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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. 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

  3. 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.

  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. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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)

  8. 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.

  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 2,7'-(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.

  11. 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.

  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. 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)

  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. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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)

  3. 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.

  4. 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

  5. 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)

  6. 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

  7. 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.

  8. 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.

  9. 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

  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. 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.

  13. 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)

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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%

  7. 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%.

  8. 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

  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

    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)

  19. 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.

  20. 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).

  1. 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.

  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. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  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. 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)

  20. 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)

  1. 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.

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  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. 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...

  16. 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 ...

  17. 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

  18. 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.

  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 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

  7. 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

  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. 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

  10. 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

  11. 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...

  12. 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...

  13. 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

  14. 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...

  15. 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.

  16. 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...

  17. 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)

  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. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  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. 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

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  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)

    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. 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.

  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. 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.

  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. 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.

  9. 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)

  10. 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.