric activity of these complexes involving different excitation and emission wavelengths. The fluorometric activity of complexes has been observed to be 100 to 1000 times higher than assay method involving ninhydrin and amino acid analyzer. The method adopted in our laboratory is rapid, versatile with good reproducibility and provides excellent results for adoption by analytical, agricultural and biomedical laboratories to estimate amino acids and metals in composite matrix. (author)

  2. Fabrication and characterization of OLED with Mg complex of 5-chloro-8-hydroxyquinoline as emission layer

    Magnesium(II) ions were complexed with 5-chloro-8-hydroxyquinoline (L) to give an MgL2 chelate that emitted green fluorescent light in tetrahydrofuran (THF) solvent as well as in solid state when excited by UV light. The complex was found to produce electroluminescent (EL) and thus OLEDs were fabricated and characterized based on this green light emitting material. In these devices the hole transport layer was obtained using a thin film of N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), LiF as hole blocking layer and tri(8-hydroxyquinoline aluminum)(Alq3) as the electron transporting layer. The EL peak was at 539 nm with 19 nm red shift from PL peak. The EL devices fabricated had a maximum brightness of 425 cd m-2

  3. Structure and vibrational spectroscopy investigation of 2-(4-chlorophenyliminomethyl)-8-hydroxyquinoline

    Zhao, Bin; Wang, Yang-yang; Zhang, Yu-hua; Dai, Li; Zhou, Zheng-yu

    2011-10-01

    2-(4-Chlorophenyliminomethyl)-8-hydroxyquinoline was synthesized and crystal data was obtained in the orthorhombic space group P-1, with Z = 4. Unit cell parameters a = 4.744(7) Å, b = 9.981(15) Å, c = 27.27(4) Å and V = 12915(3) Å 3. In this paper the structural properties and vibrational frequencies of 8-hydroxyquinoline derivative, 2CP8HQ, are studied with the B3LYP and HF methods. Two stable conformers are obtained. The calculated frequencies are in good agreement with the experiment results. It is indicated that both of theoretical calculations were suitable for molecular vibrational frequencies study and the scaled B3LYP method was superior to the scaled HF methods.

  4. Modeling of gadolinium recovery from nitrate medium with 8-hydroxyquinoline by emulsion liquid membrane

    The extraction equilibrium of Gd(III) from nitrate medium by 8-hydroxyquinoline (HOX) in toluene was studied. Liquid-liquid investigations were first carried out. Based on the equilibrium results, the extraction of Gd(III) from aqueous nitrate medium into an emulsion liquid membrane system (ELM) containing 8-hydroxyquinoline in toluene as extractant, HNO3 as stripping solution, Span-80 as surfactant was studied. The stability of the prepared ELM was studied in terms of the degree of membrane breakage. The different parameters affecting the permeation of gadolinium (III) were also studied. A general permeation model for the recovery of Gd(III) by the selected membrane is presented. The internal mass transfer in the water in oil (W/O) emulsion drop, the external mass transfer around the drop, the rates of formation and decomposition of the complex at the external aqueous-organic interface were considered.

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

    Singru, Rajesh N.; Anil B. Zade; Gurnule, Wasudeo B.

    2009-01-01

    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 tec...

  6. 8-Hydroxyquinoline Dansylates Modified with PAMAM Dendrimer as Fluorescent Fe3+ Sensors

    Yaowu Sha

    2010-04-01

    Full Text Available A series of fluorescent sensors based on 8-hydroxyquinoline dansylate as core and dendritic PAMAM as shell were synthesized. Their fluorescence characteristic and fluorescent sensing behavior toward metal ions were studied in water/methanol (1: 1, v/v. The sensors exhibit good selectivity and sensitivity for Fe3+ ion and to some extent for Cr3+ ion. The third generation dendrimer has the better sensitivity than the first and second generations.

  7. 8-Hydroxyquinoline Dansylates Modified with PAMAM Dendrimer as Fluorescent Fe3+ Sensors

    Yaowu Sha; Jin-Hui Wang; Qi Zhang

    2010-01-01

    A series of fluorescent sensors based on 8-hydroxyquinoline dansylate as core and dendritic PAMAM as shell were synthesized. Their fluorescence characteristic and fluorescent sensing behavior toward metal ions were studied in water/methanol (1: 1, v/v). The sensors exhibit good selectivity and sensitivity for Fe3+ ion and to some extent for Cr3+ ion. The third generation dendrimer has the better sensitivity than the first and second generations.

  8. Synthesis of 5-Dialkyl(arylaminomethyl-8-hydroxyquinoline Dansylates as Selective Fluorescent Sensors for Fe3+

    Yaowu Sha

    2007-05-01

    Full Text Available A series of 5-dialkyl(arylaminomethyl-8-hydroxyquinoline dansylates were synthesized and their fluoroionophoric properties toward representative alkali ions, alkaline earth ions and transition metal ions were investigated. Among the selected ions, Fe3+ caused considerable quenching of the fluorescence, while Cr3+ caused quenching to some extent. The absence of any significant fluorescence quenching effects of the other ions examined, especially Fe2+, renders these compounds highly useful Fe3+-selective fluorescent sensors.

  9. Electronic structure of tris(8-hydroxyquinoline) aluminum thin films in the pristine and reduced states

    Johansson, N.; Osada, T; Stafström, Sven; Salaneck, William R.; Parente, V.; dos Santos, D. A.; Crispin, Xavier; Bredas, J. L.

    1999-01-01

    The electronic structure of tris(8-hydroxyquinoline) aluminum (Alq(3)) has been studied in the pristine molecular solid state as well as upon interaction (doping) with potassium and lithium. We discuss the results of a joint theoretical and experimental investigation, based on a combination of x-ray and ultraviolet photoelectron spectroscopies with quantum-chemical calculations at the density functional theory level. Upon doping, each electron transferred from an alkali metal atom is stored o...

  10. Evolution of optical properties of tris (8-hydroxyquinoline) aluminum (Alq3) with atmosphere exposure

    Djurišić, AB; Chan, WK; Lau, TW; Kwong, CY; Lam, LSM

    2002-01-01

    Tris (8-hydroxyquinoline) aluminum (Alq3) represents a material of significant interest for electron transport and/or light emitting layer applications in organic light emitting diodes (OLEDs). In spite of advances in Alq3 based devices, the knowledge and understanding of the optical properties of Alq3 and its chemical and environmental stability is still limited. With the reports of decreased turn-on voltage and increased efficiency of OLEDs, the issues of lifetime and stability of those dev...

  11. New approach to synthesize 8-hydroxyquinoline-based complexes with Zn2+ and their luminescent properties

    Wang, Ruifang; Cao, Yali; Jia, Dianzeng; Liu, Lang; Li, Fang

    2013-12-01

    In this paper, zinc(II) bis-(8-hydroxyquinoline) dihydrate (ZnQ2·2H2O) and zinc(II) bis-(2-methyl-8-hydroxyquinoline) monohydrate (Zn(MQ)2·H2O) were successfully prepared by a room-temperature solid-state chemical reaction using zinc acetate (Zn(CH3COO)2·2H2O), 8-hydroxyquinoline (HQ) and 2-methyl-8-hydroxyquinoline (2-methyl-8-HQ) as the starting materials. The results of X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and thermal analysis (TG/DSC) demonstrated that the chemical composition of the products were ZnQ2·2H2O and Zn(MQ)2·H2O. The scanning electron microscopy (SEM) images and the transmission electron microscopy (TEM) images showed that the products ZnQ2·2H2O and Zn(MQ)2·H2O had sheet-like morphology with a thickness of about 50 nm. The UV-vis absorption spectra of ZnQ2·2H2O and Zn(MQ)2·H2O indicated that they existed charge transfer from the metal to the ligand (MLCT bands). The room-temperature photoluminescence (PL) spectra of ZnQ2·2H2O revealed that the sample possessed largely blue shift compared with the previous reports. Besides, the two complexes presented a consistent decline situation along with the decline concentration in chloroform solution, which due to solvate effect and structural similarity. The fluorescence quantum yields were measured at 36.58% and 0.07%, and the emission colors were blue-green and light-blue, respectively. The fluorescence quantum yield of ZnQ2·2H2O was higher than some reported similar structure. The method was believed to largely facilitate the fabrication and application of organometallic complex nanomaterials.

  12. Ultra-sensitive and selective Hg2+ chemosensors derived from substituted 8-hydroxyquinoline analogues

    Bell, Jeremy; Samb, Issa; Toullec, Patrick Y; Mongin, Olivier; Blanchard-Desce, Mireille; Michelet, Veronique; Leray, Isabelle

    2014-01-01

    Novel analogues of 8-hydroxyquinoline with phosphinate or thiophosphinate functions and styryl fluorophores in the para position to the nitrogen atom were prepared via multi-step syntheses, using phosphorylation and Wittig coupling reactions. A strong affinity between the quinoline analogues and heavy metal ions such as Pb2+, Cd2+ and Hg2+ was highlighted. The interaction of the metal ions with the nitrogen of the styrylquinoline leads to a large red shift of the absorption and emission spect...

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

    Demelash Jado; Khalid Siraj; Nathan Meka

    2014-01-01

    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 ...

  14. Novel 8-Hydroxyquinoline Derivatives as Multitarget Compounds for the Treatment of Alzheimer's Disease.

    Prati, Federica; Bergamini, Christian; Fato, Romana; Soukup, Ondrej; Korabecny, Jan; Andrisano, Vincenza; Bartolini, Manuela; Bolognesi, Maria Laura

    2016-06-20

    We discovered a small series of hit compounds that show multitargeting activities against key targets in Alzheimer's disease (AD). The compounds were designed by combining the structural features of the anti-AD drug donepezil with clioquinol, which is able to chelate redox-active metals, thus decreasing metal-driven oxidative phenomena and β-amyloid (Aβ)-mediated neurotoxicity. The majority of the new hybrid compounds selectively target human butyrylcholinesterase at micromolar concentrations and effectively inhibit Aβ self-aggregation. In addition, compounds 5-chloro-7-((4-(2-methoxybenzyl)piperazin-1-yl)methyl)-8-hydroxyquinoline (1 b), 7-((4-(2-methoxybenzyl)piperazin-1-yl)methyl)-8-hydroxyquinoline (2 b), and 7-(((1-benzylpiperidin-4-yl)amino)methyl)-5-chloro-8-hydroxyquinoline (3 a) are able to chelate copper(II) and zinc(II) and exert antioxidant activity in vitro. Importantly, in the case of 2 b, the multitarget profile is accompanied by high predicted blood-brain barrier permeability, low cytotoxicity in T67 cells, and acceptable toxicity in HUVEC primary cells. PMID:26880501

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

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

    2009-05-01

    It is now well known that zinc is crucial for the synthesis of nucleic acids and, consequently, for cellular division. However, 67Zn, 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 113Cd. In this work, we employed 13C, 113Cd 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. Polarographic study of dioxo-uranium(VI)-8-hydroxyquinoline-succinate system and thermodynamic parameters

    The dioxo-uranium(VI)-8-hydroxyquinoline-succinate system has been studied polarographically at constant ionic strength (μ = 0.6 M KCl) in aqueous alcohol (7:3) at different temperatures. The reduction of the simple and mixed complexes is reversible and diffusion controlled. The DeFord-Hume and Schaap-McMaster methods have been applied in the determination of composition and stability constants of the simple and mixed complexes respectively. The thermodynamic parameters ΔG, ΔH and ΔS have also been calculated. (author)

  17. Characterization of the Triplet State of Tris(8-hydroxyquinoline)aluminium(III) in Benzene Solution

    Burrows, Hugh D.; Fernandes, Mariana; Melo, J. Seixas de; Monkman, Andrew P.; NAVARATNAM, SUPPIAH

    2003-01-01

    The lowest triplet state of tris(8-hydroxyquinoline)aluminium(III) (Alq3) has been prepared by pulse radiolysis/energy transfer from appropriate donors in benzene solutions and has an absorption maximum around 510 nm with a lifetime of about 50 μs. It is quenched by molecular oxygen, leading to singlet oxygen formation. From flash photolysis and singlet oxygen formation measurements, a quantum yield of triplet formation of 0.24 was determined for direct photolysis of the complex. A value of 2...

  18. Intensity and temperature-dependent photoluminescence of tris (8-hydroxyquinoline) aluminum films

    Ajward, A. M.; Wang, X.; Wagner, H. P. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

    2013-12-04

    We investigate the recombination of excitons in tris (8-hydroxyquinoline) aluminum films by intensity and temperature dependent time-resolved photoluminescence (PL). At low temperature (15 K) and elevated excitation intensity the radiative emission is quenched by singlet-singlet annihilation processes. With rising temperature the PL quenching is strongly reduced resulting in a PL efficiency maximum at ∼170 K. The reduced exciton annihilation is attributed to thermally activated occupation of non-quenchable trapped exciton states. Above 170 K the PL efficiency decreases due to thermal de-trapping of radiative states and subsequent migration to non-radiative centers.

  19. Spectrophotometric determination of uranium(VI) with 7-iodo-8-hydroxyquinoline-5-sulfonic acid (ferron)

    A new method is introduced to estimate uranium(VI) spectrophotometrically by extraction of its ferron (7-iodo-8-hydroxyquinoline-5-sulfonic acid) complex with 1% tridodecylamine in chloroform at pH 4.5. The optimum absorption wavelength is 380 mm. The stoichiometry of the uranium-ferron complex as indicated by a mole ratio plot is 1:2 and its dissociation constant is 3.24x10-9. The effects of various parameters on the absorption are studied. This method has a sensitivity of 0.028 ppm on Sandell's scale. Interferences are described. (author)

  20. Luminescent reaction of lanthanum with 8-hydroxyquinoline-5-sulphonic acid and cetyltrimethyl ammonium

    The effect of surfactants on the fluorescence of REE complexes - with 8-hydroxyquinoline-5-sulphonic acid (quinozole) is investigated. The intensity of La-quinozole complex fluorescence increases by a factor of 20 in presence of cetyltrimethylammonium bromide. A complex with a ratio of La: quinozol: CTA = 1:1:1 is formed. The fluorescence intensity decreases significantly in presence of 10-fold excess of elements-quenchers (Pr, Nd). The fluorescence intensity-lanthanum concentration graph is linear over a range of 1-20 μg La. The method was used for determining lanthanum in its salts with a limit of detection 0.01 μg/ml

  1. Solvent extraction of alkaline earth elements by di-2-ethylhexylphosphoric acid and 8-hydroxyquinoline mixtures

    Solvent extraction of alkaline earth elements including Sr by mixtures of di-2-ethylhexylphosphoric acid and 8-hydroxyquinoline (8-O) in chloroform is investigated. pH constant value was kept using acetate buffer mixtures; content of the extracted element in the initial solution constituted 1·10-3mol/l. Investigation into dependence of distribution coefficients on (8-O) concentration demonstrated presence of synergism which is explained by formation of mixed complexes in the organic phase. It is shown, that increase of pH value of aqueous solution uncreases extraction of elements by organic phase

  2. Determination of complex forming conditions of 8-hydroxyquinoline with technetium-99m

    Complex forming conditions of 8-hydroxyquinoline with 99mTc have been specified. 99mTcO4- has been reduced by SnCl2 to a lower oxidation level. Labeling yields have been determined by ITLC (Instant Thin Layer Chromatography). Various parameters, such as pH, temperature, reaction time, ligand to SnCl2 ratio, which can affect the labeling yields, have been determined. Optimum conditions are 4-7 for pH; 15-20 deg C (room) for temperature, 1.55 for ligand to SnCl2 ratio and 5 min for reaction time. (author). 10 refs., 3 figs., 1 tab

  3. Synthesis of europium(III) complex with phthalocyanine and 8-hydroxyquinoline

    A novel, unspecified earlier, europium complex, C41H22EuN9O (I), with the phthalocyanine and hydroxyquinoline moieties has been synthesized. The synthesis was carried out by direct reaction between the phthalocyanine ligand and tris(8-hydroxyquinoline)europium, activated by the organic base 1,8-diazabicyclo[5.4.0]-undec-7-ene. The reaction in boiling o-dichlorobenzene yielded complex (I) isolated as a pure substance. The structure of complex (I) has been ascertained by 1H NMR, IR and UV spectroscopy, its composition - by elementary analysis

  4. Betti reaction enables efficient synthesis of 8-hydroxyquinoline inhibitors of 2-oxoglutarate oxygenases.

    Thinnes, C C; Tumber, A; Yapp, C; Scozzafava, G; Yeh, T; Chan, M C; Tran, T A; Hsu, K; Tarhonskaya, H; Walport, L J; Wilkins, S E; Martinez, E D; Müller, S; Pugh, C W; Ratcliffe, P J; Brennan, P E; Kawamura, A; Schofield, C J

    2015-10-28

    There is interest in developing potent, selective, and cell-permeable inhibitors of human ferrous iron and 2-oxoglutarate (2OG) oxygenases for use in functional and target validation studies. The 3-component Betti reaction enables efficient one-step C-7 functionalisation of modified 8-hydroxyquinolines (8HQs) to produce cell-active inhibitors of KDM4 histone demethylases and other 2OG oxygenases; the work exemplifies how a template-based metallo-enzyme inhibitor approach can be used to give biologically active compounds. PMID:26345662

  5. DFT studies of the bonding mechanism of 8-hydroxyquinoline and derivatives on the (111) aluminum surface

    Chiter, Fatah; Lacaze-Dufaure, Corinne; Tang, Hao; Pébère, Nadine

    2015-01-01

    The 8-hydroxyquinoline (8-HQ) molecule is an efficient corrosion inhibitor for aluminum and is also used in organic electronic devices. In this paper, the adsorption modes of 8-HQ and its derivatives (tautomer, dehydrogenated and hydrogenated species) on the Al(111) surface are characterized using dispersion corrected density functional theory calculations. The 8-HQ molecule is physisorbed and is chemisorbed on the aluminum surface with similar adsorption energy (-0.86 eV to -1.11 eV) and the...

  6. Rayleigh scattering and luminescence blue shift in tris(8-hydroxyquinoline)aluminum films

    The Rayleigh scattering (RS) by independent small particles is a well-known effect which also accounts for the blue color of the sky. Lately, the blue shift of the greenish emission band of thin films of Alq3, tris(8-hydroxyquinoline)aluminum, after thermal treatments of various nature has been attributed to RS. Here, we show that RS effects cannot account for the observed spectral features, which are attributed to the onset of various molecular aggregations in the otherwise amorphous films, a morphological model already utilized to explain the optical properties of Alq3

  7. Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

    Mohie E. M. Zayed

    2015-02-01

    Full Text Available The synthesis and characterization of different ether and ester derivatives of 8-hydroxyquinoline have been made. UV-visible and fluorescence spectra of these compounds have revealed spectral dependence on both solvent and O-substituent. The fluorescence intensity of ether derivatives revealed higher intensity for 8-octyloxyquinoline compared with 8-methoxyquinoline, whereas those of ester derivatives had less fluorescence than 8-hydroxyquinoline. Theoretical calculations based on Time-dependent density functional theory (TD-DFT were carried out for the quinolin-8-yl benzoate (8-OateQ compound to understand the effect of O-substituent on the electronic absorption of 8-hydroxyquinaline (8-HQ. The calculations revealed comparable results with those obtained from the experimental data. Optimized geometrical structure was calculated with DFT at B3LYP/6-311++G** level of theory. The results indicated that 8-OateQ is not a coplanar structure. The absorption spectra of the compound were computed in gas-phase and solvent using B3LYP and CAM-B3LYP methods with 6-311++G ** basis set. The agreement between calculated and experimental wavelengths was very good at CAM-B3LYP/6-311++G** level of theory.

  8. Stability constants of lanthanide(3) ions complexes with 8-hydroxyquinoline and its derivatives

    The change of successive stability constants of lanthanide ion complexes with 8-hydroxyquinoline and its derivatives: 5,7-dinitro-, 5,7-dichloro-, 5,7-dibromo-, 5,7-diiodo- and halo-5-sulfonic acids: 7-bromine- and 7-iodine-, is considered. Diagrams of lg K dependence of Ln3+ complexes on the number of f-electrons has the most spread form: increase of lg K values with Nsub(f) increase is observed, ''godolinium fracture'' is clearly manifested. When passing from stability constants of the complexes with the ratio of components 1:1 to the complexes with the ratio 1:2 and 1:3 α-coefficient value in the equation for lg K decrease, i. e. contribution of electron number Nsub(f) to stability of the given type complexes decreases. Contributions of the number of f-electrons of lanthanide trivalent ions as well as those of spin and orbital momenta of the main states to the values of stability constants of their complexes with 8-hydroxyquinoline and its derivatives are manifested in a certain regularity

  9. Synthesis and third-order optical nonlinearities of nickel complexes of 8-hydroxyquinoline derivatives

    Qian, Yan; Cai, Minmin; Wang, Shuangqing; Yi, Yuanping; Shuai, Zhigang; Yang, Guoqiang

    2010-05-01

    A nickel complex of 5-(acrylamido)methyl-8-hydroxyquinoline, bis-(5-(acrylamido)methyl-8-hydroxyquinolino) nickel(II) (Ni(AAMQ) 2) has been synthesized and its third-order nonlinear optical properties was investigated with respect to that of bis-(8-hydroxyquinolino) nickel(II) (NiQ 2) by single beam Z-scan technique. The real parts ( γR) of the molecular second-order hyperpolarizabilities were -6.0 × 10 -46 and -5.5 × 10 -46 m 5/v 2 for NiQ 2 and Ni(AAMQ) 2, respectively, indicative of similar nonlinear refraction both in sign and in magnitude. After substitution of an acrylamidomethyl group to the 8-hydroxyquinoline (8-HQ) ligand, the nonlinear absorption coefficient of Ni(AAMQ) 2 was enhanced by more than two times. The corresponding imaginary part ( γI) of the molecular second-order hyperpolarizability was 3.4 × 10 -46 m 5/v 2 for Ni(AAMQ) 2 while 1.6 × 10 -46 m 5/v 2 for NiQ 2. The increase in nonlinear absorption was attributed to the substitution effect and the enhanced transition dipole moment due to the participation of δ-donor group of CH 2 in the molecular conjugation.

  10. Studies on influence of light on fluorescence of Tris-(8-hydroxyquinoline)aluminum thin films

    Thangaraju, K.; Amaladass, P.; Bharathi, K. Shanmuga; Mohanakrishnan, A. K.; Narayanan, V.; Kumar, J.

    2009-03-01

    Tris-(8-hydroxyquinoline)aluminum (Alq 3) thin films, the most widely used electron transport/emissive material in the organic electroluminescent (EL) devices, have been deposited on glass substrates by thermal evaporation process. Alq 3 thin films were exposed to light for various time periods under normal ambient. The fluorescence of as-prepared and light exposed Alq 3 thin films and formation of luminescent quencher have been studied using fluorescence, Mass, MALDI-ToF-MS, 1H & 13C NMR, and FT-IR spectroscopy. It is observed that among the three 8-hydroxyquinoline (HQ) units in Alq 3 molecule, one HQ unit is affected during the light exposure in the normal ambient. It is found that the affected resultant Alq 3 molecule containing the carbonyl group acts as fluorescent quencher and the energy of excitons in the Alq 3 molecule in the light exposed Alq 3 thin films can be non-radiatively transferred to the neighboring fluorescent quencher, quenching the fluorescence of light exposed Alq 3 thin films in the normal ambient.

  11. Studies on influence of light on fluorescence of Tris-(8-hydroxyquinoline)aluminum thin films

    Tris-(8-hydroxyquinoline)aluminum (Alq3) thin films, the most widely used electron transport/emissive material in the organic electroluminescent (EL) devices, have been deposited on glass substrates by thermal evaporation process. Alq3 thin films were exposed to light for various time periods under normal ambient. The fluorescence of as-prepared and light exposed Alq3 thin films and formation of luminescent quencher have been studied using fluorescence, Mass, MALDI-ToF-MS, 1H and 13C NMR, and FT-IR spectroscopy. It is observed that among the three 8-hydroxyquinoline (HQ) units in Alq3 molecule, one HQ unit is affected during the light exposure in the normal ambient. It is found that the affected resultant Alq3 molecule containing the carbonyl group acts as fluorescent quencher and the energy of excitons in the Alq3 molecule in the light exposed Alq3 thin films can be non-radiatively transferred to the neighboring fluorescent quencher, quenching the fluorescence of light exposed Alq3 thin films in the normal ambient

  12. Re-condensation and decomposition of Tris(8-hydroxyquinoline)-aluminum in a vapor transport ampoule

    Kao, Fan-Hsuan; Lin, Ku-Yen; Jan, Da-Jeng; Tang, Shiow-Jing; Yang, Chun-Chuen; Lin, Chia-Her; Yeh, Jui-Ming; Chiu, Kuan-Cheng

    2012-10-01

    By choosing various crystalline forms of tris(8-hydroxyquinoline)-aluminum (Alq3) source powders and using different transport gases under various inside-pressures pin, two constitutional supersaturation (CSS) zones were observed in a vapor transport ampoule with a source temperature of 300 °C and a growth period of 5.0 h. From UV-visible spectra, the material in the lower CSS zone (with sidewall temperature Tside≅130-270 °C) was the re-condensed Alq3, while that in the upper zone (Tside around room temperature) was the decomposed 8-hydroxyquinoline (8Hq). With increasing pin from 1.3×102 to 9.3×104 Pa, the decomposition of Alq3 into 8Hq was enhanced, and the deposition of 8Hq CSS zone became apparent with the formation of several 8Hq needle crystals. In addition, a dependence of the crystal structure formed in the Alq3 CSS zone on the initial phase of the source powder was observed and discussed.

  13. Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

    Zayed, Mohie E. M.; El-Shishtawy, Reda M.; Elroby, Shaaban A.; Obaid, Abdullah Y.; Al-amshany, Zahra M.

    2015-01-01

    The synthesis and characterization of different ether and ester derivatives of 8-hydroxyquinoline have been made. UV-visible and fluorescence spectra of these compounds have revealed spectral dependence on both solvent and O-substituent. The fluorescence intensity of ether derivatives revealed higher intensity for 8-octyloxyquinoline compared with 8-methoxyquinoline, whereas those of ester derivatives had less fluorescence than 8-hydroxyquinoline. Theoretical calculations based on Time-dependent density functional theory (TD-DFT) were carried out for the quinolin-8-yl benzoate(8-OateQ) compound to understand the effect of O-substituent on the electronic absorption of 8-hydroxyquinaline (8-HQ). The calculations revealed comparable results with those obtained from the experimental data. Optimized geometrical structure was calculated with DFT at B3LYP/6-311++G** level of theory. The results indicated that 8-OateQ is not a coplanar structure. The absorption spectra of the compound were computed in gas-phase and solvent using B3LYP and CAM-B3LYP methods with 6-311++G ** basis set. The agreement between calculated and experimental wavelengths was very good at CAM-B3LYP/6-311++G** level of theory. PMID:25674853

  14. Synthesis and luminescent properties of novel bisfunctional polymeric complexes based on carbazole and 8-hydroxyquinoline groups

    Graphical abstract: Synthesis route: the ligand B8QPC was synthesized using 8-hydroxyquinoline derivative and N-butyl-3,6-diformylcarbazole through the Wittig condensation polymerization. The corresponding polymeric metal complexes were: B8QPC with Cu(II), Zn(II). -- Abstract: A fully conjugated ligand 3,6-bis (8-hydroxyquinoline-5-propenyl)-N-butyl-carbazole (B8QPC) containing hole- and electron-transporting groups was firstly synthesized through the Wittig condensation polymerization. Corresponding polymeric complexes, B8QPC (1) with Cu(II) (2) and Zn(II) (3), were synthesized and characterized by FT-IR, elemental Analysis, conductivity measurement and gel permeation chromatography (GPC). GPC indicated that the number average molecular weights (Mn) are about 3800 and the degree of polymerization (n) are about 5 for the polymeric complexes 2 and 3. UV-vis and fluorescence spectra at room temperature revealed that both the polymeric complexes 2 and 3 emit blue luminescence at 473 and 513 nm (λem,max) in DMSO solution and blue/green luminescence at 522 and 531 nm (λem,max) in solid state, respectively. Thermal property measurements show that they have good thermal stability

  15. Adsorptive removal of La(III) from aqueous solutions with 8-hydroxyquinoline immobilized GMZ bentonite

    Due to the low permeability, high swelling capacity and good retardation properties, bentonite has been considered as the main component of buffer/backfill material for high level radioactive wastes repository all over the world. The adsorptions of metal ion were widely investigated recently. In this presentation, we provide an easy-to-use method to immobilize 8-hydroxyquinoline onto the surface of bentonite for the use of adsorption studies of La(III) from the aqueous solution. The effects of various parameters such as contact time, pH of the solution, ionic strength and metal ion concentration on the adsorption were investigated by the batch experiments. The biggest adsorption capacity is 41.7 mg/g, higher than the value reported by our previous work which is performed by the raw bentonite. Langmuir isotherm fits the experimental data well and the adsorption follows pseudo-second-order kinetic model. In summary, 8-hydroxyquinoline immobilized GMZ bentonite is an effective adsorbent for the removal of La(III) from aqueous solutions. (author)

  16. A new metallostar complex based on an aluminum(III) 8-hydroxyquinoline core as a potential bimodal contrast agent

    Debroye, Elke; Dehaen, Geert; Eliseeva, Svetlana V.; Laurent, Sophie; Elst, Luce Vander; Muller, Robert N.; Binnemans, Koen; Parac-Vogt, Tatjana

    2012-01-01

    A ditopic DTPA monoamide derivative containing an 8-hydroxyquinoline moiety was synthesized and the corresponding gadolinium(III) complex ([Gd(H5)(H2O)]−) was prepared. After adding aluminum(III), the 8-hydroxyquinoline part self-assembled into a heteropolymetallic triscomplex [(Gd5)3Al(H2O)3]3−. The magnetic and optical properties of this metallostar compound were investigated in order to classify it as a potential in vitro bimodal contrast agent. The proton nuclear magnetic rela...

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

    Sharifzadeh Kamaladin; Asil Moazzam Hassanpour; Roein Zeynab; Sharifzadeh Muhammad

    2014-01-01

    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...

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

    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 ?-?* 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.

  19. 3-[(E-2-(5,7-Dichloro-8-hydroxyquinolin-2-ylvinyl]-4-hydroxyphenyl acetate

    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.

  20. Extraction-photometric determination of rare earths with quinalizarin in the presence of 8-hydroxyquinoline

    Extraction-photometric study on the reactions of the rare earths with quinalizarin (Qu) and 8-hydroxyquinoline (Ox) has shown that three-component compounds are formed which are extracted with n-butyl, isobutyl, isoamyl alcohols at an optimal pH of 6.75. The compounds are stable in time and to heating. The complexes of elements of the yttrium subgroup have an absorption maximum at 590 nm, elements of the cerium subgroup at 540 and 590 nm. In the use of the boroquinalizarin complex, the effect of pH on the complex formation decreases and the reaction sensitivity increases. The ratio-RE:Qu:Ox in the complex is 1:2:2. The reaction has been used to develop extraction-photometric procedures of determining separate rare earths in the presence of others by using the method of competitive ligands

  1. Investigation of luminescent properties of 8-hydroxyquinoline 2-aminoderivatives for their analytical application

    Luminescent properties of thirteen new 8-hydroxyquinoline 2-aminoderivatives that form with metal ions complexes characterized by different luminescence mechanisms are studied. Using methyl-bis (8-oxy-2 quinoline)amine, highly selective methods are elaborated for yttrium determination fluorescence (water-ethanol solutions, pH=7.5, reagent concentration is 1.4x10-5 M, detection limit is 0.05 μg/ml), for gadolinium determination by phosphorescence (water-ethanol solutions, pH=8.5-9.5, reagent concentration is (1.3-1.6)x10-5 M, 77 K, detection limit is 0.05 μg/ml), and for europium determination by sensitized luminescence (water-ethanol solutions, pH=8.5-9.5, reagent concentration is 3.3x10-6 M, 77 K, detection limit is 2x10-5 μg/ml)

  2. Crown ethers as synergistic agents in the solvent extraction of trivalent lanthanides with 8-hydroxyquinoline

    M. ATANASSOVA

    2008-01-01

    Full Text Available The liquid extraction of the 13 lanthanides with mixtures of 8-hydroxyquinoline (HQ and crown ethers (S dibenzo-18-crown-6 (DB18C6 and dibenzo-24-crown-8 (DB24C8 in 1,2-dichloroethane as a diluent from chloride medium at constant ionic strength μ = 0.1 was investigated. The composition of the extracted species was established as LnQ3 with HQ alone and as LnQ3·S in the presence of a crown ether. The values of the equilibrium constants were calculated. The addition of DB18C6 to the metal chelate system improved the extraction efficiency, while a weak synergistic enhancement was found when the metals were extracted with mixtures of HQ–DB24C8. The parameters of the extraction process were determined and the separation factors between two adjacent lanthanides(III were calculated.

  3. Competitive sorption of lanthanum and europium by phenolic resins containing 8-hydroxyquinoline

    Experiments are performed on La and Eu (homologs of the trivalent actinide ions) using phenolic ion exchange resins to test the development of ion specific resins needed to isolate actinide ions from waste. The resins are characterized by the moisture regain, ion exchange capacity, IR spectroscopy, and Eu distribution coefficient. The routes for the resin synthesis are presented. Both protonated and sodium forms of the resins are examined. The incorporation of 8-hydroxyquinoline in the molecular matrix of the phenolic resin is shown to exert a considerable influence upon the competitive sorption of La and Eu leading to an intra group separation. The selective (S = 6.21, 6.85 and 9.91) sorption of Eu indicates ion selective resins can be prepared which will separate specific actinide ions from nuclear waste

  4. Spectrophotometric determination of tantalum(V) with 8-hydroxyquinoline-5-sulphonic acid

    The formation of a yellow complex by the reaction between Ta(V) and 8-hydroxyquinoline-5-sulphonic acid (HQSA), has been studied spectrophotometrically in aqueous medium. At pH 6.5 the complex shows the maximum absorbance at 420 nm. The Beer's law is obeyed by the system within the concentration range of 1 mg to 6 mg per millilitre of Ta(V). The stoichiometry of the complex determined by the mole ratio and Job's method is 1:2 metal-ligand. The effect of ionic strength and temperature on chelate has been studied. The interference by various ions in the system and a probable structure of the complex are also suggested. (author)

  5. Delayed fluorescence and phosphorescence of tris-(8-hydroxyquinoline)aluminum (Alq3) and their temperature dependence

    This paper reports on delayed luminescence measurements of tris-(8-hydroxyquinoline)aluminum (Alq3) after optical excitation; these identify two bands in the emission spectrum: delayed fluorescence and phosphorescence. This is shown for different crystalline phases and for evaporated films. The assignment of the low-energy band to the phosphorescence is confirmed by lifetime measurements, and triplet energies of the meridional isomer in the α-phase and the facial isomer in the δ-phase are determined from the well-resolved vibronic progressions of the phosphorescence as 2.11±0.1 and 2.16±0.1 eV, respectively. Lifetimes of the delayed fluorescence and the phosphorescence are determined for a temperature range from 6 to 150 K, and we measured the temperature dependence of the delayed photoluminescence spectra

  6. Synthesis and photophysics of novel 8-hydroxyquinoline aluminum metal dye with hole transfer groups

    Wang, Xiaoju; Feng, Liheng; Chen, Zhaobin

    2008-12-01

    A novel luminescent dye metal complex, (CZHQ) 3Al, with 8-hydroxyquinoline aluminum and hole-transporting carbazole units was designed and synthesized. The (CZHQ) 3Al optical properties were carefully investigated by UV-vis absorption and fluorescence spectra in diluent solution. The results showed that the luminescent quantum yield of (CZHQ) 3Al was 0.62 in DMSO and it emitted red-light with the band gap of 2.89 eV estimated from the onset absorption. In addition, the light-emission of (CZHQ) 3Al can be quenched by electron acceptor (dimethylterephalate), where the process followed the Stern-Volmer equation. However, the fluorescent intensities of (CZHQ) 3Al were slowly increased with the addition of electron donor ( N, N-dimethylaniline). Furthermore, the molecular interactions of (CZHQ) 3Al with fullerene (C 60) and carbon nanotubes (CNTs) were also respectively investigated, which indicated the metal dye can be used as new fluorescent probe.

  7. Mixed ligands 8-hydroxyquinoline aluminum complex with high electron mobility for organic light-emitting diodes

    Xu, Bingshe; Chen, Liuqing; Liu, Xuguang; Zhou, Hefeng; Xu, Huixia; Fang, Xiaohong; Wang, Yanli

    2008-03-01

    A mixed ligands 8-hydroxyquinoline complex (Alq2A) with improved electron mobility was designed for organic light-emitting diodes. The electron mobility in Alq2A was determined via transient electroluminescence (EL) from bilayer devices with structure of indium tin oxide/4,4'-bis[N-(1-naphthyl)-N-Phenyl amino]biphenyl/Alq2A /LiF/Al. It was found that the electron mobility in Alq2A is between (2.7and4.4)×10-6cm2/Vs at electric fields ranging between 1.42×106 and 2.40×106V /cm, which is higher than that in Alq3. The Alq2A also shows a higher EL efficiency in steady-state EL studies, which is considered to be derived from (1) improved electron mobility, (2) high fluorescene efficiency, and (3) good film-forming.

  8. Extraction fluorimetric determination of scandium with 5,7-dinitro-8-hydroxyquinoline and insubstituted rhodamine

    A new extraction-fluorimetric method of scandium determination in the form of ion associate with unsubstituted rhodamine and 5,7-dinitro-8-hydroxyquinoline has been suggested. The associate extraction by benzene or toluene is observed in the wide range of pH values 2-6. The highest intensity of fluorescence occurs at pH 3-5. The optimum conditions of Sc determination are found according to mathematical models. Sc determination limit is 0.002 μg/ml, relative standard deviation constitutes 0.06 6-multiple amounts of beryllium, 3-multiple amounts of aluminium do not interfere with the determination of 1 μg scandium. Yttrium quenches the fluorescence of scandium ion associate

  9. Spectroscopic study of Mq3 (M=Al, Ga, In, q=8-hydroxyquinolinate) at high pressure

    A high-pressure spectroscopic investigation of OLED materials with generic formula Mq3 (M=Al, Ga, In, q=8-hydroxyquinolinate) has been carried out. The meridional isomer of Alq3, Gaq3, Inq3 and facial isomer of Alq3 have been produced and their corresponding photoluminescence emission energy has been studied as a function of the cation, pressure, excitation wavelength and isomer. A redshift in the order of 0.3 eV takes place for the pure-meridional isomer compounds in the 0-8 GPa range. We have detected the occurrence of pressure-induced phase transitions presenting hysteresis to ambient conditions. In the case of the facial isomer, luminescence does not significantly redshift until very high pressure. We interpret these features in terms of the enhancement of the intermolecular interaction.

  10. The synergistic inhibition between 8-hydroxyquinoline and chloride ion for the corrosion of cold rolled steel in 0.5 M sulfuric acid

    The corrosion inhibition of cold rolled steel in 0.5 M sulfuric acid in the presence of 8-hydroxyquinoline and sodium chloride (NaCl) has been investigated by using weight loss and electrochemical techniques. The inhibition efficiency increases with increasing concentration of 8-hydroxyquinoline at the same temperature, but decreases with increasing temperature studied. A synergistic effect exists when 8-hydroxyquinoline and chloride ions are used together to prevent cold rolled steel corrosion in 0.5 M sulfuric acid at every experimental temperature. The polarization curves show that 8-hydroxyquinoline is a cathodic inhibitor, while the complex of 8-hydroxyquinoline and NaCl is a mixed-type inhibitor. The experimental results suggested that the presence of chloride ions in the solution stabilizes the adsorption of 8-hydroxyquinoline molecules on the metal surface and improved the inhibition efficiency of 8-hydroxyquinoline. The adsorption of single 8-hydroxyquinoline follows the Temkin adsorption isotherm, but the complex accords with the Langmuir adsorption isotherm. Some thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have been calculated and discussed

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

    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.

  12. Adsorption and solid phase extraction of 8-hydroxyquinoline from aqueous solutions by using natural bentonite

    The nitrogen-heterocyclic compound 8-hydroxyquinoline (8HQ) is one of the components of coal tar and has a wide variety of uses in industry. Because of its toxicity for aquatic organisms and harmful effects for human health, the removal of 8HQ from aqueous solutions by adsorption onto natural bentonite was investigated in the present work. The experimental results show that the optimum pH value of 2.5 is favourable for the 8HQ adsorption. The experimental data were fitted well with the pseudo-second-order kinetic and Langmuir adsorption isotherm models at all studied temperatures. The maximum adsorption capacity obtained from the Langmuir isotherm model at 20 deg. C was 120.6 mg g-1. The calculated thermodynamic results such as ΔGo (-24.3 kJ mol-1) and ΔHo (-9.56 kJ mol-1) indicate that the adsorption process is spontaneous and exothermic in nature. Solid phase extraction of 8HQ was also performed. The X-ray diffractometry (XRD), Fourier Transform Infrared (FTIR) and thermogravimetric (TG) analyses were carried out in order to confirm the 8HQ adsorption onto bentonite. According to the obtained results, natural bentonite can be a reusable and effective adsorbent for the removal of 8HQ.

  13. Vibrational spectroscopic investigations, ab initio and DFT studies on 7-bromo-5-chloro-8-hydroxyquinoline

    Arjunan, V.; Mohan, S.; Ravindran, P.; Mythili, C. V.

    2009-05-01

    The Fourier transform infrared (FTIR) and FT-Raman spectra of 7-bromo-5-chloro-8-hydroxyquinoline (BCHQ) have been measured in the range 4000-400 and 4000-100 cm -1, respectively. Complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the observed FTIR and FT-Raman data. The geometry was optimised without any symmetry constrains using the DFT/B3LYP and HF methods with 6-31G** basis set. The vibrational frequencies which were determined experimentally are compared with those obtained theoretically from ab initio HF and density functional theory (DFT) gradient calculations employing the HF/6-31G** and B3LYP/6-31G** methods for the optimised geometry of the compound. The structural parameters and normal modes of vibration obtained from HF and DFT methods are in good agreement with the experimental data. Normal coordinate analysis was also carried out with ab initio force fields utilising Wilson's FG matrix method.

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

    The pseudotetrahedral complexes of [Cu(PPh3)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(PPh3)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%

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

    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%.

  16. Synthesis and optical properties of ZnO incorporated Tris-(8-hydroxyquinoline)aluminum

    Tris-(8-hydroxyquionoline)aluminum(Alq3) and different weight percentages (2 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%) of ZnO incorporated hybrid Tris-(8-hydroxyquinoline)aluminum (Alq3/ZnO) composite were synthesized by a low cost and simple precipitation method under low temperature. XRD patterns reveal that the amorphous nature of pure Alq3 particles transforms into α-phase crystalline for hybrid Alq3/ZnO composite materials. The FTIR spectrum confirms the formation of quinoline with absorption in the region 600–800 cm−1. It also reveals the stretching vibration of Zn–O at 400–500 cm−1 in Alq3/ZnO composite particles. The band gap (HOMO–LUMO) of Alq3 particles was calculated using absorption spectra and it is 2.92 eV. The photoluminescence (PL) spectrum of Alq3 particle exhibits an emission at 507 nm when excited at 390 nm. Alq3/ZnO composite containing 30 wt% of ZnO exhibits maximum luminescence intensity. - Highlights: • The SEM image does not show the individual particles under the magnification. • Stoke's shift is not altered much by incorporation of ZnO

  17. Radionuclide X-ray fluorescence analysis of selected elements in drug samples with 8-hydroxyquinoline preconcentration

    The preconcentration performance characteristics of precipitation of Mn, Fe, Co, Cu, Zn, Pb, Ni and Hg with 8-hydroxyquinoline (8HQ) and subsequent filtration through cellulose nitrate membrane were investigated for the X-ray fluorescence spectrometry identification and determination of trace metal ions in drug samples. Several parameters of the method were optimised, including pH and amount of 8HQ. The investigated ions were collected on cellulose nitrate membrane filter (Pragopor 4) as their complexes after the reaction with 8HQ. To conclude, optimal reaction conditions were found out (pH 10.5 for Fe, Co and pH 11.5 for Mn, Cu Zn, Pb and Hg, volume of 20 μl of the 2 % solution of hydroxyquinoline). Thereafter, the content of these elements was determined in the active substances of the infusion and injection solutions, i.e. NaCl, glucose and dextrane, and the results were compared with those ones obtained after the preconcentration with thioacetamid. The rapidity of this method, its multi-element character and low detection limits proved this method to be a very promising in rapid screening in quality control of drugs. (author)

  18. Novel Fluorinated 8-Hydroxyquinoline Based Metal Ionophores for Exploring the Metal Hypothesis of Alzheimer's Disease.

    Liang, Steven H; Southon, Adam G; Fraser, Benjamin H; Krause-Heuer, Anwen M; Zhang, Bo; Shoup, Timothy M; Lewis, Rebecca; Volitakis, Irene; Han, Yifeng; Greguric, Ivan; Bush, Ashley I; Vasdev, Neil

    2015-09-10

    Zinc, copper, and iron ions are involved in amyloid-beta (Aβ) deposition and stabilization in Alzheimer's disease (AD). Consequently, metal binding agents that prevent metal-Aβ interaction and lead to the dissolution of Aβ deposits have become well sought therapeutic and diagnostic targets. However, direct intervention between diseases and metal abnormalities has been challenging and is partially attributed to the lack of a suitable agent to determine and modify metal concentration and distribution in vivo. In the search of metal ionophores, we have identified several promising chemical entities by strategic fluorination of 8-hydroxyquinoline drugs, clioquinol, and PBT2. Compounds 15-17 and 28-30 showed exceptional metal ionophore ability (6-40-fold increase of copper uptake and >2-fold increase of zinc uptake) and inhibition of zinc induced Aβ oligomerization (EC50s < ∼5 μM). These compounds are suitable for further development as drug candidates and/or positron emission tomography (PET) biomarkers if radiolabeled with (18)F. PMID:26396692

  19. Synthesis, characterization and DFT calculation of 4-fluorophenyl substituted tris(8-hydroxyquinoline)aluminum(III) complexes

    Suliman, FakhrEldin O.; Al-Nafai, Isehaq; Al-Busafi, Saleh N.

    2014-01-01

    New 4-fluorophenyl substituted 8-hydroxyquinoline derivatives, 5-(4-fluorophenyl)quinolin-8-ol and 5,7-bis(4-fluorophenyl)quinolin-8-ol, were synthesized and characterized by spectroscopic methods. The aluminum complexes of 5-(4-fluorophenyl)quinolin-8-ol (AlQF) and of 5,7-bis(4-fluorophenyl)quinolin-8-ol (AlQF2) exhibit strong fluorescence emission centered at 525 nm and 530 nm respectively. The quantum yield of both complexes were enhanced compared to the parent tris(8-hydroxyquinolinato)aluminum(III) complex. Electronic structures and photophysical properties of the new complexes were investigated theoretically by ab initio and density functional theory (DFT) and time dependent DFT (TD-DFT). Geometries of the ground state (S0) and the first excited state (S1) of the new complexes were optimized at the B3LYP/6-31G(d) functional and configuration interaction singles (CIS) method respectively. The aryl substituents were found to contribute significantly to the frontier molecular orbitals (FMOs). We have observed that in both cases the lowest occupied molecular orbital (LUMO) energy decreases while the energy of the highest occupied molecular orbital is slightly increased. The most significant increase was observed for AlQF2.

  20. Ring-substituted 8-hydroxyquinoline-2-carboxanilides as potential antimycobacterial agents.

    Kos, Jiri; Zadrazilova, Iveta; Nevin, Eoghan; Soral, Michal; Gonec, Tomas; Kollar, Peter; Oravec, Michal; Coffey, Aidan; O'Mahony, Jim; Liptaj, Tibor; Kralova, Katarina; Jampilek, Josef

    2015-08-01

    In this study, a series of twenty-two ring-substituted 8-hydroxyquinoline-2-carboxanilides was prepared and characterized. Primary in vitro screening of the synthesized compounds was performed against Mycobacterium tuberculosis H37Ra, Mycobacterium avium complex and M. avium subsp. paratuberculosis. Some of the tested compounds showed the antimycobacterial activity against M. avium subsp. paratuberculosis comparable with or higher than that of rifampicin. 8-Hydroxy-N-[3-(trifluoromethyl)phenyl]- and 8-hydroxy-N-[4-(trifluoromethyl)phenyl]quinoline-2-carboxamide showed MIC=24 μM against all tested mycobacterial strains. 3-Methoxyphenyl- and 3-methylphenyl derivatives expressed MIC=27 or 29 μM also against all the tested strains. Their activity against M. avium subsp. paratuberculosis was 4-fold higher than that of rifampicin. 2-Bromophenyl- and 2-(trifluoromethyl)phenyl derivatives had MIC=23 or 24 μM against M. tuberculosis. A significant decrease of mycobacterial cell metabolism (viability of M. tuberculosis H37Ra) was observed using MTT assay. Screening of cytotoxicity of the compounds was performed using the THP-1 cells, and no significant lethal effect was observed up to tested concentration 30 μM. The structure-activity relationships are discussed. PMID:26183541

  1. Synthesis and optical properties of ZnO incorporated Tris-(8-hydroxyquinoline)aluminum

    Cuba, M.; Rathinavalli, U.; Thangaraju, K.; Muralidharan, G., E-mail: muraligru@gmail.com

    2014-09-15

    Tris-(8-hydroxyquionoline)aluminum(Alq{sub 3}) and different weight percentages (2 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%) of ZnO incorporated hybrid Tris-(8-hydroxyquinoline)aluminum (Alq{sub 3}/ZnO) composite were synthesized by a low cost and simple precipitation method under low temperature. XRD patterns reveal that the amorphous nature of pure Alq{sub 3} particles transforms into α-phase crystalline for hybrid Alq{sub 3}/ZnO composite materials. The FTIR spectrum confirms the formation of quinoline with absorption in the region 600–800 cm{sup −1}. It also reveals the stretching vibration of Zn–O at 400–500 cm{sup −1} in Alq{sub 3}/ZnO composite particles. The band gap (HOMO–LUMO) of Alq{sub 3} particles was calculated using absorption spectra and it is 2.92 eV. The photoluminescence (PL) spectrum of Alq{sub 3} particle exhibits an emission at 507 nm when excited at 390 nm. Alq{sub 3}/ZnO composite containing 30 wt% of ZnO exhibits maximum luminescence intensity. - Highlights: • The SEM image does not show the individual particles under the magnification. • Stoke's shift is not altered much by incorporation of ZnO.

  2. Studies on the extraction of rare earth complexes with 8-hydroxyquinoline

    The extraction of Y(III), La(III) and Nd(III) with 8-hydroxyquinoline (HOx) in chloroform from aqueous and water-methanol solutions have been studied. Y(III), Pr(III) and Nd(III) ions were found to be extracted from aqueous phase as the complexes LnOx3. It was stated that the addition of methanol (MeOH) to aqueous phase causes the synergistic effect. In the presence of MeOH Y(III), Pr(III) and Nd(III) under the given conditions are extracted as solvates LnOx3 · 2MeOH, whereas La(III) as self-adduct LaOx3 · HOx. The values of pH0.5, pH0.5*, suitable extraction equilibrium constants and two-phase stability constants for the complexes LnOx3 were determined. The separation factors of Y(III), Pr(III), Nd(III) for the individual rare earth elements were calculated. (author). 28 refs, 5 figs, 2 tabs

  3. 8-Hydroxyquinolines: a review of their metal chelating properties and medicinal applications

    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

  4. White light emission from exciplex using tris-(8-hydroxyquinoline)aluminum as chromaticity-tuning layer

    We demonstrate efficient organic white light-emitting devices (LEDs), using N,N prime-diphenyl-N,N prime-bis(1-naphthyl) - (1,1 prime-biphenyl)-4,4 prime-diamine (NPB) as the hole-transporting layer, 1,6-bis(2-hydroxyphenyl)pyridine boron complex [(dppy)BF] as the emitting layer, tris-(8-hydroxyquinoline)aluminum (Alq) as the electron-transporting and chromaticity-tuning layer. The white light comes from exciplex emission at the solid-state interface between (dppy)BF and NPB in addition to the exciton emission from NPB and (dppy)BF, respectively. The chromaticity of white emission can be tuned by adjusting the thickness of the Alq layer. The white LEDs with an Alq thickness of 15 nm exhibit a maximum luminescence of 2000 cd/m2 and efficiency of 0.58 lm/W, and the Commission Internationale De l'Eclairage coordinates of resulting emission vary from (0.29,0.33) to (0.31,0.35) with increasing forward bias from 10 to 25 V. The region is very close to the equienergy white point (0.33,0.33). [copyright] 2001 American Institute of Physics

  5. Infrared photoluminescence of erbium-tris(8-hydroxyquinoline) in a distributed feedback cavity

    Prezioso, S., E-mail: stefano.prezioso@aquila.infn.i [Dipartimento di Fisica, Universita dell' Aquila, gc-LNGS INFN, Via Vetoio, 67100 L' Aquila (Italy); Ottaviano, L.; Bisti, F.; Donarelli, M.; Santucci, S.; Palladino, L. [Dipartimento di Fisica, Universita dell' Aquila, gc-LNGS INFN, Via Vetoio, 67100 L' Aquila (Italy); Penna, S.; Reale, A. [Dipartimento di Ingegneria Elettronica, Universita di Roma ' Tor Vergata' , Viale Politecnico I, 00133 Roma (Italy)

    2011-04-15

    A distributed feedback (DFB) waveguide cavity with erbium-tris(8-hydroxyquinoline) has been fabricated by X-ray interference lithography in a laboratory-scale apparatus. The DFB cavity consists of a large area ({approx}8mm{sup 2}) one-dimensional grating of polymethylmethacrylate on Si (1 0 0). Structural, morphological and optical properties of the device have been studied. On-grating narrowing of the photoluminescence emission has been observed for the 492 nm grating period in correspondence to the 4f-4f Er band peak (at 1530 nm), indicating the possibility of optical gain for applications in the telecommunications. - Research Highlights: Efficient spectral selection is obtained in ErQ{sub 3}-based distributed feedback cavity. C-band emission from 4f-4f Er transition is selected for telecommunications. Nanometrically tunable cavities are cheaply made by X-ray interference lithography. ErQ{sub 3} purity is preserved on mm{sup 2} areas when deposited by vacuum thermal evaporation.

  6. Adsorption and solid phase extraction of 8-hydroxyquinoline from aqueous solutions by using natural bentonite

    Erdem, Bilge; Özcan, Adnan; Özcan, A. Safa

    2010-06-01

    The nitrogen-heterocyclic compound 8-hydroxyquinoline (8HQ) is one of the components of coal tar and has a wide variety of uses in industry. Because of its toxicity for aquatic organisms and harmful effects for human health, the removal of 8HQ from aqueous solutions by adsorption onto natural bentonite was investigated in the present work. The experimental results show that the optimum pH value of 2.5 is favourable for the 8HQ adsorption. The experimental data were fitted well with the pseudo-second-order kinetic and Langmuir adsorption isotherm models at all studied temperatures. The maximum adsorption capacity obtained from the Langmuir isotherm model at 20 °C was 120.6 mg g -1. The calculated thermodynamic results such as Δ G° (-24.3 kJ mol -1) and Δ H° (-9.56 kJ mol -1) indicate that the adsorption process is spontaneous and exothermic in nature. Solid phase extraction of 8HQ was also performed. The X-ray diffractometry (XRD), Fourier Transform Infrared (FTIR) and thermogravimetric (TG) analyses were carried out in order to confirm the 8HQ adsorption onto bentonite. According to the obtained results, natural bentonite can be a reusable and effective adsorbent for the removal of 8HQ.

  7. Room temperature ferromagnetic properties of Al-doped bis(8-hydroxyquinoline)cobalt (Coq2) molecules

    Room temperature ferromagnetic properties were obtained in an originally paramagnetic molecule bis(8-hydroxyquinoline)cobalt (Coq2) by doping a nonmagnetic element aluminum. The Al-doped Coq2 films with the thicknesses of about 200 nm were prepared on Si substrates by co-evaporating pure Coq2 powders (99%) and Al wires (99%) simultaneously at a base pressure of 1.9×10−4 Pa. The magnetic properties of the films were measured at different temperatures by using a Quantum Design superconducting quantum interference device (SQUID). The obtained maximum coercive field is about 250 Oe at 300 K. The electronic structures of Al-doped Coq2 were studied by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) analysis. The FTIR and XPS spectra indicate that the doped Al atoms prefer to interact with N and O atoms in Coq2 molecules. XAFS analysis shows that the Coq2 molecule does not decompose during the co-evaporating process. The ferromagnetism of the film is attributed to the interactions between Al and N p states in lowest unoccupied molecular orbitals (LUMO). - Highlights: • Al-doped Coq2 films were deposited on Si substrates by thermal evaporation. • Room temperature ferromagnetism was obtained in the doped films. • FTIR and XPS spectra show that Al atoms react with N and O atoms of the Coq2 molecules

  8. Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors

    吴双红; 李文连; 陈志; 李世彬; 王晓晖; 魏雄邦

    2015-01-01

    We choose 8-hydroxyquinoline derivative-metal complexes (Beq, Mgq, and Znq) as the acceptors (A) and 4,4’,4”-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) as the donor (D) respectively to study the existing energy transfer process in organic ultraviolet (UV) photodetector (PD) which has an important infl uence on the sensitivity of PD. Energy transfer process from D to A without exciplex formation is discussed, differing from the working mechanism of previous PD with Gaq [Zisheng Su, Wenlian Li, Bei Chu, Tianle Li, Jianzhuo Zhu, Guang Zhang, Fei Yan, Xiao Li, Yiren Chen and Chun-Sing Lee 2008 Appl. Phys. Lett. 93 103309)] and REq [J. B. Wang, W. L. Li, B. Chu, L. L. Chen, G. Zhang, Z. S. Su, Y. R. Chen, D. F. Yang, J. Z. Zhu, S. H. Wu, F. Yan, H. H. Liu, C. S. Lee 2010 Org. Electron. 11 1301] used as A material. Under 365-nm UV irradiation with an intensity of 1.2 mW/cm2, the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mA/W with a detectivity of 6.5×1011 Jones, which exceeds those of PDs based on Mgq (146 mA/W) and Znq (182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay. More photophysics processes of the PDs involved are discussed in detail.

  9. Comparative vibrational spectroscopic studies, HOMO-LUMO and NBO analysis of 5,7-dibromo-8-hydroxyquinoline and 5,7-dichloro-8-hydroxyquinoline based on Density Functional Theory

    Lakshmi, A.; Balachandran, V.; Janaki, A.

    2011-10-01

    Comparative studies of the Raman and infrared spectra, the geometry, frequency and intensity of the vibrational bands of 5,7-dibromo-8-hydroxyquinoline (DBHQ) and 5,7-dichloro-8-hydroxyquinoline (DCHQ) were obtained by using Density Functional Theory calculations (DFT) with B3LYP functional and 6-311++G ** basis set. The effects of bromine and chlorine substituents on the vibrational frequencies of 8-hydroxyquinoline have been investigated. The assignments have been proposed with aid of the results of normal coordinate analysis. Coupling of vibrations have been determined by calculating potential energy distributions (PEDs). The molecular stability and bond strength was investigated by applying the Natural Bond Orbital analysis (NBO). The other molecular properties like Mulliken population analysis, thermodynamic functions and polarizabilities of the title compounds have been reported. The calculated HOMO and LUMO energies show that charge transfer occur in the molecules. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP).

  10. Determination of molybdenum in steels by differential-pulse polarography of the 8-hydroxyquinoline-molybdenum(VI) complex

    The 8-hydroxyquinoline - Mo(VI) complex has a reduction half-wave potential of -0.380 V vs. SCE in 1 M NaNO3-0.01 M HNO3. Iron only interferes at concentrations higher than 1.5x10-4 M in the sample. This effect can be avoided with acetic acid. A method for the determination of molybdenum in steel based on catalytic reduction of the 8-hydroxyquinoline - Mo(VI) complex is described. A linear calibration is obtained for a concentration range from 10-8 to 10-6 M. The detection limit is about 10-10 M of Mo(VI). (author)

  11. Analytical investigation of fluorescent complexes of leucine-8-hydroxyquinaldine and leucine-8-hydroxyquinoline in aqueous phase using spectroscopic techniques

    A new method has been developed by preparing complexes involving condensation of Leucine with 8-hydroxyquinaldine and 8-hydroxyquinoline separately. The products so obtained are being investigated for identification and quantitative estimation using different spectroscopic techniques including fluorescence activity of newly synthesized complexes. The method adopted in our laboratory is rapid, versatile, reproducible and provides excellent results for adoption by analytical, agriculture and biomedical laboratories to estimate amino acids and metals in composite matrix at economical costs. Identification of amino acids in nano mole quantities has become possible by fluorescence activity of leucine- 8-hydroxyquinaldine and leucine-8-hydroxyquinoline complexes involving different excitation and emission wavelengths. This fluorescence activity of the complexes is 100 to 1000 times higher than assay method involving ninhydrin and amino acid analyzer. (author)

  12. Synthesis and Structural Characterization of [Co(Q)2(H2O)2](Q=8-Hydroxyquinoline Ion)

    HU Chang-wen; WANG Chun-xiu; LI Hui; NIU Xue-li; PAN Wan-long; GONG Yun

    2006-01-01

    The single crystal of bi (8-hydroxyquinoline) bihydrated cobalt ( Ⅱ ) complex, [ Co ( Q)2 ( H2O)2 ] (Q = 8-hydroxyquinoline ion), has been synthesized by general method and structurally characterized by single crystal X-ray diffraction. Crystal data: C18H16CoN2O4, monoclinic, C2/c, a = 1.336 2(4) nm, b = 0.941 2(3) nm, c = 1.354 3(4) nm, β= 109.672(4)°, Z= 4. In the complex, Co( Ⅱ ) ion is six-coordinated, forming a distorted octahedron. H-bonding and π-π stacking interaction play a significant role to form and stabilize the three-dimensional structure.

  13. Synthesis, Characterization, and Antibacterial Studies of Mixed Ligand Dioxouranium Complexes with 8-Hydroxyquinoline and Some Amino Acids

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

    2011-01-01

    Mixed ligand complexes of dioxouranium (VI) of the type [UO2(Q)(L)·2H2O] have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and amino acids (HL) such as L-threonine, L-tryptophan, and L-isoleucine as secondary ligands. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements, and spectral and thermal studies. The electrical conductance studies of the complexes indicate their nonelectrolytic nature. Mag...

  14. Thermogravimetric and Spectroscopic Analysis of 8-Hydroxyquinoline 5-Sulphonic Acid-melamine-formaldehyde Polymer Resin-IV

    Singru, Rajesh N.

    2012-01-01

    The title terpolymer (8-HQ5-SAMF-IV) synthesized by the condensation of 8-hydroxyquinoline 5-sulphonic acid (8-HQ5-SA) and melamine (M) with formaldehyde (F) in the presence of acid catalyst and using varied 3 : 1 : 5 molar proportions of the reacting monomers. The synthesized terpolymer was characterized by different physicochemical techniques. The thermogravimetric analysis of terpolymer resin prepared in the present study has been carried out by nonisothermal thermogravimetric analysis tec...

  15. Driving conditions dependence of magneto-electroluminescence in tri-(8-hydroxyquinoline)-aluminum based organic light emitting diodes

    Peng, Qiming; Sun, Jixiang; Li, Xianjie; Li, Mingliang; Li, Feng

    2011-01-01

    we investigated the magneto-electroluminescence (MEL) in tri-(8-hydroxyquinoline)-aluminum based organic light-emitting diodes (OLEDs) through the steady-state and transient method simultaneously. The MELs show the great different behaviors when we turn the driving condition from a constant voltage to a pulse voltage. For devices driven by the constant voltage, the MELs are similar with the literature data; for devices driven by the pulse voltage, the MELs are quite different, they firstly in...

  16. Synthesis of 5-Dialkyl(aryl)aminomethyl-8-hydroxyquinoline Dansylates as Selective Fluorescent Sensors for Fe3+

    Yaowu Sha; Feng Wang; Ruogu Peng

    2007-01-01

    A series of 5-dialkyl(aryl)aminomethyl-8-hydroxyquinoline dansylates were synthesized and their fluoroionophoric properties toward representative alkali ions, alkaline earth ions and transition metal ions were investigated. Among the selected ions, Fe3+ caused considerable quenching of the fluorescence, while Cr3+ caused quenching to some extent. The absence of any significant fluorescence quenching effects of the other ions examined, especially Fe2+, renders these compounds highly useful Fe3...

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

    Dhakite, P. A.; W. B. Gurnule

    2011-01-01

    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 poly...

  18. Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors

    Wu, Shuang-Hong; Li, Wen-Lian; Chen, Zhi; Li, Shi-Bin; Wang, Xiao-Hui; Wei, Xiong-Bang

    2015-02-01

    We choose 8-hydroxyquinoline derivative-metal complexes (Beq, Mgq, and Znq) as the acceptors (A) and 4,4',4”-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) as the donor (D) respectively to study the existing energy transfer process in the organic ultraviolet (UV) photodetector (PD), which has an important influence on the sensitivity of PDs. The energy transfer process from D to A without exciplex formation is discussed, differing from the working mechanism of previous PDs with Gaq [Zisheng Su, Wenlian Li, Bei Chu, Tianle Li, Jianzhuo Zhu, Guang Zhang, Fei Yan, Xiao Li, Yiren Chen and Chun-Sing Lee 2008 Appl. Phys. Lett. 93 103309)] and REq [J. B. Wang, W. L. Li, B. Chu, L. L. Chen, G. Zhang, Z. S. Su, Y. R. Chen, D. F. Yang, J. Z. Zhu, S. H. Wu, F. Yan, H. H. Liu, C. S. Lee 2010 Org. Electron. 11 1301] used as an A material. Under 365-nm UV irradiation with an intensity of 1.2 mW/cm2, the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mA/W with a detectivity of 6.5× 1011 Jones, which exceeds those of PDs based on Mgq (146 mA/W) and Znq (182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay. More photophysics processes of the PDs involved are discussed in detail. Project supported by the National Natural Science Foundation of China (Grant Nos. 61371046, 61405026, 61474016, and 61421002) and China Postdoctoral Science Foundation (Grant No. 2014M552330).

  19. Growth and characterization of tris(8-hydroxyquinoline)-aluminum molecular films

    Jan, Da-Jeng; Wang, Sheng-Shin; Tang, Shiow-Jing; Lin, Ku-Yen; Yang, Jiun-Jie; Shen, Ji-Lin; Chiu, Kuan-Cheng, E-mail: kcchiu@cycu.edu.tw

    2011-11-30

    Various tris(8-hydroxyquinoline)-aluminum (Alq3) molecular solid films were grown on top of indium-tin-oxide (ITO) glass substrates using physical vapor deposition. The effect of changing the growth conditions on the properties of the films was studied. From scanning electron microscopy, an Alq3 planar layer over an ITO-substrate was observed at the initial period, and an Alq3 tubular structure (which becomes dominant at substrate temperature T{sub sub} Greater-Than-Over-Equal-To 90 Degree-Sign C) was found to nucleate from this layer. From X-ray diffraction, the Alq3 planar layer possesses an amorphous character while the Alq3 tubular layer has a triclinic {alpha}-phase structure. Based on an Arrhenius plot of the growth rate versus 1/T{sub sub}, the growth behaviors in various T{sub sub}-regions were discussed to be dominated by adhesion (for T{sub sub} < 90 Degree-Sign C), steric effect (90 Degree-Sign C < T{sub sub} < 150 Degree-Sign C), and re-evaporation (T{sub sub} > 150 Degree-Sign C). Then, from optical transmission and photoluminescence spectra performed on the high crystalline Alq3 films, two signals associated with the optical-bandgap E{sub g} absorption and the gap-state absorption were determined and discussed in terms of the optical properties of the constituent Alq3 molecules. Finally, from a fit of E{sub g}(T) by an effective electron-phonon interaction model, the physical significance of these fitting parameters for the Alq3 molecular solid was investigated.

  20. Tris(8-hydroxyquinoline)aluminum (III) (Alq3) nanowires templated from an eggshell membrane

    Lee, Tu, E-mail: tulee@cc.ncu.edu.t [Department of Chemical and Materials Engineering, National Central University, 300 Jhong-Da Rd, Jhong-Li City 320, Taiwan (China); Chang, Shih Chia; Peng, Jen Fan [Department of Chemical and Materials Engineering, National Central University, 300 Jhong-Da Rd, Jhong-Li City 320, Taiwan (China)

    2010-07-30

    One to 2-{mu}m long, {<=} 400-nm wide amorphous tris(8-hydroxyquinoline)aluminum (III) (Alq3) nanowires (NWs) grown from the 15-min boiled outer shell membrane (OSM) of the hen's egg and from the OSM solution cast film via thermal evaporation with a source temperature of 260 {sup o}C and a substrate temperature of 138 {sup o}C under 6.7 x 10{sup -2} Pa gave about 1.4 to 1.7 times more photoluminescence emission than the control Alq3 sample did, which was grown from the plain glass surface. The characteristic bonding energies of C 1s X-ray photoelectron signal at 282 eV, O 1s signal at 529 eV and N 1s signal at 397 eV suggested that the relatively high NW density for the 15-min boiled OSM and the OSM solution cast film, was mainly caused by the formation of the O=C-O-C=O anhydride moiety and the C=N group in the proteinaceous OSM at high temperature of 90 {sup o}C to 100 {sup o}C. Therefore, we proposed that the 15-min boiled OSM and the OSM solution cast film apparently served as good templates by providing nano-regions of high concentration of the O=C-O-C=O anhydride groups and the C=N groups for nesting the Alq3 gas molecules to form nano-conical Alq3 nuclei for the growth of long and narrow NWs.

  1. Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors

    We choose 8-hydroxyquinoline derivative-metal complexes (Beq, Mgq, and Znq) as the acceptors (A) and 4,4',4”-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) as the donor (D) respectively to study the existing energy transfer process in the organic ultraviolet (UV) photodetector (PD), which has an important influence on the sensitivity of PDs. The energy transfer process from D to A without exciplex formation is discussed, differing from the working mechanism of previous PDs with Gaq [Zisheng Su, Wenlian Li, Bei Chu, Tianle Li, Jianzhuo Zhu, Guang Zhang, Fei Yan, Xiao Li, Yiren Chen and Chun-Sing Lee 2008 Appl. Phys. Lett. 93 103309)] and REq [J. B. Wang, W. L. Li, B. Chu, L. L. Chen, G. Zhang, Z. S. Su, Y. R. Chen, D. F. Yang, J. Z. Zhu, S. H. Wu, F. Yan, H. H. Liu, C. S. Lee 2010 Org. Electron. 11 1301] used as an A material. Under 365-nm UV irradiation with an intensity of 1.2 mW/cm2, the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mA/W with a detectivity of 6.5× 1011 Jones, which exceeds those of PDs based on Mgq (146 mA/W) and Znq (182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay. More photophysics processes of the PDs involved are discussed in detail. (paper)

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

    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

  3. TAME5OX, abiotic siderophore analogue to enterobactin involving 8-hydroxyquinoline subunits: Thermodynamic and photophysical studies

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

    2015-05-01

    The synthesis, thermodynamic and photophysical properties of trivalent metal complexes of biomimetic nonadentate analogue, 5,5‧-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1,3-diyl)bis(azanediyl)bis(methylene)diquinolin-8-ol (TAME5OX), have been described. Combination of absorption and emission spectrophotometry, potentiometry, electrospray mass spectrometry, IR, and theoretical investigation were used to fully characterize metal (Fe+3, Al+3 and Cr+3) chelates of TAME5OX. In solution, TAME5OX forms protonated complexes [M(H3L)]3+ below pH 3.4, which consecutively deprotonates through one to three-proton processes with rise of pH. The formation constants (Log β11n) of neutral complexes formed at or above physiological pH, have been determined to be 30.18, 23.27 and 22.02 with pM values of 31.16, 18.07 and 18.12 for Fe+3, Al+3 and Cr+3 ions, respectively, calculated at pH 7.4, indicating TAME5OX is a powerful among synthetic metal chelator. The results clearly demonstrate that the ligand in a tripodal orchestration firmly binds these ions over wide pH range and forms distorted octahedral complexes. The binding and the coordination event could be monitored from absorption and fluorescence spectroscopy. The high thermodynamic stability in water at physiological pH of ferric complex of TAME5OX indicates that these complexes are resistant to hydrolysis and therefore are well suited for the development of device for applications as probes. The ligand displays high sensitive fluorescence enhancement to Al3+ at pH 7.4, in water. Moreover, TAME5OX can distinguish Al3+ from Fe3+ and Cr3+ via two different sensing mechanisms: photoinduced electron transfer (PET) for Al3+ and internal charge transfer (ICT) for Fe3+ and Cr3+. Density functional theory was employed for optimization and evaluation of vibrational modes, NBO analysis, excitation and emission properties of the different species of metal complexes observed by solution studies.

  4. Pulse radiolysis studies on 8-hydroxyquinoline 5-sulphonic acid in aqueous solutions

    Reactions of e-aq, H atoms, OH/O- radicals and specific one-electron reductants/oxidants such as CO2-, (CH3)2COH, CH3CHOH, CH2OH, N3., Br2- and SO4- radicals with 8-hydroxyquinoline 5-sulphonic acid (8-HQSA) were studied at different pHs using pulse radiolysis technique. e-aq was found to react with 8-HQSA with rate constants of 1.1x1010 and 4.3x109 dm3 mol-1 s-1 at pH 7 and 13, respectively. CO2-·radicals transfer an electron to 8-HQSA (k=1x107 dm3 mol-1 s-1) at pH 7, whereas (CH3)2COH radicals undergo addition reaction. (CH3)2CO- radicals could transfer an electron to 8-HQSA at pH 13 only. The reduction potential of the semi-reduced 8-HQSA at pH 13 is thus estimated to be congruent with -2.0 V versus NHE. At pH 2.5, H atoms were found to react with 8-HQSA giving a mixture of semi-reduced species and an H-adduct. The yield of the semi-reduced species was estimated to be ∼30% by measuring the yield of MV+ radical cation formed by electron transfer. At pH 2.5, CO2-, (CH3)2COH, CH3CHOH, and CH2OH radicals react with 8-HQSA by addition giving species which were reducing in nature. OH radicals react with 8-HQSA by addition to the benzene ring giving hydroxycyclohexadienyl type of radical. The OH-adducts were found to react with oxygen to give peroxyl-type radicals. N3 and Br2- radicals were able to oxidize 8-HQSA at pH 13. Only SO4- radicals could bring about one electron oxidation of 8-HQSA at pH 7 and 3.2. (author)

  5. Eu(III) extraction by bis(2-ethylhexyl)phosphoric acid and 8-hydroxyquinoline in dodecane from perchlorate medium

    Europium(III) was extracted by bis(2-ethylhexyl)phosphoric acid (HDEHP) and 8-hydroxyquinoline (HQ) in dodecane from aqueous perchlorate media of constant ionic strength (0.1M; H+, NaClO4). Slope analysis of the data indicate that three molecules of HDEHP or HQ are attached to Eu3+. Extraction constants were obtained at different temperatures. The data were used to calculate the thermodynamic parameters (ΔG, ΔH and ΔS) for the extraction process in the two systems. When using mixtures of crown ethers with HDEHP no synergism was observed. (author) 18 refs.; 8 figs.; 3 tabs

  6. Isolation and characterisation of 2-Tert-butyl-8-hydroxyquinoline as a crystalline solid and its blue fluorescent Li complex

    Kathirgamanathan, Poopathy; Surendrakumar, Sivagnanasundram; Ravichandran, Seenivasagam; Blake, Alexander J.

    2014-01-01

    2-Tert-butyl-8-hydroxyquinoline (2-TB-8-hq) has been isolated as a crystalline solid and its X-ray structure elucidated, resolving three decades of controversy, since it was previously wrongly reported as yellow oil by some other workers. An improved synthetic method has been developed which increases the yield from 20% to 60%. The lithium complex of 2-TB-8-hq is blue emitting and the HOMO and LUMO levels are lowered by 0.86 eV and 0.74 eV, respectively, compared with the parent lithium 8-hyd...

  7. Synthesis, spectroscopic characterization, X-Ray analysis, and DFT-HF calculations of 5-ethoxymethyl-8-hydroxyquinoline

    Bougharraf, Hafida; Benallal, R.; El Faydy, M.; Mondieig, Denise; Negrier, Philippe; Sahdane, T.; Kabouchi, B; Lakhrissi, B.; Zawadzka, A.

    2016-01-01

    5-ethoxymethyl-8-hydroxyquinoline was synthesized and characterized using spectroscopic methods (1 H, 13 C NMR, IR). The crystal structure determined at room temperature (295 K) by means of X-ray powder diffraction is orthorhombic, with space group Pbca and eight molecules per unit cell (Z = 8, Z 0 = 1). The lattice parameters are: a = 7.9551(12) A ˚ , b = 17.981(3) A ˚ , c = 15.125(2) A ˚ and V = 2163.5(6) A ˚ 3. Geometric parameters and properties depending on the charge distribution around...

  8. Some features of electro-optical properties of polymeric compositions doped with 8-hydroxyquinoline based azodyes and their cobalt complexes

    Davidenko, N. A.; Davidenko, I. I.; Savchenko, I. A.; Sinyugina, A. T.; Studzinsky, S. L.; Tonkopieva, L. S.; Deberdeev, T. R.; Kolendo, A. Yu.; Zaikov, G. E.

    2014-05-01

    Polymeric composites based on the copolymer butyl methacrylate: nonyl methacrylate (3:1) doped 8-hydroxyquinoline azo dyes with donor and acceptor substitutes and their complexes with cobalt are obtained. The influence of the external electric field on the polymeric films transmission of linear polarized light in the long-wave part of the azo dyes absorption range, (corresponding ππ* azo fragments absorption range) and their metal complexes are observed. The influence of the electric field on the transmission is connected with the aligning forces for dipole moments of azobenzene groups and metal ions.

  9. Thermodynamics of Eu(III) extraction by Bis (2-ethylhexyl) phosphoric acid or 8-hydroxyquinoline in dodecane from perchlorate medium

    Europium (III) was extracted by bis (2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (Hq) at different temperatures in dodecane, from perchlorate aqueous media of constant ionic strength (0.1 M ; H+, NaCl O4). Slope analysis of the data indicated that three molecules of HDEHP or Hq are attached to Eu3+. The extraction constants were evaluated at different temperatures. The data obtained were used to calculate the thermodynamic parameters (Δ G,Δ H and Δ S ) for the two systems. Some trials to use mixtures of crown ethers with the reagents investigated but no synergism was observed. 8 fig.,3 tab

  10. Isolation and characterisation of 2-Tert-butyl-8-hydroxyquinoline as a crystalline solid and its blue fluorescent Li complex

    Poopathy Kathirgamanathan; Sivagnanasundram Surendrakumar; Seenivasagam Ravichandran; Blake, Alexander J.

    2014-01-01

    2-Tert-butyl-8-hydroxyquinoline (2-TB-8-hq) has been isolated as a crystalline solid and its X-ray structure elucidated, resolving three decades of controversy, since it was previously wrongly reported as yellow oil by some other workers. An improved synthetic method has been developed which increases the yield from 20% to 60%. The lithium complex of 2-TB-8-hq is blue emitting and the HOMO and LUMO levels are lowered by 0.86 eV and 0.74 eV, respectively, compared with the parent lithium 8-hyd...

  11. Isolation and Characterisation of 2-Tert-butyl-8-hydroxyquinoline as a Crystalline Solid and Its Blue Fluorescent Li Complex

    Kathirgamanathan, Poopathy; Surendrakumar, Sivagnanasundram; Ravichandran, Seenivasagam; Blake, Alexander J.

    2014-01-01

    2-Tert-butyl-8-hydroxyquinoline (2-TB-8-hq) has been isolated as a crystalline solid and its X-ray structure elucidated, resolving three decades of controversy, since it was previously wrongly reported as yellow oil by some other workers. An improved synthetic method has been developed which increases the yield from 20% to 60%. The lithium complex of 2-TB-8-hq is blue emitting and the HOMO and LUMO levels are lowered by 0.86 eV and 0.74 eV, respectively, compared with the parent lithium 8-hyd...

  12. Formation of stacked luminescent complex of 8-hydroxyquinoline molecules on hydroxyapatite coating by using cold isostatic pressing.

    Matsuya, Takehiko; Otsuka, Yuichi; Tagaya, Motohiro; Motozuka, Satoshi; Ohnuma, Kiyoshi; Mutoh, Yoshiharu

    2016-01-01

    Cold isostatic pressing successfully formed a chelate complex of 8-hydroxyquinoline (8 Hq) molecules on plasma-sprayed hydroxyapatite (HAp) coating by solid-state reaction. The complex emits a fluorescence peak at approximately 500 nm by UV irradiation. The red shift of the fluorescence was newly observed in the cases of highly compressed complex due to π - π stacking of aromatic ring in the molecular structure of 8 Hq. The immersed complex coating in Simulated Body Fluid (SBF) demonstrated amorphous apatite precipitation and kept its fluorescence property. PMID:26478295

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

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

    2013-07-01

    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 de-trapping 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.

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

    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 de-trapping 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

  15. Antimicrobial Activity of Metal & Metal Oxide Nanoparticles Interfaced With Ligand Complexes Of 8-Hydroxyquinoline And α-Amino Acids

    Bhanjana, Gaurav; Kumar, Neeraj; Thakur, Rajesh; Dilbaghi, Neeraj; Kumar, Sandeep

    2011-12-01

    Antimicrobial nanotechnology is a recent addition to the fight against disease causing organisms, replacing heavy metals and toxins. In the present work, mixed ligand complexes of metals like zinc, silver etc. and metal oxide have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N-and/O-donor amino acids such as L-serine, L-alanine, glycine, cysteine and histidine as secondary ligands. These complexes were characterized using different spectroscopic techniques. The complexes were tested for antifungal and antibacterial activity by using agar well diffusion bioassay.

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

    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

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

    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.

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

    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.

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

    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.

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

    Highlights: → Growth of bulk single crystal of 8-hydroxyquinoline (8-HQ) by vertical Bridgman technique for the first time. → The crystalline perfection is reasonably good. → 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.

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

    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 [Zn2L4] (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

  2. The comparison of 8-hydroxyquinoline, tropolone, and acetylaceton as mediators in the labelling of polymorphonuclear leucocytes with indium-111: A functional study

    Tropolone forms a lipophilic complex with indium-111 which is capable of mediating the labelling of polymorphonuclear leucocytes (PMNs) by this isotope; labelling efficiencies are comparable with the best achieved using 8-hydroxyquinoline and acetylacetone. However, in terms of PMN chemotaxis and phagocytosis, tropolone is significantly less toxic than either of the other ligands. 8-hydroxyquinoline was found to reduce PMN chemotaxis and phagocytosis to approximately 70% of the control values at a concentration of 20 μM. Tropolone may prove a superior labelling reagent. (orig.)

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

    Mirna Daye; Baghdad Ouddane; Jalal Halwani; Mariam Hamzeh

    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 t 1/2 5 minutes, following Langmuir adsorption model. At pH 4, the affinity of mercury is unchallenged by other metals except, fo...

  4. In situ monitoring of thermal crystallization of ultrathin tris(8-hydroxyquinoline) aluminum films using surface-enhanced Raman scattering.

    Muraki, Naoki

    2014-01-01

    Thermal crystallization of 3, 10, and 60 nm-thick tris(8-hydroxyquinoline)aluminum (Alq3) films is studied using surface-enhanced Raman scattering with a constant heating rate. An abrupt higher frequency shift of the quinoline-stretching mode is found to be an indication of a phase transition of Alq3 molecules from amorphous to crystalline. While the 60 nm-thick film shows the same crystallization temperature as a bulk sample, the thinner films were found to have a lower crystallization temperature and slower rate of crystallization. Non-isothermal kinetics analysis is performed to quantify kinetic properties such as the Avrami exponent constants and crystallization rates of ultrathin Alq3 films. PMID:24405952

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

    Zheng Hong; Cheng Xiaoman; Tian Haijun [Institute of Material Physics, Key Laboratory of Display Material and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384 (China); Zhao Geng, E-mail: zheng_033@163.com [School of Science, Tianjin University of Technology, Tianjin 300384 (China)

    2011-09-15

    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 Alq3 film. The peak field effect mobility is increased to 1.28 x 10{sup -2} cm{sup 2}/(V{center_dot}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. (semiconductor devices)

  6. Photoluminescence properties of new Zn(II) complexes with 8-hydroxyquinoline ligands: Dependence on volume and electronic effect of substituents

    Huo, Yanping; Lu, Jiguo; Hu, Sheng; Zhang, Liming; Zhao, Fenghua; Huang, Huarong; Huang, Baohua; Zhang, Li

    2015-03-01

    A series of 2-arylethenyl-8-hydroxyquinoline ligands (A1-A4) with a trimethoxyphenyl, naphthyl, 2-fluoro-4-bromophenyl and anthracenyl group and their corresponding Zn(II) complexes (B1-B4) were synthesized and characterized by means of 1H NMR, ESI-MS, FT-IR and elemental analysis. A1 and A4 were characterized by single-crystal X-ray crystallography. The aggregation behavior of zinc salt and ligands in solution was investigated by several techniques, containing 1H NMR, UV-vis and photoluminescence (PL). The electronic nature and volume of arylethenyl substituents affect the absorption wavelength, the emission color, fluorescence lifetime, fluorescence quantum yield and thermostability of Zn(II) complexes. The experiments corroborated that the properties of Zinc(II) complexes can be tuned by introducing different functional substituents.

  7. Transport of Zinc and Copper through Impregnated Cation-Exchange Membrane with 8-Hydroxyquinoline Using Electric Field

    The transport of Zn(II) and Cu(II) species across impregnated cation-exchange membrane with 8-hydroxy-quinoline in xylene was investigated. To accelerate the transport of ions, the effect of electric field was introduced. Certain parameters that affect the transport were studied. These parameters include; hydrochloric acid concentration in the feed solution, stripping solution concentration, voltage and 8-hydroxyquinoline concentration. The flux values of Zn(II) and Cu(II) were 3.7x10-9and 3.6x10-10g-eq.cm-2s-1, respectively. The separation of Zn(II) from Cu(II)was performed selectively by this technique and the use of electric field accelerated the ions transport

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

    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 Alq3 film. The peak field effect mobility is increased to 1.28 x 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. (semiconductor devices)

  9. An extractive spectrophotometry method for the determination of vanadium as V(II)-8-hydroxyquinoline complex into acetylacetone-chloroform

    A simple and rapid extractive spectrophotometric method of determination of vanadium is developed by reduction of the metal ion with Zn/Hg in presence of 8-hydroxyquinoline under acidic conditions employing acetylacetone-chloroform as extractant. No interference is shown by W(VI), Cr(VI, III), U(VI), Mo(VI), Fe(II), Co(II), Ni(II), Cu(II) and several other elements of interest. The applicability of the method is tested by analysis of a large number of different samples. The method is highly reproducible with a standard deviation of 0.0065 and Sandell's sensitivity 8.6956x10-2 μg V/cm2. Stoichiometry of the complex is also studied. (author). 1 tab., 17 refs

  10. Selective detection of 2,4,6-trinitrophenol based on a fluorescent nanoscale bis(8-hydroxyquinoline) metal complex.

    Lv, Xiao-Jun; Qi, Liang; Gao, Xiang-Yu; Wang, Huan; Huo, Yuan; Zhang, Zhi-Qi

    2016-04-01

    The reliable and accurate detection of explosives such as 2,4,6-trinitrophenol (TNP) and 2,4,6-trinitrotoluene (TNT) is in high demand for homeland security and public safety. Although extremely high sensitivity towards TNT has been demonstrated, detection of TNP remains a challenge. In this work, a fluorescent nanoscale complex composed of bis(8-hydroxyquinoline) and Al(3+) ions has been prepared, characterized and applied in detection of TNP. This complex exhibits the ability to sense the nitro explosive TNP via a fluorescence quenching mechanism with high selectivity. A simple paper test system for the rapid monitoring of TNP was also investigated. The results show that Bhq-Al is a quite ideal sensing material for trace-level detection of TNP. PMID:26838414

  11. Synthesis and photophysics of novel 8-hydroxyquinoline aluminum metal complex with 1,3,4-oxadiazole units

    Feng, Liheng; Wang, Xiaoju; Chen, Zhaobin

    2008-11-01

    A novel luminescent metal complex, (OXHQ) 3Al, with 8-hydroxyquinoline aluminum and electron-transporting 1,3,4-oxadiazole unit was designed and synthesized. The photophysical processes were investigated by UV-vis absorption and fluorescence emission spectra in diluent solution. The results showed that the luminescence quantum yield of (OXHQ) 3Al was 0.67 in DMSO and it emitted blue light with the band gap of 3.13 eV estimated from the onset absorption. In addition, the light-emitting of (OXHQ) 3Al can be quenched by electron acceptor (dimethylterephalate), where the processes followed the Stern-Volmer equation. However, with the addition of electron donor ( N, N-dimethylaniline) fluorescent intensity of (OXHQ) 3Al was increased and emission peak was lightly blue-shift. Furthermore, the molecular interactions of (OXHQ) 3Al with fullerene (C 60) or carbon nanotubes (CNTs) were also carefully investigated.

  12. Synthesis, crystal structures and fluorescent properties of two new 7-iodo-8-hydroxyquinoline-5-sulfonic acid-containing polymers

    Lu, Yongguang; Cheng, Wei; Meng, Xiangru; Hou, Hongwei

    2008-03-01

    Two new coordination polymers [Zn(IHQS)(4,4'-bipy) 1/2(H 2O) 2] n ( 1) and [Mn(IHQS)(4,4'-bipy) 1/2(H 2O) 2] n ( 2) (IHQS = 7-iodo-8-hydroxyquinoline-5-sulfonic acid) have been synthesized and characterized by single crystal X-ray diffraction. Both of them display one-dimensional chain framework in which the cage-like dimeric units formed by two metal ions, two IHQS anions and four water molecules are bridged by 4,4'-bipy. The hydrogen bonds and weak C--I···X (X = N, O, S) interactions extend the one-dimensional chains into three-dimensional supramolecular frameworks. The fluorescent properties of both polymers and IHQS were measured in solid state at room temperature. The results indicated that the emission spectra of the two polymers could be assigned to intraligand transition.

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

    Tris(8-hydroxyquinoline)aluminum (Alq3) 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 Alq3 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-C61-butyric acid methyl ester (PCBM) was tested. The devices equipped with the derivatives showed higher power conversion efficiency (η) compared to the photocells containing the parent Alq3. Open circuit voltage (Voc) was increased when the derivatives were utilized as the anodic buffer layer. Doping of the P3HT:PCBM with a small amount of Alq3 or its derivative improved short circuit current density, Voc, fill factor, and η, 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 Alq3 or its derivative as buffer layer or dopant are discussed. - Highlights: ► Tris(8-hydroxyquinoline)aluminum (Alq3) complexes in inverted organic solar cells. ► The Alq3 complexes were used as an anodic buffer layer and as a dopant. ► Efficiency increased and the derivatives revealed varying open circuit voltage. ► Photovoltaic performance was stable after storage in a dark ambient atmosphere.

  14. Effects of 2-amino-8-hydroxyquinoline interaction on the conformation of physiological isomers of human serum albumin.

    Shiriskar, Sonali M; Agarwal, Neeraj; Pissurlenkar, Raghuvir R S; Ahmad, Basir

    2015-05-01

    The methods of synthetic chemistry create small molecules rapidly for screening, and ligand-protein interaction studies provide information on how a potential drug interacts with target or carrier proteins such as serum albumin. In this work, we investigate the interaction of amino derivative of 8-hydroxyquinoline, 2-amino-8-hydroxyquinoline (A8HQ), and the effects of its binding on the conformation of different isomers of human serum albumin (HSA) using multispectroscopic techniques and molecular modeling. We found that B isomer, which exists at pH 9, bound A8HQ (K a = 1.92 ± 0.07 × 10(5) M(-1) at 298 K) more strongly as compared with N isomer (K a = 1.19 ± 0.04 × 10(5) M(-1) at 298 K) of HSA, which is known to exist around pH 6. The binding constant at physiological pH (7.4) was also determined, and the value (K a = 1.38 ± 0.05 × 10(5) M(-1) at 298 K) was found to fall between those for N and B isomers, suggesting that both the N and B isomers exist in an equilibrium in plasma. We also determined the thermodynamic parameters such as changes in enthalpy, entropy , and free energy of binding by measuring the binding at four different temperatures. Based on molecular modeling and thermodynamic studies, we propound that the A8HQ-HSA binding involves mainly hydrophobic interactions and hydrogen bonding. Site-specific marker displacement experiments and molecular modeling showed that the molecule preferably binds in subdomain IIA close to Trp214. A8HQ binding to HSA isomers was found to cause both secondary and tertiary structural alterations in the protein. PMID:25761396

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

    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

  16. Dioxyuranyl(6) complexing with 8-hydroxyquinoline and 8-mercaptoquinoline in (UO2)2[Fe(CN)6]-gelatin-immobilized matrices

    Interaction of dioxouranyl(6) with 8-hydroxyquinoline and 8-mercaptoquinoline in a gelatin-immobilized matrix in the presence of water has been studied. It is shown that in both cases addition of two molecules of each ligand to one H2UO4 fragment occurs. Gelatin as a ligand does not take part in the process

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

    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.

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

    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

  19. Toxicity of 8-Hydroxyquinoline in Cryprinus carpio Using the Acute Toxicity Test, Hepatase Activity Analysis and the Comet Assay.

    Yan, Shuaiguo; Chen, Lili; Dou, Xiaofei; Qi, Meng; Du, Qiyan; He, Qiaoqiao; Nan, Mingge; Chang, Zhongjie; Nan, Ping

    2015-08-01

    To evaluate the environmental toxicity of 8-hydroxyquinoline (8-HOQ), an important industrial raw material found in China's major ornamental fish, Cryprinus carpio, using the acute toxicity test, hepatase activity analysis and the comet assay. The results indicated that 8-HOQ had significant acute toxicity in adult C. carpio with a 96 h-LC50 of 1.15 and 0.22 mg L(-1) hepatic quinoline residues as assessed by HPLC. 8-HOQ also induced genotoxicity in the form of strand breaks in the DNA of hepatic cells as shown by the comet assay. With regard to physiological toxicity, 8-HOQ induced a decrease in the activities of hepatic GOT and GPT with increased exposure concentration and time. These data suggest that 8-HOQ may be toxic to the health of aquatic organisms when accidentally released into aquatic ecosystems. The data also suggest that the comet assay may be used in biomonitoring to determine 8-HOQ genotoxicity and hepatic GPT and GOT activities may be potential biomarkers of physiological toxicity. PMID:26067700

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

    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

  1. High voltage deposition of daughter 144Pr on platinum electrode from chlorbenzene solution of cerium 8-hydroxyquinolinate

    The deposition of 144Pr, carrier-free, on platinum electrode, formed by beta-decay of 144Ce which was in the form of cerium tetrakis (8-hydroxyquinolinate) chelate in chlorobenzene, was studied in dependence on time and intensity of the electric field. The amount of 144Pr deposited on the cathode after 20 min at the intensity of electric field 8 kV cm-1 was 14% of its total equilibrium amount in the solution. The proportion of 144Pr formed in the solution as ions was found by extrapolating the experimental relationships to be 23%. This value was similar to that of the break-up of molecular forms under the formation of simple 144Pr ions expected on the basis of the decay scheme of 144Ce and the mechanism of the energy transfer inside the atoms and molecular systems. On the basis of the mobility of cations found (9.6x10-5 cm2kV-1s-1) it was assumed that deposited ions were probably monotypes. The amount of 144Pr deposited on the anode was about 1% and that of 144Ce on both the cathode and the anode (caused by adsorption) was 0.5 to 1%. (author)

  2. Spectrophotometric determination of ionization constants of 8-hydroxyquinoline in EtOH and MeOH-water solvent system

    The dissociation constants (pKa) and Gibb's free energies of 8-hydroxyquinoline have been determined in MeOH-water and EtOH-water solvents with percent variation from 10 to 50 % at the interval of 5 percent using UV-Spectrophotometer equipped with a temperature control accuracy of +- 0.1 degree centigrade. This compound gives two dissociation constants. The first basic thermodynamic dissociation constant pKa-t is 5.087 +- 0.011 at 20 degree centigrade which is not possible to be determine spectrophotometrically. The second thermodynamic dissociation constant pKa -t determined by spectrophotometrically varies from 9.853 +-0.010 to 9.310+-0.010 and 9.901+-0.011 to 9,413 +-0.010 in EtOH - water and MeOH - water solvent systems respectively at 25 degree centigrade. The related delta G's of thermodynamic dissociation constants very from -14.025 +- 0.013 to -12.610 +-0.014 kcal/mol for both solvents at 25 degree centigrade. The curve of pKa versus temperature is a distorted parabola. The ionization constant values decrease with increasing the temperature. The significance of relative magnitudes of the values is discussed and some useful generalization constants. A computer program in GW-BASIC has been used to calculate the /values of dissociation constants. From the pKa values Gibb's free energies are computed and discussed. (author)

  3. Indium-tin-oxide-free tris(8-hydroxyquinoline) Al organic light-emitting diodes with 80% enhanced power efficiency

    Cai, Min; Xiao, Teng; Liu, Rui; Chen, Ying; Shinar, Ruth; Shinar, Joseph

    2011-10-11

    Efficient indium tin oxide (ITO)-free small molecule organic light-emitting diodes (SMOLEDs) with multilayered highly conductive poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS) as the anode are demonstrated. PEDOT:PSS/MoO{sub 3}/N,N'-diphenyl- N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPD)/tris(8-hydroxyquinoline) Al (Alq{sub 3})/4,7-diphenyl-1,10-phenanthroline (BPhen)/LiF/Al SMOLEDs exhibited a peak power efficiency of 3.82 lm/W, 81% higher than that of similar ITO-based SMOLEDs (2.11 lm/W). The improved performance is believed to be due to the higher work function, lower refractive index, and decreased surface roughness of PEDOT:PSS vs ITO, and to Ohmic hole injection from PEDOT:PSS to the NPD layer via the MoO{sub 3} interlayer. The results demonstrate that PEDOT:PSS can substitute ITO in SMOLEDs with strongly improved device performance.

  4. Influence of 8-hydroxyquinoline on properties of anodic coatings obtained by micro arc oxidation on AZ91 magnesium alloys

    Highlights: ► 8-HQ can promote the coating formation and change the coating color. ► 8-HQ can increase the coating thickness and decrease the pore size. ► Insoluble Mg(HQ)2 is formed in anodic coatings in an alkaline solution with 8-HQ. ► 8-HQ improves the corrosion resistance of the anodized magnesium alloys. - Abstract: The influence of 8-hydroxyquinoline (8-HQ) on formation and properties of anodic coatings obtained by micro arc oxidation (MAO) on AZ91 magnesium alloys was studied by scanning electron microscope (SEM), energy dispersive spectrometry (EDS), Fourier transform infrared (FT-IR) spectroscopy and potentiodynamic polarization tests. The results demonstrate that 8-HQ can decrease the solution conductivity, take part in the coating formation and change the coating color. By developing anodic coatings with increasing thickness, insoluble Mg(HQ)2 and small pore size, 8-HQ improves the corrosion resistance of the anodized magnesium alloys. The coating shows the best corrosion resistance in the solution of 10 g/L NaOH and 18 g/L Na2SiO3 with 2 g/L 8-HQ.

  5. Preconcentration and speciation of chromium(III) in waters by using 5-palmitoyl-8-hydroxyquinoline immobilized on a nonpolar adsorbent

    A method for the quantitative separation and preconcentration of trace amount Cr(III) in real samples has been developed. It is based on the sorption of Cr(III) ions onto a column of Amberlite XAD-2 resin functionalized with 5-palmitoyl-8-hydroxyquinoline reagent. The resin was used for speciation and preconcentration of chromium because this functionalized resin is selective for Cr(III) ions. The effect of pH, flow-rate, sorption capacity, reusability and effect of various metal cations and salt anions on the sorption on to the resin were investigated. The sorption is quantitative in the pH range of 4.5-7.0, and Cr (III) ion was desorbed by using hydrochloric acid. The amount of metal ion in the eluate was determined by a flame atomic absorption spectrometer. Total chromium was obtained by an efficient reduction of Cr(VI) to Cr(III) by hydroxylamine. The procedure has been applied to the determination and speciation of chromium in lake water, and in the chromium-plating baths. (author)

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

    Yang, Yin; Huang, Feng; Huber, Thomas; Su, Xun-Cheng

    2016-02-01

    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. PMID:26732873

  7. Spectrophotometric and spectroscopic studies of complexation of 8-hydroxyquinoline with π acceptor metadinitrobenzene in different polar solvents

    Khan, Ishaat M.; Ahmad, Afaq

    2009-09-01

    The complexation of electron donor-acceptor complexes of 8-hydroxyquinoline (8HQ) and metadinitrobenzene (MNB) have been studied spectrophotometrically and thermodynamically in different polar solvent at room temperature. A new absorption band due to charge transfer (CT) transition is observed in the visible region. A new theoretical model has been developed which take into account the interaction between electronic subsystem of 8HQ and MNB. The results indicate the extent of charge transfer complexes (CTCs) formation to be more in less polar solvents. Stoichiometry of the complex was found to be 1:1 by straight line method and 1H NMR between donor and acceptor at the maximum absorption bands. Ionization potential ( ID) and resonance energy ( RN) were determined from the CT transition energy in different solvents. The formation constants of the complexes were determined in different polar solvents from which Δ G° formation of the complexes was estimated and also extinction coefficient of the charge transfer complex (CTC) was calculated. Oscillator strength, transition dipole strengths and maximum wavelength of the CTC ( λCT) in various solvents and IR spectra of the CTC have also been discussed. It has been observed that all parameters described above changed with change in polarity and concentration of donor.

  8. Influence of 8-hydroxyquinoline on properties of anodic coatings obtained by micro arc oxidation on AZ91 magnesium alloys

    Zhang, R.F. [Jiangxi Key Laboratory of Surface Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); School of Material Science and Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Zhang, S.F., E-mail: zhangshufang790314@sina.com [Jiangxi Key Laboratory of Surface Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); School of Material Science and Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013 (China); Yang, N.; Yao, L.J.; He, F.X.; Zhou, Y.P.; Xu, X.; Chang, L.; Bai, S.J. [School of Material Science and Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013 (China)

    2012-10-25

    Highlights: Black-Right-Pointing-Pointer 8-HQ can promote the coating formation and change the coating color. Black-Right-Pointing-Pointer 8-HQ can increase the coating thickness and decrease the pore size. Black-Right-Pointing-Pointer Insoluble Mg(HQ){sub 2} is formed in anodic coatings in an alkaline solution with 8-HQ. Black-Right-Pointing-Pointer 8-HQ improves the corrosion resistance of the anodized magnesium alloys. - Abstract: The influence of 8-hydroxyquinoline (8-HQ) on formation and properties of anodic coatings obtained by micro arc oxidation (MAO) on AZ91 magnesium alloys was studied by scanning electron microscope (SEM), energy dispersive spectrometry (EDS), Fourier transform infrared (FT-IR) spectroscopy and potentiodynamic polarization tests. The results demonstrate that 8-HQ can decrease the solution conductivity, take part in the coating formation and change the coating color. By developing anodic coatings with increasing thickness, insoluble Mg(HQ){sub 2} and small pore size, 8-HQ improves the corrosion resistance of the anodized magnesium alloys. The coating shows the best corrosion resistance in the solution of 10 g/L NaOH and 18 g/L Na{sub 2}SiO{sub 3} with 2 g/L 8-HQ.

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

    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.

  10. Photoluminescence and thermoanalytical studies of complexes based on 5-Cl-8-hydroxyquinoline and calix[4]arene ligands

    A innovative 5-Cl-8-oxyquinolinepropoxycalix[4]arene ligand (2) have been prepared, exhibiting, at room temperature, blue fluorescent light emission and resulting in shift band to green fluorescent light (fluorescence mode) in the presence of coordinated Eu(III) and Tb(III) ions. Terbium complex presented phosphorescence emission as noted by typical bands at 490 nm, 545 nm and 585 nm. TG/DTG data exhibited typical thermal behavior for these compounds, however DSC curves showed the melting temperature near 300 °C for the samples, demonstrating an unusual thermal stability when quinoline derivatives are attached to calix[4]arene matrix. This fact strongly suggests an effective approach to preparing the photoluminescent compound associating high chemical and thermal stability. Highlights: ► Calix[4]arene with 5-Cl-8-hydroxyquinoline exhibits blue fluorescent light emission. ► Green fluorescent light resulting to coordinated Eu(III) and Tb(III) ions ► Quinoline derivatives have thermal stability when attached to calix[4]arene matrix. ► Photoluminescent compounds combining high chemical and thermal stability

  11. Investigation of organic magnetoresistance dependence on spin-orbit coupling using 8-hydroxyquinolinate rare-earth based complexes

    Carvalho, R. S.; Costa, D. G.; Ávila, H. C.; Paolini, T. B.; Brito, H. F.; Capaz, Rodrigo B.; Cremona, M.

    2016-05-01

    The recently discovered organic magnetoresistance effect (OMAR) reveals the spin-dependent behavior of the charge transport in organic semiconductors. So far, it is known that hyperfine interactions play an important role in this phenomenon and also that spin-orbit coupling is negligible for light-atom based compounds. However, in the presence of heavy atoms, spin-orbit interactions should play an important role in OMAR. It is known that these interactions are responsible for singlet and triplet states mixing via intersystem crossing and the change of spin-charge relaxation time in the charge mobility process. In this work, we report a dramatic change in the OMAR effect caused by the presence of strong intramolecular spin-orbit coupling in a series of rare-earth quinolate organic complex-based devices. Our data show a different OMAR lineshape compared with the OMAR lineshape of tris(8-hydroxyquinolinate) aluminum-based devices, which are well described in the literature. In addition, electronic structure calculations based on density functional theory help to establish the connection between this results and the presence of heavy central ions in the different complexes.

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

    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.

  13. Synthesis and luminescence properties of polymeric complexes of Cu(II), Zn(II) and Al(III) with functionalized polybenzimidazole containing 8-hydroxyquinoline side group

    Zhong, Chaofan; Wu, Qian; Guo, Rongfang; Zhang, Hailiang

    2008-02-01

    The polymeric ligand PBI-8Q ( 2) (functionalized polybenzimidazole containing 8-hydroxyquinoline side group) was successfully synthesized by the reaction of polybenzimidazole (PBI) ( 1) with 5-chloro-8-hydroxyquinoline (5-Cl-8Q) in DMSO solvent by using NaH as deprotonation reagent. Its corresponding metal complexes of Cu(II), Zn(II) and Al(III) were prepared and characterized through FT-IR, 1H NMR, molar conductance measurements and thermal analysis. The luminescence properties of all compounds were also studied by UV-vis and fluorescence spectra at ambient temperature. When excited from 338 to 415 nm, these compounds emit blue light of about 415 nm in solution and blue/green light from 483 to 552 nm in solid state, respectively. Thermal properties measurement and analysis show that they have good thermal stabilities.

  14. Simultaneous determination of Al, V, Mn and Cu from neutron-activated saline matrices by precipitation with poly-5-vinyl-8-hydroxyquinoline

    The neutron activation analysis of biological and environmental matrices suffers from interferences caused by the presence of high concentrations of activated salts in these matrices. The high gamma-ray activities of these activated salts mask the low gamma-ray activities of short half-lived isotopes (e.g., 66Cu, 56Mn, 28Al and 52V) necessitating the rapid separation of trace metals from high concentrations of salts. Poly-5-vinyl-8-hydroxyquinoline has been used to develop a new method to rapidly and quantitatively precipitate aluminium, copper, vanadium and manganese from neutron-activated biological and environmental matrices. This technique, is extremely useful for separations requiring a minimum of time. Future studies can extend the new PVO precipitation procedure to approximately 40 other elements which are known to readily chelate with 8-hydroxyquinoline. (T.G.)

  15. Structural and vibrational study of 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone - A potential metal-protein attenuating compound (MPAC) for the treatment of Alzheimer's disease

    de Freitas, Leonardo Viana; da Silva, Cecilia C. P.; Ellena, Javier; Costa, Luiz Antônio Sodré; Rey, Nicolás A.

    2013-12-01

    A comprehensive structural and vibrational study of the potential metal-protein attenuating compound 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone is reported. X-ray diffraction data, as well as FT-IR and Raman frequencies, were compared with the respective theoretical values obtained from DFT calculations. Theory agrees well with experiment. In this context, an attempt of total assignment concerning the FT-IR and Raman spectra of the title compound was performed, shedding new light on previous partial assignments published elsewhere.

  16. Tumor Cellular Proteasome Inhibition and Growth Suppression by 8-Hydroxyquinoline and Clioquinol Requires Their Capabilities to Bind Copper and Transport Copper into Cells

    Zhai, Shumei; Yang, Lei; Cui, Qiuzhi Cindy; Sun, Ying; Dou, Q. Ping; Yan, Bing

    2009-01-01

    We have previously reported that when mixed with copper, 8-hydroxyquinoline (8-OHQ) and its analog clioquinol (CQ) inhibited the proteasomal activity and proliferation in cultured human cancer cells. CQ treatment of high copper-containing human tumor xenografts also caused cancer suppression, associated with proteasome inhibition in vivo. However, the nature of copper dependence of these events has not been elucidated experimentally. In the current study, by using chemical probe molecules tha...

  17. Direct measurement of the magnetic field effects on carrier mobilities and recombination in tri-(8-hydroxyquinoline)-aluminum based light-emitting diodes

    Li, Feng; Xin, Linyuan; Liu, Shiyong; Hu, Bin

    2010-01-01

    The magnetic field effects on the carrier mobilities and recombination in tri-(8-hydroxyquinoline)-aluminum (Alq3) based light-emitting diodes have been measured by the method of transient electroluminescence. It is confirmed that the magnetic field has no effect on the electron and hole mobilities in Alq3 layers and can decrease the electron-hole recombination coefficient. The results imply that the dominant mechanism for the magnetic field effects in Alq3 based light-emitting diodes is the ...

  18. Ligand Field Affected Single-Molecule Magnet Behavior of Lanthanide(III) Dinuclear Complexes with an 8-Hydroxyquinoline Schiff Base Derivative as Bridging Ligand.

    Wang, Wen-Min; Zhang, Hong-Xia; Wang, Shi-Yu; Shen, Hai-Yun; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin

    2015-11-16

    New dinuclear lanthanide(III) complexes based on an 8-hydroxyquinoline Schiff base derivative and β-diketonate ligands, [Ln2(hfac)4(L)2] (Ln(III) = Gd (1), Tb (2), Dy (3), Ho (4), Er (5)), [Ln2(tfac)4(L)2] (Ln(III) = Gd (6), Tb (7), Dy (8), Ho (9)), and [Dy(bfac)4(L)2·C7H16] (10) (L = 2-[[(4-fluorophenyl)imino] methyl]-8-hydroxyquinoline, hfac = hexafluoroacetylacetonate, tfac = trifluoroacetylacetonate, and bfac = benzoyltrifluoroacetone), have been synthesized. The single-crystal X-ray diffraction data show that complexes 1-10 are phenoxo-O-bridged dinuclear complexes; each eight-coordinated center Ln(III) ion is in a slightly distorted dodecahedral geometry with two bidentate β-diketonate coligands and two μ2-O bridging 8-hydroxyquinoline Schiff base derivative ligands. The magnetic study reveals that 1 and 6 display cryogenic magnetic refrigeration properties, whereas complexes 3, 8, and 10 show different SMM behaviors with energy barriers of 6.77 K for 3, 19.83 K for 8, and 25.65 K for 10. Meanwhile, slow magnetic relaxation was observed in 7, while no out-of-phase alternating-current signals were found for 2. The different dynamic magnetic behaviors of two Tb2 complexes and the three Dy2 complexes mainly derive from the tiny crystal structure changes around the Ln(III) ions. It is also proved that the β-diketonate coligands can play an important role in modulating magnetic dynamics of the lanthanide 8-hydroxyquinoline Schiff base derivative system. PMID:26516660

  19. Effect of some organic solvents on complexing of uranium(6), zinc(2) and manganese(2) with azo derivation of 8-hydroxyquinoline

    A study has been made of azo derivatives of 8-hydroxyquinoline, namely, 7-(2-thiazolylazo)-8-hydroxyquinoline-5-sulfoacid, 7-(4-bromo-2-thiazolylazo)-8-hydroquinoline-5-sulfoacid and 7-(6-bromo-2-benzothiazolylazo)-8-hydroxyquinoline-5-sulfoacid, as analytical reagents with uranium (6), zinc (2) and manganese (2). The possibility is shown of using aqueous-organic mixtures containing dioxan, ethanol, acetone or dimethyl formamide to change the properties of the reagents and resulting complexes. The stability of complexes with a component ratio of 1:1 increases gradually as the polarity of the medium decreases. In the case of a uranium complex in dioxan and dimethyl formamide media, with further decrease in the medium polarity and higher pH values, a complex is formed with a component ratio of 1:2. With a slight variation in the medium polarity, in transition from compound (1:1) to compound (1:2), the stability increases stepwise at the same pH value which has been selected for compound (1:1) (uranium in acetone and ethanol media). The most sensitive reagent is 7-(2-thiazolylazo)-8-hydroxyquinone-5-sulfoacid. Aqueous-acetone and aqueous-dioxan media have been found promising for enhancing the reagent sensitivity

  20. A novel trimeric Zn (II) complex based on 8-hydroxyquinoline with trifluoromethylbenzene group: Synthesis, crystal structure, photophysical properties and DNA binding

    Huo, Yanping; Wang, Chunquan; Lu, Jiguo; Hu, Sheng; Li, Xiaoyang; Zhang, Li

    2015-10-01

    A novel 2-substituted-8-hydroxyquinoline ligand (E)-2-[2-(4-trifluoromethylphenyl)ethenyl]-8-hydroxyquinoline (3, HL) was synthesized and characterized by ESI-MS, NMR spectroscopy and elemental analysis. Using solvothermal method, a trimeric complex [Zn3L6] (4) was fabricated by self-assembly of Zn(II) ions with 3. X-ray structural analysis shows that 4 exhibits a trinuclear core, which was bridged and encapsulated by six 8-hydroxyquinolinate-based ligands. The supramolecular structure of 4 features a lamellar solid constructed by aromatic stacking interactions and nonclassical C-H···F hydrogen bonds derived from 4-trifluoromethylphenyl group of the 3. The coordination behavior of zinc salt and 3 in solution was performed by 1H NMR, UV-vis and Photoluminescence (PL). The experimental results show that the complex 4 emits yellow luminescence in the solid state. To investigate its properties further, we also studied the thermal stability, photophysical properties (fluorescent emission, lifetime) of complex 4, and the interactions between 4 and C60 or EtBr-DNA system.

  1. Design, synthesis and characterization of a highly luminescent Eu-complex monomer featuring thenoyltrifluoroacetone and 5-acryloxyethoxymethyl-8-hydroxyquinoline

    A multi-functional ligand, 5-acryloxyethoxymethyl-8-hydroxyquinoline (Hamq), was synthesized, which contained a polymerizable C=C double bond for the copolymerization with other vinyl monomers and acted as photon antenna able to transfer energy to Eu3+ ions effectively. The triplet state energy of Hamq was determined to be 22,370 cm-1 via the phosphorescence spectra of Hamq and its gadolinium complex. The title complex monomer Eu(tta)2(amq) was prepared by coordination reaction of Hamq with europium isopropoxide and 2-thenoyltrifluoroacetone (Htta) in dry organic solvents under argon atmosphere and characterized by elemental analysis and IR spectrum. The photophysical properties of the complex were studied in detail with UV-vis, luminescence spectra, luminescence lifetime and quantum yield. The complex exhibited nearly monochromatic red emission at 612 nm, a remarkable luminescence quantum yield at room temperature (30.6%) upon ligand excitation and a long 5D0 lifetime (389 μs), which indicated that the ligand Hamq could sensitize the luminescence of Eu(III) ion efficiently in Eu(tta)2(amq), resulting in a strong luminescence of its copolymer poly[MMA-co-Eu(TTA)2(amq)] under UV excitation. The excellent luminescence properties of the complex made it not only a promising light-conversion molecular device but also an excellent luminescent monomer. - Highlights: →iWe designed and synthesized a highly luminescent Eu-complex monomer. → Quantum yield and lifetime of the complex are 30.6% and 389 μs, respectively. → Excellent luminescence of the complex made it an excellent luminescent monomer.

  2. Plasma treatment of the Mg:Ag/tris-(8-hydroxyquinoline) aluminum interface in OLEDs: effects on adhesion and performance

    The adhesion of a Mg:Ag cathode to the tris-(8-hydroxyquinoline) aluminum (Alq3) in organic light emitting devices (OLEDs) can be greatly enhanced by a remote plasma treatment of the Alq3 layer using either air or N2 prior to metal deposition. The altered surface properties which lead to increased sticking coefficients of Mg and Ag, as well as enhanced adhesion, are attributed to the introduction of new functional groups into the organic layer, as observed by X-ray photoelectron spectroscopy (XPS). The storage life of the plasma treated devices in air without any capping treatment, as judged by a visible deterioration of the cathode, was increased by approximately five to six times compared to untreated OLEDs. Current-voltage characteristics and EL efficiency, however, were shown to deteriorate for devices incorporating either an air or an N2 plasma treated Alq3 layer. For OLEDs subjected to short treatment times with an N2 plasma, only a very slight increase in the turn-on voltage, of about 0.2 V, was observed. An investigation of black spot formation revealed that an air plasma treatment resulted in a five-fold decrease in the time required for 50% of the device to become non-emissive. N2 treated devices on the other hand, developed black spots at a comparable rate to the non-treated devices. Thus, a short N2 plasma treatment of the Alq3 layer prior to metal deposition improves the adhesion at the interface, thereby reducing the oxidation and degradation of the device through exposure to ambient conditions, particularly in storage

  3. Chelating resin from functionalization of chitosan with complexing agent 8-hydroxyquinoline: application for metal ions on line preconcentration system

    This study describes the functionalization of biopolymer chitosan, using the complexing agent 8-hydroxyquinoline (oxine) by reaction of diazotization. The chelating resin was characterized by degree of deacetylation, infrared, Raman spectroscopy. The efficiency of the chelating resin and accuracy of the proposed method was evaluated by the metal ion recovery technique in the analysis of potable water, lake water, seawater and a certified sample of oyster tissue. The metal ions Cd(II) and Cu(II) in the samples were previously enriched in a minicolumn and flow injection flame atomic absorption spectrometry (FI-FAAS) determined the concentrations of the analytes. The chelating resin exhibited high selectivity for Cd(II) at pH 7 and for Cu(II) at pH 10. The eluent concentration was tested by the use of HNO3 in concentrations of 0.1-3 mol l-1 maximum response was obtained at 0.5 mol l-1 for Cd(II) and Cu(II), with R.S.D. values of 0.4%. The analytes gave relative standard deviations (R.S.D.) of 1.5 and 0.7% for solutions of Cd(II) and Cu(II), respectively (n = 7) containing 20 μg l-1 of the metal ions, defining a high reproducibility. The limits of detection (LOD) were 0.1 μg l-1 for Cd(II) and 0.4 μg l-1 for Cu(II). The analytical properties of merit were obtained using the parameters previously optimized with preconcentration time of 90 s. The chelating resin showed chemical stability within a wide range of pH and the efficiency was not altered for the preconcentration of the metal ions during all the experiments

  4. Room temperature ferromagnetic properties of Al-doped bis(8-hydroxyquinoline)cobalt (Coq{sub 2}) molecules

    Jiang, Feng; Wei, Fangfang [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Yuan, Huimin [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); College of Physics and Electronic Engineering, Qilu Normal University, Jinan 250013 (China); Xie, Wanfeng; Pang, Zhiyong [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Zhang, Xijian, E-mail: zhangxijian@sdu.edu.cn [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2015-08-01

    Room temperature ferromagnetic properties were obtained in an originally paramagnetic molecule bis(8-hydroxyquinoline)cobalt (Coq{sub 2}) by doping a nonmagnetic element aluminum. The Al-doped Coq{sub 2} films with the thicknesses of about 200 nm were prepared on Si substrates by co-evaporating pure Coq{sub 2} powders (99%) and Al wires (99%) simultaneously at a base pressure of 1.9×10{sup −4} Pa. The magnetic properties of the films were measured at different temperatures by using a Quantum Design superconducting quantum interference device (SQUID). The obtained maximum coercive field is about 250 Oe at 300 K. The electronic structures of Al-doped Coq{sub 2} were studied by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) analysis. The FTIR and XPS spectra indicate that the doped Al atoms prefer to interact with N and O atoms in Coq{sub 2} molecules. XAFS analysis shows that the Coq{sub 2} molecule does not decompose during the co-evaporating process. The ferromagnetism of the film is attributed to the interactions between Al and N p states in lowest unoccupied molecular orbitals (LUMO). - Highlights: • Al-doped Coq{sub 2} films were deposited on Si substrates by thermal evaporation. • Room temperature ferromagnetism was obtained in the doped films. • FTIR and XPS spectra show that Al atoms react with N and O atoms of the Coq2 molecules.

  5. Development of a Direct and Continuous Phospholipase D Assay Based on the Chelation-Enhanced Fluorescence Property of 8-Hydroxyquinoline.

    Rahier, Renaud; Noiriel, Alexandre; Abousalham, Abdelkarim

    2016-01-01

    Through its production of phosphatidic acid (PA), phospholipase D (PLD) is strongly involved in vesicular trafficking and cell signaling, making this enzyme an important therapeutic target. However, most PLD assays developed so far are either discontinuous or based on the indirect determination of choline released during PLD-catalyzed phosphatidylcholine hydrolysis, making its kinetic characterization difficult. We present here the development of a direct, specific, and continuous PLD assay that is based on the chelation-enhanced fluorescence property of 8-hydroxyquinoline (8HQ) following Ca(2+) complexation with PLD-generated PA. The real-time fluorescence intensity from 8HQ/Ca(2+)/PA complexes can be converted to concentrations of product using a calibration curve, with a detection limit of 1.2 μM of PA on a microplate scale, thus allowing measurement of the PLD-catalyzed reaction rate parameters. Hence, this assay is well adapted for studying the substrate specificity of PLD, together with its kinetic parameters, using natural phospholipids with various headgroups. In addition, the assay was found to be effective in monitoring the competitive inhibition of PA formation in the production of phosphatidylalcohols following the addition of primary alcohols, such as ethanol, propan-1-ol, or butan-1-ol. Finally, this assay was validated using the purified recombinant Vigna unguiculata PLD, as well as the PLD from Streptomyces chromofuscus, cabbage, or peanuts, and no PA production could be detected using phospholipase A1, phospholipase A2, or phospholipase C, allowing for a reliable determination of PLD activity in crude protein extract samples. This easy to handle PLD assay constitutes, to our knowledge, the first direct and continuous PA determination method on a microplate scale. PMID:26636829

  6. Structural and optical properties of Tris(8-hydroxyquinoline) aluminum (III) (Alq{sub 3}) thermal evaporated thin films

    El-Nahass, M.M. [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Farid, A.M., E-mail: ashganfarid@hotmail.co [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Atta, A.A. [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt)

    2010-09-24

    X-ray diffraction (XRD), transmission electron microscope (TEM) micrographs and optical properties of Tris(8-hydroxyquinoline) aluminum (III) (Alq{sub 3}) have been studied. XRD of powder Alq{sub 3} showed that the material has a polycrystalline nature with triclinic structure. The crystal structure and morphology of the as-deposited and annealed (at 473 K for 2 h.) Alq{sub 3} thin films indicated that the as-deposited film is amorphous in nature, while the annealed film has a polycrystalline nature with amorphous background. The molecular structure of the Alq{sub 3} was confirmed by the analysis of (FTIR) spectra. The optical constants such as the refractive index, n, the absorption index, k and the absorption coefficient, {alpha}, of both the amorphous and polycrystalline Alq{sub 3} films were determined using spectrophotometric measurements of transmittance (T) and reflectance (R) in the wavelength range (200-2500 nm). The analysis of the data showed an indirect allowed transition energy gaps E{sub g}{sup ind} of 2.66 eV and 2.28 eV for the as-deposited and the annealed Alq{sub 3} thin films, respectively. As well as another probability of direct allowed transition was carried out with energy gaps Eg{sub 1}{sup d} of 2.82 eV, and Eg{sub 2}{sup d} of 4.14 eV for the as-deposited film and Eg{sub 1}{sup d} of 2.59 eV, Eg{sub 2}{sup d} of 3.88 eV for the annealed films, respectively. Some optical parameters namely molar extinction coefficient ({epsilon}{sub molar}), oscillator strength (f) and electric dipole strength (q{sup 2}) have been evaluated. According to the single oscillator model (SOM), some related parameters such as oscillation energy (E{sub 0}), the dispersion energy (E{sub d}), the optical dielectric constant ({epsilon}{sub {infinity}}), the lattice dielectric constant ({epsilon}{sub L}) and the ratio of free carrier concentration to its effective mass (N/m*) were estimated. Graphical representation of both the surface and volume energy loss functions

  7. Structural and photophysical studies on gallium(III) 8-hydroxyquinoline-5-sulfonates. Does excited state decay involve ligand photolabilisation?

    Ramos, M Luísa; de Sousa, Andreia R E; Justino, Licínia L G; Fonseca, Sofia M; Geraldes, Carlos F G C; Burrows, Hugh D

    2013-03-14

    Multinuclear ((1)H, (13)C and (71)Ga) magnetic resonance spectroscopy (1D and 2D), DFT calculations and luminescence techniques have been used to study 8-hydroxyquinoline-5-sulfonate (8-HQS) and its complexes with Ga(III) in aqueous solutions. The study combines the high sensitivity of luminescence techniques and the selectivity of multinuclear NMR spectroscopy with the structural details accessible through DFT calculations, and aims to obtain a complete understanding of the complexation between the Ga(3+) ion and 8-HQS, and how this influences the luminescence behaviour. A full speciation study has been performed on this system and three complexes detected, with (metal : ligand) 1 : 1, 1 : 2 and 1 : 3 stoichiometries, the results being consistent with those previously found for the system Al(III)-8-HQS. Complexation in these systems is relevant to their potential biomedical, sensing and optoelectronic applications. On binding to Ga(III), a marked increase is seen in the intensity of the 8-HQS fluorescence band, which is accompanied by changes in the absorption spectra. These support the use of 8-HQS as a sensitive fluorescent sensor to detect Ga(3+) metal ions in surface waters, biological fluids, etc., and its metal complexes as an emitting or charge transport layer in light emitting devices. However, the fluorescence quantum yield of the Ga(III)-8-HQS 1 : 3 complex is about 35% of that of the corresponding system with Al(III). Although this may be due in part to a heavy atom effect favouring S(1)→ T(1) intersystem crossing with Ga(3+), this does not agree with transient absorption measurements on the triplet state yield, which is lower with the Ga(III) system than with Al(III). Instead, it is suggested that photolabilisation of ligand exchange plays a major role in nonradiative decay of the excited state and that this is more efficient with the Ga(3+) complex. Based on these results, suggestions are made of ways of enhancing fluorescence

  8. Synthesis and luminescence properties of polymeric complexes of Cu(II), Zn(II) and Al(III) with 8-hydroxyquinoline side group-containing polystyrene

    Gao, Baojiao; Wei, Xiaopeng; Zhang, Yanyan

    2013-01-01

    Three kinds of metalloquinolate-containing polystyrene were prepared via a polymer reaction and a coordination reaction. 5-Chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction of 8-hydroxyquinoline (HQ) with 1,4-bichloromethoxy-butane as chloromethylation reagent. A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between polystyrene (PS) and CHQ in the presence of Lewis catalyst, and HQ was bonded onto the side chains of PS, obtaining 8-hydroxyquinoline-functionalized Polystyrene, HQ-PS. And then, by using one-pot method with two-stage procedures, the coordination reaction of HQ-PS and small molecule HQ with metal ions including Al(III), Zn(II) and Cu(II) ions, was allowed to be carried out, and three polymeric metalloquinolates, AlQ3-PS, ZnQ2-PS and CuQ2-PS, were successfully prepared, respectively. In the chemical structures of these polymeric metalloquinolates, metalloquinolates were chemically attached onto the side chains of PS. HQ-PS and three polymeric metalloquinolates were fully characterized by FTIR, 1H NMR and TGA. The luminescence properties of the three polymeric metalloquinolates were mainly investigated by UV/Vis absorption spectra and fluorescence emission spectra in solutions and in solid film states. When excited by the ray at about 365 nm, the three polymeric metalloquinolates have blue-green luminescence, and the main emission peaks in the DMF solutions are located at 490, 482 and 502 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. As compared with their emissions in solutions, the emissions in solid film states are red-shifted to some extent, and the main emission peaks are located at 500, 488 and 510 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. Besides, these polymeric metalloquinolates have higher thermal stability than PS as polymeric skeleton.

  9. Formation constants of mixed ligand complexes of oxovanadium(IV) with salicylic acid/5-sulphosalicylic acid/8-hydroxyquinoline-5-sulphonic acid and hippuric acid

    Equilibrium studies are described on the interaction of oxovanadium(IV) with salicylic acid (SA)/5-sulphosalicylic acid (SSA)/8-hydroxyquinoline-5-sulphonic acid (HQSA) in presence of hippuric acid. The formation of 1:1:1 mixed ligand complexes and their hydroxo derivatives inferred from the pH-metric titration curves and formation constants of 1:1:1 ternary complexes have been evaluated at 30 +- 0.5deg (μ = 0.1 M KNO3). The order of stability of ternary complexes has been found to be the same as that of 1:1 binary complexes involving hydroxy acids. (author)

  10. New Application of 2-(4-N-Phenyl-3-thiosemicarbazone)-8-hydroxyquinoline as a Sensor for Relay Recognition of Cu2+ and Sulfide in Aqueous Solution

    Fluorescent and colorimetric recognition properties of 2-(4-N-phenyl-3-thiosemicarbazone)-8-hydroxyquinoline (1) in buffered aqueous solution (1% DMSO, HEPES 20 mM, pH = 7.4) have been examined. Sensor 1 displays highly selective and sensitive recognition to Cu2+ with fluorescence 'ON-OFF' performance. The in situ formed 1-Cu2+ complex exhibits an excellent selectivity toward sulfide ions with fluorescence 'OFF-ON' behavior via Cu2+ displacement approach. Thus, relay recognition of Cu2+ and sulfide by a known molecule 1 has been achieved

  11. Stability constants of uranium(VI) and thorium(IV) complexes formed with 8-hydroxyquinoline and its 5-sulfonic acid derivative

    The stability constants of uranium(VI) and thorium(IV) complexes formed with 8-hydroxyquinoline (8-HOQ) and its 5-sulfonic acid (8-HOQ-5-SO3H) derivative have been determined using the Irving-Rossotti method, computing the Calvin-Bjerrum pH-titration data. As a result, it is determined that the thorium(IV) complexes are considerably more stable than the corresponding uranium(VI) complexes. On the other hand, the complexes formed between 8-HOQ-5-SO3H and uranium(VI) or thorium(IV) are less stable than the corresponding 8-HOQ complexes. (author) 18 refs.; 2 figs.; 1 tab

  12. Evaluation of cyclohexenoesculetin-beta-D-galactoside and 8-hydroxyquinoline-beta-D-galactoside as substrates for the detection of beta-galactosidase.

    James, A.L.; Perry, J D; Ford, M.; Armstrong, L.; Gould, F K

    1996-01-01

    We describe the synthesis of two new substrates for the detection of beta-galactosidase and evaluate their performance in comparison with that of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). Of 171 Enterobacteriaceae strains that were able to hydrolyze X-Gal, 166 (97.1%) also hydrolyzed cyclohexenoesculetin-beta-D-galactoside whereas only 96 (56.1%) showed evidence of hydrolysis of 8-hydroxyquinoline-beta-D-galactoside. No false-positive results were observed with either subst...

  13. On-Line Preconcentration and Speciation of Chromium by an 8-Hydroxyquinoline Microcolumn Immobilized on Surfactant-Coated Alumina and Flow Injection Atomic Absorption Spectrometry

    AHMADI, Seyyed Hamid; SHABANI, Ali Mohammad HAJI

    2007-01-01

    An on-line technique for the determination of chromium species with atomic absorption spectrometry is described. The method is based on separation and preconcentration of Cr(III) on a microcolumn of immobilized 8-hydroxyquinoline on surfactant-coated alumina. The adsorbed analyte is then eluted with 400 m L of 20% ethanolic solution of 1.5 mol L-1 hydrochloric acid and is transported to a flame atomic absorption spectrometer for quantification. The effects of pH, sample and eluent f...

  14. Determination of vanadium(5) and 8-hydroxyquinoline by oxidation of aniline with bromate ions in highly acidic solutions using spectrometry and thermal lensing

    When studying the rate of aniline oxidation by bromate-ions depending on the medium pH, it was revealed that pH reduction resulted in the change in characteristics of the reaction products absorption band. Physicochemical characteristics of the reaction considered occurring in highly acid medium (pH 2.4) were determined: pseudoorders in terms of oxidizing and reducing agents and effective rate constants. It is shown that aniline oxidation by bromate-ions in a highly acid medium permits reducing detection limits of vanadium(5) and 8-hydroxyquinoline (as activator of vanadium catalytic activity) both for spectrophotometric and thermal lensing detection

  15. Investigation of the magnetic field effects on the electron mobility in tri-(8-hydroxyquinoline)-aluminum based light-emitting devices

    Peng, Qiming; Sun, Jixiang; Li, Xianjie; Li, Mingliang; Li, Feng

    2011-01-01

    We investigated the mganetic field effects (MFEs) on electron mobility in tri-(8-hydroxyquinoline)-aluminum based light-emitting devices by transient-electroluminescence method upon application of various offset voltages. It is found the rising edges of EL pulses are well overlapped and the falling edges of EL pulses are separated for the magnetic field on and off when Voffset=0 V and Voffset>Vturnon of the devices. The results suggest the bipolaron model and the triplet-polaron interaction m...

  16. Motional modes in bulk powder and few-molecule clusters of tris(8-hydroxyquinoline aluminum) and their relation to spin dephasing

    Das, Lopamudra; Mateo, Jennette; Bandyopadhyay, Saumil; Bandyopadhyay, Supriyo; Edwards, Jarrod D.; Anderson, John

    2011-02-01

    The ensemble averaged spin dephasing rate of localized electrons in the organic molecule tris(8-hydroxyquinoline aluminum) or Alq3 has been found to be significantly larger in bulk powder than in single- or few-molecule clusters confined within 1-2 nm sized nanocavities [B. Kanchibotla et al., Phys. Rev. B 78, 193306 (2008)]. To understand this observation, we have compared the midinfrared absorption spectra of bulk powder and single- or few-molecule clusters. It appears that molecules have additional vibrational modes in bulk powder possibly due to multimerization. Their coupling with spin may be responsible for the increased spin dephasing rate in bulk powder.

  17. Synthesis and spectroscopic behavior of some oxovanadium(IV) and oxovanadium(V) complexes of 7-iodo-8-hydroxyquinoline-5-sulfonate

    González-Baró Ana C.; Baran Enrique J.

    2001-01-01

    The oxovanadium (IV) complex [VOL2].5H2O (1) and the oxovanadium(V) complexes K[VOL2O].4H2O) (2), [VOL2OH] (3) and [VOL2OCH3] (4) (L = potassium salt of 7-iodo-8-hydroxyquinoline-5-sulfonic acid) were prepared and characterized. The IR spectra of the solids were recorded and discussed in comparison with those of other similar compounds. The electronic absorption spectra, in different solvents, were also analyzed. Pre-resonance Raman measurements, performed with the first two mentioned complex...

  18. Nickel (II) complexes with 8-hydroxyquinoline and 8-mercaptoquinoline. Synthesis and structure of nickel 2-methyl-5-propylthio-8-hydroxyquinolinate - pyridine adduct Ni[C9H4(CH3)(SC3H7)NO]2(C5H5N)2

    Nickel 2--methyl-5-popylthio-8-hydroxyquinoline - pyridine adduct Ni[C9H4(CH3)(SC3)(SC3H7)NO]2(C5H5N2) (I) has been synthesized and investigated by X-ray diffraction analysis. The monocrystals of the title compound belong to triclinic syngony. Unit cell parameters: a=9.542(2), b=11.425(2), c=17,351(3)A; α=-86,5(2)deg, β=69.62(2)deg, γ=76.45(2)deg; V=1723.9(6)A3; ρtheor=1.313 g/cm3, Z=2; sp.gr. P1. The dynamics of the bonds in the certain nickel 8-hydroxyquinolinate adducts with pyridine has been analyzed. (authors)

  19. Characterization and determination of the thermodynamic and kinetic properties of the adsorption of molybdenum (VI) onto microcrystalline anthracene modified with 8-hydroxyquinoline

    A reliable and effective method for the determination of trace molybdenum in effluents is proposed. Molybdenum (VI) is analyzed by Microwave Plasma Torch Optical Emission Spectrometry (MPT-OES) based on the adsorption collection onto microcrystalline anthracene modified with 8-hydroxyquinoline. The possible reaction mechanism was discussed in detail and the optimum conditions for adsorption of Mo (VI) were confirmed. The experimental data were fitted well with the pseudo-second-order kinetic model and Langmuir model at all studied temperatures. The calculated thermodynamic parameters (ΔGT, ΔHT and ΔST) showed that the adsorption of molybdenum onto microcrystalline anthracene was feasible, spontaneous and endothermic at 280-320 K. The recovery of this method is in the range of 96.5%-103.3% with preconcentration factor of 100 and the limit detection after preconcentration is 0.078 μg L-1. The proposed method has been successfully applied to the determination of trace Mo (VI) in environmental water samples with satisfactory results. Highlights: → The preparation of the sorbent, MICRO-AN-8-hydroxyquinoline, is relatively simple. → Excellent properties of the sorbent have been illustrated in detail. → Exhaustive data concerning Mo(VI) adsorption behavior are provided. → Adsorption mechanism is firstly discussed from the view of ion-exchange reaction. → Offer reference for the studies on other metal ions adsorption onto the sorbent.

  20. Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

    Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

    2012-11-01

    Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

  1. Influence of 8-hydroxyquinoline addition on the corrosion behavior of commercial Al and Al-HO411 alloys in NaOH aqueous media

    Highlights: → The corrosion of commercial Al alloy is higher than that of Al-HO411 alloy. → The inhibition efficiency increases with the increasing of 8-hydroxyquinoline (8HQ) concentration. → The inhibition efficiencies of Al-HO411 samples are higher than those of commercial Al. → The 8HQ is promising candidate to be added to the coating systems as active anti-corrosive component for corrosion protection of both alloys. - Abstract: The effect of 8-hydroxyquinoline (8HQ) on the corrosion inhibition of commercial Al and Al-HO411 alloys has been investigated in NaOH solutions. Results showed that the inhibition efficiency was increased with increasing concentration of 8HQ. Al-HO411 alloy exhibited higher corrosion resistance and inhibition efficiency than the commercial Al. Examination of both samples was studied by means of optical microscope as well as energy-dispersive X-ray spectrometer. The crystallographic structure of both samples was analyzed by means of X-ray diffractometry. It was observed that protective films are formed on the surfaces that play an essential role in the corrosion inhibition of the alloys under investigation.

  2. Characterization and determination of the thermodynamic and kinetic properties of the adsorption of molybdenum (VI) onto microcrystalline anthracene modified with 8-hydroxyquinoline

    Wang Xu [College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China); Zhang Yan [College of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003 (China); Li Quanmin, E-mail: mercury6068@hotmail.com [College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China)

    2011-12-01

    A reliable and effective method for the determination of trace molybdenum in effluents is proposed. Molybdenum (VI) is analyzed by Microwave Plasma Torch Optical Emission Spectrometry (MPT-OES) based on the adsorption collection onto microcrystalline anthracene modified with 8-hydroxyquinoline. The possible reaction mechanism was discussed in detail and the optimum conditions for adsorption of Mo (VI) were confirmed. The experimental data were fitted well with the pseudo-second-order kinetic model and Langmuir model at all studied temperatures. The calculated thermodynamic parameters ({Delta}G{sup T}, {Delta}H{sup T} and {Delta}S{sup T}) showed that the adsorption of molybdenum onto microcrystalline anthracene was feasible, spontaneous and endothermic at 280-320 K. The recovery of this method is in the range of 96.5%-103.3% with preconcentration factor of 100 and the limit detection after preconcentration is 0.078 {mu}g L{sup -1}. The proposed method has been successfully applied to the determination of trace Mo (VI) in environmental water samples with satisfactory results. Highlights: {yields} The preparation of the sorbent, MICRO-AN-8-hydroxyquinoline, is relatively simple. {yields} Excellent properties of the sorbent have been illustrated in detail. {yields} Exhaustive data concerning Mo(VI) adsorption behavior are provided. {yields} Adsorption mechanism is firstly discussed from the view of ion-exchange reaction. {yields} Offer reference for the studies on other metal ions adsorption onto the sorbent.

  3. Seven phenoxido-bridged complexes encapsulated by 8-hydroxyquinoline Schiff base derivatives and β-diketone ligands: single-molecule magnet, magnetic refrigeration and luminescence properties.

    Wang, Shi-Yu; Wang, Wen-Min; Zhang, Hong-Xia; Shen, Hai-Yun; Jiang, Li; Cui, Jian-Zhong; Gao, Hong-Ling

    2016-02-28

    Seven dinuclear complexes based on 8-hydroxyquinoline Schiff base derivatives and β-diketone ligands, [RE2(hfac)4L2] (RE = Y (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6) and Lu (7); hfac(-) = hexafluoroacetylacetonate; HL = 2-[(4-chloro-phenylimino)-methyl]-8-hydroxyquinoline), have been synthesized, and structurally and magnetically characterized. Complexes 1-7 have similar dinuclear structures, in which each RE(III) ion is eight coordinated by two L(-) and two hfac(-) ligands in a distorted dodecahedron geometry. The luminescence spectra indicate that complex 3 exhibits characteristic Tb(III) ion luminescence, while 1 and 7 show HL ligand luminescence. The magnetic studies reveal that 2 features a magnetocaloric effect with the magnetic entropy change of -ΔSm = 16.83 J kg(-1) K(-1) at 2 K for ΔH = 8 T, and 4 displays slow magnetic relaxation behavior with the anisotropic barrier of 6.7 K and pre-exponential factor τ0 = 5.3 × 10(-6) s. PMID:26792239

  4. Aqueous Co(II) adsorption using 8-hydroxyquinoline anchored γ-Fe2O3@chitosan with Co(II) as imprinted ions.

    Hossein Beyki, Mostafa; Shemirani, Farzaneh; Shirkhodaie, Mahsa

    2016-06-01

    A novel, bio-based 8-hydroxyquinoline (8-HQ) anchored magnetic chitosan using Co(II) as imprinted ions was prepared and applied for selective removal of Co(II) from aqueous solutions. At first, γ-Fe2O3 has been synthesized by solvent free precipitation route and then combined with 8-hydroxyquinoline anchored chitosan using epichlorohydrin (EPH) as crosslinking agent. The FT- IR spectra showed that 8-HQ has been successfully anchored onto chitosan structure. Moreover, TEM analysis confirmed that the nanocomposite has core-shell structure. The experimental results showed that equilibrium time was 10min moreover, the maximum adsorption capacity of Co(II) with non-imprinted and surface imprinted polymer at pH 8 were 66.6 and 100mgg(-1), respectively. The selectivity coefficient of Co(II) ions relative to Cd(II), Ni(II) and Pb(II) were 11, 42 and 2, respectively. Prepared biosorbent represented good stability and good repeatability after three cycle of sorption and desorption using 0.5molL-(1) of HNO3 as eluent. Kinetic and thermodynamic behavior were also investigated and result showed that cobalt adsorption followed second order model and endothermic path. PMID:26944662

  5. 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

    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

  6. ICP-OES determination of nickel in seawater by SPE based on Ni(II)-5-vinyl-8-hydroxyquinoline ionic imprinted polymer

    Complete text of publication follows. A new ionic imprinted polymer for Ni(II) recognition/preconcentration was prepared via precipitation polymerization using 2-(diethylamino) ethyl methacrylate (DEM) and divinylbenzene as a crosslinking agent in the presence of nickel(II) and 5-vynil-8-hydroxyquinoline. It has been demonstrated that Ni(II)-Ionic Imprinted Polymer synthesized by the precipitation polymerization technique from a ternary pre-polymerization complex formed by the template (Ni), the monomer (DEM) and a non-vinylated chelating agent (8-hydroxyquinoline, 8-HQ) offers imprinting properties for the template (Ni(II)) and also for Cu(II), Pb(II) and Zn(II) with analytical recoveries close to 100% for all elements. Since the complexing agent (8-HQ) is trapped into the polymeric matrix, but is not linked to the polymer chains, specific interactions between the functional groups (present in the monomer and the complexing agent) and other trace elements rather than Ni may occur. To overcome this lack of selectivity a new monomer (5-vynil-8-hydroxyquinoline) was synthesised and submitted to the same polymerization process, in order to fix the 8-HQ to the polymeric matrix, avoiding the 'flexibility' of the imprinting cavities, and so, improving selectivity. Results have shown that the new IIP is more selective than the previous polymer. In addition, the polymer does not interact with alkaline or alkaline-earth metals, so Na, K, Mg and Ca from the seawater salt matrix could be effectively removed. Variables affecting the IIP-solid phase extraction (SPE) process (pH, load and elution flow rate and concentration and volume of the eluting solution) were completely studied. ICP-OES has been used as multi-element detector. Acidified seawater samples must only be treated to fix an alkaline pH (9.00.1) and passed through IIP-SPE cartridges. After seawater sample loading (100 mL), analytes were eluted with 2.5mL of 2.0M nitric acid, offering a pre-concentration factor of

  7. The rapid separation of trace metals from neutron-activated saline matrices by chelation on a poly-5-vinyl-8-hydroxyquinoline column

    Instrumental neutron activation analysis of biological and environmental samples suffers from interferences caused by high salt concentrations. Poly-5-vinyl-8-hydroxyquinoline coated on controlled pore diameter glass beads is suggested as a chelating column for the rapid removal of aluminum, vanadium, copper and manganese from neutron-activated sea water samples. Separation from bulk elements is satisfactory at flow rates of 20 ml min-1. With addition of carriers and with chemical yield determinations, relative standard deviations of 2--10% can be achieved for spike concentrations of 0.1 μg Mn ml-1, 0.3 μg V ml-1, 20 μg V ml-1 and 1.0 μg Cu ml-1

  8. Improved organic light-emitting device with tris-(8-hydroxyquinoline) aluminium inserted between hole-injection layer and hole-transporting layer

    A layer of tris-(8-hydroxyquinoline) aluminium (Alq3), which is normally used as an electron-transporting and emissive layer, was incorporated between the hole-transporting layer and the hole-injection layer to balance the electron-hole injection. The Alq3 layer performed to block the hole current which is a majority carrier in a typical organic light-emitting device. An increase in current efficiency by almost 30%, from 3.1 to 4.0 cd A-1, with a minimum voltage shift was achieved with a 2 nm Alq3 layer as a hole-blocking layer. A reduction in HTL thickness was observed to reduce the efficiency due to electron leakage to the HIL, whereby an inefficient exciplex emission was observed

  9. Improved efficiency in organic light-emitting devices with tris-(8-hydroxyquinoline) aluminium doped 9,10-di(2-naphthyl) anthracene emission layer

    Organic light-emitting devices with tris-(8-hydroxyquinoline) aluminium (Alq3) doped 9,10-di(2-naphthyl) anthracene (ADN) as the emission layer (EML) have been fabricated. These devices exhibit efficient electroluminescence (EL) originated from the Alq3 as the mass ratio of Alq3 to ADN was varied from 1 to 50%. The devices with an optimal Alq3 mass ratio of 10 wt% showed a peak EL efficiency and an external quantum efficiency of 9.1 cd A-1 and 2.7% at a luminance of 1371 cd m-2, which is improved by a factor of 2.2 compared with 4.1 cd A-1 and 1.2% at a luminance of 3267 cd m-2 for conventional devices with the neat Alq3 as the EML.

  10. 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)

    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

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

    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 2.33eV to 1.83eV) 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. PMID:27372510

  12. Synthesis and electroluminescence characterization of a new aluminum complex, [8-hydroxyquinoline] bis [2, 2'bipyridine] aluminum Al(Bpy)2q

    Rahul, Kumar; Ritu, Srivastava; Punita, Singh

    2016-01-01

    We have synthesized and characterized a new electroluminescent material, [8-hydroxyquinoline] bis [2,2'bipyridine] aluminum. A solution of this material Al(Bpy)2q in toluene showed absorption maxima at 380 nm, which was attributed to the moderate energy (π-π*) transitions of the aromatic rings. The photoluminescence spectrum of Al(Bpy)2q in the toluene solution showed a peak at 518 nm. This material shows thermal stability up to 300 °C. The structure of the device is ITO/F4-TCNQ (1 nm)/α-NPD (35 nm)/Al(Bpy)2q (35 nm)/ BCP (6 nm)/Alq3 (28 nm)/LiF (1 nm)/Al (150 nm). This device exhibited a luminescence peak at 515 nm (CIE coordinates, x = 0.32, y = 0.49). The maximum luminescence of the device was 214 cd/m2 at 21 V. The maximum current efficiency of OLED was 0.12 cd/A at 13 V and the maximum power efficiency was 0.03 lm/W at 10 V.

  13. Spin dependent transport and magnetic properties in Fe{sub 4}N/tris(8-hydroxyquinoline) aluminum/Co organic spin valves fabricated by facing-target sputtering

    Li, Zirun [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China); Wang, Xiaocha [Tianjin Key Laboratory of Film Electronic & Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Dai, Haitao [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China); Mi, Wenbo, E-mail: miwenbo@tju.edu.cn [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China); Bai, Haili [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China)

    2015-08-03

    Spin-dependent electronic transport and magnetic properties of Fe{sub 4}N/tris(8-hydroxyquinoline) aluminum (Alq{sub 3})/Co organic spin valves (OSVs) are investigated. Fe{sub 4}N/Alq{sub 3}/Co OSVs with different Alq{sub 3} thicknesses t exhibit an inverse magnetoresistance (MR), which comes from the opposite effective spin polarization at the two ferromagnetic electrode/Alq{sub 3} interfaces. For the antiparallel configurations, MR at 3 K presents the obvious asymmetry, corresponding to the asymmetric hysteresis loop. The asymmetric loops of magnetization and MR can be attributed to the magnetic coupling at the Alq{sub 3}/Co interface. The interfacial diffusion between Co and Alq{sub 3} is weak due to the advantages of facing-target sputtering. Below 120 nm, MR increases with the increased t owing to the decreased effect of the ill-defined layer. The reduced MR at 260 nm is ascribed to the decline of spin polarization. - Highlights: • Fe{sub 4}N/Alq{sub 3}/Co organic spin valves exhibit an inverse magnetoresistance. • Asymmetric magnetoresistance is attributed to interfacial magnetic coupling. • The advantages of facing-target sputtering make interfacial diffusion weak.

  14. Structural, electronic, and magnetic properties of tris(8-hydroxyquinoline)iron(III) molecules and their magnetic coupling with ferromagnetic surface: first-principles study.

    Jiang, W; Zhou, M; Liu, Z; Sun, D; Vardeny, Z V; Liu, F

    2016-05-01

    Using first-principles calculations, we have systematically investigated the structural, electronic, and magnetic properties of facial (fac-) and meridional (mer-) tris(8-hydroxyquinoline)iron(III) (Feq3) molecules and their interaction with ferromagnetic substrate. Our calculation results show that for the isolated Feq3, mer-Feq3 is more stable than the fac-Feq3; both Feq3 isomers have a high spin-state of 5 μ B as the ground state when an on-site Hubbard-U term is included to treat the highly localized Fe 3d electrons; while the standard DFT calculations produce a low spin-state of 1 μ B for mer-Feq3. These magnetic behaviors can be understood by the octahedral ligand field splitting theory. Furthermore, we found that fac-Feq3 has a stronger bonding to the Co surface than mer-Feq3 and an anti-ferromagnetic coupling was discovered between Fe and Co substrate, originating from the superexchange coupling between Fe and Co mediated by the interface oxygen and nitrogen atoms. These findings suggest that Feq3 molecular films may serve as a promising spin-filter material in spintronic devices. PMID:27044670

  15. Two polymeric metal complexes based on polycarbazole containing complexes of 8-hydroxyquinoline with Zn(II) and Ni(II) in the backbone: Synthesis, characterization and photovoltaic applications

    Highlights: ► We have synthesized two photosensitizers of D–π–A polymeric metal complexes. ► The polymeric metal complexes possess excellent thermal stability and good open-circuit voltages. ► The application of the photosensitizers in dye-sensitized solar cells was investigated. ► The polymeric metal complex containing d10 Zn(II) exhibited better device performance than that containing low spin d8 Ni(II). - Abstract: Two novel polymeric metal complexes PZn(Q)2–C and PNi(Q)2–C based on polycarbazole containing complexes of 8-hydroxyquinoline with Zn(II) and Ni(II) were synthesized and applied in dye-sensitized solar cells (DSSCs) as photosensitizers. They possess moderate thermal stability and good open-circuit voltages, and the power conversion efficiency of them reached to 1.11% and 0.45%, respectively, under simulated AM 1.5 G solar irradiation (100 mW cm−2), which shows a new strategy to design photosensitizers for DSSCs.

  16. Improved performances of red organic light-emitting devices by co-doping a rubrene derivative and DCJTB into tris-(8-hydroxyquinoline) aluminum host

    Li Tianle [Physics Department, School of Science, Maoming University, Maoming 525000 (China); Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Li Wenlian, E-mail: wllioel@yahoo.com.c [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Li Xiao [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Chu Bei, E-mail: beichubox@hotmail.co [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Su Zisheng; Han Liangliang; Chen Yiren [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Hu Zhizhi; Zhang Zhiqiang [Optic Photo-Electronic Materials and Research Development Center, Liaoning University of Science and Technology, Anshan 114044 (China)

    2010-10-15

    Performances of red organic light-emitting device were improved by co-doping 2-formyl-5,6,11,12-tetraphenylnaphthacene (2FRb) and 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetra-methyljulolidyl-9-enyl) -4H-pyran (DCJTB) in tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) host as the emitting layer. The device with 1 wt% DCJTB and 2.4 w% 2FRb in Alq{sub 3} host gave a saturated red emission with CIE chromaticity coordinates of (0.65, 0.35) and a maximum current efficiency as high as 6.45 cd/A, which are 2 and 2.4 fold larger than that of the device with 1 wt% DCJTB (3.28 cd/A) in Alq{sub 3} host and the device with 2.4 wt% 2FRb (2.72 cd/A) in Alq{sub 3} host at the current density of 20 mA/cm{sup 2}, respectively. The improvement could be attributed to the effective utilization of host energy by both energy transfer and trapping in the electroluminescence process and the depression of concentration quenching between the dopants molecules.

  17. Simultaneous determination of neodymium and erbium in rare earth mixture with 5,7-dibromo-8-hydroxyquinoline and TX-100 by third-derivative spectrophotometry

    The absorption spectra of 4f electron transitions of the complexes of neodymium and erbium with 5,7-dibromo-8-hydroxyquinoline in the presence of octylphenol poly(ethyleneglycol)ether have been studied by normal and third-derivative spectrophotometry. The proposed method is free of interference of other rare earths. The calibration graphs were linear up to 18 μg/ml of neodymium and 21 μg/ml of erbium (in the final solution). The derivative molar absorptivities are 395 l.mol-1.cm-1 for neodymium and 342 l.mol-1.cm-1 for erbium. The corresponding values of Sandell's sensitivity were 0.36 and 0.49 μg.cm-2, respectively. The relative standard deviations evaluated from ten independent determinations of 2.5 μg/ml of neodymium and erbium are 1.5 and 3.8% for neodymium and 1.8 and 4.1% for erbium in absence and presence of 70 μg of lanthanum, respectively. The detection limits (signal to noise ratio = 2) are 0.23 μg/ml for neodymium and 0.30 μg/ml for erbium. The method has been used for the determination of neodymium and erbium in mixed rare earths with satisfactory results

  18. Two polymeric metal complexes based on polycarbazole containing complexes of 8-hydroxyquinoline with Zn(II) and Ni(II) in the backbone: Synthesis, characterization and photovoltaic applications

    Deng Jinyan; Guo Lihui; Xiu Qian; Zhang Lirong; Wen Gaojun [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, College of Chemistry, Xiangtan, Hunan 411105 (China); Zhong Chaofan, E-mail: zhongcf798@yahoo.com.cn [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Xiangtan University, College of Chemistry, Xiangtan, Hunan 411105 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We have synthesized two photosensitizers of D-{pi}-A polymeric metal complexes. Black-Right-Pointing-Pointer The polymeric metal complexes possess excellent thermal stability and good open-circuit voltages. Black-Right-Pointing-Pointer The application of the photosensitizers in dye-sensitized solar cells was investigated. Black-Right-Pointing-Pointer The polymeric metal complex containing d{sup 10} Zn(II) exhibited better device performance than that containing low spin d{sup 8} Ni(II). - Abstract: Two novel polymeric metal complexes PZn(Q){sub 2}-C and PNi(Q){sub 2}-C based on polycarbazole containing complexes of 8-hydroxyquinoline with Zn(II) and Ni(II) were synthesized and applied in dye-sensitized solar cells (DSSCs) as photosensitizers. They possess moderate thermal stability and good open-circuit voltages, and the power conversion efficiency of them reached to 1.11% and 0.45%, respectively, under simulated AM 1.5 G solar irradiation (100 mW cm{sup -2}), which shows a new strategy to design photosensitizers for DSSCs.

  19. Crystal structure of an oxalate-bridged tetranuclear 8-hydroxyquinoline Zn(II cluster: [Zn4Q6(Ox]0.5n

    YUNCHENG CUI

    2011-04-01

    Full Text Available The chain structure of a tetranuclear zinc(II cluster [Zn4Q6(Ox]0.5n ([Zn4 (C9H6NO 6(C2O4]0.5n (1 (Q = 8-hydroxyquinoline anion, Ox = oxalate dianion was determined by X-ray crystallography and characterized by elemental analysis, IR spectroscopy and thermal analysis. It crystallizes in the monoclinic system, space group P21/n (No. 14, with the lattice parameters a = 13.2222(15 Å, b = 11.0566(12 Å, c = 16.2224(18 Å, β = 92.1770(10°, V = 2369.9(5 Å3, Z = 4, Mr = 607.23 g mol-1, Dc = 1.702 g cm-3. The tetranuclear zinc(II clusters form 1D polymeric chains parallel to the b-axis. The π–π stacking interactions involving aryl rings support the formation of the 1D polymeric structure. The neighboring polymeric chains are connected by C–H···π interactions.

  20. TDDFT study on the excited-state proton transfer of 8-hydroxyquinoline: Key role of the excited-state hydrogen-bond strengthening

    Lan, Sheng-Cheng; Liu, Yu-Hui

    2015-03-01

    Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations have been employed to study the excited-state intramolecular proton transfer (ESIPT) reaction of 8-hydroxyquinoline (8HQ). Infrared spectra of 8HQ in both the ground and the lowest singlet excited states have been calculated, revealing a red-shift of the hydroxyl group (-OH) stretching band in the excited state. Hence, the intramolecular hydrogen bond (O-H···N) in 8HQ would be significantly strengthened upon photo-excitation to the S1 state. As the intramolecular proton-transfer reaction occurs through hydrogen bonding, the ESIPT reaction of 8HQ is effectively facilitated by strengthening of the electronic excited-state hydrogen bond (O-H···N). As a result, the intramolecular proton-transfer reaction would occur on an ultrafast timescale with a negligible barrier in the calculated potential energy curve for the ESIPT reaction. Therefore, although the intramolecular proton-transfer reaction is not favorable in the ground state, the ESIPT process is feasible in the excited state. Finally, we have identified that radiationless deactivation via internal conversion (IC) becomes the main dissipative channel for 8HQ by analyzing the energy gaps between the S1 and S0 states for the enol and keto forms.

  1. Absorption spectra of 4f electron transitions of neodymium and erbium with 8-hydroxyquinoline-5-sulphonic acid and diethylamine systems and its analytical application

    In this paper the absorption spectra of 4f electron transitions of the systems of neodymium and erbium with 8-hydroxyquinoline-5-sulphonic acid and diethylamine have been studied by normal and third-derivative spectrophotometry. Their molar absorptivities are 80 1.mol-1.cm-1 for neodymium and 65 1.mol-1.cm-1 for erbium. Use of the third-derivative spectra, eliminates the interference by other rare earths and increases the sensitivity for Nd and Er. The derivative molar absorptivities are 390 1.mol-1.cm-1 for Nd and 367 1.mol-1.cm-1 for Er. The calibration graphs were linear up to 11.8 μg/ml of Nd and 12.3 μg/ml of Er, respectively. The relative standard deviations evaluated from eleven independent determinations of 7.2 μg/ml (for Nd) and 8.3 μg/ml (for Er) are 1.3% and 1.4%, respectively. The detection limits are 0.2 μg/ml for Nd and 0.3 μg/ml for Er. The method has been developed for determining those two elements in mixture of lanthanides by means of the third-derivative spectra and the analytical results obtained are satisfactory

  2. 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)

    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.

  3. Synthesis, spectroscopic, thermal, voltammetric studies and biological activity of crystalline complexes of pyridine-2,6-dicarboxylic acid and 8-hydroxyquinoline

    Çolak, Alper Tolga; Çolak, Ferdağ; Yeşilel, Okan Zafer; Büyükgüngör, Orhan

    2009-11-01

    Two new compounds (8-H 2Q) 2[M(dipic) 2]·6H 2O (M = Co ( 1) and Ni ( 2), 8-HQ = 8-hydroxyquinoline, dipic = dipicolinate) have been prepared and characterized by elemental analysis, spectral (IR and UV-vis), thermal analyses, magnetic measurements and single-crystal X-ray diffraction techniques. Both 1 and 2 consist two 8-hydroxyquinolinium cations, one bis(dipicolinate)M(II) anion [M = Co(II), Ni(II)] and six uncoordinated water molecules. Both 1 and 2 crystallize in the monoclinic space group C2/c. In the compounds anion, each dipic ligand simultaneously exhibits tridentate coordination modes through N atom of pyridine ring and oxygen atoms of the carboxylate groups. The crystal packing of 1 and 2 is a composite of intermolecular hydrogen bonding and C-O⋯π interactions. The in vitro antibacterial and antifungal activities of 1 and 2 were evaluated by the agar well diffusion method by MIC tests. Both new compounds showed the same antimicrobial activity against Gram-positive bacteria and yeast and fungi expect Gram-negative bacteria.

  4. White light emission from Mn2+ doped ZnS nanocrystals through the surface chelating of 8-hydroxyquinoline-5-sulfonic acid

    White light emitting semiconductor nanocrystals (NCs) have been successfully synthesized from 8-hydroxyquinoline-5-sulfonic acid (HQS) decorated manganese doped ZnS NCs through fine tuning the surface-coordination emission and dopant emission of the NC host. The HQS functionalized manganese doped ZnS NCs (QS-ZnS:Mn), with a cubic crystal structure, have the same diameter of about 4.0 nm as ZnS:Mn NCs without HQS. The intensity of the surface-coordination emission peak increased with increasing HQS content or augmenting excited wavelength. The emission of white light was achieved by carefully controlling the dosage of HQS in NCs and appropriately tuning the excited wavelength. The color coordinates (0.35, 0.34) for the efficient white light emitting NCs were very close to the ideal Commission Internationale de l'Eclairage (CIE) chromaticity coordinates for pure white light (0.33, 0.33). The photoluminescence (PL) decay study revealed that the white light emitting NCs exhibited maximum lifetime values at different emission peaks for different NC samples. The study results also indicated that the HQS molecules were attached to the surface of ZnS:Mn NCs in a single coordination fashion due to the steric hindrance effect of the special spherical surface of NCs, which made the QS-ZnS:Mn NCs possess stable and high fluorescent properties in different organic solvents as compared with the conventional small molecule complexes.

  5. Structural, electronic, and magnetic properties of tris(8-hydroxyquinoline)iron(III) molecules and their magnetic coupling with ferromagnetic surface: first-principles study

    Jiang, W.; Zhou, M.; Liu, Z.; Sun, D.; Vardeny, Z. V.; Liu, F.

    2016-05-01

    Using first-principles calculations, we have systematically investigated the structural, electronic, and magnetic properties of facial (fac-) and meridional (mer-) tris(8-hydroxyquinoline)iron(III) (Feq3) molecules and their interaction with ferromagnetic substrate. Our calculation results show that for the isolated Feq3, mer-Feq3 is more stable than the fac-Feq3; both Feq3 isomers have a high spin-state of 5 μ B as the ground state when an on-site Hubbard-U term is included to treat the highly localized Fe 3d electrons; while the standard DFT calculations produce a low spin-state of 1 μ B for mer-Feq3. These magnetic behaviors can be understood by the octahedral ligand field splitting theory. Furthermore, we found that fac-Feq3 has a stronger bonding to the Co surface than mer-Feq3 and an anti-ferromagnetic coupling was discovered between Fe and Co substrate, originating from the superexchange coupling between Fe and Co mediated by the interface oxygen and nitrogen atoms. These findings suggest that Feq3 molecular films may serve as a promising spin-filter material in spintronic devices.

  6. JLK1486, a Bis 8-Hydroxyquinoline-Substituted Benzylamine, Displays Cytostatic Effects in Experimental Gliomas through MyT1 and STAT1 Activation and, to a Lesser Extent, PPARγ Activation12

    Bruyère, Céline; Madonna, Sébastien; Van Goietsenoven, Gwendoline; Mathieu, Véronique; Dessolin, Jean; Kraus, Jean-Louis; Lefranc, Florence; Kiss, Robert

    2011-01-01

    Gliomas account for 5% to 7% of all solid cancers in adults and up to 30% of solid cancers in children; glioblastomas are the most malignant type of glioma and often have dismal prognoses. The alkylating agent temozolomide provides the greatest chemotherapeutic benefits currently available; however, glioblastoma patients cannot be cured. Novel drugs that efficiently combat glioblastomas are therefore of great interest. We report here that JLK1486, an 8-hydroxyquinoline-substituted benzylamine...

  7. A Potent (R)-alpha-bis-lipoyl Derivative Containing 8-Hydroxyquinoline Scaffold: Synthesis and Biological Evaluation of Its Neuroprotective Capabilities in SH-SY5Y Human Neuroblastoma Cells

    Ivana Cacciatore; Erika Fornasari; Leonardo Baldassarre; Catia Cornacchia; Stefania Fulle; Ester Sara Di Filippo; Tiziana Pietrangelo; Francesco Pinnen

    2013-01-01

    A novel bis-lipoyl derivative containing 8-hydroxyquinoline scaffold (LA-HQ-LA, 5) was synthesized as a new multifunctional drug candidate with antioxidant, chelant, and neuroprotective properties for the treatment of neurodegenerative diseases. We have investigated the potential effectiveness of LA-HQ-LA against the cytotoxicity induced by 6-OHDA and H2O2 on human neuroblastoma SH-SY5Y cell line. Our outcomes showed that LA-HQ-LA resulted in significant neuroprotective and antioxidant effect...

  8. Lithium hydroxide doped tris(8-hydroxyquinoline) aluminum as an effective interfacial layer in inverted bottom-emission organic light-emitting diodes

    Lithium hydroxide doped tris(8-hydroxyquinoline) aluminum (Alq3:LiOH) is used as an effective interfacial layer for the fabrication of efficient inverted bottom-emission organic light-emitting diodes (IBOLEDs). When 15% LiOH was doped into an Alq3 electron-transporting layer, the device properties such as the turn-on voltage, maximum luminance, and device efficiency improved, becoming better than those obtained with LiF doping and comparable to those of β-naphthylphenylbiphenyl diamine (NPB)/Alq3-based OLEDs with conventional geometry. Electrical analysis reveals that LiOH-doped Alq3 layers have an enhanced electron injection and transport ability. X-ray and ultraviolet photoelectron spectroscopy results clearly show that the dipole layer formed at the indium tin oxide (ITO)/organic interface contributed to the reduction of the ITO work function, resulting in a decrease of the electron injection barrier. The enhanced electron injection and transport efficiency improves the charge carrier balance in IBOLEDs and leads to better device efficiency. Furthermore, improved morphology of the organic layer can be obtained by doping LiOH into Alq3, which improves device operational stability under thermal stress. - Highlights: • Inverted bottom-emission organic light-emitting diodes with Alq3:LiOH interfacial layer were investigated. • Alq3:LiOH layers possess an enhanced electron injection and transporting ability. • The dipole layer is formed at the Alq3:LiOH/indium tin oxide interface. • Alq3:LiOH interfacial layer stabilizes the surface morphology of the Alq3 film

  9. Spectroscopic studies of proton-transfer and metal-ion binding of a solution-phase model for silica-immobilized 8-hydroxyquinoline

    The proton-transfer and stepwise metal-ion complex formation reactions of the water-soluble 8HQ ligand, 5-(p-sulfophenylazo)-8-hydroxyquinoline, are investigated in order to understand the interfacial reactivity of the analogous ligand immobilized to silica by a phenylazo linker on the 5-position on the quinoline ring. Raman spectra of the ligand are acquired to determine whether the same tautomerization equilibrium exists for the solution-phase model compound as for the silica-immobilized ligand. UV-Vis absorption spectra of aqueous solutions of the ligand are acquired as a function of pH and metal-ion concentration. The stepwise reactions are monitored, equilibrium constants are determined, and component spectra are resolved using multivariable least-squares (MVLS) methods. These methods were shown to be capable of resolving component spectra made up of broad bands that differ by only a 3 nm band shift. The acid dissociation constants of the ligand were determined to be: pKA1 of 3.78±0.3 and pKA2 of 7.94±0.4. The equilibrium constants for ligand binding to Cu2+ were also measured and found to be K10=1.4 (±0.3)x1010 and K20=2.0 (±0.5)x107. The first ligand binding constant was compared to the complexation of the silica-immobilized 8HQ ligand. The formation constant for the 1:1 ligand:Cu2+ solution complex was ∼30-times greater than that of the silica-immobilized 8HQ ligand. This is likely due to interactions of the immobilized ligand with the nearby silica surface that change its affinity for metal-ion binding

  10. Enzymatic synthesis of {sup 125/131}I labeled 8-hydroxyquinoline glucuronide and in vitro/in vivo evaluation of biological influence

    Yesilagac, Reyhan [Ege University, Institute of Nuclear Science, 35100 Bornova, Izmir (Turkey); Unak, Perihan, E-mail: perihan.unak@ege.edu.t [Ege University, Institute of Nuclear Science, 35100 Bornova, Izmir (Turkey); Medine, E. Ilker; Ichedef, Cigdem A. [Ege University, Institute of Nuclear Science, 35100 Bornova, Izmir (Turkey); Ertay, Turkan [Dokuz Eyluel University, Medical School, Department of Nuclear Medicine, Inciralti, Izmir (Turkey); Mueftueler, F.Z. Biber [Ege University, Institute of Nuclear Science, 35100 Bornova, Izmir (Turkey)

    2011-02-15

    8-Hydroxyquinoline (8-OHQ) is a long-known molecule which due to its metal-complexation ability is frequently used for analysis. It is also called oxine. Oxine and derivatives have been investigated to process antitumor and antimicrobial activities. 8-Hydroxyquinolyl-glucuronide (8-OHQ-Glu) was enzymatically synthesized using microsome preparates separated from Hutu-80 cells, labeled with {sup 125}I to perform a radionuclide labeled prodrug and investigated of its biological affinities on Hutu-80 (human duodenum intestinal adenocarcinoma), Caco-2 (human colorectal adenocarcinoma), Detroit 562 (human pharynx adenocarcinoma) cells and ACBRI 519 (primary human small intestine epithelial cells) in this work. UDP-glucuronyl transferase (UDPGT) rich microsome preparates, which are used for glucuronidation in enzymatic synthesis, were extracted from Hutu-80 cells. 8-OHQ-Glu components were labeled using iodogen method with {sup 125}I and {sup 131}I. Structural analyses were performed with LC/MS/MS, {sup 1}H NMR and {sup 13}C-MMR for identify and measure chemical constituents. Results confirmed expected molecular structure. 8-OHQ-Glu could successfully radioiodinated with {sup 125/131}I according to iodogen method. {sup 125}I-8-OHQ-glucuronide incorporated with human gastrointestinal cancer cells such as Detroit-562 (human pharynx adenocarcinoma) (12.6%), Caco-2 (human colorectal adenocarcinoma) (7.8%), Hutu- 80 (human duodenum intestinal adenocarcinoma) (9.5%) and ACBRI 519 (primary human small intestine epithelial cells) (6.40%). {sup 131}I-8-OHQ-Glu was tested in mice bearing subcutaneously implanted Caco-2 colorectal adenocarcinoma cells. The results demonstrated that radioiodinated 8-OHQ-Glu may be promising anticancer prodrug.

  11. A Simple Spectrophotometric Method for the Trace Determination of Zinc in Some Real, Environmental, Biological, Pharmaceutical, Milk and Soil Samples Using 5,7- Dibromo-8-hydroxyquinoline

    A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of zinc using 5,7-dibromo-8-hydroxyquinoline (DBHQ) has been developed. DBHQ reacts in a slightly acidic solution (0.000001-0.000007 M H/sub 2/SO/sub 4/) with zinc to give a pale-yellow chelate, which has an absorption maximum at 391 nm. The reaction is instantaneous and absorbance remains stable for over 24 hrs. The average molar absorption co-efficient and Sandell's sensitivity were found to be 1.62 x 10/sup 5/ L mol/sup -1/ cm/sup -1/ and 10 ng cm/sup -2/ of Zn, respectively. Linear calibration graphs were obtained for 0.02-4 mg L/sup -1/ of Zn having detection limit of 5 mu g L/sup -1/ and RSD 0 - 2%. The stoichiometric composition of the chelate is 1:2 (Zn : DBHQ). A large excess of over 50 cations, anions and some common complexing agents (such as chloride, azide, tartrate, EDTA, oxalate, SCN-etc) do not interfere in the determination. The method was successfully used in the determination of zinc in several Standard Reference Materials (alloys and steels) as well as in some environmental waters (potable and polluted), biological samples (human blood and urine), soil samples, milk samples, pharmaceutical samples and complex synthetic mixtures.The results of the proposed method for biological samples were comparable with AAS and were found to be in excellent agreement. The method has high precision and accuracy (s = +- 0.01 for 0.5 mg L/sup -1/). (author)

  12. Lithium hydroxide doped tris(8-hydroxyquinoline) aluminum as an effective interfacial layer in inverted bottom-emission organic light-emitting diodes

    Kao, Po-Ching, E-mail: pckao@mail.ncyu.edu.tw; Lu, Chia-Wen; Lin, Jie-Han; Lin, Yeh-Kai

    2014-11-03

    Lithium hydroxide doped tris(8-hydroxyquinoline) aluminum (Alq{sub 3}:LiOH) is used as an effective interfacial layer for the fabrication of efficient inverted bottom-emission organic light-emitting diodes (IBOLEDs). When 15% LiOH was doped into an Alq{sub 3} electron-transporting layer, the device properties such as the turn-on voltage, maximum luminance, and device efficiency improved, becoming better than those obtained with LiF doping and comparable to those of β-naphthylphenylbiphenyl diamine (NPB)/Alq{sub 3}-based OLEDs with conventional geometry. Electrical analysis reveals that LiOH-doped Alq{sub 3} layers have an enhanced electron injection and transport ability. X-ray and ultraviolet photoelectron spectroscopy results clearly show that the dipole layer formed at the indium tin oxide (ITO)/organic interface contributed to the reduction of the ITO work function, resulting in a decrease of the electron injection barrier. The enhanced electron injection and transport efficiency improves the charge carrier balance in IBOLEDs and leads to better device efficiency. Furthermore, improved morphology of the organic layer can be obtained by doping LiOH into Alq{sub 3}, which improves device operational stability under thermal stress. - Highlights: • Inverted bottom-emission organic light-emitting diodes with Alq{sub 3}:LiOH interfacial layer were investigated. • Alq{sub 3}:LiOH layers possess an enhanced electron injection and transporting ability. • The dipole layer is formed at the Alq{sub 3}:LiOH/indium tin oxide interface. • Alq{sub 3}:LiOH interfacial layer stabilizes the surface morphology of the Alq{sub 3} film.

  13. An effective in vitro and in vivo antileishmanial activity and mechanism of action of 8-hydroxyquinoline against Leishmania species causing visceral and tegumentary leishmaniasis.

    Costa Duarte, Mariana; Dos Reis Lage, Letícia Martins; Lage, Daniela Pagliara; Mesquita, Juliana Tonini; Salles, Beatriz Cristina Silveira; Lavorato, Stefânia Neiva; Menezes-Souza, Daniel; Roatt, Bruno Mendes; Alves, Ricardo José; Tavares, Carlos Alberto Pereira; Tempone, André Gustavo; Coelho, Eduardo Antonio Ferraz

    2016-02-15

    The development of new therapeutic strategies to treat leishmaniasis has become a priority. In the present study, the antileishmanial activity of 8-hydroxyquinoline (8-HQN) was investigated against in vitro promastigotes and in vivo intra-macrophage amastigotes of three Leishmania species: Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis. Studies were performed to establish the 50% Leishmania inhibitory concentration (IC50) of 8-HQN, as well as its 50% cytotoxic concentration (CC50) on murine macrophages and in human red blood cells. The inhibition of macrophages infection was also evaluated using parasites that were pre-treated with 8-HQN. The effects of this compound on nitric oxide (NO) production and in the mitochondrial membrane potential were also evaluated. Finally, the therapeutic efficacy of 8-HQN was assessed in a known murine model, L. amazonensis-chronically infected BALB/c mice. Our results showed that 8-HQN was effective against promastigote and amastigote stages of all tested Leishmania species, presenting a selectivity index of 328.0, 62.0 and 47.0 for L. amazonensis, L. infantum and L. braziliensis, respectively. It was effective in treating infected macrophages, as well as in preventing the infection of these cells using pre-treated parasites. In addition, 8-HQN caused an alteration in the mitochondrial membrane potential of the parasites. When administered at 10mg/kg body weight/day by subcutaneous route, this product was effective in reducing the lesion diameter, as well as the parasite load in evaluated tissues and organs of infected animals. The results showed the in vitro and in vivo efficacy of 8-HQN against three different Leishmania species causing tegumentary and/or visceral leishmaniasis, and it could well be used for future therapeutic optimization studies to treat leishmaniasis. PMID:26827866

  14. A Simple Spectrophotometric Method for the Trace Determination of Zinc in Some Real, Environmental, Biological, Pharmaceutical, Milk and Soil Samples Using 5,7- Dibromo-8-hydroxyquinoline

    M. Jamaluddin Ahmed

    2013-06-01

    Full Text Available A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of zinc using 5,7-dibromo-8-hydroxyquinoline (DBHQ has been developed. DBHQ reacts in a slightly acidic solution (0.000001-0.000007 M H2S04 with zinc to give a pale-yellow chelate, which has an absorption maximum at 391 nm. The reaction is instantaneous and absorbance remains stable for over 24 hrs. The average molar absorption co-efficient and Sandell's sensitivity were found to be 1.62 x 105 L mol -1 cm -1 and 10 ng cm-2 of Zn, respectively. Linear calibration graphs were obtained for 0.02-4 mg L-1 of Zn having detection limit of 5 µg L-1 and RSD 0 - 2%. The stoichiometric composition of the chelate is 1:2 (Zn : DBHQ. A large excess of over 50 cations, anions and some common complexing agents (such as chloride, azide, tartrate, EDTA, oxalate, SCN- etc do not interfere in the determination. The method was successfully used in the determination of zinc in several Standard Reference Materials (alloys and steels as well as in some environmental waters (potable and polluted, biological samples (human blood and urine, soil samples, milk samples, pharmaceutical samples and complex synthetic mixtures.The results of the proposed method for biological samples were comparable with AAS and were found to be in excellent agreement.The method has high precision and accuracy (s = ± 0.01 for 0.5 mg L-1.

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

    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. PMID:26466301

  16. Enzymatic synthesis of 125/131I labeled 8-hydroxyquinoline glucuronide and in vitro/in vivo evaluation of biological influence

    8-Hydroxyquinoline (8-OHQ) is a long-known molecule which due to its metal-complexation ability is frequently used for analysis. It is also called oxine. Oxine and derivatives have been investigated to process antitumor and antimicrobial activities. 8-Hydroxyquinolyl-glucuronide (8-OHQ-Glu) was enzymatically synthesized using microsome preparates separated from Hutu-80 cells, labeled with 125I to perform a radionuclide labeled prodrug and investigated of its biological affinities on Hutu-80 (human duodenum intestinal adenocarcinoma), Caco-2 (human colorectal adenocarcinoma), Detroit 562 (human pharynx adenocarcinoma) cells and ACBRI 519 (primary human small intestine epithelial cells) in this work. UDP-glucuronyl transferase (UDPGT) rich microsome preparates, which are used for glucuronidation in enzymatic synthesis, were extracted from Hutu-80 cells. 8-OHQ-Glu components were labeled using iodogen method with 125I and 131I. Structural analyses were performed with LC/MS/MS, 1H NMR and 13C-MMR for identify and measure chemical constituents. Results confirmed expected molecular structure. 8-OHQ-Glu could successfully radioiodinated with 125/131I according to iodogen method. 125I-8-OHQ-glucuronide incorporated with human gastrointestinal cancer cells such as Detroit-562 (human pharynx adenocarcinoma) (12.6%), Caco-2 (human colorectal adenocarcinoma) (7.8%), Hutu- 80 (human duodenum intestinal adenocarcinoma) (9.5%) and ACBRI 519 (primary human small intestine epithelial cells) (6.40%). 131I-8-OHQ-Glu was tested in mice bearing subcutaneously implanted Caco-2 colorectal adenocarcinoma cells. The results demonstrated that radioiodinated 8-OHQ-Glu may be promising anticancer prodrug.

  17. Highly sensitive gold nanoparticles-based optical sensing of DNA hybridization using bis(8-hydroxyquinoline-5-solphonate)cerium(III) chloride as a novel fluorescence probe.

    Shamsipur, Mojtaba; Memari, Zahra; Ganjali, Mohammad Reza; Norouzi, Parviz; Faridbod, Farnoush

    2016-01-25

    A simple and sensitive method for the detection of DNA hybridization in a homogeneous format was developed, using bis(8-hydroxyquinoline-5-solphonate)cerium(III) chloride (Ce(QS)2Cl) as a novel fluorescent probe. The method is based on fluorescence quenching by gold nanoparticles used as both nanoscafolds for the immobilization of the probe DNA sequence, which is related to Alicyclobacillus acidophilus strain TA-67 16S ribosomal RNA, and nanoquenchers of the Ce(QS)2Cl probe. The probe DNA-functionalized GNPs were synthesized by derivatizing the colloidal gold nanoparticles solution with 3-thiolated 16-base oligonucleotides. Addition of sequence-specific target DNAs (16 bases) into the mixture containing probe DNA-functionalized GNPs and fluorescent probe lead to the quenching of Ce(QS)2Cl fluorescence at 360 nm (λex=270 nm), due to DNA hybridization, the resulting quenched intensity being proportional to the concentration of target DNA. Under optimal conditions of pH 7.4 and Ce(QS)2Cl concentration of 1.0 × 10(-7) M, the linear dynamic range found to be 1.0 × 10(-10)-3.0 × 10(-8) M DNA, with a limit of detection of 7.0 × 10(-11) M. The interaction mechanism for the binding of Ce(QS)2Cl to DNA was studied in detail, and results proved that the interaction mode between Ce(QS)2Cl and DNA is groove binding, with a binding constant of 1.0 × 10(5) M(-1). PMID:26600117

  18. Rapid separation and determination of trace metals in neutron activated high saline matrices by precipitation with poly-5-vinyl-8-hydroxyquinoline

    Trace metals are present in sea water and in biological matrices in concentrations from 0.01 ppB to 100 ppM while the ''salt'' (i.e., sodium chloride and bromide) concentration of these matrices varies from 1,000 to 20,000 ppM. Instrumental Neutron Activation Analysis (INAA) is a sensitive technique for the determination of more than seventy elements at the ppB level. However, the presence of high ''salt'' concentrations interferes with the determination of short half-lived species by INAA. Trace amounts of 2.3 min. 28Al, 3.75 min. 52V, 5.75 min. 66Cu and 2.58 hr. 56Mn may not be determined in high ''salt'' matrices by INAA without a rapid separation of the metal of interest from the bulk of the salt matrix. Poly-5-vinyl-8-hydroxyquinoline (PVO) coated on glass beads has been used as a chelation exchange column to effect the desired separation. With this technique, chemical yields must be determined for each sample and standard separation increasing the time necessary for a complete analysis and the uncertainty of the result of the analysis. A separation technique which does not require the determination of chemical yields was developed using PVO as a precipitation reagent. The PVO precipitates are completely formed in less than one minute and may be separated from saline matrices in less than four minutes. The application of the PVO precipitation technique to activated biological and environmental matrices demonstrates the usefulness of this novel separation reagent

  19. 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

    This paper presents a study of quiescent microdialysis sampling of Cr3+, Cu2+, Ni2+ and Pb2+ 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

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

    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

  1. New Application of 2-(4-N-Phenyl-3-thiosemicarbazone)-8-hydroxyquinoline as a Sensor for Relay Recognition of Cu{sup 2+} and Sulfide in Aqueous Solution

    Tang, Lijun; Zhou, Pei; Huang, Zhenlong; Zhao, Jia; Cai, Mingjun [Bohai Univ., Jinzhou (China)

    2013-10-15

    Fluorescent and colorimetric recognition properties of 2-(4-N-phenyl-3-thiosemicarbazone)-8-hydroxyquinoline (1) in buffered aqueous solution (1% DMSO, HEPES 20 mM, pH = 7.4) have been examined. Sensor 1 displays highly selective and sensitive recognition to Cu{sup 2+} with fluorescence 'ON-OFF' performance. The in situ formed 1-Cu{sup 2+} complex exhibits an excellent selectivity toward sulfide ions with fluorescence 'OFF-ON' behavior via Cu{sup 2+} displacement approach. Thus, relay recognition of Cu{sup 2+} and sulfide by a known molecule 1 has been achieved.

  2. Investigation of Al{sub 2}O{sub 3} barrier film properties made by atomic layer deposition onto fluorescent tris-(8-hydroxyquinoline) aluminium molecular films

    Maindron, Tony; Aventurier, Bernard [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Ghazouani, Ahlem; Jullien, Tony [LETI/DTSI/SDEP/Laboratoire Dépôt Equipe 2, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Rochat, Névine [LETI/DTSI/Service de Caractérisation des Matériaux et Composants, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Simon, Jean-Yves; Viasnoff, Emilie [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2013-12-02

    Al{sub 2}O{sub 3} films have been deposited at 85 °C by atomic layer deposition onto single 100 nm thick tris-(8-hydroxyquinoline) aluminium (AlQ{sub 3}) films made onto silicon wafers. It has been found that a thick ALD-deposited Al{sub 2}O{sub 3} layer (> 11 nm) greatly prevents the photo-oxidation of AlQ{sub 3} films when exposed to continuous UV irradiation (350 mW/cm{sup 2}). Thin Al{sub 2}O{sub 3} thicknesses (< 11 nm) on the contrary yield lower barrier performances. Defects in the Al{sub 2}O{sub 3} layer have been easily observed as non-fluorescent AlQ{sub 3} singularities, or black spots, under UV light on the system Si/AlQ{sub 3}/Al{sub 2}O{sub 3} stored into laboratory conditions (22 °C/50% Relative Humidity (RH)) for long time scale (∼ 2000 h). Accelerated aging conditions in a climatic chamber (85 °C/85% RH) also allow faster visualization of the same defects (168 h). The black spot density grows upon time and the black spot density occurrence rates have been calculated to be 0.024 h{sup −1}·cm{sup −2} and 0.243 h{sup −1}·cm{sup −2} respectively for the two testing conditions. A detailed investigation of these defects did show that they cannot be ascribed to the presence of a detectable particle. In that sense they are presumably the consequence of the existence of nanometre-scaled defects which cannot be detected onto fresh samples. Interestingly, an additional overcoating of ebeam-deposited SiO{sub 2} onto the Si/AlQ{sub 3}/Al{sub 2}O{sub 3} sample helps to decrease drastically the black spot density occurrence rates down to 0.004 h{sup −1}·cm{sup −2} and 0.04 h{sup −1}·cm{sup −2} respectively for 22 °C/50% RH and 85 °C/85% RH testing conditions. These observations highlight the moisture sensitivity of low temperature ALD-deposited Al{sub 2}O{sub 3} films and confirm the general idea that a single Al{sub 2}O{sub 3} ALD film performs as an ultra-high barrier but needs to be overprotected from water condensation by an

  3. On-line preconcentration/determination of cadmium in drinking water on activated carbon using 8-hydroxyquinoline in a flow injection system coupled to an inductively coupled plasma optical emission spectrometer

    An on-line cadmium preconcentration and determination system implemented with inductively coupled plasma optical emission spectrometry associated to flow injection was studied. Cadmium was retained as Cd-8-hydroxyquinoline complex at pH 10.0. The cadmium complex was removed from the conical minicolumn packed with activated carbon with 20% (v/v) nitric acid. An enrichment factor of 80-fold for a sample volume of 50 ml was obtained. The detection limit (DL) value for the preconcentration of 50 ml of sample was 18 ng l-1. The relative standard deviation was 2.5%, calculated from the peak heights obtained. The calibration graph using the preconcentration system for cadmium was linear with a correlation coefficient of 0.9995 at levels near the DLs up to at least 100 ng ml-1. The method was successfully applied to the determination of total cadmium in drinking water samples

  4. Proton ligand stability constants of 7-iodo-8-hydroxyquinoline-5-sulphonic acid and metal-ligand stability constants of its complexes with lanthanides(III) in various mixed aqueous solvents

    Proton-ligand formation constants of 7-iodo-8-hydroxyquinoline-5-sulphonic acid(L) have been measured in aqueous and mixed aqueous solvents. The trend in Psub(K)sup(H) values is interpreted in terms of the dielectric constants of the media and proton-solvent interactions. Stabilities of the binary complexes of the ligand with La, Pr, Nd, Sm, Gd, Tb, Dy have been measured in these media. Trend in stabilities with increase in 1/ε of the media is discussed. Step-wise stability constants for ternary complexes M-L-EDTA/NTA have also been measured. ΔH and ΔS values are interpreted in terms of charge neutralisation, steric effects, ion desolvation, etc. The ΔG and ΔH terms are further separated into electrostatic and cratic components. Results indicate that at the ternary step the bonding is more covalent. (author). 16 refs., 4 tables

  5. A Potent (R-alpha-bis-lipoyl Derivative Containing 8-Hydroxyquinoline Scaffold: Synthesis and Biological Evaluation of Its Neuroprotective Capabilities in SH-SY5Y Human Neuroblastoma Cells

    Ivana Cacciatore

    2013-01-01

    Full Text Available A novel bis-lipoyl derivative containing 8-hydroxyquinoline scaffold (LA-HQ-LA, 5 was synthesized as a new multifunctional drug candidate with antioxidant, chelant, and neuroprotective properties for the treatment of neurodegenerative diseases. We have investigated the potential effectiveness of LA-HQ-LA against the cytotoxicity induced by 6-OHDA and H2O2 on human neuroblastoma SH-SY5Y cell line. Our outcomes showed that LA-HQ-LA resulted in significant neuroprotective and antioxidant effects against H2O2- and 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cells, as assessed by MTT assay. In particular, it showed potent neuroprotective effects against 6-OHDA in RA/PMA differentiated cells at all the tested concentrations.

  6. Analytical performance of a lab-made concomitant metal analyzer to generate volatile species of Ag, Au, Cd, Cu, Ni, Sn and Zn using 8-hydroxyquinoline as a reaction media.

    Villanueva-Alonso, Julia; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

    2012-10-15

    This study evaluated the main parameters affecting Ag, Au, Cd, Cu, Ni, Sn and Zn vapor generation using a lab-made concomitant metal analyzer (CMA) as a reaction chamber and gas-liquid separator. The modifier used in the reaction media was 8-hydroxyquinoline, and Inductively-Coupled Plasma Optical Emission Spectrometry was used as detection technique. The performance of the lab-made concomitant analyzer was compared with the performance of a continuous flow gas-liquid separator and of a cyclonic spray chamber. Standards were prepared in acid media and included 1 mg L(-1) of Co as a catalyzer. The optimum concentrations of the reagents in the standards were: 450 mg L(-1) of 8-hydroxyquinoline and 0.4 M nitric acid. The optimum concentration of sodium borohydride to generate the vapors was 2.25% (w/v) (prepared in 0.4% (w/v) NaOH). The volatile species were swept from the CMA to the torch by an argon flow of 0.6 mL min(-1). The use of the CMA led to an improvement of the detection limits for some elements compared to conventional nebulization: 1.1 μg L(-1) for Ag, 7.0 μg L(-1) for Au and 4.3 μg L(-1) for Sn. The limit of detection for Cu was 1.4 μg L(-1) and for Ni 22.5 μg L(-1). The direct mixing of the reagents on the spray chamber was not effective for Cd and Zn; a deviation of the linearity was observed for these elements. PMID:23141310

  7. 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

    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.

  8. Effect of a thin layer of tris (8-hydroxyquinoline) aluminum doped with 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) on the chromaticity of white organic light-emitting devices

    Efficient white organic light-emitting devices (OLEDs) are demonstrated by inserting a thin layer of tris (8-hydroxyquinoline) aluminum (Alq) doped with 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) (DCJTB) into N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB) layer. Alq without doping is used as an electron-transporting layer and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine or BCP) as an exciton-blocking layer. NPB layers are separated by the doped Alq layer, the layer that sandwiched between BCP and doped Alq layers acts as a blue-emitting layer, and the other as a hole-transporting layer. The doped Alq layer acts as a red and green-emitting as well as chromaticity-tuning layer, whose thickness and position as well as the concentration of DCJTB in Alq permit the tuning of the device spectrum to achieve a balanced white emission with Commission Internationale De L'Eclairage (CIE) coordinates of (0.33, 0.33). The device has a maximum luminance of 6745 cd/m2, a maximum external efficiency of 1.36 %, corresponding to 2.56 cd/A

  9. 8-Hydroxyquinoline inhibits iNOS expression and nitric oxide production by down-regulating LPS-induced activity of NF-κB and C/EBPβ in Raw 264.7 cells

    In activated macrophage, large amounts of nitric oxide (NO) are generated by inducible nitric oxide synthase (iNOS), resulting in acute or chronic inflammatory disorders. In Raw 264.7 cells stimulated with lipopolysaccharide (LPS) to mimic inflammation, 8-hydroxyquinoline (8HQ) inhibited the LPS-induced expression of both iNOS protein and mRNA in a parallel dose-dependent manner. 8HQ did not enhance the degradation of iNOS mRNA. To investigate the mechanism by which 8HQ inhibits iNOS gene expression, we examined the activation of MAP kinases in Raw 264.7 cells. We did not observe any significant change in the phosphorylation of MAPKs between LPS alone and LPS plus 8HQ-treated cells. Moreover, 8HQ significantly inhibited the DNA-binding activity of nuclear factor-κB (NF-κB) and CCAAT/enhancer-binding protein β (C/EBPβ), but not activator protein-1 and cAMP response element-binding protein. Taken together, these results suggest that 8HQ acts to inhibit inflammation through inhibition of NO production and iNOS expression through blockade of C/EBPβ DNA-binding activity and NF-κB activation

  10. CoFe2O4 nano-particles functionalized with 8-hydroxyquinoline for dispersive solid-phase micro-extraction and direct fluorometric monitoring of aluminum in human serum and water samples.

    Abdolmohammad-Zadeh, Hossein; Rahimpour, Elaheh

    2015-06-30

    A simple dispersive solid-phase micro-extraction method based on CoFe2O4 nano-particles (NPs) functionalized with 8-hydroxyquinoline (8-HQ) with the aid of sodium dodecyl sulfate (SDS) was developed for separation of Al(III) ions from aqueous solutions. Al(III) ions are separated at pH 7 via complex formation with 8-HQ using the functionalized CoFe2O4 nano-particles sol solution as a dispersed solid-phase extractor. The separated analyte is directly quantified by a spectrofluorometric method at 370nm excitation and 506nm emission wavelengths. A comparison of the fluorescence of Al(III)-8-HQ complex in bulk solution and that of Al(III) ion interacted with 8-HQ/SDS/CoFe2O4 NPs revealed a nearly 5-fold improvement in intensity. The experimental factors influencing the separation and in situ monitoring of the analyte were optimized. Under these conditions, the calibration graph was linear in the range of 0.1-300ngmL(-1) with a correlation coefficient of 0.9986. The limit of detection and limit of quantification were 0.03ngmL(-1) and 0.10ngmL(-1), respectively. The inter-day and intra-day relative standard deviations for six replicate determinations of 150ngmL(-1) Al(III) ion were 2.8% and 1.7%, respectively. The method was successfully applied to direct determine Al(III) ion in various human serum and water samples. PMID:26041520

  11. M(II) transfer across a liquid-liquid microinterface facilitated by a complex formation with 8-Hydroxyquinoline: Application to quantification of Pb(II), Cd(II) and Zn(II) alone or in mixture in effluents

    Highlights: • Study of assisted transfer of lead ions by 8-HQ at water/1,2-DCE for the first time. • Formation of a monocharged specie in good agreement with the solution chemistry. • Possible quantification by cyclic and square wave voltammetry measurements. • Quantification of Pb(II) ions until 0.2 ppm lower than the limit fixed in industrial effluents. • Highlighting of the interesting overall quantification of heavy metals: Lead, Cadmium and Zinc. - Abstract: For the first time, the assisted transfer of Pb(II) across a water/1,2-Dichloroethane (DCE) microinterface was investigated in the presence of 8-Hydroxyquinoline (named also oxine or 8-HQ) in the organic phase. A monocharged complex was formed in the aqueous phase and then transferred in the organic phase. A good relationship was obtained between currents and Pb(II) concentrations in the 10−4 to 5 10−3 M range and 10−5 to 6 10−5 M range using cyclic voltammetry and square wave voltammetry respectively. In presence of other heavy metals such as Cd(II) and Zn(II), only one electrochemical process is observed regardless of the mixture. Moreover, stationary currents increase in direct linear relation with the sum of M(II) concentrations added in water, allowing an overall detection of heavy metals. This result indicates that this method can be very interesting for monitoring all toxic metals in effluents. The limit of detection was found equal to 0.2 ppm for lead. This value allows us to reach levels significant for industrial effluents, in comparison to the limits fixed by the French ministry of ecology for lead, cadmium and zinc to 0.5 ppm, 0.2 ppm and 2.0 ppm respectively. This study highlights the real interest of devices based on a liquid-liquid microinterface

  12. 8-羟基喹啉锌/碳微球复合材料的合成表征及发光性能%Synthesis and characterization and luminescence property of bis(8-hydroxyquinoline)zinc/carbon microspheres composite

    杨永珍; 韩艳星; 刘伟峰; 刘红艳; 刘旭光; 许并社

    2011-01-01

    The composites of bis(8-hydroxyquinoline) zinc (Znq2) and carbon microspheres (CMSs) were synthesized by rheological phase reaction. Their structure and photoluminescence property were characterized by the field emission scanning electron microscopy, X-ray diffraction, thermogravimetry, X-ray photoelectron spectroscopy, Fourier transformation infrared absorption spectrometry and fluorospectrophotometer. The results show that Znq2 is loaded on the surfaces of uniform CMSs with 300~400 nm in diameters in the form of non-covalent bond and the peak wavelength of the composite is 540 nm in photoluminescence spectra. It is expected to apply in the field of organic electroluminescence for Znq2/CMSs composite.%利用流变相反应法制备了碳微球(CMSs)负载8-羟基喹啉锌(Znq2)的复合材料.通过场发射扫描电子显微镜、X射线衍射仪、热重分析仪、X射线光电子能谱仪、傅里叶红外光谱仪和荧光分光光度计等对Znq2/CMSs复合材料结构和发光性能进行了表征和分析.结果表明:Znq2以非共价键形式负载于直径均匀的CMSs(300~400 nm)表面,形成了一种Znq2/CMSs复合材料,该复合材料在黄光(540 nm)区发光,有望应用于有机电致发光领域.

  13. Oxocomplexes of Mo(VI) and W(VI) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of the metal ion on the photophysical behaviour.

    Ramos, M Luísa; Justino, Licínia L G; Abreu, Paulo E; Fonseca, Sofia M; Burrows, Hugh D

    2015-11-28

    Multinuclear ((1)H, (13)C, (95)Mo and (183)W) NMR spectroscopy, combined with DFT calculations, provides detailed information on the complexation between the Mo(VI) and W(VI) oxoions and 8-hydroxyquinoline-5-sulfonate (8-HQS) in aqueous solution. Over the concentration region studied, Mo(VI) and W(VI) oxoions form three homologous complexes with 8-HQS in water in the pH range 2-8. Two of these, detected at pH complex, dominant at slightly higher pH values (5-8) for solutions with a 1 : 1 metal : ligand molar ratio, has a binuclear M2O5(2+) centre coordinated to two 8-HQS ligands. The two metal atoms are bridged by three oxygen atoms, two coming from 8-HQS, together with the M-O-M bridge of the bimetallic centre. We show that the long-range exchange corrected BOP functional with local response dispersion (LCBOPLRD), together with explicit solvent molecules, leads to geometries that readily converge to equilibrium structures having realistic bridging O8-HQS-M bonds. Previous attempts to calculate the structures of such binuclear complexes using DFT with the B3LYP functional have failed due to difficulties in treating the weak interaction in these bridged structures. We believe that the LCBOPLRD method may be of more general application in theoretical studies in related binuclear metal complexes. UV/visible absorption and luminescence spectra of all the complexes have also been recorded. The complex between Mo(vi) and 8-HQS is only weakly luminescent, in contrast to what has been observed with this ligand and many other metal ions. We suggest that this is due to the presence of low-lying ligand-to-metal charge transfer (LMCT) states close to the emitting ligand-based level which quench the emission. However, with W(VI), DFT calculations show that the LMCT states are now much higher in energy than the ligand based levels, leading to a marked increase in fluorescence. PMID:26498366

  14. Crystal structure of 8-hydroxyquinoline: a new monoclinic polymorph

    Raúl Castañeda

    2014-09-01

    Full Text Available In an attempt to grow 8-hydroxyquinoline–acetaminophen co-crystals from equimolar amounts of conformers in a chloroform–ethanol solvent mixture at room temperature, the title compound, C9H7NO, was obtained. The molecule is planar, with the hydroxy H atom forming an intramolecular O—H...N hydrogen bond. In the crystal, molecules form centrosymmetric dimers via two O—H...N hydrogen bonds. Thus, the hydroxy H atoms are involved in bifurcated O—H...N hydrogen bonds, leading to the formation of a central planar four-membered N2H2 ring. The dimers are bound by intermolecular π–π stacking [the shortest C...C distance is 3.2997 (17 Å] and C—H...π interactions into a three-dimensional framework. The crystal grown represents a new monoclinic polymorph in the space group P21/n. The molecular structure of the present monoclinic polymorph is very similar to that of the orthorhombic polymorph (space group Fdd2 studied previously [Roychowdhury et al. (1978. Acta Cryst. B34, 1047–1048; Banerjee & Saha (1986. Acta Cryst. C42, 1408–1411]. The structures of the two polymorphs are distinguished by the different geometries of the hydrogen-bonded dimers, which in the crystal of the orthorhombic polymorph possess twofold axis symmetry, with the central N2H2 ring adopting a butterfly conformation.

  15. 5,6,7-Trichloro-2-methoxy-8-hydroxyquinoline

    Qiu-Mao Chen

    2011-05-01

    Full Text Available In the title compound, C10H6Cl3NO2, a mean plane fitted through all non-H atoms has an r.m.s. deviation of 0.035 Å. In the crystal, adjacent molecules are connected by O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.650 (1 Å], resulting in an infinite chain which propagates in the b-axis direction.

  16. Far-infrared spectra of lanthanide complexes with 8-hydroxyquinoline

    Vibrational spectra of lanthanide oxines have been measured in the far-infrared region. In addition, the similar yttrium complex was investigated for further experimental evidence for the proposed band assignments. The most important metal-oxygen and metal-nitrogen bond vibrations have been attributed to absorptions between 390-350cm-1 and 210-170cm-1, respectively. (Author)

  17. Preparation and Herbicidal Activity of Halogenated 8-Hydroxyquinoline-2-carboxanilides

    Kos, J.; Machalová, P.; Pesko, M.; Goněc, T.; Bobál, P.; Oravec, Michal; Liptaj, T.; Králová, K.; Jampílek, J.

    Basilej: MDPI, 2013 - (Seijas, J.; Vázquez, T.; Lin, S.), "B013" [International Electronic Conference on Synthetic Organic Chemistry /17./. Basel (CH), 1.11.2013-30.11.2013] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : Hydroxyquinoline-2-carboxamides * PET inhibition * spinach chloroplasts * structure-activity relationships Subject RIV: EH - Ecology, Behaviour http://www.sciforum.net/conference/ecsoc-17/paper/2261

  18. 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

    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.

  19. Metal-ion chelation chromatography on silica-immobilized 8-hydroxyquinoline

    A chromatographically useful packing is prepared by immobilizing 8-hydoxyquinoline on Porasil. This material, whose capacity is about 50 μequiv/g, behaves with an efficiency of about 0.2 to 0.5 mm/theoretical plate but is capable of separating such similar metal ions as Co-Ni, Cd-Pb-Zn, and La-Gd-Yb at trace levels employing both isocratic and continuous gradient elution. On a fundamental level, the relationship between solution chelate stability and chromatographic behavior is described. 9 figures, 2 tables

  20. Synthesis, analysis and radiolysis of the cobalt III 8 hydroxyquinolinate complex

    The cobalt III 8-hidroxyquinolinate complex was syntetized from a solution of cobalt II. The compound was analysed by IR absorption spectroscopy, elemental analysis and by the determination of number of ligands. The radiolytic degradation was verified by spectrophotometry after submitting samples of 10-3 M complex in ethanolic solution to different doses of gamma radiation from a 60Co source. The change of maximum absorbance of the complex with different doses of gamma radiation and its UV-VIS absorption spectra are presented. The complex in the solid state was also irradiated with 6,9 Mrad of gamma radiation but it didn't present degradation. (Author)

  1. A new chelating sorbent with 8-hydroxyquinoline groups and its chromatographic application

    Hrubý, Martin; Beneš, Milan J.

    Katowice : Polskie Towarzystwo Chemiczne, 2001. s. S11-K4. ISBN 83-90-1844-5-1. [Zjazd Naukowy Polskiego Towarzystwa Chemicznego i Stowarzyszenia Inzynierow i Technikow Przemyslu Chemicznego /44./. 09.09.2001-13.09.2001, Katowice] R&D Projects: GA ČR GA203/01/1310 Subject RIV: CD - Macromolecular Chemistry

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

    Pingaew R; Nantasenamat C; Prachayasittikul S; Ruchirawat S; Prachayasittikul V

    2014-01-01

    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; 4Laborato...

  3. Characterization of a new 8-hydroxyquinoline modified resin gel for DGT technique

    Gregušová, Michaela; Dočekal, Bohumil; Dočekalová, H.

    Santa Margherita di Pula, 2009. s. 12. [Conference on DGT and the Environment. 07.10.2009-09.10.2009, Santa Margherita di Pula] Institutional research plan: CEZ:AV0Z40310501 Keywords : DGT technique * speciation analysis * Spheron-Oxin Subject RIV: CB - Analytical Chemistry, Separation

  4. Investigation on growth, structure and characterization of succinate salt of 8-hydroxyquinoline: An organic NLO crystal

    Thirumurugan, R.; Babu, B.; Anitha, K.; Chandrasekaran, J.

    2015-04-01

    8-Hydroxyquinolinium succinate (8-HQSU) has been synthesized and single crystals were grown from ethanol solvent by employing the technique of slow evaporation at room temperature. The structure of the grown crystal has been elucidated by single crystal X-ray diffraction analysis. It reveals that 8-HQSU crystallizes in monoclinic system with non-centro symmetric space group P21. FTIR, 1H and 13C NMR spectral investigations have been carried out to identify the vibrational modes of various functional groups and placement of proton and carbon in the 8-HQSU compound, respectively. UV-vis-NIR transmission spectrum shows the cutoff wavelength around 357 nm. In addition, a photoluminescence spectral analysis was carried out for 8-HQSU crystals. The thermal properties of crystals were evaluated from TGA and DTA techniques and the crystal was found to be stable up to 145 °C. The dielectric studies show that the dielectric constant and dielectric loss decrease exponentially with frequency at different temperatures. Photoconductivity studies were carried out on the grown crystals it reveals the positive photo conducting nature. Powder second harmonic generation property of the crystal was confirmed by Kurtz and Perry powder SHG technique and it is found to be 1.3 times greater than that of KDP.

  5. Characterization of a new 8-hydroxyquinoline modifed resin gel for DGT technique

    Gregušová, Michaela; Dočekal, Bohumil

    Brno : FCH VUT v Brně, 2009 - (Omelka, L.; Weiter, M.; Dzik, P.), s. 177-181 ISBN 978-80-214-4008-1. [Studentská odborná konference Chemie a společnost 2009. Brno (CZ), 03.12.2009] Institutional research plan: CEZ:AV0Z40310501 Keywords : DGT technique * 8-hydroxychinoline * uranium Subject RIV: CB - Analytical Chemistry, Separation

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

    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.

  7. Investigations into the bovine serum albumin binding and fluorescence properties of Tb (III) complex of a novel 8-hydroxyquinoline ligand

    Zhao, Mingming; Tang, Ruiren; Xu, Shuai

    2015-01-01

    A novel ligand, 2-methyl-6-(8-quinolinyl)-dicarboxylate pyridine (L), and its corresponding Tb (III) complex, Na4Tb(L)2Cl4·3H2O, were successfully prepared and characterized. The luminescence spectra showed that the ligand L was an efficient sensitizer for Tb (III) luminescence. The interaction of the complex with bovine serum albumin (BSA) was investigated through fluorescence spectroscopy under physiological conditions. The Stern-Volmer analysis indicated that the fluorescence quenching was resulted from static mechanism. The binding sites (n) approximated 1.0 and this meant that interaction of Na4Tb(L)2Cl4·3H2O with BSA had single binding site. The results showed van der Waals interactions and hydrogen bonds played major roles in the binding reaction. Furthermore, circular dichroism (CD) spectra indicated that the conformation of BSA was changed.

  8. Chlorido(8-hydroxyquinoline-κ2N,O(quinolin-8-olato-κ2N,Ozinc methanol monosolvate

    Ezzatollah Najafi

    2011-09-01

    Full Text Available In the title compound, [Zn(C9H6NOCl(C9H7NO]·CH3OH, the ZnII ion is N,O-chelated by both a neutral and a deprotonated quinolin-8-ol ligand, with a chloride ligand in the apical site completing the square-pyramidal coordination geometry. The ZnII ion is displaced by 0.586 Å in the direction of the chloride ligand from the atoms forming the square plane. In the crystal, the components are linked by intermolecular O—H...O hydrogen bonds, generating chains along the b axis.

  9. Optical and morphological modifications in post-thermally treated tris(8-hydroxyquinoline) gallium films deposited on quartz substrates

    Muhammad, Fahmi Fariq, E-mail: fahmi982@gmail.com; Sulaiman, Khaulah

    2014-11-14

    This work reports the optical and morphological modifications in vacuum deposited Gaq3 films upon thermal annealing. The annealing process has been carried out under flowing nitrogen gas for 10 min. It was noticed from the results that at 235 °C a broad absorption spectrum and increased photoluminescence to five times stronger than that of pristine film was achieved. Scanning electron microscopy and X-ray diffraction techniques ascertained morphological changes towards the formation of amorphous nanorods. The improvement in optical properties of Gaq3 films was found to be resulted from this morphological modification. The nanostructure formation was seen to be a viable method to enhance the morpho-optical properties of Gaq3 films, making Gaq3 a promising candidate for the application in organic electronics technology. - Highlights: • Post-thermal treatment under N{sub 2} gas produced amorphous nanorod in Gaq3 film. • The optical response of Gaq3 film was tuned through morphological modification. • Luminescence was increased to five times stronger than that of pristine Gaq3.

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

    Marisa S. Crespi; Clóvis A. Ribeiro; Valentina C. M. Greenhalf; Henrique E. Zorel Jr.

    1999-01-01

    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 cel...

  11. 8-Hydroxyquinoline-based inhibitors of the Rce1 protease disrupt Ras membrane localization in human cells.

    Mohammed, Idrees; Hampton, Shahienaz E; Ashall, Louise; Hildebrandt, Emily R; Kutlik, Robert A; Manandhar, Surya P; Floyd, Brandon J; Smith, Haley E; Dozier, Jonathan K; Distefano, Mark D; Schmidt, Walter K; Dore, Timothy M

    2016-01-15

    Ras converting enzyme 1 (Rce1) is an endoprotease that catalyzes processing of the C-terminus of Ras protein by removing -aaX from the CaaX motif. The activity of Rce1 is crucial for proper localization of Ras to the plasma membrane where it functions. Ras is responsible for transmitting signals related to cell proliferation, cell cycle progression, and apoptosis. The disregulation of these pathways due to constitutively active oncogenic Ras can ultimately lead to cancer. Ras, its effectors and regulators, and the enzymes that are involved in its maturation process are all targets for anti-cancer therapeutics. Key enzymes required for Ras maturation and localization are the farnesyltransferase (FTase), Rce1, and isoprenylcysteine carboxyl methyltransferase (ICMT). Among these proteins, the physiological role of Rce1 in regulating Ras and other CaaX proteins has not been fully explored. Small-molecule inhibitors of Rce1 could be useful as chemical biology tools to understand further the downstream impact of Rce1 on Ras function and serve as potential leads for cancer therapeutics. Structure-activity relationship (SAR) analysis of a previously reported Rce1 inhibitor, NSC1011, has been performed to generate a new library of Rce1 inhibitors. The new inhibitors caused a reduction in Rce1 in vitro activity, exhibited low cell toxicity, and induced mislocalization of EGFP-Ras from the plasma membrane in human colon carcinoma cells giving rise to a phenotype similar to that observed with siRNA knockdowns of Rce1 expression. Several of the new inhibitors were more effective at mislocalizing K-Ras compared to a potent farnesyltransferase inhibitor (FTI), which is significant because of the preponderance of K-Ras mutations in cancer. PMID:26706114

  12. Effect of thermal annealing on the structural and optical properties of tris-(8-hydroxyquinoline)aluminum(III) (Alq3 ) films.

    Cuba, M; Muralidharan, G

    2015-05-01

    Tris-(8-hydroxyquionoline)aluminum (Alq3 ) was synthesized and coated on to a glass substrate using the dip coating method. The structural and optical properties of the Alq3 film after thermal annealing from 50°C to 300°C in 50° steps was studied. The films have been prepared with 2 to 16 layers (42-324 nm). The thickness and thermal annealing of Alq3 films were optimized for maximum luminescence yield. The Fourier transform infrared spectrum confirms the formation of quinoline with absorption in the region 700 - 500/cm. Partial sublimation and decomposition of quinoline ion was observed with the Alq3 films annealed at 300°C. The X-ray diffraction pattern of the Alq3 film annealed at 50°C to 150°C reveals the amorphous nature of the films. The Alq3 film annealed above 150°C were crystalline nature. Film annealed at 150°C exhibits a photoluminescence intensity maximum at 512 nm when excited at 390 nm. The Alq3 thin film deposited with 10 layers (220 nm) at 150°C exhibited maximum luminescence yield. PMID:25044340

  13. Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance

    Zhang, Sijie; Gillin, W. P., E-mail: w.gillin@qmul.ac.uk [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Willis, M. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Gotto, R.; Roy, K. A.; Kreouzis, T. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Rolfe, N. J. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); University of Surrey, Guildford, Surrey GU2 5XH (United Kingdom)

    2014-01-27

    The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminium tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.

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

    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...

  15. The effect of sucrose and 8-hydroxyquinoline sulphate (8-HQS on keeping qualities of bud-cut Chrysanthemum flowers and the level of reducing sugars in the florets

    Aleksandra Łukaszewska

    2013-12-01

    Full Text Available Chrysanthemums harvested as buds of 50-60 mm in diameter and held in the solutions of sucrose and 8-HQS had inflorescences of quality equal to those opened on the plant and better than flowers placed in water. Exogenous sucrose prolonged vase-life of cv. 'Bronze Bornholm' but did not affect cv. 'Crimson Robe'. No difference was observed in the quality of flowers placed in different sucrose concentrations. All the solutions which improved keeping qualities of cut chrysanthemums caused considerable increase in the flower fresh and dry matter. Also an increase in reducing sugars was found in flowers of both cultivars he1d in the solutions of sucrose and 8-HQS.

  16. Stability of 8-hydroxyquinoline aluminum films encapsulated by a single Al{sub 2}O{sub 3} barrier deposited by low temperature atomic layer deposition

    Maindron, Tony, E-mail: tony.maindron@cea.fr [CEA-LETI, MINATEC Campus, LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Simon, Jean-Yves; Viasnoff, Emilie [CEA-LETI, MINATEC Campus, LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Lafond, Dominique [CEA-LETI, MINATEC Campus, LETI/DTSI/SCMC/, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2012-09-30

    100 nm thick 8-AlQ{sub 3} films deposited onto silicon wafers have been encapsulated by mean of low temperature atomic layer deposition of Al{sub 2}O{sub 3} (20 nm). Investigation of the film evolution under storage test as harsh as 65 Degree-Sign C/85% RH has been investigated up to {approx} 1000 h and no severe degradation could be noticed. The results have been compared to raw AlQ{sub 3} films which deteriorate far faster in the same conditions. For that purpose, fluorescence measurements and atomic force microscopy have been used to monitor the film evolution while transmission electron microscopy has been used to image the interface between AlQ{sub 3} and Al{sub 2}O{sub 3}. This concept of bilayer AlQ{sub 3}/Al{sub 2}O{sub 3} barrier films has finally been tested as an encapsulation barrier onto an organic light-emitting diode. - Highlights: Black-Right-Pointing-Pointer Thin Al{sub 2}O{sub 3} films have been deposited by atomic layer deposition onto organic films. Black-Right-Pointing-Pointer AlQ{sub 3}/Al{sub 2}O{sub 3}-encapsulated organic light-emitting diodes show long-term stability. Black-Right-Pointing-Pointer Unencapsulated reference AlQ{sub 3} films degrade much faster.

  17. The novel mitochondrial iron chelator 5-((methylamino)methyl)-8-hydroxyquinoline protects against mitochondrial-induced oxidative damage and neuronal death.

    Mena, Natalia P; García-Beltrán, Olimpo; Lourido, Fernanda; Urrutia, Pamela J; Mena, Raúl; Castro-Castillo, Vicente; Cassels, Bruce K; Núñez, Marco T

    2015-08-01

    Abundant evidence indicates that iron accumulation, oxidative damage and mitochondrial dysfunction are common features of Huntington's disease, Parkinson's disease, Friedreich's ataxia and a group of disorders known as Neurodegeneration with Brain Iron Accumulation. In this study, we evaluated the effectiveness of two novel 8-OH-quinoline-based iron chelators, Q1 and Q4, to decrease mitochondrial iron accumulation and oxidative damage in cellular and animal models of PD. We found that at sub-micromolar concentrations, Q1 selectively decreased the mitochondrial iron pool and was extremely effective in protecting against rotenone-induced oxidative damage and death. Q4, in turn, preferentially chelated the cytoplasmic iron pool and presented a decreased capacity to protect against rotenone-induced oxidative damage and death. Oral administration of Q1 to mice protected substantia nigra pars compacta neurons against oxidative damage and MPTP-induced death. Taken together, our results support the concept that oral administration of Q1 is a promising therapeutic strategy for the treatment of NBIA. PMID:26051278

  18. Studies on antitumor mechanism of two planar platinum(II) complexes with 8-hydroxyquinoline: synthesis, characterization, cytotoxicity, cell cycle and apoptosis.

    Qin, Qi-Pin; Chen, Zhen-Feng; Qin, Jiao-Lan; He, Xiao-Ju; Li, Yu-Lan; Liu, Yan-Cheng; Huang, Ke-Bin; Liang, Hong

    2015-03-01

    [Pt(Q)2] (1) and [Pt(MQ)2] (2) exhibited enhanced cytotoxicity against BEL-7404, Hep-G2, NCI-H460, T-24, A549 tumor cells but low cytotoxicity on normal HL-7702 cells. 1 and 2 could cause the cell cycle arrest in G2 and S phase, respectively. While pifithrin-α, a specific p53 inhibitor, induced cell cycle arrest in G1 phase. Although 1, 2 and pifithrin-α caused serious inhibition on p53, 1 and 2 significantly cause the loss of mitochondrial membrane potential and increase of the reactive oxygen species level, cytochrome c, apaf-1 and caspase-3/9 ratio in BEL-7404 cells. 1 and 2 may trigger the cell apoptosis through a mitochondrial dysfunction pathway whereas pifithrin-α does not. The interactions of 1 and 2 with DNA are most probably via an intercalation. PMID:25575314

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

    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. PMID:26575324

  20. Controlling hole-transport in aluminum tris (8-hydroxyquinoline), Alq3-based organic light emitting diodes to improve the device lifetime by an oxidized transport layer

    Mathai, Mathew K.; Papadimitrakopoulos, Fotios; Hsieh, Bing R.

    2004-06-01

    A salt containing polymer, called an oxidized transport layer (OTL), was investigated for hole injection and transport into Alq3-based multilayered organic light emitting diode (OLED) devices. The OTL comprises an aryldiamine containing hole transport polymer binder with a corresponding low molecular weight radical cation salt. We demonstrate herein that the OTL behaves like a tunable resistor for holes, and its hole-transport properties can be controlled by the salt concentration and thickness of the OTL. Based on a careful analysis of the current density-voltage (J-V) device characteristics as a function of the above parameters, electron/hole currents were balanced to minimize oxidative degradation of Alq3. It was found that an OLED device (ITO/OTL/NPB/Alq3/CsF/Al) with a 5000 Å thick OTL at 5% salt concentration operated with a half-life exceeding 1000 h at a constant current of 10 mA/cm2. Similar devices with 2.5% and 10% salt doping showed an order of magnitude lower half-life attributed to unbalanced carrier concentrations. Moreover, by demonstrating that the majority of the field drops across the Alq3 layer, the doping level as opposed to OTL thickness was established as the primary contributor controlling hole transport in these OLEDs. This beneficial behavior is, however, observed only above a certain OTL thickness in the vicinity of 5000 Å.

  1. The Role of Weak Interactions in the Mechano-induced Single-Crystal-to-Single-Crystal Phase Transition of 8-Hydroxyquinoline-Based Co-crystals.

    Liu, Jie; Liu, Guangfeng; Liu, Yang; Zheng, Xiaoxin; Han, Quanxiang; Ye, Xin; Tao, Xutang

    2016-06-01

    Mechano-induced single-crystal-to-single-crystal (SCSC) phase transitions in crystalline materials that change their properties have received more and more attention. However, there are still too few examples to study molecular-level mechanisms in the mechano-induced SCSC phase transitions, making the systematic and in-depth understanding very difficult. We report that bis-(8-hydroxyquinolinato) palladium(II)-tetracyanoquinodimethane (PdQ2 -TCNQ) and bis-(8-hydroxyquinolinato) copper(II)-tetracyanoquinodimethane (CuQ2 -TCNQ) show very different mechano-response behaviors during the SCSC phase transition. Phase transition in CuQ2 -TCNQ can be triggered by pricking on the crystal surface, while in PdQ2 -TCNQ it can only be induced by applying pressure uniformly over the whole crystal face. The crystallography data and Hirshfeld surface analysis indicate that the weak intra-layer C-H⋅⋅⋅O, C-H⋅⋅⋅N hydrogen bonds and inter-layer stacking interactions determine the feasibility of the SCSC phase transition by mechanical stimuli. Weaker intra-layer interactions and looser inter-layer stacking make the SCSC phase transition occur much more easily in the CuQ2 -TCNQ. PMID:27124771

  2. 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

    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。

  3. catena-Poly[[[diaquabis(8-hydroxyquinoline N-oxide-κO1cobalt(II]-μ-2,5-dimethylpyrazine 1,4-dioxide-κ2O1:O4] bis(perchlorate

    Li Qin Gu

    2010-04-01

    Full Text Available In the title complex, {[Co(C6H8N2O2(C9H7NO2(H2O2](ClO42}n, the CoII ion lies on an inversion centre and is coordinated in a slightly distorted octahedral environment. The 2,5-dimethylpyrazine 1,4-dioxide ligand, which also lies on an inversion center, acts as a bridging ligand, linking symmetry-related CoII ions [Co...Co = 8.669 (3 Å] and forming one-dimensional chains along the b axis. In the crystal structure, these chains are linked by intermolecular aqua–perchlorate O—H...O hydrogen bonds, forming two-dimensional layers which are in turn connected into a three-dimensional network via π–π stacking interactions between quinoline rings, with a centroid–centroid distance of 3.580 (3 Å. An intermolecular O—H...Cl interaction is also present.

  4. Arene ruthenium oxinato complexes: Synthesis, molecular structure and catalytic activity for the hydrogenation of carbon dioxide in aqueous solution

    Thai, Trieu-Tien; Therrien, Bruno; Süss-Fink, Georg

    2010-01-01

    Two families of arene ruthenium oxinato complexes of the types [(η6-arene)Ru(η2-N,O-L)Cl] and [(η6-arene)Ru(η2-N,O-L)(OH2)]+ have been synthesized from the dinuclear precursors [(η6-arene)RuCl2]2 (arene = para-cymeme or hexamethylbenzene) and the corresponding oxine LH (LH = 8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline, 5,7-dichloro-8-hydroxyquinoline, 5-nitro-8-hydroxyquinoline, 5,7-dimethyl-8-hydroxyquinoline, 5,7-dichloro-2-methyl-8-hydroxyquinoline). The molecular structures of the neu...

  5. 8-羟基脱氧鸟苷水平对糖尿病患者胰岛功能损害的相关性研究%Correlation of 8-hydroxyquinoline Deoxyguanosine Levels with Pancreas Islet Dysfunction in Diabetic Patients

    梅礼军; 王林川

    2013-01-01

    Objective To observe the expression levels of 8 - hydroxy-deoxyguanosine (8-OHdG) in patients with different glucose metabolism and its relationship with islet dysfunction.Methods Based on the 75 g oral glucose tolerance test (OGTT), the patients were divided into 3 groups: normal glucose tolerance (NGT) group (30 patients), isolated impaired glucose tolerance (IGT) group (28 patients), type 2 diabetes mellitus (T2DM) group (28 patients), and 30 healthy subjects were selected as the healthy control group (healthy control, HC) . The triglyceride (TG) and total cholesterol (TC), glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), insulin resistance index, insulin and c-peptide area under the curve (AUC) were detected, and compared between groups, and the correlation between 8-OHdG and these indexes was analyzed. Results There was no difference in FBG values between NGT group and HC group, the indicators of patients in other groups were higher than HC group,the difference was statistically significant (P 0.05) . 8-OHdG was correlated with FBG, HbA1c, HOMA-IR, C peptide AUC, insulin AUC, and the correlation coefficients were 0.704, 0.713, 0.665, 0.825 and 0.653, respectively, the differences were statistically significant. Conclusions 8-OHdG levels can reflect the status of islet dysfunction,and can be used as an indicator of islet function for diabetic patients.%目的观察8-羟基脱氧鸟苷(8-OHdG)水平在不同糖代谢患者中的表达水平,探讨其与胰岛功能损害的相关关系.方法依据75 g葡萄糖耐量试验(OGTT)分为正常糖耐量(NGT)组30例,单纯糖耐量异常(IGT)组28例,2型糖尿病(T2DM)组28例,并设立健康对照组(healthy control,HC)30例,检测患者三酰甘油(TG)和总胆固醇(TC),糖化血红蛋白(HbA1c),空腹血糖(FBG),计算胰岛素抵抗指数,胰岛素及c肽曲线下面积(AUC),比较各组间差异,并分析8-OHdG与各指标的相关关系.结果除NGT组FBG值与HC组间无差异外,其它组各指标均高于HC组,差异有统计学意义(P<0.01);IGT组FBG、8-OHdG、HbA1C、HOMA-IR高于NGT组,差异有统计学意义(P<0.01);T2DM组FBG、8-OHdG、HbA1C、HOMA-IR高于IGT组.胰岛素AUC在NGT、IGT和T2DM组间无差异(P>0.05);8-OHdG与FBG、HbA1c、HOMA-IR、C肽AUC、胰岛素AUC均有相关性,相关系数依为0.704,0.713,0.665,0.825,0.653,差异均有统计学意义.结论8-OHdG水平能够反应胰岛功能受损的状态,可作为判断糖尿病患者胰岛功能的检测指标.

  6. Palladium-catalysed reactions of 8-hydroxy- and 8-benzyloxy-5,7-diiodoquinoline under aminocarbonylation conditions

    Takács, Attila; Szilágyi, Antal; Ács, Péter; Márk, László; Peixoto, Andreia F.; Mariette M. Pereira; Kollár, László

    2011-01-01

    Various 5-carboxamido-7-iodo-8-benzyloxyquinolines were synthesised via selective aminocarbonylation of 5,7-diiodo-8-benzyloxyquinoline in the presence of ‘in situ’ generated palladium(0) catalysts. Under similar conditions (50 °C, 80 bar CO), 5,7-bis(N-tert-butyl-glyoxylamido)-8-hydroxyquinoline was obtained using tert-butylamine as N-nucleophile. The unprotected 5,7-diiodo-8-hydroxyquinoline underwent dehydroiodination resulting in 8-hydroxyquinoline as the major product.

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

    Vandna Nishal; Devender Singh; Raman Kumar Saini; Vijeta Tanwar; Shri Bhagwan; Sonika Kadyan; Ishwar Singh; Pratap Singh Kadyan

    2015-01-01

    Synthesis and photoluminescent behaviour of mixed ligand based beryllium complexes with 2-(2-hydroxyphenyl)benzoxazole (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, nuc...

  8. Vibrational spectra of the Ga(III) complexes with oxine and clioquinol

    Wagner, Claudia C.; González-Baró, Ana C.; Baran, Enrique J.

    2011-09-01

    The FTIR and FT-Raman spectra of the gallium(III) complexes of 8-hydroxyquinoline (oxine) and 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol), were recorded and briefly discussed by comparison with the spectra of the uncoordinated ligands and with some related species.

  9. Bis{2-[1-(8-hydroxy-2-quinolylmethyl)-1H-benzimidazol-2-yl]quinolin-8-ol} toluene solvate

    Qing-Ming Wang; Qi Ma; Hui-Li Chen

    2010-01-01

    Crystals of the title compound, 2C26H18N4O2·C7H8, were obtained from the reaction of 8-hydroxyquinoline with 1,2-phenylenediamine in methanol and recrystallized from toluene. The compound contains three essentially planar ring systems: the benzimidazole ring (r.m.s. deviation = 0.039 Å) and two 8-hydroxyquinoline rings (r.m.s. deviations of 0.0056 Å in both rings). The benzimidazole ring and one 8-hydroxyquinoline ring are almost co-planar, formi...

  10. 8-Hy­droxy-2-methyl­quinolinium tetra­chlorido(quinolin-2-olato-κ2 N,O)stannate(IV) methanol disolvate

    Ezzatollah Najafi; Mostafa M. Amini; Seik Weng Ng

    2011-01-01

    In the reaction of 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline and stannic chloride, the 2-methyl-8-hydroxyquinoline is protonated, yielding the disolvated title salt, (C10H10NO)[SnCl4(C9H6NO)]·2CH3OH. The SnIV atom in the anion is N,O-chelated by the hydroxyquinolinate in a cis-SnNOCl4 octahedral geometry. In the crystal, the cation, anion and solvent molecules are linked by N—H...O, O—H...O and O—H...Cl hydrogen bonds, generating a three-dimensiona...

  11. 8-Hydroxy-2-methylquinolinium tetrachlorido(quinolin-2-olato-κ2N,Ostannate(IV methanol disolvate

    Ezzatollah Najafi

    2011-02-01

    Full Text Available In the reaction of 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline and stannic chloride, the 2-methyl-8-hydroxyquinoline is protonated, yielding the disolvated title salt, (C10H10NO[SnCl4(C9H6NO]·2CH3OH. The SnIV atom in the anion is N,O-chelated by the hydroxyquinolinate in a cis-SnNOCl4 octahedral geometry. In the crystal, the cation, anion and solvent molecules are linked by N—H...O, O—H...O and O—H...Cl hydrogen bonds, generating a three-dimensional network.

  12. Fluorescence in complexes based on quinolines-derivatives: a search for better fluorescent probes.

    Mecca, Carolina Z P; Fonseca, Fernando L A; Bagatin, Izilda A

    2016-11-01

    Quinoline-derived fluorescent complexes were designed; synthesized by the reaction of 5-nitro-8-hydroxyquinoline and 5-chloro-8-hydroxyquinoline with Al(3+), Mg(2+), Zn(2+), and Cd(2+) salts (1-8); and characterized. The (1)H NMR spectra of complexes 1 and 5, containing Al(3+), were consistent with an octahedral structure having approximate D3 symmetry, and the results supported the favored facial isomer (fac). Data for complexes 2-4 and 6-8 supported the formation of tetrahedral structures. Intense luminescence was detected for complexes 5-8, even with the naked eye, as indicated by quantum yield values of 0.087, 0.094, 0.051, and 0.021, respectively. Furthermore, in contrast to 5-nitro-8-hydroxyquinoline, the 5-chloro-8-hydroxyquinoline ligand exhibited bands at different energies depending on the coordinated metal, which supported its potential application in ionic and biological probes, as well as in cell imaging. PMID:27288961

  13. Synthesis, Characterization and Antifungal Activity of Novel Quinazolin-4-one Derivatives Containing 8-Hydroxyquinazoline Ligand and its Various Metal Complexes

    R. T. Vashi; Patel, S.B.

    2009-01-01

    Novel ligands containing quinazoline-4-one-8-hydroxyquinoline (QQ) merged moieties were prepared and characterized. For this anthranilic acid and 5-bromoanthranilic acid were converted respectively into 2-chloromethyl–3-(4-methyl phenyl)-3(H)-quinazoline-4-one and 2-chloromethyl–3-(methyl phenyl)-6-bromo-3(H)-quinazoline-4-one. Both these compounds were condensed with 5-amino-8-hydroxyquinoline. The so called resulted compounds were named respectively as 2-[(8-hydroxy-quinolinyl) –5- amino me...

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

    Maria Paulina Ulczycka; Agnieszka Krzymińska

    2013-01-01

    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 posthar...

  15. A MurF Inhibitor That Disrupts Cell Wall Biosynthesis in Escherichia coli▿

    Baum, Ellen Z.; Crespo-Carbone, Steven M.; Klinger, Alexandra; Foleno, Barbara D.; Turchi, Ignatius; Macielag, Mark; Bush, Karen

    2007-01-01

    MurF is an essential enzyme of bacterial cell wall biosynthesis. Few MurF inhibitors have been reported, and none have displayed measurable antibacterial activity. Through the use of a MurF binding assay, a series of 8-hydroxyquinolines that bound to the Escherichia coli enzyme and inhibited its activity was identified. To derive additional chemotypes lacking 8-hydroxyquinoline, a known chelating moiety, a pharmacophore model was constructed from the series and used to select compounds for te...

  16. Time-Resolved Pump-Probe X-ray Absorption Fine Structure Spectroscopy of Gaq3

    Dicke, Benjamin

    2014-01-01

    Gallium(tris-8-hydroxyquinoline) (Gaq3) belongs to a class of metal organic compounds, usedas electron transport layer and emissive layer in organic light emitting diodes. Many researchactivities have concentrated on the optical and electronic properties, especially of the homologuemolecule aluminum(tris-8-hydroxyquinoline) (Alq3). Knowledge of the first excited state S1structure of these molecules could provide deeper insight into the processes involved into the operationof electronic device...

  17. Hydroxyquinolines inhibit ribonucleic acid-dependent deoxyribonucleic acid polymerase and inactivate Rous sarcoma virus and herpes simplex virus.

    Rohde, W; Mikelens, P; Jackson, J; Blackman, J; Whitcher, J; Levinson, W

    1976-08-01

    8-Hydroxyquinoline and several of its derivatives inactivate the transforming ability of Rous sarcoma virus and inhibit its ribonucleic acid-dependent deoxyribonucleic acid polymerase activity. The copper complex of these metal-binding ligands is as active as the free ligand. The activity of the 8-hydroxyquinolines is approximately 50-fold more effective than another group of metal-binding compounds that we have tested, the thiosemicarbazones. In contrast to the potency of the 8-hydroxyquinolines to inactivate Rous sarcoma virus, no intracellular inhibition of transformation could be demonstrated at a concentration that did not affect the growth and appearance of the cells. Cellular deoxyribonucleic acid synthesis was inhibited to a greater extent than was ribonucleic acid or protein synthesis. The phenomenon of "concentration quenching" was observed with high concentrations of drug, causing less inhibition of deoxyribonucleic acid synthesis than was observed with lower concentrations. Herpes simplex virus type 1 was inactivated also by the 8-hydroxyquinolines and their copper complexes. No intracellular inhibition of plaque formation was observed. Treatment with 8-hydroxyquinoline sulfate had no effect on the resolution of herpetic keratitis in rabbits. Some 8-hydroxyquinolines bind to deoxyribonucleic acid in the presence of copper, a phenomenon that may be important in their antiviral activity. PMID:185949

  18. Synthesis and Characterization of Well-Defined Soluble Alq3- and Znq2-Functionalized Polymers via RAFT Copolymerization

    Chengchao Wang

    2010-01-01

    Full Text Available The reversible addition-fragmentation chain transfer (RAFT copolymerizations of 2-((8-hydroxyquinolin-5-ylmethoxyethyl methacrylate (HQHEMA with styrene (St or methyl methacrylate (MMA were successfully carried out in the presence of 2-cyanoprop-2-yl dithionaphthalenoate (CPDN. The polymerization behaviors showed the typical living natures by the first-order polymerization kinetics, the linear dependence of molecular weights of the polymers on the monomer conversions with the relatively narrow molecular weight distributions (Mw/Mn, and the successful chain extension experiments. The soluble polymers having tris(8-hydroxyquinolinealuminum (Alq3 and bis(8-hydroxyquinoline znic(II (Znq2 side chains were obtained via complexation of the polymers with aluminium isopropoxide or zinc acetate in the presence of monomeric 8-hydroxyquinoline, which had strong fluorescent emission at 520 nm. The obtained polymers were characterized by GPC, 1H NMR, UV-vis, and fluorescent spectra.

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

    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.

  20. 8-Hydroxy-2-methylquinolinium tetrachlorido(pyridine-2-carboxylato-κ2N,Ostannate(IV

    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.

  1. Selective Dendritic Fluorescent Sensors for Zn(II

    Yaowu Sha

    2008-04-01

    Full Text Available A series of dendritic 8-hydroxyquinoline (8-HQ and 5-dialkyl(arylaminomethyl-8-HQ derivatives were synthesized and their fluoroionophoric properties towardrepresentative alkali, alkaline earth, group IIIA and transition metal ions wereinvestigated. Among the selected ions, Zn(II enhanced the fluorescence of N-di-(methoxycarbonylethylaminoethyl-3-[4-(8-hydroxyquinolin-5-ylmethylpiperazin-1-yl]-propanoic amide] (7 by 31-fold, while Al(III caused enhancement to some extent. Theabsence of any significant fluorescence enhancement by the other ions examined renders 7a highly useful Zn(II-selective fluorescent sensor.

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

    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)

  3. New resin gel for uranium determination by diffusive gradient in thin films technique

    Gregušová, Michaela; Dočekal, Bohumil

    2011-01-01

    Roč. 684, 1-2 (2011), s. 142-146. ISSN 0003-2670 R&D Projects: GA ČR GAP503/10/2002 Institutional research plan: CEZ:AV0Z40310501 Keywords : diffusive gradient in thin film technique * 8- hydroxyquinoline resin gel * uranium determination Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.555, year: 2011

  4. Bis{2-[1-(8-hydroxy-2-quinolylmethyl-1H-benzimidazol-2-yl]quinolin-8-ol} toluene solvate

    Qing-Ming Wang

    2010-03-01

    Full Text Available Crystals of the title compound, 2C26H18N4O2·C7H8, were obtained from the reaction of 8-hydroxyquinoline with 1,2-phenylenediamine in methanol and recrystallized from toluene. The compound contains three essentially planar ring systems: the benzimidazole ring (r.m.s. deviation = 0.039 Å and two 8-hydroxyquinoline rings (r.m.s. deviations of 0.0056 Å in both rings. The benzimidazole ring and one 8-hydroxyquinoline ring are almost co-planar, forming a dihdral angle of 3.1 (2°. The other 8-hydroxyquinoline ring is almost perpendicular to the benzimidazole plane with a dihedral angle of 86.2 (2°. Intramolecular O—H...N contacts are present. The crystal structure is stabilized by intermolecular O—H...N interactions. The complete toluene molecule is generated by crystallographic inversion symmetry; therefore its methyl group is disordered over two sites of equal occupancy.

  5. Synthesis of Borinic Acids and Borinate Adducts Using Diisopropylaminoborane.

    Marciasini, Ludovic; Cacciuttolo, Bastien; Vaultier, Michel; Pucheault, Mathieu

    2015-07-17

    In situ formation of aryl Grignard under Barbier condition and diisopropylaminoborane as boron source allows a complete control of the addition onto the boron electrophile. Analytically pure borinic acid derivatives were produced at the gram scale without column chromatography and isolated as borinates adducts, with ethanolamine or 8-hydroxyquinoline, after workup. PMID:26183591

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

    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…

  7. Molybdenum separation process by liquid-liquid extraction. [In presence of uranium]. Procede de separation du molybdene par extraction liquide-liquide

    Beutier, D.; Le Quesne, Y.

    1987-07-24

    Molybdenum in sulfuric solution is contacted with an orgaic liquid phase containing as extracting agent a compound with an active group 8-hydroxyquinoline then molybdenum is recovered with an alkaline aqueous solution. Application is made to uranium mining industry because the process is selective even in presence of uranium.

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

    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.

  9. New rare-earth quinolinate complexes for organic light-emitting devices

    Camargo, H. [Physics Department, Pontifical Catholic University of Rio de Janeiro, 22453-900 Rio de Janeiro (Brazil); Paolini, T.B. [Chemistry Institute, Department of Fundamental Chemistry, University of São Paulo, USP, 05599-970 São Paulo (Brazil); Niyama, E. [Physics Department, Pontifical Catholic University of Rio de Janeiro, 22453-900 Rio de Janeiro (Brazil); Brito, H.F. [Chemistry Institute, Department of Fundamental Chemistry, University of São Paulo, USP, 05599-970 São Paulo (Brazil); Cremona, M., E-mail: cremona@fis.puc-rio.br [Physics Department, Pontifical Catholic University of Rio de Janeiro, 22453-900 Rio de Janeiro (Brazil)

    2013-01-01

    Because of its thermal and morphological stability and optical and electrical properties, tris(8-hydroxyquinoline) aluminum (Alq{sub 3}) is one of the most widely used electron transporting materials in organic light-emitting devices (OLEDs). The search for substitutes for this compound constitutes an important field of research in organic electronics. We report on a study of a new rare-earth tetrakis 8-hydroxyquinoline complex. Synthesis of tris complexes with rare-earth metals and 8-hydroxyquinoline resulted in unstable compounds. However, the inclusion of an additional quinoline group stabilized these compounds. Li[RE(q){sub 4}] (where RE = La{sup 3+}, Lu{sup 3+} and Y{sup 3+} and q = 8-hydroxyquinoline) were synthesized and then used as the electron-transporting and emitting layer in OLEDs. Thin films were deposited in a high-vacuum environment by thermal evaporation on quartz and silicon substrates. Optical characterization of the RE complexes revealed emission in the 510–525 nm range, the same as that observed for Alq{sub 3}, while absorption was observed at wavelengths of 382 nm for the Y/La complexes and 388 nm for the Lu complex. The OLEDs were fabricated with an indium tin oxide layer (ITO) as the anode, (N,N′-bis (1-naphtyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine) NPB as the hole-transporting layer (25 nm), Li[RE(q){sub 4}] as the electron-transporting and emitting layer (40 nm) and aluminum as the cathode (120 nm). The electroluminescence (EL) spectra showed a broad band from 520 to 540 nm and green-colored emission associated with the 8-hydroxyquinoline ligand. There was an interesting dependence of the maximum energy peak position and half-width of the emission band in the EL spectra on the atomic radius of the RE ion used. The best luminance for the OLEDs produced in this study was achieved with the Li[RE(q){sub 4}] compound. The optical and electrical properties of this OLED were comparable to those of similar devices based on Alq{sub 3

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

    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.

  11. Insights Into the Solution Crystallization of Oriented Alq3 and Znq2 Microprisms and Nanorods.

    Boulet, Joel; Mohammadpour, Arash; Shankar, Karthik

    2015-09-01

    Optimized solution-based methods to grow high quality micro- and nanocrystals of organic semi-conductors with defined size, shape and orientation are important to a variety of optoelectronic applications. In this context, we report the growth of single crystal micro- and nanostructures of the organic semiconductors Tris(8-hydroxyquinoline)aluminum (Alq3) and bis(8-hydroxyquinoline)zinc (Znq2) terminating in flat crystal planes using a combination of evaporative and antisolvent crystallization. By controlling substrate-specific nucleation and optimizing the conditions of growth, we generate vertically-oriented hexagonal prism arrays of Alq3, and vertical half-disks and sharp-edged rectangular prisms of Znq2. The effect of process variables such as ambient vapour pressure, choice of anti-solvent and temperature on the morphology and crystal habit of the nanostructures were studied and the results of varying them catalogued to gain a better understanding of the mechanism of growth. PMID:26716228

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

    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.

  13. Oxidation of Alcohols Catalyzed by Ruthenium Complexes with Iodosylbenzene as Oxidant

    Zi Qiang LEI; Qiao Xiang KANG; Xiang Zhen BAI; Zhi Wang YANG; Qing Hua ZHANG

    2005-01-01

    Five ruthenium complexes such as Phen-Ru-Phen, Phen-Ru-Bipy, Phen-Ru-Quin,Quin-Ru-Quin and Bipy-Ru-Quin (where Phen=1, 10-phenanthroline, Quin=8-hydroxyquinoline,Bipy=2, 2′-bipyridine) were synthesized and used as catalysts for the oxidation of benzylic and primary aliphatic alcohols with iodosylbenzene as oxidant. The oxidations were carried out at room temperature, affording the corresponding aldehydes and ketones with high selectivity.

  14. Facile and green fabrication of organic single-crystal hollow micro/nanostructures

    Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.

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

    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.

  16. Synthesis and investigation of enneachloroditungstates (3) with hydroxyquinoline, mercaptoquinoline, nicotinic acid

    Complexes of (HL)3W2Cl9 (L-8-hydroxyquinoline, 8-mercaptoquinoline, 4-pyridine carboxylic acid) were prepared by exchange reaction of (NH4)3W2Cl9 with corresponding ligands in hydrochloric acid. Their structure and composition were supported by the data of element analysis, infrared and electron spectroscopy, thermomagnetic and thermogravimetric measurements. Dehydrohalogenation of complexes was conducted and intermediate products characterized by the series of physicochemical methods were separated

  17. SYNTHESIS, CHARACTERIZATION AND CHELATING PROPERTIES OF PYRIMIDINE-QUINOLINE COMBINED MOLECULE WITH TRANSITION METALS

    Purvesh J. Shah

    2013-09-01

    Full Text Available The treatment of ethyl-6-methyl-2-oxo-4-phenyl-1,2-dihydropyrimidone-5-carboxylate with 5-amino-8-hydroxyquinoline afford a N-(4-hydroxyquinolin-5-yl-6-methyl-2-oxo-4-phenyl-1,2-dihydro pyrimidine-5-carboxamide(PDHQ. The transition metal complexes of Cu2+,Co2+ ,Ni2+, Mn2+ and Zn2+ of PDHQ have been prepared and characterized by elemental analysis, spectral studies, magnetic moment determination, molar conductivity measurement and microbicidal activity.

  18. Homo- and heterodinuclear luminescent helicates

    Osecka, Olga

    2008-01-01

    The specific photophysical properties of the NIR-emissive lanthanide-based complexes attract much attention due to the potential applications in medical diagnostic and optoelectronics. On the other hand, luminescent helicates are in the focus of attention of supramolecular chemistry. In this thesis, the self-assembly principles are applied to prepare mono- and dinuclear lanthanide(III)-containing systems using 8-hydroxyquinoline and its derivatives as building blocks. First, effective pathway...

  19. Synthesis and Characterization of Well-Defined Soluble Alq3- and Znq2-Functionalized Polymers via RAFT Copolymerization

    Wang, Chengchao; ZHANG Wei; Zhou, Nianchen; Qiu, Yansheng; Cheng, Zhengping; Zhu, Xiulin

    2010-01-01

    The reversible addition-fragmentation chain transfer (RAFT) copolymerizations of 2-((8-hydroxyquinolin-5-yl)methoxy)ethyl methacrylate (HQHEMA) with styrene (St) or methyl methacrylate (MMA) were successfully carried out in the presence of 2-cyanoprop-2-yl dithionaphthalenoate (CPDN). The polymerization behaviors showed the typical living natures by the first-order polymerization kinetics, the linear dependence of molecular weights of the polymers on the monomer conversions with the relativel...

  20. Facile and green fabrication of organic single-crystal hollow micro/nanostructures

    Yang Jun; Chen Yingzhi; Ou Xuemei; Zhang Xiaohong [Nano-organic Photoelectronic Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhang Xiujuan, E-mail: xjzhang@suda.edu.cn, E-mail: xhzhang@mail.ipc.ac.cn [Functional Nano and Soft Materials Laboratory (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)

    2011-07-15

    Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.

  1. Spin dependent transport in organic light-emitting diodes

    Silva, G. B.; C.F.O. Graeff; Nuesch, F.; Zuppiroli, L.

    2005-01-01

    Electrically Detected Magnetic Resonance (EDMR) was used to study a series of multilayer organic devices based on aluminum (III) 8-hydroxyquinoline. These devices were designed to identify the micoscopic origin of different spin dependent process, i.e. hopping and exciton formation. EDMR is demonstrated to probe molecular orbitals of charge, and thus indirectly explore interfaces, exciton formation, charge accumalation and electric fields in operating organic based devices.

  2. Phytotoxic compounds from roots of Centaurea diffusa Lam.

    Quintana, Naira; El Kassis, Elie G; Stermitz, Frank R.; Vivanco, Jorge M.

    2009-01-01

    An extract of roots of Centaurea diffusa (diffuse knapweed) yielded caryophyllene oxide and linoleic acid which were shown to be phytotoxic. Also isolated were germacrene B, a previously-known phytotoxin as well as the inactive polyene aplotaxene. A combination of these compounds, if transferred to the soil, could be one factor in the invasive behavior of this weed. Contrary to a literature report, 8-hydroxyquinoline was not detected in root exudates of in vitro grown C. diffusa nor could it ...

  3. Synthesis and pharmacological activities of 2-methyl-8-quinolyloxypropylamines

    Reddy YSR

    2007-01-01

    Full Text Available Starting chloropropane derivative (2 was prepared by the reaction of 2-methyl-8-hydroxyquinoline (1 with 1- bromo-3-chloropropane in presence of a base. Various new 1-(2-methyl-8-quinolyloxy-3-propylamines (3a-3j have been synthesized by the condensation of 1-(2-methyl-8-quinolyloxy-3-chloropropane (2 with different amines. Compounds were screened for the possible central nervous system depressant activities. Some of them showed moderate central nervous system depressant activity.

  4. 8-Hydroxy-2-methylquinolinium diiodido(2-methylquinolin-8-olato-κ2N,Ozincate

    Ezzatollah Najafi

    2011-09-01

    Full Text Available The reaction of 2-methyl-8-hydroxyquinoline and zinc iodide in acetonitrile affords the title salt, (C10H10NO[Zn(C10H8NOI2], in which the ZnII ion is coordinated by a N,O-chelating 2-methylquinolin-8-olate ligand and two iodide ligands in a distorted tetrahedral geometry. The cation is linked to the anion by an O—H...O hydrogen bond.

  5. Electrochemical generation of Cu(I) complexes in aqueous solutions studied by on-line mass spectrometry

    Prudent, M.; Roussel, C.; Girault, H H

    2007-01-01

    Taking advantage of the electrochemical aspects of electrospray ionization (ESI) sources in positive ionization mode mass spectrometry (MS), aqueous copper complexes are electrogenerated using sacrificial copper electrodes. When using 8-hydroxyquinoline or batho-cuproine, two chelating agents for Cu2+ and Cu+ ions, respectively, the electrodissolution of copper leads to the formation of the respective complexes that are then analyzed by MS. This electrochemical generation of copper(I) comple...

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

    Satyanarayana K.V.V.; Nageswara Rao P.

    2013-01-01

    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 respe...

  7. Radioassay process and compositions useful therein

    A method is provided for radioassaying a warmblooded animal which comprises administering to the animal an essentially organic solvent-free, aqueous solution containing a small amount of a radioactive indium-8-hydroxyquinoline or blood cells radioactively labeled by that solution. The amount is to be sufficient for detection by external imaging. The animal is subject to external imaging for detecting accumulated radioactivity to determine its location in the body of the animal

  8. Structural aspects of adducts of N-phthaloylglycine and its derivatives

    Barooah, Nilotpal; Sarma, Rupam J.; Batsanov, Andrei S.; Baruah, Jubaraj B.

    2006-06-01

    N-phthaloylglycine forms 2:1 adduct with 1,3-dihydroxybenzene and 1:2 adduct with 2-aminopyrimidine. Whereas N-phthaloylglycine form salts with 2,6-diaminopyridine and with 8-hydroxyquinoline. The 1:1 adduct of N, N'-bis(glycinyl)pyromellitic diimide with dimethylsulphoxide, 2-aminopyrimidine and 4,4'-dihydroxybiphenyl are prepared and characterised. The reaction of N, N'-bis(glycinyl)pyromellitic diimide with 2,6-diaminopyridine gives corresponding salt.

  9. Bis(μ-2-methylquinolin-8-olato-κ3N,O:O;κ3O:N,O-bis[(acetato-κO(methanol-κOzinc(II

    Seik Weng Ng

    2009-05-01

    Full Text Available The reaction of zinc acetate and 2-methyl-8-hydroxyquinoline in methanol yielded the centrosymmetric dinuclear title compound, [Zn2(C10H8NO2(CH3CO22(CH3OH2], which has the Zn atom within a distorted NO4 trigonal–bipyramidal coordination geometry. Methanol–acetate O—H...O hydrogen bonds link the dinculear units into a linear supramolecular chain extending parallel to [100].

  10. Analysis of metal ions in crude oil by reversed-phase high performance liquid chromatography using short column.

    Salar Amoli, H; Porgam, A; Bashiri Sadr, Z; Mohanazadeh, F

    2006-06-16

    In this study a rapid, simultaneous analysis of V, Ni, Fe and Cu in crude oil was achieved by high performance liquid chromatography using 10 cm length reversed-phase C18 column. Since the amount of metal ions is at a very low level, in this work, solvent extraction of metals by a ligand such as 8-hydroxyquinoline from acidic media was investigated with some modification to previous procedures. Average extraction recoveries were 99, 85, 94 and 96 for V, Ni, Fe and Cu, respectively. The proposed method was successfully applied to the crude oil which was obtained from Koshk area in southern Iran. Fast analysis of metal ion in reversed-phase short column was achieved with methanol/water (55/45, v/v) and the detection limits measured as three times the background noise were obtained. Also it was shown that if small amount of 8-hydroxyquinoline was added to the mobile phase, the peak height and the peak symmetry were improved. A typical chromatogram for the separation of the 8-hydroxyquinoline complexes of V (V), Ni (II), Fe (III) and Cu (II) in crude oil was obtained in less than 4 min. PMID:16723133

  11. Aluminum surface corrosion and the mechanism of inhibitors using pH and metal ion selective imaging fiber bundles.

    Szunerits, Sabine; Walt, David R

    2002-02-15

    The localized corrosion behavior of a galvanic aluminum copper couple was investigated by in situ fluorescence imaging with a fiber-optic imaging sensor. Three different, but complementary methods were used for visualizing remote corrosion sites, mapping the topography of the metal surface, and measuring local chemical concentrations of H+, OH-, and Al3+. The first method is based on a pH-sensitive imaging fiber, where the fluorescent dye SNAFL was covalently attached to the fiber's distal end. Fluorescence images were acquired as a function of time at different areas of the galvanic couple. In a second method, the fluorescent dye morin was immobilized on the fiber-optic imaging sensor, which allowed the in situ localization of corrosion processes on pure aluminum to be visualized over time by monitoring the release of Al3+. The development of fluorescence on the aluminum surface defined the areas associated with the anodic dissolution of aluminum. We also investigated the inhibition of corrosion of pure aluminum by CeCl3 and 8-hydroxyquinoline. The decrease in current, the decrease in the number of active sites on the aluminum surface, and the faster surface passivation are all consistent indications that cerium chloride and 8-hydroxyquinoline inhibit corrosion effectively. From the number and extent of corrosion sites and the release of aluminum ions monitored with the fiber, it was shown that 8-hydroxyquinoline is a more effective inhibitor than cerium chloride. PMID:11866069

  12. Structures and magnetic properties of several phenoxo-O bridged dinuclear lanthanide complexes: Dy derivatives displaying substituent dependent magnetic relaxation behavior.

    Wang, Wen-Min; Qiao, Wan-Zhen; Zhang, Hong-Xia; Wang, Shi-Yu; Nie, Yao-Yao; Chen, Hong-Man; Liu, Zhen; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin

    2016-05-10

    Nine dinuclear Ln(iii) complexes, [Ln(dbm)2(L)]2 (Ln = Eu (), Tb (), Dy (), Ho (), Er ()) and [Ln(dbm)2(L')]2 (Ln = Tb (), Dy (), Ho (), Er ()) (dbm = 1,3-diphenyl-1,3-propanedione, HL = 2-[[(4-methoxy-phenyl)imino]methyl]-8-hydroxy-quinoline and HL' = 2-[[(4-ethoxyphenyl)imino]methyl]-8-hydroxyquinoline) have been synthesized, and structurally and magnetically characterized. The nine complexes are all phenoxo-O bridged binuclear complexes, in which Ln1 and Ln1a are in an eight-coordinated environment bridged by two phenoxido oxygen atoms of two 8-hydroxyquinoline Schiff base ligands. Although complexes and have very similar structures, magnetic studies reveal that they exhibit different magnetic relaxation behaviors with the effective barriers (ΔE/kB) of 34.5 K for and 67.6 K for . The dissimilar dynamic magnetic behaviors of and mostly result from the different electron-donating effect induced by the two alkoxy (-OCH3 and -OC2H5) of the 8-hydroxyquinoline Schiff base ligands. Meanwhile, for complexes , , and , there are no observed magnetic relaxation behaviors under a zero dc field. In addition, the luminescence properties of , and were studied. PMID:27095548

  13. The effect of electron donating and withdrawing groups on the morphology and optical properties of Alq{sub 3}

    Duvenhage, M.M. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein ZA9300 (South Africa); Visser, H.G. [Department of Chemistry, University of the Free State, Bloemfontein ZA9300 (South Africa); Ntwaeaborwa, O.M. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein ZA9300 (South Africa); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, PO Box 339, Bloemfontein ZA9300 (South Africa)

    2014-04-15

    By adding electron donating (EDG) and withdrawing groups (EWG) to the Tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) molecule, the emission color can be tuned. In this study the effect of EDG and EWG on the morphology and optical properties of Alq{sub 3} were investigated. Alq{sub 3} powders was synthesized with an EDG (–CH{sub 3}) substituted at positions 5 and 7 ((5,7-dimethyl-8-hydroxyquinoline) aluminum) and EWG (–Cl) at position 5 ((5-chloro-8-hydroxyquinoline) aluminum). A broad absorption band at ∼380 nm was observed for Alq{sub 3}. The bands of the substituted samples were red-shifted. The un-substituted Alq{sub 3} showed a high intensity emission peak at 500 nm. The –Cl and –CH{sub 3} samples showed a red-shift of 33 and 56 nm respectively. The morphology of the samples was studied using a scanning electron microscope. The photo degradation of the samples was also investigated and the dimethyl sample shows the least degradation to the UV irradiation over the 24 h of continuous irradiation.

  14. Study on the structure and luminescence properties of the coordinated ZnO crystallites

    Chen, Qian-huo; Liu, Qing; Li, Qing; Sheng, Yu; Zhang, Wen-gong

    2013-10-01

    The coordinated ZnO nanoparticles and crystallites have been produced by focused pulsed laser ablation of ZnO target submerged in the ethanol solution of 8-hydroxyquinoline. The structure of the nanoparticles was characterized by high-resolution transmission electron microscopy (HRTEM). The ZnO crystallites properties were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis coupled to differential scanning calorimetry (TG/DSC), X-ray photoelectron spectroscopy (XPS) and luminescence spectrometry. The results show the surface Zn2+ ions of the ZnO nanoparticles are coordinated by the 8-hydroxyquinoline. The crystal class and the space group of the coordinated ZnO crystallites are triclinic and P-1(2), respectively. The lattice parameters are refined to a=1.1904 nm, b=1.2135 nm, c=0.8586 nm, α=108.28∘, β=100.27∘ and γ=85.50∘, respectively. The coordinated ZnO crystallites have better thermo stability than bis(8-hydroxyquinoline)zinc and can emit yellow-green light under UV and visible radiations.

  15. A novel Lu{sup 3+} fluorescent nano-chemosensor using new functionalized mesoporous structures

    Hosseini, Morteza, E-mail: smhosseini@khayam.ut.ac.ir [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza; Rafiei-Sarmazdeh, Zahra; Faridbod, Farnoush [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Goldooz, Hassan; Badiei, Alireza [School of Chemistry, University College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Nourozi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Mohammadi Ziarani, Ghodsi [Department of Chemistry, Faculty of Science, Alzahra University, Tehran (Iran, Islamic Republic of)

    2013-04-10

    Graphical abstract: A novel Lu{sup 3+} sensitive fluorescent chemosensor is constructed through the preparation of 8-hydroxyquinoline functionalized mesoporous silica with ordered hexagonal array structure (LUS-SPS-Q). Fluorescence measurements revealed that the emission intensity of the Lu{sup 3+}-bound mesoporous material increases significantly upon addition of various concentrations of Lu{sup 3+}, while the mono-, di-, trivalent cations result in either unchanged or weakened intensities. Highlights: ► 8-Hydroxyquinoline functionalized mesoporous silica is introduced as a selective fluorescent probe for lutetium ions. ► Fluorescent intensity of the chemical probe enhances upon binding to lutetium ions. ► Fluorescence measurements were done in a suspension of mesoporous silica in aqueous solution. -- Abstract: A new Lu{sup 3+} sensitive fluorescent chemosensor is designed using 8-hydroxyquinoline functionalized mesoporous silica with highly ordered structure (LUS-SPS-Q). The characterization of LUS-SPS-Q showed that the organized structure has been preserved after the post grafting procedure. The synthesized material showed a selective interaction with Lu{sup 3+} ion, most probably due to the presence of the fluorophore moiety at its surface. The emission intensity of the Lu{sup 3+}-bound mesoporous material increases with an increase in concentrations of Lu{sup 3+} ion. Addition of other mono-, di-, trivalent ions resulted in insignificant change in the fluorescent intensity. The enhancement of fluorescence is attributed to the strong covalent binding of Lu{sup 3+} ion. The linear response range of Lu{sup 3+} chemo-sensor was from 1.6 × 10{sup −7} to 1.0 × 10{sup −5} mol L{sup −1}. The Limit of detection obtained was 8.2 × 10{sup −8} mol L{sup −1} and the pH range which the proposed chemo-sensor can be applied was 3.3–8.3.

  16. Repulsive tip tilting as the dominant mechanism for hydrogen bond-like features in atomic force microscopy imaging

    Lee, Alex J.; Sakai, Yuki; Kim, Minjung; Chelikowsky, James R.

    2016-05-01

    Experimental atomic force microscopy (AFM) studies have reported distinct features in regions with little electron density for various organic systems. These unexpected features have been proposed to be a direct visualization of intermolecular hydrogen bonding. Here, we apply a computational method using ab initio real-space pseudopotentials along with a scheme to account for tip tilting to simulate AFM images of the 8-hydroxyquinoline dimer and related systems to develop an understanding of the imaging mechanism for hydrogen bonds. We find that contrast for the observed "hydrogen bond" feature comes not from the electrostatic character of the bonds themselves but rather from repulsive tip tilting induced by neighboring electron-rich atoms.

  17. Development of technology for the large-scale preparation of 60Co polymer film source

    60Co sources (∼37 kBq) in the form of a thin film are widely used in position identification of perforation in offshore oil-well explorations. This paper describes the large-scale preparation of such sources using a radioactive polymer containing 60Co. 60Co was extracted into chloroform containing 8-hydroxyquinoline. The chloroform layer was mixed with polymethyl methacrylate (PMMA) polymer. A large film was prepared using the polymer solution containing the complex. The polymer film was then cut into circular sources, mounted on a source holder and supplied to various users

  18. ELECTRICAL PROPERTIES OF POLYSTYRENE MATRIX DOPED BY GOLD NANOPARTICLES AND 8HQ

    We explored the modification of polymeric film conductivity by changing the conducting filler percentage in the frame of the percolation theory. The polymeric film is a polystyrene (PS) matrix, while the fillers are gold nanoparticles capped with 1-dodecanethiol (Au-DT NPs) and small conjugated molecules 8- hydroxyquinoline (8HQ). Experimental results show, that increasing the Au- DT and 8HQ wt%, film conductivity increases by up to three orders of magnitude due to charge transfer in the 3D network composed by Au- DT NPs and 8HQ

  19. Synthesis, Characterization, and Biological Activity of 5-Phenyl-1,3,4-thiadiazole-2-amine Incorporated Azo Dye Derivatives

    Chinnagiri T. Keerthi Kumar

    2013-01-01

    Full Text Available 5-Phenyl-1,3,4-thiadiazole-2-amine has been synthesized by single step reaction. A series of heterocyclic azodyes were synthesized by diazotisation of 5-phenyl-1,3,4-thiadiazole-2-amine by nitrosyl sulphuric acid followed by coupling with different coupling compounds such as 8-hydroxyquinoline, 2,6-diaminopyridine, 2-naphthol, N,N-dimethyl aniline, resorcinol, and 4,6-dihydroxypyrimidine. The dyes were characterized by UV-Vis, IR, 1H-NMR, 13C NMR, and elemental analysis. The synthesized compounds were also screened for biological activity.

  20. Organic Light-Emitting Diodes Based on New Oxadiazole and Pyrazoline Derivatives

    ZHANG Zhi-Ming; ZHANG Rui-Feng; WU Fang; MA Yu-Guang; LI Guo-Wen; TIAN Wen-Jing; SHEN Jia-Cong

    2000-01-01

    The bilayer heterojunction devices were fabricated successfully by using a novel oxadiazole derivative: 2, 2-(2,5-thiophenediyl) bis (5-(4-methyl) phenyl-1,3, 4-oxadiazole) (T-OXD) as the electron-transporting layer (ETL)and a pyrazoline derivative:1-phenyl-3-(dimethylamino)styryl-5-(p-(dimethylamino) phenyl)pyrazoline (PDP) as the light-emitting layer and the hole-transporting layer. The emission at 500nm was derived from PDP layer.In comparison with the bilayer device of tris (8-hydroxyquinoline) aluminum (Alq) as the ETL, the luminous efficiency of the PDP/T-OXD heterojunction device was enhanced by 104 times.

  1. Xenobiotics enhance laccase activity in alkali-tolerant γ-proteobacterium JB Xenobióticos aumentam a atividade de lacase em γ-Proteobacterium JB alcali-tolerante

    Gursharan Singh; Mona Batish; Prince Sharma; Neena Capalash

    2009-01-01

    Various genotoxic textile dyes, xenobiotics, substrates (10 µM) and agrochemicals (100 µg/ml) were tested for enhancement of alkalophilic laccase activity inγ-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 enhance...

  2. 2-((Pyren-1-ylmethylaminomethylquinolin-8-ol

    Carlos Lodeiro

    2010-10-01

    Full Text Available A new fluorescent compound L1 derived from 1-pyrenemethylamine hydrochloride (A has been synthesized by classical Schiff-base reaction between (A and 8-hydroxyquinoline-2-carbaldehyde (B followed by a chemical reduction with NaBH4. The chemical structure was confirmed by elemental analysis, FAB-MS spectrometry and by IR, UV-vis and 1H-NMR spectroscopy. The photophysical characterization was achieved by UV-vis and emission spectroscopy and lifetime measurements. Compound L1 was explored as pH fluorescent chemosensor in water-acetonitrile (95.5/0.5 v:v solutions.

  3. 8-Hydroxy-2-methylquinolinium dichlorido(2-methylquinolin-8-olato-κ2N,Ozincate acetonitrile disolvate

    Ezzatollah Najafi

    2011-09-01

    Full Text Available The reaction of 2-methyl-8-hydroxyquinoline and zinc chloride in acetonitrile affords the title solvated salt, (C10H10NO[Zn(C10H8NOCl2]·2CH3CN, in which the ZnII atom is coordinated by an N,O-chelating 2-methylquinolin-8-olate ligand and two chloride ligands in a distorted tetrahedral geometry. The cation is linked to the heterocyclic anion by an O—H...O hydrogen bond and the quinolinium H atom forms a intermolecular N—H...N hydrogen bond with one of the acetonitrile solvent molecules.

  4. Probing triplet-triplet annihilation zone and determining triplet exciton diffusion length by using delayed electroluminescence

    Luo, Yichun; Aziz, Hany

    2010-05-01

    The literature shows that triplet-triplet annihilation (TTA) can provide a substantial contribution to the electroluminescence (EL) of fluorescent organic light-emitting devices (OLEDs). In this study, we utilized delayed EL measurements to probe the TTA emission zone of archetypical 8-hydroxyquinoline aluminum (Alq3) based OLEDs. The results demonstrate that the TTA emission zone of these devices is much larger than the prompt emission zone of singlet states that are formed in the electron-hole recombination. The larger TTA emission zone is attributed to the longer diffusion length of the Alq3 triplet states (60 nm) than that of Alq3 singlet states (20 nm).

  5. Synthesis of quinolinequinone derivatives and related carbocyclic compounds

    Samuel Attah Egu

    2014-09-01

    Full Text Available Palladium-catalyzed Buchwald-Hartwig aminations of various quinolinequinone derivatives give excellent yields of novel 6-arylamino derivatives of the disubstituted quinolinequinones and 3-arylamino derivatives of the corresponding naphthoquinones. The precursor quinolinequinones are prepared in a three-step sequence from 8-hydroxyquinoline. The transition-metal-catalyzed arylations of 6,7-dibromo-5,8-quinolinequinone, 6,7-dichloro-5,8-quinolinequinone and 2,3-dichloro-1,4-naphthoquinone are reported for the first time and offer fast and easy access to their derivatives.

  6. 8-Hydroxy-2-methylquinolinium tetrachlorido(quinolin-8-olato-κ2N,Ostannate(IV

    Ezzatollah Najafi

    2012-06-01

    Full Text Available The reaction of 8-hydroxyquinoline, 2-methylquinolin-8-ol and stannic chloride yields the protonated 8-hydroxy-2-methylquinolinium species. In the title salt, (C10H10NO[Sn(C9H6NOCl4], the SnIV cation is N,O-chelated by the quinolin-8-olate anion and is further coordinated by four Cl− anions in a distorted cis-SnNOCl4 octahedral geometry. In the crystal, the cation is linked to the anion by an O—H...O hydrogen bond.

  7. 8-Hydroxy-2-methylquinolinium diiodido(2-methylquinolin-8-olato-κ2N,Ozincate(II methanol monosolvate

    Seik Weng Ng

    2010-10-01

    Full Text Available The anion of the title salt, (C10H10NO[Zn(C10H8NOI2]·CH3OH, has its metal atom N,O-chelated by the deprotonated 2-methyl-8-hydroxyquinoline ligand. The hydroxy unit of the cation is a hydrogen-bond donor to the alkoxide O atom of the tetrahedrally coordinated anion, whereas the ammonium cation acts as a hydrogen-bond donor to the methanolic O atom. In the crystal, adjacent ion pairs and solvent molecules are linked by a methanol–halogen O—H...I hydrogen bond, generating a chain running along the a axis.

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

    Hansen, Poul Erik; Spanget-Larsen, Jens

    2012-01-01

    -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 is...... harmonic and PT2 anharmonic approximations, as well as on experimental NMR parameters, i.e., proton chemical shifts (δH) and two-bond deuterium isotope effects on 13C chemical shifts (2ΔCOD). The procedures are applied in a discussion of the spectra of 2,6-dihydroxy-4-methylbenzaldehyde and 8...

  9. Chemistry of Pyrones, Part 5: New Crown Ether and Podand Derivatives of 3,5-Bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one

    Alireza Banaei

    2001-08-01

    Full Text Available New podand and crown ether derivatives of 3,5-disubstituted 4H-pyran-4-one (8-11 were prepared by the nucleophilic substitution reaction of 3,5-bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one with o-nitrophenol, 8-hydroxyquinoline, 2-hydroxymethyl pyridine and triethyleneglycol, respectively. The yield of 3,5-bis[(2-formylphenoxy methyl]-2,6-diphenyl-4H-pyran-4-one has been improved by modification of our previous method using NaOH instead of Et3N.

  10. Influence of fillers concentration on electrical properties of polystyrene matrix doped by gold nanoparticles and 8HQ

    Scaldaferri, R.; Salzillo, G.; Pepe, G. P.; Barra, M.; Cassinese, A.; Pagliarulo, V.; Borriello, A.; Fusco, L.

    2009-11-01

    The analysis of the electrical properties of polystyrene films containing gold nanoparticles capped with 1-dodecanethiol and 8-hydroxyquinoline molecules is reported. The conductivity of the nanocomposite as a function of the doping level has been investigated both in planar and stacked configurations. While the former configuration evidenced low field tunneling between nanoparticles in the polymer matrix, stacked devices allowed us to investigate the main phenomena ruling the transport properties when switching effects are present close to critical electric fields. In particular, through the analysis of current-voltage characteristics we studied the charge transport at different fillers concentrations and sketched a physical picture of conductivity in such nanocomposite systems.

  11. Bromido(quinolin-8-ol-κ2N,O(quinolin-8-olato-κ2N,Ozinc(II methanol monosolvate

    Seik Weng Ng

    2010-10-01

    Full Text Available The title compound, [ZnBr(C9H6NO(C9H7NO]·CH3OH, has its metal atom N,O-chelated by a neutral and a deprotonated 8-hydroxyquinoline ligand. The hydroxy unit of the neutral ligand is a hydrogen-bond donor to the methanol O atom and the alkoxy O atom of the monoanionic ligand is a hydrogen-bond acceptor to the methanol O atom. In the crystal, adjacent molecules are linked by these two hydrogen bonds, generating a chain running along the a axis.

  12. a Simple Method for Preparation of Fluorescent Nanostructure Silica with Hexagonal Array

    Badiei, Alireza; Goldooz, Hassan

    A nanostructure modified silica with good fluorescence properties was prepared by grafting Al3+ ions on the surface of nanoporous silica and then binding of 8-hydroxyquinoline (8-HQ) to the grafted Al3+ ions. The prepared material, denoted as NS-AlQ2, was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), nitrogen adsorption-desorption measurements, FT-IR and fluorescence spectra. This compound shows emission spectra approximately in the emission range of AlQ3 complex. This procedure provides a simple method for grafting fluorescent molecules in the channels of nanoporous silica materials.

  13. Copper–phenanthroline catalysts for regioselective synthesis of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and of pyrrolo[1,2-a]phenanthrolines under mild conditions

    Rupankar Paira

    2014-03-01

    Full Text Available A new series of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and pyrrolo[1,2-a]phenanthrolines were efficiently built up from an 8-hydroxyquinoline derivative or phenanthroline via 1,3-dipolar cycloaddition reaction involving non-stabilized azomethine ylides, generated in situ from the parent furo[3,2-h]quinoliniums/phenanthroliums, in presence of a copper(II chloride–phenanthroline catalytic system. The methodology combines general applicability with high yields.

  14. 8-Hydroxy-2-methylquinolinium dichlorido(2-methylquinolin-8-olato-κ2N,Ozincate(II methanol solvate

    Seik Weng Ng

    2009-05-01

    Full Text Available The reaction of zinc chloride and 2-methyl-8-hydroxyquinoline in methanol yielded the title monosolvated salt, (C10H10NO[ZnCl2(C10H8NO]·CH3OH, which has the Zn atom within a distorted Cl2NO tetrahedral coordination geometry. Supramolecular chains feature in the crystal structure, comprising all components of the structure stabilized by a combination of O—H...O, N—H...O and O—H...Cl hydrogen bonding.

  15. Tailoring the energy level alignment at the Co/Alq{sub 3} interface by controlled cobalt oxidation

    Haag, Norman; Steil, Sabine; Großmann, Nicolas; Fetzer, Roman; Cinchetti, Mirko; Aeschlimann, Martin [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schroedinger-Strasse 46, 67663 Kaiserslautern (Germany)

    2013-12-16

    We have studied the influence of oxygen exposure at the prototypical interface between cobalt and the organic semiconductor tris(8-hydroxyquinoline)aluminum (III) (Alq{sub 3}) by photoemission spectroscopy. We find that oxidation of the cobalt leads to a gradual suppression of hybrid interface states, to a progressive change in the work function and to a continuous energetic shift of the molecular orbitals towards higher binding energies. Based on these observations, we propose controlled oxidation of the ferromagnetic electrode as an easy and effective possibility to tune the performance of organic spintronics devices.

  16. Surface Complexation-Based Biocompatible Magnetofluorescent Nanoprobe for Targeted Cellular Imaging.

    Bhandari, Satyapriya; Khandelia, Rumi; Pan, Uday Narayan; Chattopadhyay, Arun

    2015-08-19

    We report the synthesis of a magnetofluorescent biocompatible nanoprobe-following room temperature complexation reaction between Fe3O4-ZnS nanocomposite and 8-hydroxyquinoline (HQ). The composite nanoprobe exhibited high luminescence quantum yield, low rate of photobleaching, reasonable excited-state lifetime, luminescence stability especially in human blood serum, superparamagnetism and no apparent cytotoxicity. Moreover, the nanoprobe could be used for spatio-controlled cell labeling in the presence of an external magnetic field. The ease of synthesis and cell labeling in vitro make it a suitable candidate for targeted bioimaging applications. PMID:26226317

  17. 8-Hydroxy-2-methylquinolinium dibromido(2-methylquinolin-8-olato-κ2N,Ozincate acetonitrile monosolvate

    Ezzatollah Najafi

    2011-09-01

    Full Text Available The reaction of 2-methyl-8-hydroxyquinoline and zinc bromide in acetonitrile affords the title solvated salt, (C10H10NO[ZnBr2(C10H8NO]·CH3CN, in which the ZnII ion is coordinated by a N,O-chelating 2-methylquinolin-8-olate ligand and two bromide ligands in a distorted tetrahedral geometry. The cation is linked to the anion by an O—H...O hydrogen bond and the quinolinium H atom forms an intermolecular N—H...N hydrogen bond with the acetonitrile solvent molecule.

  18. Deep-red to near-infrared electrophosphorescence based on bis(8-hydroxyquinolato) platinum(II) complexes

    Xiang, Hai-Feng; Xu, Zong-Xiang; Roy, V. A. L.; Yan, Bei-Ping; Chan, Siu-Chung; Che, Chi-Ming; Lai, P. T.

    2008-04-01

    A series of neutral platinum(II) complexes with substituted 8-hydroxyquinoline ligands for use in organic electroluminescent devices have been prepared. These platinum(II) complexes give deep-red to near-infrared phosphorescence with λmax ,peak from 650to695nm and λmax ,shoulder from 705to755nm. High-performance organic light-emitting devices are obtained using these bis(8-hydroxyquinolato) platinum(II) complexes as a deep-red to near-infrared emitter with maximum external quantum efficiency, luminous efficiency, and turn-on voltage of 1.7%, 0.32cd/A, and 3.2V, respectively.

  19. 8-Hydroxy-2-methylquinolinium dibromido(2-methylquinolin-8-olato-κ2N,Ozincate(II methanol monosolvate

    Seik Weng Ng

    2010-10-01

    Full Text Available The anion of the title salt, (C10H10NO[ZnBr2(C10H8NO]·CH3OH, has its metal atom N,O-chelated by the deprotonated 2-methyl-8-hydroxyquinoline ligand. The hydroxy unit of the cation is a hydrogen-bond donor to the alkoxide O atom of the tetrahedrally coordinated anion, whereas the ammonium cation is a hydrogen-bond donor to the methanolic O atom. In the crystal, adjacent ion pairs and solvent molecules are linked by a methanol–halogen O—H...Br hydrogen bond, generating a chain running along the a axis.

  20. Simulated imaging of intermolecular bonds using high throughput real-space density functional calculations

    Lee, Alex; Kim, Minjung; Chelikowsky, James

    2015-03-01

    Recent experimental noncontact atomic force microscopy (AFM) studies on 8-hydroxyquinoline (8-hq) assemblies have imaged distinct lines between molecules that are thought to represent intermolecular bonding. To aid the interpretation of these images, we calculate simulated AFM images of an 8-hq dimer with a CO functionalized tip using a real-space pseudopotential formalism. We examine the effects of Pauli repulsion and tip probe relaxation as explanations for the enhanced resolution that resolves these intermolecular force lines. Our study aims to compute ab initio real-space images of intermolecular interactions.

  1. Dynamic modification of silicon gel with complexing reagents grafted by hydrophobic groups and following sorption of metals

    Retention of group reagents of three classes: dioximes, β-diketones, 8-hydroxyquinoline and its derivatives (8-Ox, MO, PAO), as well as HDEHP on hydrophobic silica gel C15, was studied under dynamic conditions. Retention dependences on Kdistr of reagent were obtained, from which the possibility of correct choice of reagent with required properties fit for the preparation of noncovalently modified sorbent follows. Sorptional behaviour of Cd, Co(2), Zn, Mg, Cu, Pb on the sorbents prepared is considered. Retention series are obtained, which are well comparable with the extraction ones

  2. Continuous wave laser induced transfer of organic semiconductors

    Fitl, P.; Vrňata, M.; Myslík, V.; Kopecký, D.; Vlček, J.; Tomeček, D.; Novotný, Michal

    Kyoto: JSAP- MRS Joint Symposia 2013, 2013 - (Tabata, H.). JSAP- MRS -B-014-JSAP- MRS -B-014 [JSAP- MRS Joint Symposia 2013. 16.09.2013-20.09.2013, Kyoto] R&D Projects: GA ČR(CZ) GAP108/11/1298 Institutional support: RVO:68378271 Keywords : organic semiconductors * phthalocyanines * Tris-(8-hydroxyquinoline) aluminum * Laser Induced Forward Transfer Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.gakkai-web.net/gakkai/jsap/jsap_mrs/hp/images/temp/ MRS _pro.pdf

  3. On the possibility of photometric determination of beryllium in the presence of aluminium by chromazurol S in aqua-organic media

    The possibility is shown to improve the selectivity of photometric determination of beryllium in the presence of aluminium using the reaction with Chromazurol S (CAS) in organo-aqueous solution and 8-hydroxyquinoline as masking agent. A mixture, containing propanol, 2-3 vol.% H2O and 1-2 vol.% acetic acid, is an optimal medium for the reaction betWeen beryllium and CAS. Determination of 0.45 μg of beryllium in the presence of 2000-fold amounts of aluminiUm is possible. Some other elements (mass excess is bracketed): nickel (7800) indium (2500), zink (700) do not hinder the reaction between beryllium and CAS

  4. Application of EMA, Fluorescent Staining and FISH of rDNA in Analysis of Aloe vera (L.) Burm. f. Chromosomes

    JHA, Timir Baran; Yamamoto, Masashi; ヤマモト, マサシ; 山本, 雅

    2012-01-01

    Fluorescent banding patterns and the locations of the ribosomal RNA gene (rDNA) of Indian Aloe vera (L.) Burm. f. chromosomes were determined. Root tips were pretreated in 2 mM 8- hydroxyquinoline at 10 to 12℃ for 3h. The chromosome samples were prepared by the enzymatic maceration and air-drying method (EMA). The best preparation, with all chromosomes relatively extended and well spread without cytoplasm, was obtained following enzymatic condition of 0.67% Cellulase Onozuka RS, 0.5% Macerozy...

  5. Flow injection sorbent extraction of metals with activated carbon and its application to flame atomic absorption spectrometry

    In the present study activated carbon was used as a sorbent material for the flow injection on-line sorbent extraction of metal ions combined with atomic absorption spectrometry. On-line chelation of zinc was performed with 8-Hydroxyquinoline and the resultant metal chelate was adsorbed on the activated carbon, then adsorbed with zinc acid and on-line detected with flame AAS. Various parameters affecting the zinc enrichment were optimized and the method was applied for the determination of zinc in tap water, natural water, boiled and tea samples. The results obtained with the present method were compared with those obtained by the ICP-AES. (author)

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

    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. Corrosion Behavior of Passivated 316LSS with Ag Coating as PEMFC Bipolar Plate

    Naibao Huang; Chenghao Liang; Hongtao Wang; Lishuang Xu; Hongfeng Xu

    2011-01-01

    A new chemical passivation technique, which contained 20 g/L hydrogen peroxide, 3.75 g/L sodium silicate, 1.25 g/L sodium carbonate, 3.75 g/L lactic acid and 0.75 g/L 8-hydroxyquinoline, was used to modify 316 stainless steel with Ag coating (Ag-coated 316SS) as PEMFC bipolar plates. The results indicated that the compact passive film had been obtained on the surface of Ag-coated 316SS. The passivation process could not only increase contact angle (from 58∘ to 104∘) but also decreased pinhole...

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

    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. PMID:18964076

  9. Highly sensitive heavy metal ion detection using AlQ3 microwire functionalized QCM

    Can, Nursel; Aǧar, Meltem; Altındal, Ahmet

    2016-03-01

    Tris(8-hydroxyquinoline) aluminum (Alq3) microwires was successfully synthesized for the fabrication of Alq3 microwires-coated QCM sensors to detect the heavy metal ions in aqueous solution. AT-cut quartz crystal microbalance (QCM) of 10 MHz fundamental resonance frequency having gold electrodes were used as transducers. Typical measuring cycle consisted of repeated flow of target measurands through the flow cell and subsequent washing to return the baseline. The QCM results indicated that the Alq3 microwires exhibit excellent sensitivity, stability and short response-recovery time, which are much attractive for the development of portable and highly sensitive heavy metal ion sensors in water samples.

  10. 8-Hydroxy-2-methylquinolinium tetrachlorido(quinolin-8-olato-κ2N,O)stannate(IV) acetonitrile monosolvate

    Marzieh Vafaee; Gholamhossein Mohammadnezhad; Amini, Mostafa M.; Seik Weng Ng

    2010-01-01

    In the title solvated salt, (C10H10NO)[SnCl4(C9H6NO)]·CH3CN, the SnIV atom is chelated by the N,O-bidentate 8-hydroxyquinolinate ligand and four chloride ions, generating a distorted SnONCl4 octahedral coordination geometry for the metal. In the crystal, the cations are linked to the anions and the solvent molecules by O—H...O and N—H...N hydrogen bonds, respectively.

  11. 8-Hydroxy-2-methylquinolinium tetrachlorido(quinolin-8-olato-κ2N,Ostannate(IV acetonitrile monosolvate

    Marzieh Vafaee

    2010-04-01

    Full Text Available In the title solvated salt, (C10H10NO[SnCl4(C9H6NO]·CH3CN, the SnIV atom is chelated by the N,O-bidentate 8-hydroxyquinolinate ligand and four chloride ions, generating a distorted SnONCl4 octahedral coordination geometry for the metal. In the crystal, the cations are linked to the anions and the solvent molecules by O—H...O and N—H...N hydrogen bonds, respectively.

  12. Plutonium extraction by the formation of insoluble salts (1960)

    The aim of this work is to convert Pu IV nitrate in solution into an insoluble salt. Three methods have been studied: 1) the conventional oxalic acid method was improved; 2) precipitation with 8-hydroxyquinoline was tried; 3) the hydrogen peroxide method was adapted to the eluates of the ionic resins from Marcoule. The yield from the oxalic process has been increased (loss of Pu in the mother-liquor brought from 200 mg/l to 20 mg/l). The study of Pu IV precipitation by 8-hydroxyquinoline has shown that the yield is excellent (Pu concentration in the mother-liquor less than 5 mg/h), but decontamination from impurities is nil. Finally, experiments on the precipitation by hydrogen peroxide of Pu IV solutions at the concentrations normally obtained from the anionic resins at Marcoule have given us good yields (Pu concentration in the mother-liquor less than 7 mg/l), and the purification is better than that obtained by oxalic acid (1000 ppm total impurities after a precipitation). (author)

  13. Determination of trace levels of dissolved vanadium in seawater by use of synthetic complexing agents and inductively coupled plasma-atomic emission spectroscopy (ICP-AES)

    Abbasse, G.; Ouddane, B.; Fischer, J.C. [Univ. des Sciences et Technologies et Lille, Lab. de Chimie Analytique et Marine (ELICO), UPRESA CNRS 8013, Villeneuve d' Ascq (France)

    2002-11-01

    In the determination of traces of dissolved vanadium in complex matrices such as seawater, separation and enrichment from the matrix is of special importance. A wide variety of methods has been proposed for preconcentration, depending to the nature of samples and the methods to be used for measurement. Among these methods separation techniques based on sorption on to chelating resins seem convenient, rapid, and capable of achieving a high concentration factor. The methods proposed in this paper are based on the transformation of all dissolved vanadium species in seawater into organic complexes by use of synthetic complexing agents such as dithizone, luminol, or 8-hydroxyquinoline; the resulting vanadium-organic complexes were sorbed on to a C{sub 18} column at a flow rate of 5 mL min{sup -1}. The vanadium sorbed on the C{sub 18} columns was then stripped by use of nitric acid (2 mol L{sup -1}) and analysed by inductively coupled plasma-atomic emission spectroscopy, ICP-AES. This method was optimised and use of other chelating resins, such as chelamine, chelex-100, and immobilised 8-hydroxyquinoline and was compared by passing seawater samples directly over the resins. The experimental conditions (pH, acid used for elution, and contact time between the liquid sample and the resin) were optimised. The results were compared for all the resins used and were indicative of excellent and coherent reproducibility. (orig.)

  14. An improved and highly useful method for the gravimetric determination of molybdenum in molybdenum concentrates

    The dried molybdenum concentrate is treated with hydrofluoric acid and nitric acid for its dissolution and the solution thus obtained is neutralized with ammonia and then acidified with dilute sulfuric acid. From the acidified solution molybdenum is precipitated with 8-hydroxyquinoline (oxine). The precipitate is digested on a steam bath, filtered, washed with warm water and dried at 130℃. Then it was heated in a Muffle furnace at around 600℃, for an hour, cooled and then weighed. The product was again heated at 750℃ for about 1 h, cooled and constant weight was taken. The difference of weight (the weight of the product obtained after heating at 600℃ minus the weight of the product obtained at 750℃) gave the actual content of molybdenum as MoO3. A substantial/major modification of the earlier reported 8-hydroxyquinoline (oxine) method for the gravimetric determination of molybdenum has been made in the proposed method. The advantages of the proposed method over the oxine method are (i) free from most interferences, (ii) accuracy and precision of the method have been improved substantially and (iii) the results obtained from the application of the proposed method to different molybdenum concentrates are reliable. (author)

  15. Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

    Cai Kaiyong, E-mail: Kaiyong_cai@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Sui Xiaojing; Hu Yan [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Zhao Li [China National Centre for Biotechnology Development, No. 16, Xi Si Huan Zhong Lu, Haidian District, Beijing 100036 (China); Lai Min; Luo Zhong; Liu Peng; Yang Weihu [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2011-12-01

    To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: {yields} Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. {yields} The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. {yields} The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

  16. Enhancement of the power conversion efficiency for organic photovoltaic cells with a Liq/bathocuproine electron transport bilayer

    Organic photovoltaic (OPV) cells based on a poly(3-hexylthiophene) (P3HT):fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) electron transport layer were fabricated to enhance their power conversion efficiency (PCE). Absorbance spectra showed that the absorbance intensity of the spectra for the P3HT:PCBM active layer with a Liq layer in the wavelength between 500 and 600 nm was enhanced due to the damage of the active layer. The PCE of the fabricated OPV cells with a Liq/BCP layer was significantly enhanced by up to 4.29% in comparison with that of OPV cells with a BCP or a Liq layer. - Highlights: • Organic photovoltaic cell with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) layer. • The BCP layer prevented the performance deterioration. • The efficiency of the photovoltaic cell with a BCP/Liq layer was enhanced

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

    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.

  18. Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

    To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: → Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. → The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. → The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

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

    Hansen, Poul Erik; Spanget-Larsen, Jens

    2012-06-01

    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 in the harmonic and PT2 anharmonic approximations, as well as on experimental NMR parameters, i.e., proton chemical shifts (δH) and two-bond deuterium isotope effects on 13C chemical shifts (2ΔCOD). The procedures are applied in a discussion of the spectra of 2,6-dihydroxy-4-methylbenzaldehyde and 8-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 is supported by correlation with the IR spectra of a series of substituted derivatives.

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

    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.

  1. Influence of various chemical compounds on postharvest longevity of cut leaves of Waldsteinia geoides Willd.

    Maria P. Ulczycka-Walorska

    2014-09-01

    Full Text Available The influence of conditioning and different methods of application of chemical compounds on cut leaves of Waldsteinia geoides was assessed. Gibberellic acid and benzyladenine at a concentration of 50 or 100 mg × dm-3, and 8-hydroxyquinoline sulphate at a concentration of 200 mg × dm-3 were used in the process of conditioning. The leaves were conditioned in two different ways. In the first one, half of leaf stalks were soaked for 24 hours. In the latter, whole leaf blades were dipped for thirty seconds. Cut leaves were stored either in water or in the solution of 8-hydroxyquinoline sulphate at a concentration of 200 mg × dm-3. It was both the chemical compounds applied and the application method that influenced the postharvest longevity of the leaves. The leaves conditioned in 8HQS and stored in water, those conditioned in BA at a concentration of 50 mg × dm-3 and stored in 8HQS, and those which were not conditioned and stored in 8HQS exhibited the highest level of postharvest longevity. The application of 8HQS for conditioning had a favorable effect on the increase in the weight of Waldsteinia geoides cut leaves. 8HQS applied in storing resulted in a smaller decrease in the values of the leaf greenness index.

  2. Structure-based development of nitroxoline derivatives as potential multifunctional anti-Alzheimer agents.

    Knez, Damijan; Brus, Boris; Coquelle, Nicolas; Sosič, Izidor; Šink, Roman; Brazzolotto, Xavier; Mravljak, Janez; Colletier, Jacques-Philippe; Gobec, Stanislav

    2015-08-01

    Tremendous efforts have been dedicated to the development of effective therapeutics against Alzheimer's disease, which represents the most common debilitating neurodegenerative disease. Multifunctional agents are molecules designed to have simultaneous effects on different pathological processes. Such compounds represent an emerging strategy for the development of effective treatments against Alzheimer's disease. Here, we report on the synthesis and biological evaluation of a series of nitroxoline-based analogs that were designed by merging the scaffold of 8-hydroxyquinoline with that of a known selective butyrylcholinesterase inhibitor that has promising anti-Alzheimer properties. Most strikingly, compound 8g inhibits self-induced aggregation of the amyloid beta peptide (Aβ1-42), inhibits with sub-micromolar potency butyrylcholinesterase (IC50=215 nM), and also selectively complexes Cu(2+). Our study thus designates this compound as a promising multifunctional agent for therapeutic treatment of Alzheimer's disease. The crystal structure of human butyrylcholinesterase in complex with compound 8g is also solved, which suggests ways to further optimize compounds featuring the 8-hydroxyquinoline scaffold. PMID:26116179

  3. Enhancement of the power conversion efficiency for organic photovoltaic cells with a Liq/bathocuproine electron transport bilayer

    Xu, Ke; Kim, Dae Hun; Lee, Se Han; Kim, Tae Whan, E-mail: twk@hanyang.ac.kr

    2013-11-29

    Organic photovoltaic (OPV) cells based on a poly(3-hexylthiophene) (P3HT):fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) electron transport layer were fabricated to enhance their power conversion efficiency (PCE). Absorbance spectra showed that the absorbance intensity of the spectra for the P3HT:PCBM active layer with a Liq layer in the wavelength between 500 and 600 nm was enhanced due to the damage of the active layer. The PCE of the fabricated OPV cells with a Liq/BCP layer was significantly enhanced by up to 4.29% in comparison with that of OPV cells with a BCP or a Liq layer. - Highlights: • Organic photovoltaic cell with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) layer. • The BCP layer prevented the performance deterioration. • The efficiency of the photovoltaic cell with a BCP/Liq layer was enhanced.

  4. Electrochemistry and spectroelectrochemistry of bioactive hydroxyquinolines: a mechanistic study.

    Sokolová, Romana; Nycz, Jacek E; Ramešová, Šárka; Fiedler, Jan; Degano, Ilaria; Szala, Marcin; Kolivoška, Viliam; Gál, Miroslav

    2015-05-21

    The oxidation mechanism of selected hydroxyquinoline carboxylic acids such as 8-hydroxyquinoline-7-carboxylic acid (1), the two positional isomers 2-methyl-8-hydroxyquinoline-7-carboxylic acid (3) and 2-methyl-5-hydroxyquinoline-6-carboxylic acid (4), as well as other hydroxyquinolines were studied in aprotic environment using cyclic voltammetry, controlled potential electrolysis, in situ UV-vis and IR spectroelectrochemistry, and HPLC-MS/MS techniques. IR spectroelectrochemistry showed that oxidation unexpectedly proceeds together with protonation of the starting compound. We proved that the nitrogen atom in the heterocycle of hydroxyquinolines is protonated during the apparent 0.7 electron oxidation process. This was rationalized by the autodeprotonation reaction by another two starting molecules of hydroxyquinoline, so that the overall oxidation mechanism involves two electrons and three starting molecules. Both the electrochemical and spectroelectrochemical results showed that the oxidation mechanism is not influenced by the presence of the carboxylic group in the chemical structure of hydroxyquinolines, as results from oxidation of 2,7-dimethyl-5-hydroxyquinoline (6). In the presence of a strong proton acceptor such as pyridine, the oxidation ECEC process involves two electrons and two protons per one molecule of the hydroxyquinoline derivative. The electron transfer efficiency of hydroxyquinolines in biosystems may be related to protonation of biocompounds containing nitrogen bases. Molecular orbital calculations support the experimental findings. PMID:25915694

  5. Translational downregulation of HSP90 expression by iron chelators in neuroblastoma cells.

    Sidarovich, Viktoryia; Adami, Valentina; Gatto, Pamela; Greco, Valentina; Tebaldi, Toma; Tonini, Gian Paolo; Quattrone, Alessandro

    2015-01-01

    Iron is an essential cellular nutrient, being a critical cofactor of several proteins involved in cell growth and replication. Compared with normal cells, neoplastic cells have been shown to require a greater amount of iron, thus laying the basis for the promising anticancer activity of iron chelators. In this work, we evaluated the effects of molecules with iron chelation activity on neuroblastoma (NB) cell lines. Of the 17 iron chelators tested, six reduced cell viability of two NB cell lines with an inhibition of growth of 50% below 10 µM; four of the six molecules-ciclopirox olamine (CPX), piroctone, 8-hydroxyquinoline, and deferasirox-were also shown to efficiently chelate intracellular iron within minutes after addition. Effects on cell viability of one of the compounds, CPX, were indeed dependent on chelation of intracellular iron and mediated by both G0/G1 cell cycle block and induction of apoptosis. By combined transcriptome and translatome profiling we identified early translational downregulation of several members of the heat shock protein group as a specific effect of CPX treatment. We functionally confirmed iron-dependent depletion of HSP90 and its client proteins at pharmacologically achievable concentrations of CPX, and we extended this effect to piroctone, 8-hydroxyquinoline, and deferasirox. Given the documented sensitivity of NB cells to HSP90 inhibition, we propose CPX and other iron chelators as investigational antitumor agents in NB therapy. PMID:25564462

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

    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

  7. Nanomolar colorimetric quantitative detection of Fe3 + and PPi with high selectivity

    Li, Zhanxian; Li, Haixia; Shi, Caixia; Yu, Mingming; Wei, Liuhe; Ni, Zhonghai

    2016-04-01

    A novel rhodamine and 8-hydroxyquinoline-based derivative was synthesized, which is shown to act as a colorimetric chemosensor for Fe3 + in aqueous solution with high selectivity over various environmentally and biologically relevant metal ions and anions with a distinct color change from colorless to pink in very fast response time (sensor can be as low as 15 nM. The 'in situ' prepared Fe3 + complex (1 ṡ Fe) showed high selectivity toward PPi against many common anions, and sensitivity (the LOD can be as low as 71 nM). In addition, both the chemosensor and the 'in situ' prepared Fe3 + complex are reusable for the detection of Fe3 + and PPi respectively.

  8. Nanomolar colorimetric quantitative detection of Fe(3+) and PPi with high selectivity.

    Li, Zhanxian; Li, Haixia; Shi, Caixia; Yu, Mingming; Wei, Liuhe; Ni, Zhonghai

    2016-04-15

    A novel rhodamine and 8-hydroxyquinoline-based derivative was synthesized, which is shown to act as a colorimetric chemosensor for Fe(3+) in aqueous solution with high selectivity over various environmentally and biologically relevant metal ions and anions with a distinct color change from colorless to pink in very fast response time (sensor can be as low as 15nM. The 'in situ' prepared Fe(3+) complex (1⋅Fe) showed high selectivity toward PPi against many common anions, and sensitivity (the LOD can be as low as 71nM). In addition, both the chemosensor and the 'in situ' prepared Fe(3+) complex are reusable for the detection of Fe(3+) and PPi respectively. PMID:26878355

  9. Optical characterization of a new soluble Alq3 derivative having a 5-alkyl group

    We synthesized a new green-emitting material 5-{(5-bicyclo[2.2.1]hept-5-en-2-yl-methoxy)-pentylamino]-methyl} -8-quinolinato-(di-8-hydroxyquinoline)-aluminium (5-A-Alq3) by modifying the well-known green-emitting molecule tris(8-hydroxyquinolinato)aluminium (Alq3). The new molecule 5-A-Alq3 is soluble in conventional organic solvents, whereas luminescent and current carrying properties of Alq3 are preserved. We carried out a thorough optical characterization of 5-A-Alq3 and compared its optical characteristics with those of Alq3. Moreover, we demonstrated the operation of an organic light-emitting diode that had a 5-A-Alq3 emitting layer, and showed an electroluminescence spectrum with a peak at 542 nm.

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

    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.

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

    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.

  12. Responses of the L5178Y tk/sup +//tk/sup -/ mouse lymphoma cell forward mutation assay. II. 18 coded chemicals

    McGregor, D.B.; Brown, A.; Cattanach, P.; Edwards, I.; McBride, D.; Caspary, W.J.

    1988-01-01

    Eighteen chemicals were tested for their mutagenic potential in the L5178Y tk/sup +///sup -/ mouse lymphoma cell forward mutation assay by the use of procedures based upon those described previously. Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 ..mu..g/ml. The chemicals were tested at least twice. Significant responses were obtained with benzofuran, benzyl chloride, bromodichloromethane, butylated hydroxytoluene, chlorendic acid, o-chlorobenzalmalonitrile, 1,2,3,4-diepoxybutane, dimethyl formamide, dimethyl hydrogen phosphite, furfural, glutaraldehyde, hydroquinone, 8-hydroxyquinoline, and resorcinol. Apart from bromodichloromethane, butylated hydroxytoluene and dimethyl hydrogen phosphite, rat liver S9 mix was not a requirement for the activity of any of these compounds. Chemicals not identified as mutagens were water, tert-butyl alcohol, pyridine, and witch hazel.

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

    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...

  14. Extraction of copper(II) and zinc(II) from chloride media with mixed extractants

    Extraction of copper(II) and zinc(II) from acidic chloride solutions with mixtures of two extractants: a basic or solvating one and a chelating extractant was discussed. Processes for recovery and separation of Cu(II) from Zn(II) were proposed, which consist of the following steps: extraction from chloride media with the formation of metal chlorocomplex ion pair or solvate, scrubbing of chloride ions with an aqueous solution of appropriate pH with simultaneous transfer of the metal ion to the chelate, traditional stripping with sulphuric acid and conditioning of the basic extractant. Both effective recovery and separation of metal ions with simultaneous change of the system from the chloride to the sulphate state can be achieved. A bifunctional reagent, such as alkyl derivative of 8-hydroxyquinoline, can be also used instead of the extractant mixture. (author)

  15. Extractant of copper(II) and zinc(II) from chloride media with mixed extractants

    Extraction of copper(II) and zinc(II) from acidic chloride solutions with mixtures of two extractants: a basic or solvating one and a chelating extractant was discussed. The processes for recovery and separation of Cu(II) from Zn(II) were proposed. The processes consist of the following steps: extraction from chloride media with the formation of metal chloro-complex ion pair or solvate, scrubbing of chloride ions with an aqueous solution of appropriate pH with simultaneous transfer of the metal ion to the chelate, traditional stripping with sulphuric acid and conditioning of the basic extractant. Both effective recovery and separation of metal ions with simultaneous change of the system from the chloride to sulphate one can be achieved. A bifunctional reagent, such as alkyl-derivative of 8-hydroxyquinoline, can be also used instead of the extractant mixture. (authors)

  16. White organic light-emitting diodes based on a combined electromer and monomer emission in doubly-doped polymers

    We report on white organic light-emitting diodes (WOLEDs) based on polyvinylcarbazole (PVK) doped with 1,1-bis((di-4-tolylamino)phenyl)cyclohexane (TAPC) and perylene, and investigate the luminescence mechanism of the devices. The chromaticity of light emission can be tuned by adjusting the concentration of the dopants. White light with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33, 0.34) is achieved by mixing the yellow electromer emission of TAPC and the blue monomer emission of perylene from the device ITO/PVK: TAPC: perylene (100:9:1 in wt.) (100 nm)/tris-(8-hydroxyquinoline aluminum (Alq3) (10 nm)/Al. The device exhibits a maximal luminance of 3727 cd/m2 and a current efficiency of 2 cd/A. (interdisciplinary physics and related areas of science and technology)

  17. Preparation of gallium-68 radiopharmaceuticals for positron tomography. Progress report, November 1, 1978-October 31, 1979

    Although the germanium-gallium generator is probably the only source of positron-emitting radionuclides that would enable the wide application of positron tomography, the generator system in use suffers from several major disadvantages. The most important of these is that the generator is eluted with EDTA, and EDTA forms a very strong chelate with gallium. In order to produce radiopharmaceuticals other than gallium-68 EDTA it is necessary to break the stable EDTA complex and remove all the EDTA. A new generator system using a solvent extraction system which will produce gallium-68 8-hydroxyquinoline, a weak chelate has been developed. Using this agent, several gallium-68 radiopharmaceuticals have been synthesized and tested in vitro and in vivo. Attempts have been made using polarographic and chromatographic techniques to investigate the stability of gallium-68 complexes with a series of cryptates

  18. Radio frequency magnetron sputter-deposited indium tin oxide for use as a cathode in transparent organic light-emitting diode

    Indium tin oxide (ITO) films were prepared by radio frequency magnetron sputtering at room temperature, for use as a cathode in a transparent organic light-emitting diode (TOLED). To minimize damage to the TOLED by the ITO sputtering process, the target-to-substrate distance was increased to 20 cm. An ITO film deposited at the optimum oxygen partial pressure exhibited an electrical resistivity as low as 4.06 x 10-4 Ω cm and a high optical transmittance of 91% in the visible range. The film was used as a transparent cathode for a TOLED with structure of an ITO coated glass substrate / Naphthylphenyldiamide (60 nm) / Tris-(8-hydroxyquinoline) aluminum (60 nm) / LiF (1 nm) / Al (2 nm) / Ag (8 nm) / ITO cathode (100 nm). A maximum luminance of 37,000 cd/m2 was obtained. The device performance was comparable to a conventional OLED

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

    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.

  20. Corrosion Behavior of Passivated 316LSS with Ag Coating as PEMFC Bipolar Plate

    Naibao Huang

    2011-01-01

    Full Text Available A new chemical passivation technique, which contained 20 g/L hydrogen peroxide, 3.75 g/L sodium silicate, 1.25 g/L sodium carbonate, 3.75 g/L lactic acid and 0.75 g/L 8-hydroxyquinoline, was used to modify 316 stainless steel with Ag coating (Ag-coated 316SS as PEMFC bipolar plates. The results indicated that the compact passive film had been obtained on the surface of Ag-coated 316SS. The passivation process could not only increase contact angle (from 58∘ to 104∘ but also decreased pinhole defects of Ag-coated 316SS. Electrochemical test manifested that the passivation process could reduce Ag-coated 316SS's double layer capacitance (Cd, and increase its charge transfer resistance. So, it provided significant protection against corrosion for Ag-coated 316SS in PEMFC environment.

  1. UV exposure and photon degradation of Alq3 powders

    Tris-(8-hydroxyquinoline)aluminum (Alq3) is a widely used light emitting material. It is also used as an electron transporting layer in organic light emitting devices (OLEDs). Degradation is, however, a major problem in these devices. The device performance is affected by parameters such as air, moisture and light exposure. In this work the effect of photon degradation of Alq3 in air is investigated. Alq3 phosphor powder was synthesized using a co-precipitation method and recrystalized in acetone. The structure of the sample was determined by using x-ray diffraction (XRD). The averaging particle size estimated from the broadened XRD peaks using Scherrer's equation was 40±4 nm in diameter. The excitation photoluminescence data that was collected correspond well to the absorption data. To study the photon degradation, the sample was irradiated with an UV lamp for ∼330h. The emission data was collected and the change in photoluminescence intensity with time was monitored.

  2. Tubular solids of lanthanide-doped polyoxometalates in micrometer-scale: synthesis and NIR-luminescent properties

    A series of lanthanide-doped polyoxometalate microtubes, Ln-SiW12 (Ln=Nd, Dy and Yb), have been synthesized, and characterized by X-ray diffraction, elemental analysis and thermogravimetric analysis. In the microtubes, the lanthanide cations combine with polyanions through electrostatic interaction. Furthermore, the lanthanide-doped microtubes were chelated with 8-hydroxyquinoline (HQ) in a post-synthesis step (designed as LnQ-SiW12). The LnQ-SiW12 show characteristic near-infrared (NIR) luminescence, corresponding to Ln3+ ions due to efficient energy transfer from Q to the Ln3+ ions through antenna effect. - Highlights: • A series of lanthanide-doped polyoxometalate microtubes have been firstly synthesized. • The Ln-SiW12 microtubes were chelated with HQ in a post-synthesis step. • The LnQ-SiW12 microtubes show characteristic NIR luminescence through antenna effect

  3. The influence of exciton behavior on luminescent characteristics of organic light-emitting diodes

    We used N,N'-bis-(1-naphthyl)-N,N'-1-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB), 4,4'-N,N'-dicarbazole-biphenyl (CBP) and tris(8-hydroxyquinoline) aluminum (Alq3) to fabricate tri-layer electroluminescent (EL) device (device structure: ITO/NPB/CBP/Alq3/Al). In photoluminescence (PL) spectra of this device, the emission from NPB shifted to shorter wavelength accompanying with the decrease of its emission intensity and moreover the emission intensity of Alq3 increased relatively with the increase of reverse bias voltage. The blue-shifted emission and the decrease in emission intensity of NPB were attributed to the polarization and dissociation of NPB excitons under reverse bias voltage. The increase of emission intensity of Alq3 benefited from the recombination of electrons (produced by the dissociation of NPB exciton) and holes (injected from the Al cathode)

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

    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.

  5. Linewidth Narrowing and Intensity Enhancement of Wavelength Tunable MOLEDs

    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.

  6. PURIFICATION AND CHARACTERIZATION OF KERATINASE FROM HAIR-DEGRADING STREPTOMYCES ALBUS

    Sreenivasa Nayaka, Gireesh Babu K and GM Vidyasagar*

    2013-03-01

    Full Text Available The keratinase waste produced in large quantities all over the world from animals and birds including human beings. As the physiological and chemical methods of keratin degradation are not easy possible, the biological method has gained importance. The present study investigated purified keratinase from Keratinolytic Streptomyces albus. The cell-bound keratinolytic enzyme was purified 32.72-fold by gel filtration chromatography. The enzyme was characterized as a serine protease with a molecular mass of 29-35kD. Optimal activity pH and Temperature was measured at 7.0 and 400C furthermore, the various inhibitors had different effect on enzyme activity. PMSF and heavy metal ion HgCl2 were the most potent inhibitors and EDTA induced the activity by more than 135%, 2-mercaptoethanol did not show any impact on the enzyme, where pCMB, KCN, 8-hydroxyquinoline and cystine inhibited activity moderately.

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

    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.

  8. Combination treatment with fasudil and clioquinol produces synergistic anti-tumor effects in U87 glioblastoma cells by activating apoptosis and autophagy.

    He, Mingliang; Luo, Ming; Liu, Qingyu; Chen, Jingkao; Li, Kaishu; Zheng, Meiguang; Weng, Yinlun; Ouyang, Leping; Liu, Anmin

    2016-04-01

    Survival of patients with glioblastoma (GBM) remains poor, and novel treatment methods are urgently needed. In this study, we tested the effects of a combination of fasudil, a ROCK inhibitor, and clioquinol, an 8-hydroxyquinoline derivative with antimicrobial properties, on human GBM U87 cells. Combination treatment synergistically inhibited the viability of glioma cells but not mouse normal neuron HT22 cells and significantly induced mitochondria-mediated apoptosis. Moreover, the combination was also found to trigger macro-autophagy (henceforth referred to as autophagy) by increasing the expression levels of several proteins involved in the induction of autophagy. Further studies showed that 3-methyladenine (3-MA) or chloroquine (CQ), two autophagy inhibitors, abrogated the cytotoxic effects of the combination treatment as well as the autophagy. Overall, we demonstrated that fasudil and clioquinol show synergistic anti-cancer effects, providing evidence for the further development of combination therapy for GBM. PMID:26725099

  9. SYNTESIS AND CHARACTERISATION OF SOME MIXED LIGAND COMPLEXES OF THALLIUM (I METAL

    Kumari Seema* and Rajneesh Kumar

    2014-11-01

    Full Text Available The present investigation has been undertaken to examine complex formation by thallium (I derivatives of 2-nitro phenol (ONP, 2,4-dinitrophenol (DNP, 2,4,6-trinitrophenol (TNP, 1- nitroso-2-naphthol (1N2N, 8-hydroxyquinoline (8HQ, and 2-aminobenzoic acid (OABA with thioacetamide. They have general formula [ML (L′ 2], where M = Tl (I, L = deprotonated ONP, DNP, TNP, 8-HQ, 1N2N and OABA and L′ = thioacetamide. Thioacetamide is ambidentate ligand and can donate through sulfur or nitrogen or both. The preparation of mixed ligand complex with the thallium (I salt of o-nitrophenol and 2, 4-dinitrophenol with the thioacetamide (TAD was unsuccessful.

  10. Synchronous Tricolor Emission-Based White Light from Quantum Dot Complex.

    Pramanik, Sabyasachi; Bhandari, Satyapriya; Roy, Shilaj; Chattopadhyay, Arun

    2015-04-01

    Herein we report the generation of synchronous tricolor emission for a single wavelength excitation from a quantum dot complex (QDC). The single-component QDC was formed out of a complexation reaction, at room temperature, between ligand-free Mn(2+)-doped ZnS quantum dots (Qdots) and a mixture of two organic ligands (acetylsalicylic acid and 8-hydroxyquinoline). Furthermore, the tunability in chromaticity color coordinates, which is important for solid-state lighting, was achieved following the synthesis of QDC. Moreover, the photostable QDC emitted white light (λex 320 nm) with (0.30, 0.33) and (0.32, 0.32) chromaticity color coordinates in the liquid and the solid phases, respectively. Hence, the white light-emitting QDC may be a superior material for light-emitting applications. PMID:26262986

  11. Tip relaxation in atomic force microscopy imaging simulations to resolve intermolecular bonds

    Lee, Alex; Sakai, Yuki; Chelikowsky, Jim

    Experimental noncontact atomic force microscopy (AFM) studies have reported distinct lines in regions with no electron density for a variety of systems. The appearance of these lines is unexpected because Pauli repulsion is thought to be the dominant factor in the AFM imaging mechanism. These lines have been proposed to represent intermolecular bonding. Recent theoretical studies have shown that accounting for tip probe relaxation can sharpen images and highlight features that make simulations more comparable to experiment. We will apply a similar tip relaxation scheme to our computational method-which uses an ab initio real-space pseudopotential formalism with frozen density embedding theory added-to the study of dibenzo[a,h]thianthrene and an 8-hydroxyquinoline dimer to develop our interpretation of imaged intermolecular bonds. Work is supported by the DOE under DOE/DE-FG02-06ER46286 and by the Welch Foundation under Grant F-1837. Computational resources were provided by NERSC and XSEDE.

  12. Kinetics of transient electroluminescence in organic light emitting diodes

    Shukla, Manju; Kumar, Pankaj; Chand, Suresh; Brahme, Nameeta; Kher, R. S.; Khokhar, M. S. K.

    2008-08-01

    Mathematical simulation on the rise and decay kinetics of transient electroluminescence (EL) in organic light emitting diodes (OLEDs) is presented. The transient EL is studied with respect to a step voltage pulse. While rising, for lower values of time, the EL intensity shows a quadratic dependence on (t - tdel), where tdel is the time delay observed in the onset of EL, and finally attains saturation at a sufficiently large time. When the applied voltage is switched off, the initial EL decay shows an exponential dependence on (t - tdec), where tdec is the time when the voltage is switched off. The simulated results are compared with the transient EL performance of a bilayer OLED based on small molecular bis(2-methyl 8-hydroxyquinoline)(triphenyl siloxy) aluminium (SAlq). Transient EL studies have been carried out at different voltage pulse amplitudes. The simulated results show good agreement with experimental data. Using these simulated results the lifetime of the excitons in SAlq has also been calculated.

  13. Exciton formation in dye doped OLEDs using electrically detected magnetic resonance

    Batagin-Neto, Augusto; Gómez, Jorge A.; Castro, Fernando A.; Nüesch, Frank; Zuppiroli, Libero; Graeff, Carlos F. O.

    2012-02-01

    Electrically Detected Magnetic Resonance (EDMR) was used to investigate the influence of dye doping molecules on spin-dependent exciton formation in Aluminum (III) 8-hydroxyquinoline (Alq3) based OLEDs with different device structures and temperature ranges. 4-(dicyanomethylene)-2-methyl-6-{2-[(4-diphenylamino-phenyl]ethyl}-4H-pyran (DCM-TPA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene) were used as dopants. A strong temperature dependence have been observed for doped OLEDs, with a decrease of two orders of magnitude in EDMR signal for temperatures above 200 K. The signal temperature dependence were fitted supposing different spin-lattice relaxation processes. The results suggest that thermally activated vibrations of dopants molecules induce spin pair dissociation, reducing the signal.

  14. Tubular solids of lanthanide-doped polyoxometalates in micrometer-scale: synthesis and NIR-luminescent properties

    Yu, Xia [Key Laboratory of Polyoxometalate Science of the Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024 (China); Analytical and Testing Center, Beihua University, Jilin, 132013 (China); Peng, Jun, E-mail: jpeng@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of the Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024 (China); Shi, Zhenyu; Shen, Yan; Zhang, Zheyu; Li, Guangzhe [Key Laboratory of Polyoxometalate Science of the Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024 (China)

    2015-04-15

    A series of lanthanide-doped polyoxometalate microtubes, Ln-SiW{sub 12} (Ln=Nd, Dy and Yb), have been synthesized, and characterized by X-ray diffraction, elemental analysis and thermogravimetric analysis. In the microtubes, the lanthanide cations combine with polyanions through electrostatic interaction. Furthermore, the lanthanide-doped microtubes were chelated with 8-hydroxyquinoline (HQ) in a post-synthesis step (designed as LnQ-SiW{sub 12}). The LnQ-SiW{sub 12} show characteristic near-infrared (NIR) luminescence, corresponding to Ln{sup 3+} ions due to efficient energy transfer from Q to the Ln{sup 3+} ions through antenna effect. - Highlights: • A series of lanthanide-doped polyoxometalate microtubes have been firstly synthesized. • The Ln-SiW{sub 12} microtubes were chelated with HQ in a post-synthesis step. • The LnQ-SiW{sub 12} microtubes show characteristic NIR luminescence through antenna effect.

  15. Unusual Cyclodextrin Derivatives as a New Avenue to Modulate Self- and Metal-Induced Aβ Aggregation.

    Oliveri, Valentina; Bellia, Francesco; Pietropaolo, Adriana; Vecchio, Graziella

    2015-09-28

    Mounting evidence suggests an important role of cyclodextrins in providing protection in neurodegenerative disorders. Metal dyshomeostasis is reported to be a pathogenic factor in neurodegeneration because it could be responsible for damage involving oxidative stress and protein aggregation. As such, metal ions represent an effective target. To improve the metal-binding ability of cyclodextrin, we synthesized three new 8-hydroxyquinoline-cyclodextrin conjugates with difunctionalized cyclodextrins. In particular, the 3-difunctionalized regioisomer represents the first example of cyclodextrin with two pendants at the secondary rim, resulting in a promising compound. The derivatives have significant antioxidant capacity and the powerful activity in inhibiting self-induced amyloid-β aggregation seems to be led by synergistic effects of both cyclodextrin and hydroxyquinoline. Moreover, the derivatives are also able to complex metal ions and to inhibit metal-induced protein aggregation. Therefore, these compounds could have potential as therapeutic agents in diseases related to protein aggregation and metal dyshomeostasis. PMID:26298549

  16. An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III ions

    Markus Albrecht

    2009-12-01

    Full Text Available A facile synthesis of a highly preorganized tripodal enterobactine-type ligand 1a-H3 consisting of a chiral C3-symmetric macrocyclic peptide and three tridentate 2-amido-8-hydroxyquinoline coordinating units is presented. Complex formation with various metal ions (Al3+, Ga3+, Fe3+, La3+ and Eu3+ was investigated by spectrophotometric methods. Only in the case of La3+ and Eu3+ were well defined 1 : 1 complexes formed. On the basis of CD spectroscopy and DFT calculations the configuration at the metal centre of the La3+ complex was determined to show Λ helicity. The coordination compounds [(1aLn] presented should be prototypes for further lanthanide(III complexes with an enterobactine analogue binding situation.

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

    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. PMID:26725969

  18. Substrate temperature controls molecular orientation in two-component vapor-deposited glasses.

    Jiang, J; Walters, D M; Zhou, D; Ediger, M D

    2016-04-01

    Vapor-deposited glasses can be anisotropic and molecular orientation is important for organic electronics applications. In organic light emitting diodes (OLEDs), for example, the orientation of dye molecules in two-component emitting layers significantly influences emission efficiency. Here we investigate how substrate temperature during vapor deposition influences the orientation of dye molecules in a model two-component system. We determine the average orientation of a linear blue light emitter 1,4-di-[4-(N,N-diphenyl)amino]styryl-benzene (DSA-Ph) in mixtures with aluminum-tris(8-hydroxyquinoline) (Alq3) by spectroscopic ellipsometry and IR dichroism. We find that molecular orientation is controlled by the ratio of the substrate temperature during deposition and the glass transition temperature of the mixture. These findings extend recent results for single component vapor-deposited glasses and suggest that, during vapor deposition, surface mobility allows partial equilibration towards orientations preferred at the free surface of the equilibrium liquid. PMID:26922903

  19. Fused Methoxynaphthyl Phenanthrimidazole Semiconductors as Functional Layer in High Efficient OLEDs.

    Jayabharathi, Jayaraman; Ramanathan, Periyasamy; Karunakaran, Chockalingam; Thanikachalam, Venugopal

    2016-01-01

    Efficient hole transport materials based on novel fused methoxynaphthyl phenanthrimidazole core structure were synthesised and characterized. Their device performances in phosphorescent organic light emitting diodes were investigated. The high thermal stability in combination with the reversible oxidation process made promising candidates as hole-transporting materials for organic light-emitting devices. Highly efficient Alq3-based organic light emitting devices have been developed using phenanthrimidazoles as functional layers between NPB [4,4-bis(N-(1-naphthyl)-N-phenylamino)biphenyl] and Alq3 [tris(8-hydroxyquinoline)aluminium] layers. Using the device of ITO/NPB/4/Alq3/LiF/Al, a maximum luminous efficiency of 5.99 cd A(-1) was obtained with a maximum brightness of 40,623 cd m(-2) and a power efficiency of 5.25 lm W(-1). PMID:26585347

  20. White organic light-emitting diodes based on a combined electromer and monomer emission in doubly-doped polymers

    Meng, Ling-Chuan; Lou, Zhi-Dong; Yang, Sheng-Yi; Hou, Yan-Bing; Teng, Feng; Liu, Xiao-Jun; Li, Yun-Bai

    2012-08-01

    We report on white organic light-emitting diodes (WOLEDs) based on polyvinylcarbazole (PVK) doped with 1,1-bis((di-4-tolylamino)phenyl)cyclohexane (TAPC) and perylene, and investigate the luminescence mechanism of the devices. The chromaticity of light emission can be tuned by adjusting the concentration of the dopants. White light with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33, 0.34) is achieved by mixing the yellow electromer emission of TAPC and the blue monomer emission of perylene from the device ITO/PVK: TAPC: perylene (100:9:1 in wt.) (100 nm)/tris-(8-hydroxyquinoline aluminum (Alq3) (10 nm)/Al. The device exhibits a maximal luminance of 3727 cd/m2 and a current efficiency of 2 cd/A.

  1. Current fluctuations in polystyrene nano-compounds

    Scaldaferri, R.; Bonavolontà, C.; Pepe, G. P.; Salzillo, G.; Borriello, A.; Pedaci, I.

    2010-01-01

    The current fluctuations in a polystyrene matrix (PS) doped by gold nanoparticles (Au-NPs) and small conjugated molecules of 8-hydroxyquinoline (8HQ) have been characterized. The electrical properties of the PS composite allow using it as a responsive layer in non-volatile memory devices due to its switching capability between two well separated conducting states. The analysis of current fluctuations at fixed bias voltages showed the presence of two states in charge carrier transport regardless of the operating conducting state of the device. Moreover, noise spectra have been investigated in the low frequency region, allowing the estimation of charge relaxation times between current levels in the two memory states. The presence of these slow and large fluctuations can seriously affect the final electrical performances of this class of nanostructured memories.

  2. Fabrication of TiO{sub 2} nanotubes by atomic layer deposition and their photocatalytic and photoelectrochemical applications

    Wang, Chih-Chieh; Kei, Chi-Chung; Perng, Tsong-Pyng, E-mail: tpperng@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)

    2011-09-07

    The formation of TiO{sub 2} nanotubes was conducted by atomic layer deposition (ALD) with tris-(8-hydroxyquinoline) gallium (GaQ{sub 3}) nanowires as a template at different substrate temperatures, 50, 100, and 200 deg. C. TiO{sub 2} nanotubes were formed only at 50 and 100 deg. C. Although a higher growth rate at 50 deg. C was observed, nanotubes with better uniformity, conformality, and less residual chloride were obtained at 100 deg. C because of a different formation mechanism. A photocatalysis test of TiO{sub 2} nanotubes prepared by different cycle numbers at 100 {sup 0}C was conducted. It showed that TiO{sub 2} nanotubes prepared by 400 cycles of ALD and treated at 700 deg. C for 1 h to form anatase phase had the best photocatalytic performance. Compared with P-25, the nanotubes showed higher photocatalytic degradation of rhodamine B and water splitting efficiency.

  3. Novel 5-carboxy-8-HQ based histone demethylase JMJD2A inhibitors: introduction of an additional carboxyl group at the C-2 position of quinoline.

    Feng, Taotao; Li, Dongdong; Wang, Hai; Zhuang, Jian; Liu, Fang; Bao, Qichao; Lei, Yonghua; Chen, Weilin; Zhang, Xiaojin; Xu, Xiaoli; Sun, Haopeng; You, Qidong; Guo, Xiaoke

    2015-11-13

    A series of JMJD2A inhibitors had been designed by analyzing the binding mode of 5-carboxy-8-hydroxyquinoline (5-carboxy-8-HQ) with JMJD2A. The inhibitory activity of the synthesized compounds against JMJD2A was determined, followed by docking simulations to understand the structure-activity relationships. Compounds with potent JMJD2A inhibitory activity demonstrated outstanding selectivity for JMJD2A over PHD2. Several potent compounds were selected to evaluate their anti-proliferative activity on tumor cell lines. Among them, compound 6p displayed the best anti-proliferative activity. Based on these in vitro biological data, seven compounds were chosen to determine their physicochemical properties. Compound 6p displayed good aqueous solubility and better permeability than 5-carboxy-8-HQ. Our data recognized that compound 6p could be considered as a starting point for development of new JmjC inhibitors. PMID:26491978

  4. Organic light-emitting diodes with nanostructured fullerene ultrathin layers

    Lü, Zhaoyue; Deng, Zhenbo; Zheng, Jianjie; Yin, Yuehong; Chen, Yanli; Wang, Yongsheng

    2010-01-01

    Organic light-emitting diodes (OLEDs) with nanostructured fullerene (C 60) ultrathin layers were fabricated. The luminance and efficiency are decreased due to exciton quenching in the OLEDs with C 60 layers at the N,N‧-Di (naphth-2-yl)-N, N‧-diphenyl-benzidine (NPB)/8-hydroxyquinoline aluminum (Alq 3) interface. It is opposite to the results reported by Kato [K. Kato, K. Takahashi, K. Suzuki, T. Sato, K. Shinbo, F. Kaneko et al., Curr. Appl. Phys. 5, 2005, 321]. And C 60 ultrathin layers play a role of weak p-type delta-dopant in the NPB layer due to forming of a charge transfer complex C 60-:NPB +. The current density and luminance are enhanced in the OLEDs with 0.7 nm C 60 ultrathin layers inserted in NPB layer. A suggested explanation is p-type delta-doping effect in the NPB layer which increases the charge mobility of NPB films.

  5. Comparing a series of 8-quinolinolato complexes of aluminium, titanium and zinc as initiators for the ring-opening polymerization of rac-lactide.

    Bakewell, Clare; Fateh-Iravani, Giovanna; Beh, Daniel W; Myers, Dominic; Tabthong, Sittichoke; Hormnirun, Pimpa; White, Andrew J P; Long, Nicholas; Williams, Charlotte K

    2015-07-21

    The preparation and characterization of a series of 8-hydroxyquinoline ligands and their complexes with Ti(IV), Al(III) and Zn(II) centres is presented. The complexes are characterized using NMR spectroscopy, elemental analysis and, in some cases, by single crystal X-ray diffraction experiments. The complexes are compared as initiators for the ring-opening polymerization of racemic-lactide; all the complexes show moderate/good rates and high levels of polymerization control. In the case of the titanium or aluminium complexes, moderate iso-selectivity is observed (Pi = 0.75), whereas in the case of the zinc complexes, moderate hetero-selectivity is observed (Ps = 0.70). PMID:25748327

  6. 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

    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.

  7. Magnetoresistance in organic spin-valve devices with low work-function metal

    Jang, H.-Jae; Pernstich, Kurt P.; Gundlach, David J.; Jurchescu, Oana D.; Richter, Curt A.

    2012-02-01

    Organic thin-films have recently generated interest for studies related to spin-based phenomena. Long spin transport through organic semiconductors has been predicted due to their weak spin-orbit and small hyperfine interactions. This property gives them great potential for spintronic applications. While magnetoresistance (MR) has been reported by multiple research groups, controversy still remains over whether the basic mechanism is the transport of spin-polarized carriers through the organic semiconducting thin films or transport via unintended tunneling paths through the devices. We investigate the MR of organic thin-film spin valve devices fabricated from tris[8-hydroxyquinoline]aluminium (Alq3), high Tc transition ferromagnetic metals, and low work-function metals. The devices are fabricated without the exposure to the air to minimize the oxidation. We observe the MR as large as 3 % at 4.5K in devices containing Alq3 as thick as 150 nm.

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

    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.

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

    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.

  10. MULTILAYER ORGANIC LEDS BASED ON A NEW DYE-DOPED POLYMER

    Zhi-yuan Xie; Jing-song Huang; Chuan-nan Li; Bu-wen Xiao; Shi-yong Liu; Dong-feng Li

    1999-01-01

    A blue dye, 1-benzothiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m2 and 0.31 m/W, respectively.

  11. Determination of trace elements in acid rain by reversed-phase extraction chromatography and neutron activation

    A preconcentration neutron activation analysis (PNAA) method involving reversed-phase extraction chromatography on 8-hydroxyquinoline-loaded Amberlite XAD-2 resin has been developed for the simultaneous determination of selected trace elements in acid rain and natural water samples. Quantitative retention has been achieved for Co, Cu, Hg, V and Zn at pH 6.0 and for Cd at pH 7.0. Various factors that can influence the preconcentration procedure have been studied in detail. Concentrations of the elements have been determined by the direct irradiation of the resin without eluting them from the column. Both precision and accuracy of the PNAA method are very good. The detection limits vary between 0.01 and 3 ppb. (author) 48 refs.; 2 figs.; 4 tabs

  12. 8-Hydroxyqunoline adsorption from aqueous solution using powdered orange peel: kinetic and isotherm study

    Siraj Khalid

    2015-12-01

    Full Text Available Adsorption of 8-hydroxyquinoline (8HQ on powdered orange peel (POP, a locally available adsorbent, has been studied. Experiment was performed on different 8HQ concentration, particle size, and adsorbent dosage. The Langmuir and Freundlich adsorption isotherm model has been tested. The obtained results best fitted the Langmuir model, suggesting monolayer adsorption of 8HQ on POP. The kinetic studies for the adsorption process were also carried out using pseudo-first- and pseudo-second-order models, and the data obtained is best fitted to the pseudo-second-order kinetic model. Thermodynamic parameters were calculated for the adsorption process and the result showed that the values of ΔGads, ΔHads, and ΔSads are −1171.4J/mol, −140J/mol and −40.5 J/K at 303 K. Thus, it can be summarized that the adsorption of 8HQ is spontaneous, chemisorbed, monolayer, and exothermic

  13. Improvement of Efficiency and Brightness of Red Organic Light-Emitting Devices Using Double-Quantum-Well Configuration

    Mi, Rui; Cheng, Gang; Zhao, Yi; Xie, Wen-Fa; Hou, Jing-Ying; Ding, Tao; Liu, Shi-Yong

    2004-03-01

    We present red double-quantum-well organic light-emitting devices (DQW-OLEDs), in which N,N-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyo-4,4'-diamine (NPB) is used as potential barriers and hole transport layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-thtramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped tris (8-hydroxyquinoline) aluminium (Alq3) as potential wells and emitter, undoped Alq3 as electron transport layer, respectively. The turn-on voltage is about 4 V. The maximum brightness and electroluminescent (EL) efficiency of the DQW device can reach 5916 cd m-2 at 16 V and 2.85 cd A-1 at 7 V, respectively. In addition, the EL efficiency of the DQW device is relatively independent of the drive voltage in the range from 5 V to 16 V.

  14. Improvement of Efficiency and Brightness of Red Organic Light-Emitting Devices Using Double-Quantum-Well Configuration

    MI Rui; CHENG Gang; ZHAO Yi; XIE Wen-Fa; HOU Jing-Ying; DING Tao; LIU Shi-Yong

    2004-01-01

    @@ We present red double-quantum-well organic light-emitting devices (DQW-OLEDs), in which N,N-bis-(1-naphthyl)N,N′-diphenyl-1,1′-biphenyo-4,4'-diamine (NPB) is used as potential barriers and hole transport layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7, 7-thtramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped tris (8-hydroxyquinoline) aluminum (Alq3) as potential wells and emitter, undoped Alq3 as electron transport layer, respectively. The turn-on voltage is about 4 V. The maximum brightness and electroluminescent (EL) efficiency of the DQW device can reach 5916cd m-2 at 16 V and 2.85cd A-1 at 7 V, respectively. In addition, the EL efficiency of the DQW device is relatively independent of the drive voltage in the range from 5 V to 16 V.

  15. 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

    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.

  16. Mediation of donor-acceptor distance in an enzymatic methyl transfer reaction.

    Zhang, Jianyu; Kulik, Heather J; Martinez, Todd J; Klinman, Judith P

    2015-06-30

    Enzymatic methyl transfer, catalyzed by catechol-O-methyltransferase (COMT), is investigated using binding isotope effects (BIEs), time-resolved fluorescence lifetimes, Stokes shifts, and extended graphics processing unit (GPU)-based quantum mechanics/molecular mechanics (QM/MM) approaches. The WT enzyme is compared with mutants at Tyr68, a conserved residue that is located behind the reactive sulfur of cofactor. Small (>1) BIEs are observed for an S-adenosylmethionine (AdoMet)-binary and abortive ternary complex containing 8-hydroxyquinoline, and contrast with previously reported inverse (molecular dynamics. These experimental and computational results are discussed in the context of active site compaction that requires an ionization of substrate within the enzyme ternary complex. PMID:26080432

  17. Karyotype Study on Scilla scilloides (Lindl.) Druce in Yantai%烟台绵枣儿的核型研究

    王爱云; 赵彦宏; 刘林德; 王丽娟

    2008-01-01

    [Objective] The aim of this study was to investigate the chromoseome number and the karyotype of Scilla scilloides in Yantai. [Method] Root tips of Scilla scilloides were pretreated by 8-hydroxyquinoline, then fixed, dissociated and stained for slice production. The chromosome number was ana-lyzed by microscopic examination, and then cells with good chromosomal morphology and dispersal chromosome were studied by microscopic photos. [Re-sult] The somatic chromosome number of Scilla scilloides in Yantai was 2n=16+1Bs, while the karyotype formula was K (2n)=2x=16+1Bs=6m+4sm (2SAT)+4st+2t+1Bs and the karyotype classification was "3B" type. [Conclusion] Karyotype comparison, division of cell type and evolution of Scilla scilloides in Yantai are discussed, which provides basis for cytogenetics, evolutionary genetics, modem taxonomy and genetic breeding.

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

    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.

  19. Rapid radiochemical separation of short-lived radionuclides in neutron-activated samples

    Radiochemical separation procedures based on the removal of metal ions by columns of C18-bonded silica gel after selective complexation are examined and the simplicity of the method demonstrated by its application to determination of Mn, Cu and Zn in neutron-activated biological material from the following solutions (pH 0-10, sulphate concentration 0,18M and 1,44M SO4): 8-hydroxyquinoline (oxine), ammonium pyrrolidinedithiocarbamate (APDC), cupferron (CUP), 1-(2-pyridylazo)-2-naphthol (PAN), 1-(2'-thiazolylazo)-2-naphthol (TAN), 4-(2-pyridylazo) resorcinol (PAR), diethylammonium diethyldithiocarbamate (DDC), potassium ethyl xanthate (PEX), acetylacetone (AcAc) or thenoyltrifluoracetone (TTA). The method is rapid and reliable and readily adaptable in all radiochemical laboratories

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

    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. PMID:21406339

  1. Comparison of two lab-made spray chambers based on MSIS™ for simultaneous metal determination using vapor generation-inductively coupled plasma optical emission spectroscopy.

    Fuentes-Cid, A; Villanueva-Alonso, J; Peña-Vázquez, E; Bermejo-Barrera, P

    2012-10-24

    The objective of this study is to evaluate the performance of two lab-made systems based on the Multimode Introduction System (MSIS™) and the modified MSIS™, to generate and introduce vapors of Ag, Cu, Cd, Cu, Ni, Sn, Zn, and also Au in the ICP torch. An univariate procedure was used to select the optimized working conditions (Ar flow, sample, reductant and waste flows, and reagent concentrations). Optimum conditions for working with modified MSIS were: nitric acid concentration 0.35 M, 8-hydroxyquinoline concentration: 40 mg L(-1), sodium borohydride concentration: 1.75% (w/v)+0.4% (w/v) NaOH, argon purge flow to sweep the vapors to the torch: 1.2 L min(-1), sample flow and sodium borohydride flows: 2.3 L min(-1); waste flow: 7.7 mL min(-1). For the optimum working conditions for lab-made MSIS in dual mode the concentration of 8-hydroxyquinoline was 225 mg L(-1), the Ar purge flow was 0.75 L min(-1), and the conventional nebulization flow was 2.3 L min(-1). The sensitivity obtained was higher using the lab-made MSIS than using the lab-made modified MSIS or a forced outlet gas-liquid separator. The limits of detection were better for Au, Cd, Sn than those obtained using conventional nebulization; the measurements were precise (RSDs≤5% in dual mode) and a good accuracy was obtained in the determination of Cd, Cu, Ni and Zn in a wastewater reference material using aqueous calibration and the lab-made MSIS in dual mode. PMID:23036464

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

    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

  3. Bipolar Alq{sub 3}-based complexes: Effect of hole-transporting substituent on the properties of Alq{sub 3}-center

    Luo Jianxin [Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Department of Materials and Chemical Engineering, Hunan Institute of Technology, Hengyang, Hunan 421002 (China); Lu Mangeng, E-mail: mglu@gic.ac.cn [Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Yang Chaolong [Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Tong Bihai [Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Maanshan 243002 (China); Liang Liyan [Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China)

    2012-09-15

    Two bipolar Alq{sub 3}-based complexes, tris{l_brace}5-[(carbazole-9'-yl)methyl]-8-hydroxyquinoline{r_brace} aluminum (Al(CzHQ){sub 3}) and tris{l_brace}5-[(phenothiazine-9'-yl)methyl]-8-hydroxyquinoline{r_brace} aluminum (Al(PHQ){sub 3}), involving an Alq{sub 3}-center and three hole-transporting substituents (carbazole or phenothiazine), were prepared and characterized. Effects of hole-transporting substituent on the properties of Alq{sub 3}-center were investigated in detail. It is found that the two complexes have improved hole-transporting performance and appropriate thermal stability (the 5%-weight-loss temperatures T{sub 5%}>260 Degree-Sign C). Photoluminescence (PL) spectra indicate that both energy transfer and electron transfer can take place simultaneously in the PL process of these complexes. Both thermodynamics and dynamics of the electron transfer were studied and corresponding parameters were calculated. Energy transfer is favorable for the PL of Alq{sub 3}-center, while electron transfer is unfavorable for the PL of Alq{sub 3}-center. These results will be useful to explore novel OLEDs material with increased efficiency. - Highlights: Black-Right-Pointing-Pointer Effects of substituent on the properties of Alq{sub 3}-center were investigated. Black-Right-Pointing-Pointer Energy transfer and electron transfer can transfer from substituent to Alq{sub 3}-center. Black-Right-Pointing-Pointer The thermodynamics and dynamics of electron transfer were studied. Black-Right-Pointing-Pointer The mechanisms of PL and EL of Al(CzHQ){sub 3} were studied and compared with each other.

  4. A facile and novel organic coprecipitation strategy to prepare layered cathode material Li[Li0.2Mn0.54Ni0.13Co0.13]O2 with high capacity and excellent cycling stability

    Yuan, Xiaolei; Xu, Qun-jie; Wang, Cong; Liu, Xinnuan; Liu, Haimei; Xia, Yongyao

    2015-04-01

    The lithium-rich layered cathode material Li[Li0.2Mn0.54Ni0.13Co0.13]O2 with high capacity and excellent cycling stability, is successfully synthesized through a facile organic co-precipitation route. The as-obtained material exhibits a well-crystallization and uniform size distribution, above which have been characterized and observed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Moreover, FT-IR spectra proves that the addition of metal ions Mn+ induces a red-shift of the bond of C-N groups of the 8-hydroxyquinoline, which is used as the precipitant in this work, and most probably due to the strong complexation effect of metal ions Mn+ with N and O atoms of 8-hydroxyquinoline, and simultaneously the co-precipitation process occurred. The electrochemical results reveal that the cathode material derived from this novel organic co-precipitation route exhibits improved electrochemical performance, of which could provide an initial discharge capacity of 287.2 mAhg-1at 0.2C within a potential range of 2.0-4.8 V at room temperature, even at high C-rate of 2C, this material could also deliver a capacity of 212.1 mAh g-1 with 97.7% capacity retention after 100 cycles. Therefore, it is proposed that this organic co-precipitation might be a high-efficiency strategy to synthesize alternative electrode materials with improved performance.

  5. 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)

    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).

  6. Synthesis, characterization and evaluation of ionic-imprinted polymers for solid-phase extraction of nickel from seawater

    Several nickel ion imprinted polymers were prepared via precipitation polymerization using 4-vinylpyridine or 2-(diethylamino) ethyl methacrylate as monomers (vinylated reagents) and a cross-linking agent divinylbenzene in the presence of nickel(II) alone or nickel(II) and 8-hydroxyquinoline (non-vinylated reagent). For all cases, 2,2'-azobisisobutyronitrile (AIBN) was used as an initiator and an acetonitrile/toluene (3:1) mixture was chosen as a porogen. After packing the polymer particles into empty SPE cartridges, nickel(II) ions were removed by washing with 50 mL of 2.0 M nitric acid. Characterization of the polymer particles has been carried out by scanning electron microscopy, energy dispersive X-ray fluorescence and elemental analysis. The best nickel imprinting properties were given by polymers synthesized in the presence of 8-hydroxyquinoline and 2-(diethylamino) ethyl methacrylate as a monomer. The optimum pH for quantitative nickel retention was 8.5 ± 0.5, while elution was completed with 2.5 mL of 2.0 M nitric acid. When using polymer masses of 300 mg, sample volumes until 250 mL can be passed through the cartridges without reaching the breakthrough volume. Therefore, a pre-concentration factor of 100 has been reached when eluting with 2.5 mL of the elution solution. Electrothermal atomic absorption spectrometry has been used as a detector for nickel determination. The limit of detection of the method was 0.050 μg L-1 (pre-concentration factor of 100), while the relative standard deviation for eleven replicates was 6%. Accuracy of the method was assessed by analyzing different certified reference materials: SLEW-3 (estuarine water) and TM-23.3 and TM-24 (lake water)

  7. Synthesis, characterization and evaluation of ionic-imprinted polymers for solid-phase extraction of nickel from seawater

    Otero-Romani, Jacobo; Moreda-Pineiro, Antonio [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain); Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain)], E-mail: pilar.bermejo@usc.es; Martin-Esteban, Antonio [Department of Environment, National Institute for Agriculture and Food Research (INIA), Carretera de A Coruna, Km 7.5, 28040 Madrid (Spain)

    2008-12-07

    Several nickel ion imprinted polymers were prepared via precipitation polymerization using 4-vinylpyridine or 2-(diethylamino) ethyl methacrylate as monomers (vinylated reagents) and a cross-linking agent divinylbenzene in the presence of nickel(II) alone or nickel(II) and 8-hydroxyquinoline (non-vinylated reagent). For all cases, 2,2'-azobisisobutyronitrile (AIBN) was used as an initiator and an acetonitrile/toluene (3:1) mixture was chosen as a porogen. After packing the polymer particles into empty SPE cartridges, nickel(II) ions were removed by washing with 50 mL of 2.0 M nitric acid. Characterization of the polymer particles has been carried out by scanning electron microscopy, energy dispersive X-ray fluorescence and elemental analysis. The best nickel imprinting properties were given by polymers synthesized in the presence of 8-hydroxyquinoline and 2-(diethylamino) ethyl methacrylate as a monomer. The optimum pH for quantitative nickel retention was 8.5 {+-} 0.5, while elution was completed with 2.5 mL of 2.0 M nitric acid. When using polymer masses of 300 mg, sample volumes until 250 mL can be passed through the cartridges without reaching the breakthrough volume. Therefore, a pre-concentration factor of 100 has been reached when eluting with 2.5 mL of the elution solution. Electrothermal atomic absorption spectrometry has been used as a detector for nickel determination. The limit of detection of the method was 0.050 {mu}g L{sup -1} (pre-concentration factor of 100), while the relative standard deviation for eleven replicates was 6%. Accuracy of the method was assessed by analyzing different certified reference materials: SLEW-3 (estuarine water) and TM-23.3 and TM-24 (lake water)

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

    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

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

    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

  10. Photonic hybrid crystals constructed from in situ host-guest nanoconfinement of a light-emitting complex in metal-organic framework pores

    Chaudhari, Abhijeet K.; Ryder, Matthew R.; Tan, Jin-Chong

    2016-03-01

    We report the concept underpinning the facile nanoconfinement of a bulky luminous guest molecule in the pores of a metal-organic framework (MOF) host, which yields a hybrid host ⊃ guest nanomaterial with tunable opto-electronic characteristics and enhanced photostability. Utilizing an in situ host-guest confinement strategy enabled by molecular self-assembly, we show that the highly emitting ZnQ [Zn-(bis-8-hydroxyquinoline)] guest complexes could be rapidly encapsulated within the sodalite nanocages of zeolitic imidazolate framework (ZIF-8) host crystals. The nature of optical and electronic transitions phenomena of the guest-encapsulated ZIF-8 ⊃ ZnQ has been elucidated by means of fluorescence and absorption spectroscopy measurements, and substantiated further via theoretical molecular orbital calculations revealing the plausible host-guest charge transfer mechanism involved. Evidence suggests that its photophysical properties are not only strongly determined by the host-guest co-operative bonding interactions within the environment of the confined MOF nanocage, but also can be engineered to manipulate its emission color chromaticity or to shield light-sensitive emitting guests against rapid photochemical degradation.We report the concept underpinning the facile nanoconfinement of a bulky luminous guest molecule in the pores of a metal-organic framework (MOF) host, which yields a hybrid host ⊃ guest nanomaterial with tunable opto-electronic characteristics and enhanced photostability. Utilizing an in situ host-guest confinement strategy enabled by molecular self-assembly, we show that the highly emitting ZnQ [Zn-(bis-8-hydroxyquinoline)] guest complexes could be rapidly encapsulated within the sodalite nanocages of zeolitic imidazolate framework (ZIF-8) host crystals. The nature of optical and electronic transitions phenomena of the guest-encapsulated ZIF-8 ⊃ ZnQ has been elucidated by means of fluorescence and absorption spectroscopy measurements, and

  11. Mixoploidia em híbridos de capim-elefante x milheto tratados com agentes antimitóticos Mixoploidy in napiergrass x pearl millet hybrids treated with antimitotic agents

    Juscélio Clemente de Abreu

    2006-11-01

    Full Text Available O objetivo deste trabalho foi avaliar métodos de duplicação cromossômica, com uso de agentes antimitóticos e diversos materiais botânicos como explantes dos híbridos entre capim-elefante (Pennisetum purpureum Schum. e milheto (Pennisetum glaucum (L. R. Br.. Utilizaram-se soluções de colchicina a 50 mg L-1 e 100 mg L-1, e de ciclohexamida 25 mg L-1:8-hidroxiquinoleína 300 mg L-1 (1:1, aplicadas in vitro em segmentos nodais, e in vivo em plântulas e perfilhos, com diferentes períodos de exposição. O efeito dos antimitóticos foi avaliado por meio da taxa de sobrevivência, do número cromossômico e da presença de anomalias no ciclo celular, em meristemas de raízes das plantas sobreviventes. A colchicina apresentou melhor efeito sobre as plântulas, enquanto a ciclohexamida:8-hidroxiquinoleína (1:1 atuou melhor sobre os perfilhos. Observou-se ocorrência de mixoploidia em células que apresentaram de 14 até 42 cromossomos, o que indica que houve duplicação seguida de eliminação cromossômica, confirmada pelas aberrações cromossômicas. Das células analisadas 86,4%, em média, apresentaram número cromossômico diferente de 21.The objective of this work was to evaluate methods of chromosome duplication, using antimitotic agents and several botanical materials as explant hybrids between napiergrass (Pennisetum purpureum Shum. and pearl millet (Pennisetum glaucum (L. R. Br.. Colchicine (50 mg L-1 and 100 mg L-1 and cycloheximide:8-hydroxyquinoline (1:1 (25 mg L-1:300 mg L-1 solutions have been applied in vivo to shoots and in vitro to seedlings and tillers. The antimitotic effect has been evaluated through survival rate, chromosome number and presence of cell cycle anomalies at the root tips of surviving plants. The best results have been obtained when seedlings have been treated with colchicine and tillers with cycloheximide: 8-hydroxyquinoline. Mixoploidy has been observed in cells having 14 to 42 chromosomes, indicating

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

    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

  13. [Pretreatment of Aluminum-Lithium Alloy Sample and Determination of Argentum and Lithium by Spectral Analysis].

    Zhou, Hui; Tan, Qian; Gao, Ya-ling; Sang, Shi-hua; Chen, Wen

    2015-10-01

    Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Flame Atomic Absorption Spectrometry (FAAS) and Visible Spectrometry (VS) was applied for determination of Ag and Li in lithium-aluminium alloy standard sample and test sample, their respective advantages and disadvantages were compared, the excellent selectivity of ICP-OES was confirmed by analyses of certified standard sample. Three different sample digestion methods were compared and discussed in this study. It was found that the better accuracy would be obtained by digesting sample with chloroazotic acid while the content of Li was measured by FAAS, and it was better to digest sample with hydrochloric acid and hydrogen peroxide while determining Ag and Li by ICP-OES simultaneously and determining Ag by FAAS and VS. The interference of co-existing elements and elimination methods was detailedly discussed. Ammonium hydroxide was added to adjust the sample solution into alkalescent and Al, Ti, Zr was precipitated by forming hydroxide precipitation, Mg and Cu was formed complex precipitation with 8-hydroxyquinoline in this condition, then the interference from matrix element to determinate Ag by FAAS was eliminated. In addition, phosphate was used to precipitate Ti to eliminate its interference for determination of Li by FAAS. The same treatment of determination for Ag by FAAS was used to eliminate the interference of matrix element for determination of Ag by VS, the excess of nitrate was added into sample and heated to release Ag+ from silver chloride complex, and the color of 8-hydroxyquinoline was eliminated because of decomposed by heating. The accuracy of analysis result for standard sample was conspicuously improved which confirms the efficient of the method to eliminate interference in this study. The optimal digestion method and eliminate interference method was applied to lithium-aluminium alloy samples. The recovery of samples was from 100.39% to 103.01% by ICP-OES determination for Ag

  14. Synthesis of 1-azabenzo[a]phenoxazin-5-one and 11-amino-1,8,10-triazabenzo[a]phenoxazin-5-one and their functionalized aryl derivatives via Mizoroki-Heck arylation methodology

    Oni Timothy Toba

    2015-03-01

    Full Text Available The synthesis of angular 1-azabenzo[a]phenoxazin-5-one and 11-amino-1,8,10-triazabenzo[a]phenoxazin-5-one and their functionalized aryl derivatives via Mizoroki-Heck arylation methodology is reported. 11-Amino-1,8,10-triazabenzo[a]phenoxazin-5-one (16 and 1-azabenzo[a]phenoxazin-5-one (18 were synthesized by the reaction of 7-chloro-5,8-quinolinequinone (obtained by a multistage conversion of 8-hydroxyquinoline with 4,5-diamino-6-hydroxypyrimidine and 2-aminophenol respectively in the presence of anhydrous sodium acetate. 11-Amino-1,8,10-triazabenzo[a]phenoxazin-5-one and 1-azabenzo[a]phenoxazin-5-one were subjected to Mizoroki-Heck coupling reaction by refluxing with iodobenzene derivatives, using 1,4-bis(diphenylphosphinobutane-palladium(11 chloride as catalyst, 1,4-bis-(2-hydroxy-3,5-ditert-butylbenzylpiperazine as ligand and methanol as solvent at 60-650C for 4 h to afford in excellent yield aryl derivatives of angular 11-amino-1,8,10-triazabenzo[a]phenoxazin-5-one (19a-c and 1-azabenzo[a]phenoxazin-5-one (20a-c respectively. The structures were established by UV/visible, FTIR, proton-NMR and carbo-13 NMR spectral and elemental analysis.

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

    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.

  16. Microextraction Methods for Preconcentration of Aluminium in Urine Samples

    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.

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

    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.

  18. SYNTHESIS, STRUCTURE AND PROPERTIES OF CHARGE-TRANSFER COMPLEX BASED ON CONTAINING TUNGSTOPHOSPHORIC (-ARSENIC) HETEROPOLYACID WITH DAWSON STRUCTURE%含Dawson结构杂多钨磷(砷)酸电荷转移配合物的合成、结构与性质

    柳士忠; 王峥; 库宗军; 张卫华

    1999-01-01

    Eight new organo-polyoxoinetalate charge transfer complexes (DH)6X2W18O62(solv)n(D=Oxin(8-hydroxyquinoline), Py(Pyridine), Tol(toluene), A(aniline), DMA (N,N-dimethyaniline), DEA(N,N-diethylaniline), X=P, As; solv=DMF, H2O) was synthesized and characterized by using elemental analysis, IR, ESR. Polarographly, CV. Conductivity measurement, and X-ray circle diffraction. The results showed that the crystal of (H2quinH)6P2W18O62·20H2O is Triclinic Crystal System, Space group P, with a=1.4659(5), b=2.045(8), c=2.1153(4) nm, α=90.01(3), β=87.95(2), γ=89.05(3)°, V=6.3393(35) nm3. This shows that under the irradiated title compound charge transfer between the organic donor and polyoxometalate anion has taken place.Polargraphy and cyclic Voltammetry show that the (H2quinH)6P2W18O62·20H2O undergoes three one-electron reversible reduction steps in aqueous solution and four one-electron quasi-reversible reduction in DMF. Room temperature Conductivities of eight the title compounds ranging from 1.2×10-8 to 3.6×10-9 S·cm-1 showed weak semiconducting behaviors.

  19. Polymetallic lanthanide (III) complexes for the design of new luminescent materials

    The incorporation of f elements in highly organized polymetallic complexes is of great interest in supramolecular chemistry and allows the combination of their nano-scopic size with the magnetic or optical properties of the metal ions. However due to the difficulty in controlling the coordination environment of these ions, the assembly of lanthanide-based polynuclear architectures has lagged behind that of other systems. These factors make the rational design for the construction of supramolecular lanthanide complexes quite challenging. In order to better understand the factors determining the assembly of lanthanide-based polymetallic arrays, we designed two different types of organic ligands, which favor, in one case, formation of infinite polymetallic complexes (coordination polymers), and in the case the assembly of discrete polymetallic architectures. Thus, we show that the use of flexible and multi-dentate picolinate-derivative ligands enables the formation of infinite and luminescent infinite frameworks which display very interesting luminescent properties. Geometry of the ligand has a great influence on the final network architecture. Particularly, implementation of four picolinate units within a tetrapodal ligand results in the controlled assembly of 1-D coordination polymers. Conversely to favor the controlled assembly of discrete polymetallic arrays we use dissymmetric ligands which displays low denticity. Complexation studies of a tridentate 8- hydroxyquinoline-derivative ligand as well as a tetradentate ligand possessing an oxazoline ring are presented. (author)

  20. Metal quinolinolate-fullerene(s) donor-acceptor complexes: evidence for organic LED molecules acting as electron donors in photoinduced electron-transfer reactions.

    D'Souza, Francis; Maligaspe, Eranda; Zandler, Melvin E; Subbaiyan, Navaneetha K; Ohkubo, Kei; Fukuzumi, Shunichi

    2008-12-17

    Tris(quinolinolate)aluminum(III) (AlQ3) is the most widely used molecule in organic light-emitting devices. There exists a strong demand for understanding the photochemical and photophysical events originating from this class of molecules. This paper provides the first report on the electron donor ability of MQ(n) (M = Al or Zn for n = 3 or 2) complexes covalently connected to a well-known electron acceptor, fullerene. To accomplish this, fullerene was functionalized with 8-hydroxyquinoline at different ligand positions and their corresponding zinc(II) and aluminum(III) complexes were formed in situ. The weakly fluorescent metal quinolinolate-fullerene complexes formed a new class of donor-acceptor conjugates. The stoichiometry and structure of the newly formed metal quinolinolate-fullerene complexes were established from various spectroscopic methods including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and computational density functional theory studies. Electrochemical studies involving free-energy calculations suggested the possibility of photoinduced electron transfer from excited metal-quinolinolate complex to the appended fullerene entity. Femtosecond transient absorption studies confirmed such a claim and analysis of the kinetic data allowed us to establish the different photophysical events in sufficient detail. The novel features of this class of donor-acceptor conjugates include faster charge recombination compared to charge separation and decay of the charge-separated state to populate the low-lying fullerene triplet state in competition with direct charge recombination to the ground state. PMID:19053486

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

    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. PMID:26784148

  2. Effects of the Na2CO3 dopant on electron injection and transport in organic light emitting devices

    Na2CO3 is used as an n-type dopant to improve the electro-optical properties of tris(8-hydroxyquinoline)aluminum (Alq3)-based organic light-emitting diodes (OLEDs). Device properties such as the turn-on voltage, maximum luminance, and device efficiency were improved as Na2CO3 was doped. The higher mobility of Na2CO3-doped samples has been derived using space-charge-limited current measurements. Photoelectron spectroscopy results show that some electrons transfer from Na2CO3 into Alq3, which moves the Fermi level close to the lowest unoccupied molecular orbital of Alq3. Therefore, both the electron-transporting ability and electron-injection efficiency were enhanced, which improves the charge carrier balance in OLEDs and leads to better device efficiency. - Highlights: ► Na2CO3-doped OLEDs have improved opto-electrical properties. ► Na2CO3-doped Alq3 layers possess an enhanced electron injection ability. ► The higher mobility of the Na2CO3-doped samples derived by the SCLC model. ► The reaction between Na2CO3 and Alq3 results in an electron transfer process. ► The Na2CO3-doping moves the Fermi level close to the LUMO of Alq3

  3. Dependence of the efficiency improvement of organic light-emitting diodes on the thickness of the Cs2CO3 electron-injection layer

    An efficiency improvement of organic light-emitting diodes (OLEDs) was studied by varying the thickness of the electron-injection layer (EIL). First, an optimum EIL thickness of Cs2CO3 was confirmed by using a simulation program. Then, the OLEDs were designed to have a structure of indium-tin-oxide (ITO)/ N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD)/ tris(8-hydroxyquinolinate) aluminum (Alq3)/ cesium carbonate (Cs2CO3)/ aluminum (Al). By using the thermal evaporation method, we manufactured specimens to the optimum thickness of the material found in the simulation, and we investigated how the Cs2CO3 EIL affected the efficiency of the OLEDs. As a result, because the Cs2CO3 EIL reduced the potential barrier in the cathode by 0.08 eV, it facilitated the movement of electrons, which confirmed that the Cs2CO3 improved the efficiency of the OLEDs as it increased recombination by blocking hole movement. When compared to the device without the EIL, the device with a 1.0 nm-thick Cs2CO3 EIL showed an excellent efficiency. The luminance and the external quantum efficiency increased about 600% and 500%, respectively.

  4. Enhanced brightness of organic light-emitting diodes based on Mg:Ag cathode using alkali metal chlorides as an electron injection layer

    Different thicknesses of cesium chloride (CsCl) and various alkali metal chlorides were inserted into organic light-emitting diodes (OLEDs) as electron injection layers (EILs). The basic structure of OLED is indium tin oxide (ITO)/N,N′-diphenyl-N,N′-bis(1-napthyl-phenyl)-1.1′-biphenyl-4.4′-diamine (NPB)/tris-(8-hydroxyquinoline) aluminum (Alq3)/Mg:Ag/Ag. The electroluminescent (EL) performance curves show that both the brightness and efficiency of the OLEDs can be obviously enhanced by using a thin alkali metal chloride layer as an EIL. The electron injection barrier height between the Alq3 layer and Mg:Ag cathode is reduced by inserting a thin alkali metal chloride as an EIL, which results in enhanced electron injection and electron current. Therefore, a better balance of hole and electron currents at the emissive interface is achieved and consequently the brightness and efficiency of OLEDs are improved. - Highlights: ► Alkaline metal chlorides were used as electron injection layers in organic light-emitting diodes based on Mg:Ag cathode. ► Brightness and efficiency of OLEDs with alkaline metal chlorides as electron injection layers were all greatly enhanced. ► The Improved OLED performance was attributed to the possible interfacial chemical reaction. ► Electron-only devices are fabricated to demonstrate the electron injection enhancement.

  5. Reduction of driving voltage in organic light-emitting diodes with molybdenum trioxide in CuPc/NPB interface

    A novel structure of organic light-emitting diode was fabricated by inserting a molybdenum trioxide (MoO3) layer into the interface of hole injection layer copper phthalocyanine (CuPc) and hole transport layer N,N'-diphenyl-N,N'-bis(1-napthyl-phenyl)-1,1'-biphenyl-4,4'-diamine (NPB). It has the configuration of ITO/CuPc(10 nm)/MoO3(3 nm)/NPB(30 nm)/ tris-(8-hydroxyquinoline) aluminum (Alq3)(60 nm)/LiF(0.5 nm)/Al. The current density-voltage-luminance (J-V-L) performances show that this structure is beneficial to the reduction of driving voltage and the enhancement of luminance. The highest luminance increased by more than 40% compared to the device without hole injection layer. And the driving voltage was decreased obviously. The improvement is ascribed to the step barrier theory, which comes from the tunnel theory. The power efficiency was also enhanced with this novel device structure. Finally, 'hole-only' devices were fabricated to verify the enhancement of hole injection and transport properties of this structure.

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

    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. PMID:18034504

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

    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.

  8. Modified ionic liquid cold-induced aggregation dispersive liquid-liquid microextraction followed by atomic absorption spectrometry for trace determination of zinc in water and food samples

    We report on a new method for the microextraction and determination of zinc (II). The ion is accumulated via ionic-liquid cold-induced aggregation dispersive liquid-liquid microextraction (IL-CIA-DLLME) followed by flame atomic absorption spectrometry (FAAS). The ionic liquid (IL) 1-hexyl-3-methylimidazolium hexafluorophosphate is dispersed into a heated sample solution containing sodium hexafluorophosphate as a common ion source. The solution is then placed in an ice-water bath upon which a cloudy solution forms due to the decrease of the solubility of the IL. Zinc is complexed with 8-hydroxyquinoline and extracted into the IL. The enriched phase is dissolved in a diluting agent and introduced to the FAAS. The method is not influenced by variations in the ionic strength of the sample solution. Factors affecting the performance were evaluated and optimized. At optimum conditions, the limit of detection is 0.18 μg L-1, and the relative standard deviation is 3.0% (at n=5). The method was validated by recovery experiments and by analyzing a certified reference material and successfully applied to the determination of Zn (II) in water and food samples. (author)

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

    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.

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

    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.

  11. Preparation of gallium-68 radiopharmaceuticals for positron tomography. Progress report, November 1, 1980-December 31, 1981

    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 68Ga/68Ge 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 68Ga-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 68Ga-radiopharmaceuticals. Several years ago, we developed a new generator using a solvent extraction system which produces 68Ga-oxine (8-hydroxyquinoline), a weak chelate. We have also carried out studies to compare generator systems which produce 68Ga in an ionic form. Using the gallium-68 eluted from these various generator systems, several 68Ga-labeled radiopharmaceuticals have been synthesized and tested in vitro and in vivo. In addition, attempts have been made to design and synthesize a lipophilic ligand for gallium-68. The stability of radiogallium complexed with a series of potentially lipophilic complexing agents has been studied using chromatographic techniques and in vivo distribution data. The potential of these complexing agents for altering the biodistribution of gallium radiopharmaceuticals has also been investigated

  12. Phenolics and Plant Allelopathy

    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.

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

    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.

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

    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)

  15. Red organic light emitting device based on TPP and a new host material

    Janghouri, Mohammad; Mohajerani, Ezeddin; Amini, Mostafa M.; Najafi, Ezzatollah

    2014-02-01

    A novel coating method for fabrication of red OLEDs by using a new host material has been developed with the aid of a single furnace. The host material, zinc complex, was prepared from the reaction of zinc acetate and 2-methyl-8-hydroxyquinoline and after characterization by UV-vis, FT-IR, and 1H NMR spectroscopes was used as an emitting material in the fabrication of OLEDs. Since meso-tetraphenylporphyrin (TPP) and zinc complex have a close molecular weight, both materials were evaporated from a single furnace. Devices with TPP and structures of ITO/PEDOT:PSS (55 nm)/PVK (90 nm)/zinc complex:TPP (65 nm)/Al (180 nm) were fabricated; Without TPP green and with TPP red emission was achieved. The device with 2 % TPP that doped into the zinc complex showed the purest red emission among all devices. The device showed the CIE coordinates of 0.70 and 0.28 at 14 V and a maximum luminance of about 94.2 cd/m2. This new method is a promising candidate for fabrication of low cost red OLEDs with a more homogeneous layer.

  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

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

    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−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−1 with a limit of detection of 4.9 μg L−1 and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L−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

  18. Monolayer Phases of a Dipolar Perylene Derivative on Au(111) and Surface Potential Build-Up in Multilayers.

    Niederhausen, Jens; Kersell, Heath R; Christodoulou, Christos; Heimel, Georg; Wonneberger, Henrike; Müllen, Klaus; Rabe, Jürgen P; Hla, Saw-Wai; Koch, Norbert

    2016-04-19

    9-(Bis-p-tert-octylphenyl)-amino-perylene-3,4-dicarboxy anhydride (BOPA-PDCA) is a strongly dipolar molecule representing a group of asymmetrically substituted perylenes that are employed in dye-sensitized solar cells and hold great promise for discotic liquid crystal applications. Thin BOPA-PDCA films with orientated dipole moments can potentially be used to tune the energy-level alignment in electronic devices and store information. To help assessing these prospects, we here elucidate the molecular self-assembly and electronic structure of BOPA-PCDA employing room temperature scanning tunneling microscopy and spectroscopy in combination with ultraviolet and X-ray photoelectron spectroscopies. BOPA-PCDA monolayers on Au(111) exclusively form in-plane antiferroelectric phases. The molecular arrangements, the increase of the average number of molecules per unit cell via ripening, and the rearrangement upon manipulation with the STM tip indicate an influence of the dipole moment on the molecular assembly and the rearrangement. A slightly preferred out-of-plane orientation of the molecules in the multilayer induces a surface potential of 1.2 eV. This resembles the giant surface potential effect that was reported for vacuum-deposited tris(8-hydroxyquinoline)aluminum and deemed applicable for data storage. Notably, the surface potential in the case of BOPA-PDCA can in part be reversibly removed by visible light irradiation. PMID:26991048

  19. Alkali Metal Complexes: Mixed Ligand Complexes of Some Alkali Metal Salts of Some Organic Acids with Isonitroso-PMethylace to phenone

    O.P. Gupta

    2016-02-01

    Full Text Available A number of mixed ligand complexes of alkali metal salts of o-nitrophenol,2,4-dinitrophenol, 2,4,6,- trinitrophenol, 1-nitroso-2- naphthol and 8- hydroxyquinoline with Insoniroso–p methylacetopheone have been synthesized in absolute ethanol & characterized by elemental analysis and I .B. spectral data. Their I.R spectral data indicate the presence of hydrogen bonding in them, which many be one of the dominant factors of their stability. Further appreciable shift in 1650 cm-1 band (possibly vC=O and 1600 cm-1 band (possibly vC=NSuggests their coordination behavior in these mixed ligand complexes The reactions that take place in natural systems are highly specific and selective. Alkali metal ions actively participate in most of the reaction occurring in the biological systems, which are dominated by mixed ligand complexes. Studies of such mixed ligand complexes of alkali metals can threw light in understanding the role and mechanism of selective absorption of alkali metals ions by plants Coordinating ability of alkali metal with isonitrosoacetophenone1-2 and transition metals with isonitrosoacetophenone3 and isonitroso-p-methylacetophenone4 have been reported earlier. In the present paper we report the mixed ligand complexes of alkali metal salts having the general formula ML.HL, ‘ where M=Li, Na & K and L=deprotonated o- nitrophenol, 2,4 dinitrophenol, 2, 4, 6- trinitrophenol, 1-nitroso-2-naphthol or 8- hydroxquinoline; HL’= p -MeHINAP (isonitroso-p-methylacetophenone.

  20. New resin gel for uranium determination by diffusive gradient in thin films technique.

    Gregusova, Michaela; Docekal, Bohumil

    2011-01-17

    A new resin gel based on Spheron-Oxin(®) chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin(®) functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10(2) mg L(-1). The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel. PMID:21167996