WorldWideScience

Sample records for 8-hydroxyquinoline

  1. Adsorption Kinetic of 8-Hydroxyquinoline on Malachite

    OpenAIRE

    Oprea, Gabriela; Angela MICHNEA; Mihali, Cristina

    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

    Directory of Open Access Journals (Sweden)

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

    Science.gov (United States)

    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.

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

    Indian Academy of Sciences (India)

    Walaa A E Omar; Osmo E O Hormi

    2015-11-01

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

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

    Institute of Scientific and Technical Information of China (English)

    OUYANG Xinhua; ZENG Heping; XIE Yan

    2007-01-01

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

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

    International Nuclear Information System (INIS)

    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.)

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

    Directory of Open Access Journals (Sweden)

    Jukka Korpela

    2012-09-01

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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

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

    2016-07-01

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

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

    International Nuclear Information System (INIS)

    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

  11. Understanding M-ligand bonding and mer-/fac-isomerism in tris(8-hydroxyquinolinate) metallic complexes.

    Science.gov (United States)

    Lima, Carlos F R A C; Taveira, Ricardo J S; Costa, José C S; Fernandes, Ana M; Melo, André; Silva, Artur M S; Santos, Luís M N B F

    2016-06-28

    Tris(8-hydroxyquinolinate) metallic complexes, Mq3, are one of the most important classes of organic semiconductor materials. Herein, the nature of the chemical bond in Mq3 complexes and its implications on their molecular properties were investigated by a combined experimental and computational approach. Various Mq3 complexes, resulting from the alteration of the metal and substitution of the 8-hydroxyquinoline ligand in different positions, were prepared. The mer-/fac-isomerism in Mq3 was explored by FTIR and NMR spectroscopy, evidencing that, irrespective of the substituent, mer- and fac-are the most stable molecular configurations of Al(iii) and In(iii) complexes, respectively. The relative M-ligand bond dissociation energies were evaluated experimentally by electrospray ionization tandem mass spectrometry (ESI-MS-MS), showing a non-monotonous variation along the group (Al > In > Ga). The results reveal a strong covalent character in M-ligand bonding, which allows for through-ligand electron delocalization, and explain the preferred molecular structures of Mq3 complexes as resulting from the interplay between bonding and steric factors. The mer-isomer reduces intraligand repulsions, being preferred for smaller metals, while the fac-isomer is favoured for larger metals where stronger covalent M-ligand bonds can be formed due to more extensive through-ligand conjugation mediated by metal "d" orbitals. PMID:27273193

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

    Science.gov (United States)

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

    2014-07-14

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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    Demelash Jado

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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%

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  7. 8-Hydroxyquinolines: a review of their metal chelating properties and medicinal applications

    Directory of Open Access Journals (Sweden)

    Prachayasittikul V

    2013-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Oliver N F King

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

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

    Directory of Open Access Journals (Sweden)

    Prachayasittikul V

    2014-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-20

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2009-04-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Zheng Hong; Cheng Xiaoman; Tian Haijun; Zhao Geng

    2011-01-01

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  1. Spectrofluorimetric Determination of Magnesium ( Ⅱ ) with 7- (8-Hydroxy-3, 6-Disulfonaphthylazo)8-Hydroxyquinoline-5-Sulfonic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new fluorescent reagent, 7- (8-hydroxy-3, 6-disulfonaphthylazo)-8-hydroxyquinoline-5-sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1: 1 fluorescent complex with λex/λem=356/495 nm immediately at room temperature in ammonia-ammonium chloride buffer (pH 10. 7). A linear relationship was obtained in the magnesium concentration range of 0160 ng@ mL-1 with the detection limit of 0. 04 ng@ mL-1 The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103. 75% and 98. 16%, respectively.

  2. Adsorption of lead (II) ions onto novel cassava starch 5-choloromethyl-8-hydroxyquinoline polymer from an aqueous medium.

    Science.gov (United States)

    Shah, Prapti U; Raval, Nirav P; Vekariya, Mayur; Wadhwani, Poonam M; Shah, Nisha K

    2016-01-01

    Adsorption of lead (II) ions onto cassava starch 5-choloromethyl-8-hydroxyquinoline polymer (CSCMQ) was investigated with the variation in the parameters of pH, contact time, lead (II) ions concentration, temperature and the adsorbent dose. The Langmuir and Freundlich models have been applied. CSCMQ was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Results showed that the adsorption process was better described by the Langmuir model. Adsorption kinetics data obtained for the metal ions sorption were investigated using pseudo-first-order, pseudo-second-order and intraparticle diffusion model. The maximum adsorption capacities (qm) were 46.512, 43.859 and 42.735 mg/g at 25, 35 and 45 °C, respectively. The dynamical data fit well with the second-order kinetics model. The results indicate that CSCMQ could be employed as low-cost material for the adsorption of Pb(II) ions from aqueous medium. PMID:27533869

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-30

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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2010-07-01

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

  11. Improved immobilization of 8-hydroxyquinoline on polyacrylonitrile fiber and application of the material to the determination of trace metals in seawater by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wen Bei; Shan Xiaoquan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, BJ (China)

    2002-11-01

    A modified synthetic method has been developed for immobilization of 8-hydroxyquinoline on polyacrylonitrile fiber. The synthetic conditions, e.g. reagent concentration, reaction temperature and time, were optimized. The features of the newly-modified fiber are higher exchange capacity compared with most other materials containing immobilized 8-hydroxyquinoline, better mechanic characteristics, high stability at both high and low pH, and ease of synthesis. This modified fiber can concentrate and separate trace metals from matrices with higher concentrations of alkali and alkaline earth elements. To validate the characteristics of the modified fiber, trace metals Ag, Be, Cd, Co, Cu, Mn, Ni, Pb, and Zn in the certified reference materials river water (SLRS-4) and seawater (CASS-4, NASS-5, SLEW-3) were preconcentrated before determination by inductively coupled plasma mass spectrometry. Good agreement was obtained between the data obtained by this method and the certified values. (orig.)

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

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

    2012-08-01

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

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

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    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

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

    CERN Document Server

    Stary, J

    1979-01-01

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

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. 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)

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

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

    2016-12-01

    In this work the optical response, spectroscopic behaviour, and optoelectronic properties of solution and solid state composite systems based on α,ω-dihexylsexithiophene/tris(8-hydroxyquinolinate) gallium (DH6T/Gaq3) are studied upon the incorporation of different molar percentages of Gaq3. UV-vis, PL, FTIR spectrophotometers and SEM technique were utilized to perform the investigations. The results showed a reduced energy band (Eg) (from 2.33eV 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

  10. 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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-03

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

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

    Institute of Scientific and Technical Information of China (English)

    李小芳; 冯小强; 张宏伟; 杨声

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    吴伟明; 徐晶; 梁晓鹏; 柴敏平; 程明焱; 蒋小岗

    2012-01-01

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

  15. 8-羟基喹啉锌/碳微球复合材料的合成表征及发光性能%Synthesis and characterization and luminescence property of bis(8-hydroxyquinoline)zinc/carbon microspheres composite

    Institute of Scientific and Technical Information of China (English)

    杨永珍; 韩艳星; 刘伟峰; 刘红艳; 刘旭光; 许并社

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-09-01

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

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

    International Nuclear Information System (INIS)

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

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

    Institute of Scientific and Technical Information of China (English)

    王欣; 骆开均; 蒋世平; 贾娟; 陈艳芳

    2011-01-01

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

  19. Single-Molecule-Magnet Behavior and Fluorescence Properties of 8-Hydroxyquinolinate Derivative-Based Rare-Earth Complexes.

    Science.gov (United States)

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

    2016-09-01

    Five tetranuclear rare-earth complexes, [RE4(dbm)4L6(μ3-OH)2] [HL = 5- (4-fluorobenzylidene)-8-hydroxylquinoline; dbm = 1,3-diphenyl-1,3-propanedione; RE = Y (1), Eu (2), Tb (3), Dy (4), Lu (5)], have been synthesized and completely characterized. The X-ray structural analyses show that each [RE4] complex is of typical butterfly or rhombus topology. Each RE(III) center exists in an eight-coordinated square-antiprism environment. Magnetic studies reveal that complex 4 displays single-molecule-magnet behavior below 10 K under a zero direct-current field, with an effective anisotropy barrier (ΔE/kB = 56 K). The fluorescence properties of complexes 1-5 were also investigated. Complexes 2-4 showed their characteristic peaks for the corresponding RE(III) center, while complexes 1 and 5 showed the same emission peaks with the ligand when they were excited at the same wavelength. PMID:27560459

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

    Science.gov (United States)

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

    2004-06-01

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

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

    Science.gov (United States)

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

    2015-12-15

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

  2. The Influences of different cathode materials on Tris-(8-Hydroxyquinoline)- Aluminum Doped with CsNO3 in Organic Light emitting Devices

    Science.gov (United States)

    Chen, Mei-Hsin; Lu, Yin-Jui; Wu, Chung-Chih; Wu, Chih-I.

    2008-03-01

    This paper presents the investigations of interfacial interactions and electron-injection mechanisms between cesium nitrate (CsNO3) and different cathode materials. By using ultraviolet and x-ray photoemission spectroscopy, the properties of electronic structures and the interfacial chemistry are studied. According to our results, there exists a phenomenon of electron exchange at the interface results in changes of Aluminum 2s core level binding energy by 1 eV when aluminum was deposited on CsNO3. This means electrons transfer from cathode materials to the surface of CsNO3, forming a strong dipolar field at the interface and reduction of the electron injection barrier. But, in contract, there exists nearly no reaction between CsNO3 and silver cathode. The evidences show that CsNO3 is more effective only with aluminum cathode due to a reaction between Aluminum, Cesium and Nitrogen atoms.

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Institute of Scientific and Technical Information of China (English)

    白志飞; 李代文; 姚玉元; 吕汪洋; 黄三庆; 陈文兴

    2015-01-01

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

  5. Mechanism and Fluorescence Spectra of 5,6,11,12-Tetraphenyl-tetracene Doped 8-Hydroxyquinoline System%5,6,11,12-四苯基四苯并掺杂8-羟基喹啉铝薄膜的荧光谱及发光机理

    Institute of Scientific and Technical Information of China (English)

    李宏建; 彭景翠; 瞿述; 夏辉; 许雪梅; 罗小华

    2002-01-01

    用高荧光染料的5,6,11,12-四苯基四苯并对8-羟基喹啉铝进行掺杂,测量其光致发光和电致发光谱.结果表明:在低掺杂时,主发光体是Alq,掺入的Rubrene作为客发光体只是在Alq带隙中引入了分立能级;随着掺入的Rubrene浓度增加,Rubrene成了主发光体,Alq变成了客发光体,出现了发光体的互换现象.由于Rubrene的吸收光谱与Alq的发射谱重叠较大,在光致发光中存在从Alq向Rubrene的能量传递和电荷转移过程,而电致发光则是由于Rubrene导带(LUMO)比Alq导带(LUMO)低很多,且它们价带(HOMO)基本相同,使得从负电极注入到Rubrene导带中电子浓度远大于注入到Alq导带中电子浓度,造成Rubrene导带电子与价带空穴复合的几率比Alq中的复合几率大得多,其EL主要是Rubrene的发光.

  6. 8-羟基脱氧鸟苷水平对糖尿病患者胰岛功能损害的相关性研究%Correlation of 8-hydroxyquinoline Deoxyguanosine Levels with Pancreas Islet Dysfunction in Diabetic Patients

    Institute of Scientific and Technical Information of China (English)

    梅礼军; 王林川

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    秦明林; 张灯青; 金武松

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

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

    OpenAIRE

    Dicke, Benjamin

    2014-01-01

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

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

    Science.gov (United States)

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

    1976-08-01

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

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

    Science.gov (United States)

    Gill, John

    1980-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Beutier, D.; Le Quesne, Y.

    1987-07-24

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

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

    Institute of Scientific and Technical Information of China (English)

    Wei JIANG; Hengyi ZHANG; Yu LIU

    2009-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    OpenAIRE

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

    2013-01-01

    Three simple, selective and rapid spectrophotometric methods have been established for the determination of cinitapride hydrogen tartrate (CHT) in pharmaceutical tablets. The proposed methods are based on the diazotization of CHT with sodium nitrite and hydrochloric acid, followed by coupling with resorcinol, 1-benzoylacetone and 8-hydroxyquinoline in alkaline medium for methods A, B and C respectively. The formed azo dyes are measured at 442, 465 and 552 nm for methods A, B and C respe...

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

    Directory of Open Access Journals (Sweden)

    Vandna Nishal

    2015-01-01

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

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

    Science.gov (United States)

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

    2006-06-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Zi Qiang Lei; Jian Qiang Wang; Peng Hua Yan

    2008-01-01

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

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

    Science.gov (United States)

    Szunerits, Sabine; Walt, David R

    2002-02-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-10

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2000-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    Science.gov (United States)

    Lajunen, L H; Kubin, A

    1986-03-01

    Methods are presented for determination of molybdenum in plant tissue by flame and graphite-furnace atomic-absorption spectrometry and direct-current argon-plasma emission spectrometry. The samples are digested in HNO(3)-H(2)SO(4)-HC1O(4) mixture, and Mo is separated and concentrated by chelation and extraction. Three organic solvents (methyl isobutyl ketone, di-isobutyl ketone and isoamyl alcohol) and two ligands (8-hydroxyquinoline and toluene-3,4-dithiol) were studied. The procedure were tested on pine needle and birch leaf samples. PMID:18964076

  9. Dynamic modification of silicon gel with complexing reagents grafted by hydrophobic groups and following sorption of metals

    International Nuclear Information System (INIS)

    Retention of group reagents of three classes: dioximes, β-diketones, 8-hydroxyquinoline and its derivatives (8-Ox, MO, PAO), as well as HDEHP on hydrophobic silica gel C15, was studied under dynamic conditions. Retention dependences on Kdistr of reagent were obtained, from which the possibility of correct choice of reagent with required properties fit for the preparation of noncovalently modified sorbent follows. Sorptional behaviour of Cd, Co(2), Zn, Mg, Cu, Pb on the sorbents prepared is considered. Retention series are obtained, which are well comparable with the extraction ones

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

    Science.gov (United States)

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

    2016-05-01

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

  11. Highly sensitive heavy metal ion detection using AlQ3 microwire functionalized QCM

    Science.gov (United States)

    Can, Nursel; Aǧar, Meltem; Altındal, Ahmet

    2016-03-01

    Tris(8-hydroxyquinoline) aluminum (Alq3) microwires was successfully synthesized for the fabrication of Alq3 microwires-coated QCM sensors to detect the heavy metal ions in aqueous solution. AT-cut quartz crystal microbalance (QCM) of 10 MHz fundamental resonance frequency having gold electrodes were used as transducers. Typical measuring cycle consisted of repeated flow of target measurands through the flow cell and subsequent washing to return the baseline. The QCM results indicated that the Alq3 microwires exhibit excellent sensitivity, stability and short response-recovery time, which are much attractive for the development of portable and highly sensitive heavy metal ion sensors in water samples.

  12. Corrosion Behavior of Passivated 316LSS with Ag Coating as PEMFC Bipolar Plate

    OpenAIRE

    Naibao Huang; Chenghao Liang; Hongtao Wang; Lishuang Xu; Hongfeng Xu

    2011-01-01

    A new chemical passivation technique, which contained 20 g/L hydrogen peroxide, 3.75 g/L sodium silicate, 1.25 g/L sodium carbonate, 3.75 g/L lactic acid and 0.75 g/L 8-hydroxyquinoline, was used to modify 316 stainless steel with Ag coating (Ag-coated 316SS) as PEMFC bipolar plates. The results indicated that the compact passive film had been obtained on the surface of Ag-coated 316SS. The passivation process could not only increase contact angle (from 58∘ to 104∘) but also decreased pinhole...

  13. Determination of trace levels of dissolved vanadium in seawater by use of synthetic complexing agents and inductively coupled plasma-atomic emission spectroscopy (ICP-AES)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasse, G.; Ouddane, B.; Fischer, J.C. [Univ. des Sciences et Technologies et Lille, Lab. de Chimie Analytique et Marine (ELICO), UPRESA CNRS 8013, Villeneuve d' Ascq (France)

    2002-11-01

    In the determination of traces of dissolved vanadium in complex matrices such as seawater, separation and enrichment from the matrix is of special importance. A wide variety of methods has been proposed for preconcentration, depending to the nature of samples and the methods to be used for measurement. Among these methods separation techniques based on sorption on to chelating resins seem convenient, rapid, and capable of achieving a high concentration factor. The methods proposed in this paper are based on the transformation of all dissolved vanadium species in seawater into organic complexes by use of synthetic complexing agents such as dithizone, luminol, or 8-hydroxyquinoline; the resulting vanadium-organic complexes were sorbed on to a C{sub 18} column at a flow rate of 5 mL min{sup -1}. The vanadium sorbed on the C{sub 18} columns was then stripped by use of nitric acid (2 mol L{sup -1}) and analysed by inductively coupled plasma-atomic emission spectroscopy, ICP-AES. This method was optimised and use of other chelating resins, such as chelamine, chelex-100, and immobilised 8-hydroxyquinoline and was compared by passing seawater samples directly over the resins. The experimental conditions (pH, acid used for elution, and contact time between the liquid sample and the resin) were optimised. The results were compared for all the resins used and were indicative of excellent and coherent reproducibility. (orig.)

  14. An improved and highly useful method for the gravimetric determination of molybdenum in molybdenum concentrates

    International Nuclear Information System (INIS)

    The dried molybdenum concentrate is treated with hydrofluoric acid and nitric acid for its dissolution and the solution thus obtained is neutralized with ammonia and then acidified with dilute sulfuric acid. From the acidified solution molybdenum is precipitated with 8-hydroxyquinoline (oxine). The precipitate is digested on a steam bath, filtered, washed with warm water and dried at 130℃. Then it was heated in a Muffle furnace at around 600℃, for an hour, cooled and then weighed. The product was again heated at 750℃ for about 1 h, cooled and constant weight was taken. The difference of weight (the weight of the product obtained after heating at 600℃ minus the weight of the product obtained at 750℃) gave the actual content of molybdenum as MoO3. A substantial/major modification of the earlier reported 8-hydroxyquinoline (oxine) method for the gravimetric determination of molybdenum has been made in the proposed method. The advantages of the proposed method over the oxine method are (i) free from most interferences, (ii) accuracy and precision of the method have been improved substantially and (iii) the results obtained from the application of the proposed method to different molybdenum concentrates are reliable. (author)

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  16. Translational downregulation of HSP90 expression by iron chelators in neuroblastoma cells.

    Science.gov (United States)

    Sidarovich, Viktoryia; Adami, Valentina; Gatto, Pamela; Greco, Valentina; Tebaldi, Toma; Tonini, Gian Paolo; Quattrone, Alessandro

    2015-01-01

    Iron is an essential cellular nutrient, being a critical cofactor of several proteins involved in cell growth and replication. Compared with normal cells, neoplastic cells have been shown to require a greater amount of iron, thus laying the basis for the promising anticancer activity of iron chelators. In this work, we evaluated the effects of molecules with iron chelation activity on neuroblastoma (NB) cell lines. Of the 17 iron chelators tested, six reduced cell viability of two NB cell lines with an inhibition of growth of 50% below 10 µM; four of the six molecules-ciclopirox olamine (CPX), piroctone, 8-hydroxyquinoline, and deferasirox-were also shown to efficiently chelate intracellular iron within minutes after addition. Effects on cell viability of one of the compounds, CPX, were indeed dependent on chelation of intracellular iron and mediated by both G0/G1 cell cycle block and induction of apoptosis. By combined transcriptome and translatome profiling we identified early translational downregulation of several members of the heat shock protein group as a specific effect of CPX treatment. We functionally confirmed iron-dependent depletion of HSP90 and its client proteins at pharmacologically achievable concentrations of CPX, and we extended this effect to piroctone, 8-hydroxyquinoline, and deferasirox. Given the documented sensitivity of NB cells to HSP90 inhibition, we propose CPX and other iron chelators as investigational antitumor agents in NB therapy. PMID:25564462

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-30

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  19. Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

    International Nuclear Information System (INIS)

    To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: → Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. → The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. → The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

  20. Enhancement of the power conversion efficiency for organic photovoltaic cells with a Liq/bathocuproine electron transport bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ke; Kim, Dae Hun; Lee, Se Han; Kim, Tae Whan, E-mail: twk@hanyang.ac.kr

    2013-11-29

    Organic photovoltaic (OPV) cells based on a poly(3-hexylthiophene) (P3HT):fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) electron transport layer were fabricated to enhance their power conversion efficiency (PCE). Absorbance spectra showed that the absorbance intensity of the spectra for the P3HT:PCBM active layer with a Liq layer in the wavelength between 500 and 600 nm was enhanced due to the damage of the active layer. The PCE of the fabricated OPV cells with a Liq/BCP layer was significantly enhanced by up to 4.29% in comparison with that of OPV cells with a BCP or a Liq layer. - Highlights: • Organic photovoltaic cell with a bathocuproine (BCP)/8-hydroxyquinoline lithium (Liq) layer. • The BCP layer prevented the performance deterioration. • The efficiency of the photovoltaic cell with a BCP/Liq layer was enhanced.

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

    Science.gov (United States)

    Devi, Jai; Batra, Nisha

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-01-01

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

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

    Science.gov (United States)

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

    2013-11-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-01

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

  5. Simulating atomic force microscope images with density functional theory: The role of nonclassical contributions to the force

    Science.gov (United States)

    Schaffhauser, Philipp; Kümmel, Stephan

    2016-07-01

    We discuss a scheme for calculating atomic force microscope images within the framework of density functional theory (DFT). As in earlier works [T. L. Chan et al., Phys. Rev. Lett. 102, 176101 (2009), 10.1103/PhysRevLett.102.176101; M. Kim and J. R. Chelikowsky, Appl. Surf. Sci. 303, 163 (2014), 10.1016/j.apsusc.2014.02.127] we do not simulate the cantilever explicitly, but consider it as a polarizable object. We go beyond previous studies by discussing the role of exchange and correlation effects; i.e., we approximately take into account the Pauli interaction between sample and cantilever. The good agreement that we find when comparing our calculated images to experimental images for the difficult case of the 8-hydroxyquinoline molecule demonstrates that exchange-correlation effects can play an important role in the DFT-based interpretation of AFM images.

  6. Tubular solids of lanthanide-doped polyoxometalates in micrometer-scale: synthesis and NIR-luminescent properties

    International Nuclear Information System (INIS)

    A series of lanthanide-doped polyoxometalate microtubes, Ln-SiW12 (Ln=Nd, Dy and Yb), have been synthesized, and characterized by X-ray diffraction, elemental analysis and thermogravimetric analysis. In the microtubes, the lanthanide cations combine with polyanions through electrostatic interaction. Furthermore, the lanthanide-doped microtubes were chelated with 8-hydroxyquinoline (HQ) in a post-synthesis step (designed as LnQ-SiW12). The LnQ-SiW12 show characteristic near-infrared (NIR) luminescence, corresponding to Ln3+ ions due to efficient energy transfer from Q to the Ln3+ ions through antenna effect. - Highlights: • A series of lanthanide-doped polyoxometalate microtubes have been firstly synthesized. • The Ln-SiW12 microtubes were chelated with HQ in a post-synthesis step. • The LnQ-SiW12 microtubes show characteristic NIR luminescence through antenna effect

  7. Amplified Spontaneous Emission of Organic Pyridinium Dye doped Polymeric Waveguide

    Institute of Scientific and Technical Information of China (English)

    XI Zun; YE Li-Hua; WANG Qiong; XU Deng; LU Chang-Gui; HU Guo-Hua; CUI Yi-Ping

    2009-01-01

    An organic dye salt trans-4-[p-(N-hydroxyethy1-N-methylamino)styryl]-N-methylpyridinium iodide (ASPI) is doped with an electron transport organic molecule tris(8-hydroxyquinoline) aluminium (Alq3) in a host matrix of poly(methylmethacrylate) (PMMA), and the amplified spontaneous emission (ASE) is studied. By efficient Forster energy transfer from Alq3 to ASPI, it is demonstrated that the ASE threshold of ASPI:Alq3:PMMA waveguide (about 11 μJ/pulse) is much lower than that of ASPI:PMMA system (about 38μJ/pulse). Meanwhile, the peak position of ASE can be controlled by the effect of film thickness on waveguide modes. We show that the ASE peak position can be tuned over 37nm. These characteristics indicate the ASPI:AIq3 system as a promising gain medium for optical amplifiers and organic semiconductor lasers.

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

    Science.gov (United States)

    Peng, Qiming; Li, Xianjie; Li, Feng

    2012-12-01

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

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

    Directory of Open Access Journals (Sweden)

    ALEXEI N. PANKRATOV

    2007-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

    LIAO Meng-xia; DENG Tian-long

    2006-01-01

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

  11. Improvement of Efficiency and Brightness of Red Organic Light-Emitting Devices Using Double-Quantum-Well Configuration

    Science.gov (United States)

    Mi, Rui; Cheng, Gang; Zhao, Yi; Xie, Wen-Fa; Hou, Jing-Ying; Ding, Tao; Liu, Shi-Yong

    2004-03-01

    We present red double-quantum-well organic light-emitting devices (DQW-OLEDs), in which N,N-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyo-4,4'-diamine (NPB) is used as potential barriers and hole transport layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-thtramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped tris (8-hydroxyquinoline) aluminium (Alq3) as potential wells and emitter, undoped Alq3 as electron transport layer, respectively. The turn-on voltage is about 4 V. The maximum brightness and electroluminescent (EL) efficiency of the DQW device can reach 5916 cd m-2 at 16 V and 2.85 cd A-1 at 7 V, respectively. In addition, the EL efficiency of the DQW device is relatively independent of the drive voltage in the range from 5 V to 16 V.

  12. Improvement of Efficiency and Brightness of Red Organic Light-Emitting Devices Using Double-Quantum-Well Configuration

    Institute of Scientific and Technical Information of China (English)

    MI Rui; CHENG Gang; ZHAO Yi; XIE Wen-Fa; HOU Jing-Ying; DING Tao; LIU Shi-Yong

    2004-01-01

    @@ We present red double-quantum-well organic light-emitting devices (DQW-OLEDs), in which N,N-bis-(1-naphthyl)N,N′-diphenyl-1,1′-biphenyo-4,4'-diamine (NPB) is used as potential barriers and hole transport layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7, 7-thtramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped tris (8-hydroxyquinoline) aluminum (Alq3) as potential wells and emitter, undoped Alq3 as electron transport layer, respectively. The turn-on voltage is about 4 V. The maximum brightness and electroluminescent (EL) efficiency of the DQW device can reach 5916cd m-2 at 16 V and 2.85cd A-1 at 7 V, respectively. In addition, the EL efficiency of the DQW device is relatively independent of the drive voltage in the range from 5 V to 16 V.

  13. 8-Hydroxyqunoline adsorption from aqueous solution using powdered orange peel: kinetic and isotherm study

    Directory of Open Access Journals (Sweden)

    Siraj Khalid

    2015-12-01

    Full Text Available Adsorption of 8-hydroxyquinoline (8HQ on powdered orange peel (POP, a locally available adsorbent, has been studied. Experiment was performed on different 8HQ concentration, particle size, and adsorbent dosage. The Langmuir and Freundlich adsorption isotherm model has been tested. The obtained results best fitted the Langmuir model, suggesting monolayer adsorption of 8HQ on POP. The kinetic studies for the adsorption process were also carried out using pseudo-first- and pseudo-second-order models, and the data obtained is best fitted to the pseudo-second-order kinetic model. Thermodynamic parameters were calculated for the adsorption process and the result showed that the values of ΔGads, ΔHads, and ΔSads are −1171.4J/mol, −140J/mol and −40.5 J/K at 303 K. Thus, it can be summarized that the adsorption of 8HQ is spontaneous, chemisorbed, monolayer, and exothermic

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  16. Corrosion Behavior of Passivated 316LSS with Ag Coating as PEMFC Bipolar Plate

    Directory of Open Access Journals (Sweden)

    Naibao Huang

    2011-01-01

    Full Text Available A new chemical passivation technique, which contained 20 g/L hydrogen peroxide, 3.75 g/L sodium silicate, 1.25 g/L sodium carbonate, 3.75 g/L lactic acid and 0.75 g/L 8-hydroxyquinoline, was used to modify 316 stainless steel with Ag coating (Ag-coated 316SS as PEMFC bipolar plates. The results indicated that the compact passive film had been obtained on the surface of Ag-coated 316SS. The passivation process could not only increase contact angle (from 58∘ to 104∘ but also decreased pinhole defects of Ag-coated 316SS. Electrochemical test manifested that the passivation process could reduce Ag-coated 316SS's double layer capacitance (Cd, and increase its charge transfer resistance. So, it provided significant protection against corrosion for Ag-coated 316SS in PEMFC environment.

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

    Institute of Scientific and Technical Information of China (English)

    陈静; 傅宏祥; 童进

    2001-01-01

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

  18. MULTILAYER ORGANIC LEDS BASED ON A NEW DYE-DOPED POLYMER

    Institute of Scientific and Technical Information of China (English)

    Zhi-yuan Xie; Jing-song Huang; Chuan-nan Li; Bu-wen Xiao; Shi-yong Liu; Dong-feng Li

    1999-01-01

    A blue dye, 1-benzothiazoly-3-phenyl-pyrazoline (BTPP) was found to function as bright light emitting dye in organic electroluminescent devices. This heterocyclic compound exhibits good characteristics of blue photoluminescence and electroluminescence, which has emission peak at 445 nm. The thin films of fluorescent dye dispersed in poly(N-vinylcarbazole) (PVK) could serve as light-emitting layers in multilayer organic LEDs. 2-(4-Biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and tris-(8-hydroxyquinoline) aluminum (Alq3) were introduced into double-layer and three-layer devices respectively. The introduction of electron transport material Alq3 enhanced the electron injection and luminous efficiency, as compared with double-layer devices. Maximum brightness and luminous efficiency can be reached up to 190 cd/m2 and 0.31 m/W, respectively.

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

    Indian Academy of Sciences (India)

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

    2015-02-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王爱云; 王艳化; 任晓莉; 张琳丰

    2009-01-01

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

  1. Fabrication of Green Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    高德青; 黄春辉; 奎热西; 刘凤琴

    2002-01-01

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

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

    Science.gov (United States)

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

    2015-04-01

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

  3. Linewidth Narrowing and Intensity Enhancement of Wavelength Tunable MOLEDs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  4. UV exposure and photon degradation of Alq3 powders

    International Nuclear Information System (INIS)

    Tris-(8-hydroxyquinoline)aluminum (Alq3) is a widely used light emitting material. It is also used as an electron transporting layer in organic light emitting devices (OLEDs). Degradation is, however, a major problem in these devices. The device performance is affected by parameters such as air, moisture and light exposure. In this work the effect of photon degradation of Alq3 in air is investigated. Alq3 phosphor powder was synthesized using a co-precipitation method and recrystalized in acetone. The structure of the sample was determined by using x-ray diffraction (XRD). The averaging particle size estimated from the broadened XRD peaks using Scherrer's equation was 40±4 nm in diameter. The excitation photoluminescence data that was collected correspond well to the absorption data. To study the photon degradation, the sample was irradiated with an UV lamp for ∼330h. The emission data was collected and the change in photoluminescence intensity with time was monitored.

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

    Science.gov (United States)

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

    2016-02-01

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

  6. Responses of the L5178Y tk/sup +//tk/sup -/ mouse lymphoma cell forward mutation assay. II. 18 coded chemicals

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, D.B.; Brown, A.; Cattanach, P.; Edwards, I.; McBride, D.; Caspary, W.J.

    1988-01-01

    Eighteen chemicals were tested for their mutagenic potential in the L5178Y tk/sup +///sup -/ mouse lymphoma cell forward mutation assay by the use of procedures based upon those described previously. Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 ..mu..g/ml. The chemicals were tested at least twice. Significant responses were obtained with benzofuran, benzyl chloride, bromodichloromethane, butylated hydroxytoluene, chlorendic acid, o-chlorobenzalmalonitrile, 1,2,3,4-diepoxybutane, dimethyl formamide, dimethyl hydrogen phosphite, furfural, glutaraldehyde, hydroquinone, 8-hydroxyquinoline, and resorcinol. Apart from bromodichloromethane, butylated hydroxytoluene and dimethyl hydrogen phosphite, rat liver S9 mix was not a requirement for the activity of any of these compounds. Chemicals not identified as mutagens were water, tert-butyl alcohol, pyridine, and witch hazel.

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

    CERN Document Server

    Bayliss, S M

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hana Bunzen

    2013-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-05

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

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

    Science.gov (United States)

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

    2011-03-01

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

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

    Science.gov (United States)

    Budimir, Ana

    2011-03-01

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

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

    Science.gov (United States)

    Budimir, Ana

    2011-03-01

    In the last few years, various studies have been providing evidence that metal ions are critically involved in the pathogenesis of major neurological diseases (Alzheimer, Parkinson). Metal ion chelators have been suggested as potential therapies for diseases involving metal ion imbalance. Neurodegeneration is an excellent target for exploiting the metal chelator approach to therapeutics. In contrast to the direct chelation approach in metal ion overload disorders, in neurodegeneration the goal seems to be a better and subtle modulation of metal ion homeostasis, aimed at restoring ionic balance. Thus, moderate chelators able to coordinate deleterious metals without disturbing metal homeostasis are needed. To date, several chelating agents have been investigated for their potential to treat neurodegeneration, and a series of 8-hydroxyquinoline analogues showed the greatest potential for the treatment of neurodegenerative diseases. PMID:21406339

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Karyotype Study on Scilla scilloides (Lindl.) Druce in Yantai%烟台绵枣儿的核型研究

    Institute of Scientific and Technical Information of China (English)

    王爱云; 赵彦宏; 刘林德; 王丽娟

    2008-01-01

    [Objective] The aim of this study was to investigate the chromoseome number and the karyotype of Scilla scilloides in Yantai. [Method] Root tips of Scilla scilloides were pretreated by 8-hydroxyquinoline, then fixed, dissociated and stained for slice production. The chromosome number was ana-lyzed by microscopic examination, and then cells with good chromosomal morphology and dispersal chromosome were studied by microscopic photos. [Re-sult] The somatic chromosome number of Scilla scilloides in Yantai was 2n=16+1Bs, while the karyotype formula was K (2n)=2x=16+1Bs=6m+4sm (2SAT)+4st+2t+1Bs and the karyotype classification was "3B" type. [Conclusion] Karyotype comparison, division of cell type and evolution of Scilla scilloides in Yantai are discussed, which provides basis for cytogenetics, evolutionary genetics, modem taxonomy and genetic breeding.

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

    Indian Academy of Sciences (India)

    Prithiviraj Khakhlary; Jubaraj B Baruah

    2015-02-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-28

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

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

    Directory of Open Access Journals (Sweden)

    Júlia de Pietro

    2012-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

    DING Lei; ZHANG Fang-Hui

    2011-01-01

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

  1. Photonic hybrid crystals constructed from in situ host-guest nanoconfinement of a light-emitting complex in metal-organic framework pores

    Science.gov (United States)

    Chaudhari, Abhijeet K.; Ryder, Matthew R.; Tan, Jin-Chong

    2016-03-01

    We report the concept underpinning the facile nanoconfinement of a bulky luminous guest molecule in the pores of a metal-organic framework (MOF) host, which yields a hybrid host ⊃ guest nanomaterial with tunable opto-electronic characteristics and enhanced photostability. Utilizing an in situ host-guest confinement strategy enabled by molecular self-assembly, we show that the highly emitting ZnQ [Zn-(bis-8-hydroxyquinoline)] guest complexes could be rapidly encapsulated within the sodalite nanocages of zeolitic imidazolate framework (ZIF-8) host crystals. The nature of optical and electronic transitions phenomena of the guest-encapsulated ZIF-8 ⊃ ZnQ has been elucidated by means of fluorescence and absorption spectroscopy measurements, and substantiated further via theoretical molecular orbital calculations revealing the plausible host-guest charge transfer mechanism involved. Evidence suggests that its photophysical properties are not only strongly determined by the host-guest co-operative bonding interactions within the environment of the confined MOF nanocage, but also can be engineered to manipulate its emission color chromaticity or to shield light-sensitive emitting guests against rapid photochemical degradation.We report the concept underpinning the facile nanoconfinement of a bulky luminous guest molecule in the pores of a metal-organic framework (MOF) host, which yields a hybrid host ⊃ guest nanomaterial with tunable opto-electronic characteristics and enhanced photostability. Utilizing an in situ host-guest confinement strategy enabled by molecular self-assembly, we show that the highly emitting ZnQ [Zn-(bis-8-hydroxyquinoline)] guest complexes could be rapidly encapsulated within the sodalite nanocages of zeolitic imidazolate framework (ZIF-8) host crystals. The nature of optical and electronic transitions phenomena of the guest-encapsulated ZIF-8 ⊃ ZnQ has been elucidated by means of fluorescence and absorption spectroscopy measurements, and

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

    Institute of Scientific and Technical Information of China (English)

    凡杰; 安飞飞; 郑峰

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Linda Cattin

    2014-03-01

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

  5. Multi-objective optimization of microcavity OLEDs with DBR mirror

    Science.gov (United States)

    Lu, Albert W.; Chan, J.; Ng, Alan Man Ching; Djurišić, A. B.; Rakić, A. D.

    2007-02-01

    In this work, the emission efficiency and spectral shift with respect to viewing angle were optimized by optimizing the design of the multi-layer top mirror of a microcavity OLED device. We first established criteria for the emission side mirror in order to optimize light intensity and spectral shift with viewing angle. Then we designed mirror using metallic and dielectric layers based on the target defined. The electroluminescence emission spectra of a microcavity OLED consisting of widely used organic materials, N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) (Alq 3) as emitting and electron transporting layer was then calculated. Silver was used as the anode and back reflection mirror for the microcavity OLED. The simulation was performed for both the conventional LiF/Al cathode/top mirror and the optimized 5-layered top mirror. Our results indicate that by following the design procedure outlined, we simultaneously optimize the device for better light intensity and spectral shift with viewing angle.

  6. White Light Electroluminescence by Organic-Inorganic Heterostructures with CdSe Quantum Dots as Red Light Emitters

    Directory of Open Access Journals (Sweden)

    Ilker Oner

    2011-01-01

    Full Text Available We have developed a white organic light-emitting diode featuring a double emission layer comprising a blue light-emitting conductive polymer as a host material for Cadmium Selenide (CdSe quantum dots as red light emitters and tris-(8-hydroxyquinoline aluminium thin layer for green light emission. The Commission Internationale de l'Eclairage coordinates of the emitting light of the device were found to be (0.32, 0.40 which were only slightly changed over a range of applied voltages between 5 and 10 volts. The use of CdSe nanocrystalline quantum dots (surface-stabilized with hexadecylamine/trioctylphosphine oxide ligands in the hybrid heterostructure with poly(9,9-di-n-octylfluorenyl-2,7-diyl conductive polymer was studied for a variety of CdSe concentrations developing the performance of the device in means of overcoming segregation problems in the blend. Besides, constituents' ratio was further examined for the exploration of possible energy transfer from polymer host material to the CdSe quantum dots as a key factor for well-balanced emission in the electroluminescent devices.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-15

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

  8. Influence of the substrate platform on the opto-electronic properties of multi-layer organic light-emitting field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Generali, Gianluca; Capelli, Raffaella; Toffanin, Stefano; Muccini, Michele [Consiglio Nazionale delle Ricerche (CNR), Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), via P. Gobetti 101, I-40129 Bologna (Italy); Dinelli, Franco, E-mail: g.generali@bo.ismn.cnr.it, E-mail: m.muccini@bo.ismn.cnr.it [Consiglio Nazionale delle Ricerche (CNR), INO U.O.S. ' A. Gozzini' Area della Ricerca di Pisa - S. Cataldo, via Moruzzi 1, I-56124 Pisa (Italy)

    2011-06-08

    In this paper, we present a study of the effects of the influence of the substrate platform on the properties of a three-layer vertical hetero-junction made of thin films of {alpha}, {omega}-diperfluorohexyl-4T (DHF4T), a blend of tris(8-hydroxyquinoline)aluminium (Alq3) and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) and {alpha}, {omega}-dihexyl-quaterthiophene (DH4T). The hetero-junction represents the active component of an organic light-emitting transistor (OLET). The substrate platforms investigated in this study are glass/indium-tin-oxide/poly(methyl-methacrylate) (PMMA) and Si{sup ++}/silicon oxide (SiO{sub 2})/PMMA. The first platform is almost completely transparent to light and therefore is very promising for use in OLET applications. The second one has been chosen for comparison as it employs standard microelectronic materials, i.e. Si{sup ++}/SiO{sub 2}. We show how different gate materials and structure can affect the relevant field-effect electrical characteristics, such as the charge mobility and threshold voltage. By means of an atomic force microscopy analysis, a systematic study has been made in order to correlate the morphology of the active layers with the electrical properties of the devices.

  9. Hygiene in the prevention of udder infections. IV. Evaluation of teat dips with excised cows' teats.

    Science.gov (United States)

    Philpot, W N; Boddie, R L; Pankey, J W

    1978-07-01

    Suspensions of Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, and Pseudomonas aeruginosa were used to contaminate teats excised from cows. Commercially available teat dips were applied for evaluation of comparative germicidal activity. Iodophors, sodium hypochlorite, and sodium dichloro-s-triazenetrione were highly effective against all four test organisms. Quarternary ammonium, chlorhexidine, and cetylpyridinium chloride were effective against Staphylococcus aureus, and Streptococcus agalactiae but not Escherichia coli and Pseudomonas aeruginosa. Bronopol and 8-hydroxyquinoline sulfate were marginally effective on the two Gram positive organisms and ineffective on the two Gram negatives. Three of the dips were ineffective against all four pathogens; two were in nonaqueous bases, and the other was a blend of pine oil and antibodies with udder origin. In other trials, iodophor at .3% titratable iodine was highly effective against Staphylococcus aureus and Streptococcus agalactiae. Products containing .5 and 1% iodophor maintained effectiveness after each was used to dip 140 teats under conditions of commercial dairying. Logarithmic reduction in the geometric mean number of organisms recovered from teats was more meaningful for evaluating data than percent reduction. PMID:100535

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

    Science.gov (United States)

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

    2014-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Seleem Hussein S

    2011-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  13. SYNTHESIS, STRUCTURE AND PROPERTIES OF CHARGE-TRANSFER COMPLEX BASED ON CONTAINING TUNGSTOPHOSPHORIC (-ARSENIC) HETEROPOLYACID WITH DAWSON STRUCTURE%含Dawson结构杂多钨磷(砷)酸电荷转移配合物的合成、结构与性质

    Institute of Scientific and Technical Information of China (English)

    柳士忠; 王峥; 库宗军; 张卫华

    1999-01-01

    Eight new organo-polyoxoinetalate charge transfer complexes (DH)6X2W18O62(solv)n(D=Oxin(8-hydroxyquinoline), Py(Pyridine), Tol(toluene), A(aniline), DMA (N,N-dimethyaniline), DEA(N,N-diethylaniline), X=P, As; solv=DMF, H2O) was synthesized and characterized by using elemental analysis, IR, ESR. Polarographly, CV. Conductivity measurement, and X-ray circle diffraction. The results showed that the crystal of (H2quinH)6P2W18O62·20H2O is Triclinic Crystal System, Space group P, with a=1.4659(5), b=2.045(8), c=2.1153(4) nm, α=90.01(3), β=87.95(2), γ=89.05(3)°, V=6.3393(35) nm3. This shows that under the irradiated title compound charge transfer between the organic donor and polyoxometalate anion has taken place.Polargraphy and cyclic Voltammetry show that the (H2quinH)6P2W18O62·20H2O undergoes three one-electron reversible reduction steps in aqueous solution and four one-electron quasi-reversible reduction in DMF. Room temperature Conductivities of eight the title compounds ranging from 1.2×10-8 to 3.6×10-9 S·cm-1 showed weak semiconducting behaviors.

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

    Science.gov (United States)

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

    2015-04-21

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

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

    Directory of Open Access Journals (Sweden)

    Mahmoud Chamsaz

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-10-01

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

  17. A New Conducting Polymer Electrode for Organic Electroluminescence Devices

    Institute of Scientific and Technical Information of China (English)

    QU Shu; PENG Jing-Cui

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2007-12-01

    We demonstrate reversible quenching of the photoluminescence from single CdSe/ZnS colloidal quantum dots embedded in thin films of the molecular organic semiconductor N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) in a layered device structure. Our analysis, based on current and charge carrier density, points toward field ionization as the dominant photoluminescence quenching mechanism. Blinking traces from individual quantum dots reveal that the photoluminescence amplitude decreases continuously as a function of increasing forward bias even at the single quantum dot level. In addition, we show that quantum dot photoluminescence is quenched by aluminum tris(8-hydroxyquinoline) (Alq3) in chloroform solutions as well as in thin solid films of Alq3 whereas TPD has little effect. This highlights the importance of chemical compatibility between semiconductor nanocrystals and surrounding organic semiconductors. Our study helps elucidate elementary interactions between quantum dots and organic semiconductors, knowledge needed for designing efficient quantum dot organic optoelectronic devices. PMID:18034504

  20. High-Efficiency Organic Double-Quantum-Well Light-Emitting Devices Using 5,6,11,12-Tetraphenylnaphthacene Sub-monolayer as Potential Well

    Institute of Scientific and Technical Information of China (English)

    谢文法; 李传南; 刘式墉

    2003-01-01

    The double-quantum-well organic light-emitting devices of indium-tin-oxide (ITO)/NPB (50 nm)/rubrene (0.05 nm)/NPB(4nm)/rubrene (0.05nm)/Alqa (50nm)/LiF (0.5nm)/Al were fabricated, in which N,N-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) is used as a barrier potential or hole transport layer, tris (8-hydroxyquinoline) aluminium (Alq3) used as electron transport layer, and 5,6,11,12-tetraphenylnaphthacene (rubrene) as a potential well and emitter. The brightness can reach 18610cd/m2 at 13 V. The maximum electroluminescent efficiency of the device was 6.61 cd/A at 7V, which was higher than that of common dope-type devices. In addition, the electroluminescence efficiency is relatively independent of the drive voltage in the range from 5 to 13 V.

  1. Nondoped-type White Organic Light-Emitting Diode Using Star-Shaped Hexafluorenylbenzene as an Energy Transfer Layer

    Institute of Scientific and Technical Information of China (English)

    Jun-sheng Yu; Tao Ma; Shuang-ling Lou; Ya-dong Jiang; Qing Zhang

    2008-01-01

    White organic light-emitting diodes (WOLEDs) with a structure of indium-tin-oxide (ITO)/N,N'-bis(1-naphthyl)-N,N'-diphenyl-(1, 1'-biphenyl)-4,4'-diamine (NPB) / 1,2,3,4,5,6-hexakis(9,9-diethyl-9H-fluoren-2-yl)benzene (HKEthFLYPh)/5,6,11,12-tetraphenylnaphtacene (rubrene)/tris(8-hydroxyquinoline) aluminum (Alq3)/Mg:Ag were fabricated by vacuum deposition method, in which a novel star-shaped hexafluorenyl-benzene HKEthFLYPh was used as an energy transfer layer, and an ultrathin layer of rubrene was inserted between HKEthFLYPh and Alq3 layers as a yellow light-emitting layer instead of using a time-consuming doping process. A fairly pure WOLED with Commissions Internationale De L'Eclairage (CIE) coordinates of (0.32, 0.33) was obtained when the thickness of rubrene was 0.3 nm, and the spectrum was insensitive to the applied voltage. The device yielded a maximum luminance of 4816 cd/m2 at 18 V.

  2. On the origin of exciton formation in dye doped Alq{sub 3} OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J.A. [FFCLRP-USP, Departamento de Fisica, Sao Paulo (Brazil); Castro, F.A. [National Physical Laboratory, Materials Division, Teddington (United Kingdom); Nueesch, F. [Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Functional Polymers, Duebendorf (Switzerland); Zuppiroli, L. [Institut des Materiaux, EPFL, Laboratoire d' Optoelectronique des Materiaux Moleculaire, Lausanne (Switzerland); Graeff, C.F.O. [FC-UNESP, Departamento de Fisica, Sao Paulo (Brazil)

    2012-09-15

    Electrically Detected Magnetic Resonance (EDMR) was used to investigate the influence of dye doping on spin-dependent exciton formation in aluminum (III) 8-hydroxyquinoline (Alq{sub 3}) based Organic Light Emitting Diodes (OLEDs) with different device structures. 4-(dicyanomethylene)-2-methyl-6-{l_brace}2-[(4-diphenylamino)-phenyl]ethyl{r_brace}-4H-pyran (DCM-TPA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene) were used as dopants. Results at room temperature show significant differences on the EDMR spectra (g-factor and linewidth) of doped and undoped devices. Signals from DCM-TPA and Rubrene dye doped OLEDs showed strong temperature dependence, with signal intensity increasing by 2 orders of magnitude below 200 K for DCM-TPA dye doped OLEDs and increasing by {proportional_to}1 order of magnitude below 225 K for the Rubrene dye doped device, while undoped devices shows almost no temperature dependence. By adding a ''spacer'' layer of undoped Alq{sub 3} at the recombination zone, changes in bias voltage were used to shift the recombination from doped to undoped region and correlate that with changes in the EDMR spectrum. Our results are indicating that charge trapping on the dopant followed by recombination is the main mechanism of light emission in the investigated devices. (orig.)

  3. Lifetime obtained by ion beam assisted deposition

    International Nuclear Information System (INIS)

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H2O and O2. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances

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

    International Nuclear Information System (INIS)

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

  5. Tuning open-circuit voltage in organic solar cells by magnesium modified Alq3

    Science.gov (United States)

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

    2011-01-01

    The low molecular weight tris-(8-hydroxyquinoline) aluminum (Alq3) has been incorporated with magnesium (Mg) that altered the nature of its opto-electronic characteristics. The lowering of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) in Mg:Alq3, compared to pure Alq3, creates a stronger field (exceeding the exciton binding energy) at the donor-acceptor junction to dissociate the photo-generated exciton and also provides a low barrier for electron transport across the device. In an electron-only device (described in the text), a current enhancement in excess of 103, with respect to pure Alq3, could be observed at 10 V applied bias. Optimized Mg:Alq3 layer, when introduced in the photovoltaic device, improves the power conversion efficiencies significantly to 0.15% compared to the pure Alq3 device. The improvement in the photovoltaic performance has been attributed to the superior exciton dissociation and carrier transport. PMID:22087050

  6. ET-AAS determination of aluminium in dialysis concentrates after continuous flow solvent extraction.

    Science.gov (United States)

    Komárek, J; Cervenka, R; Růzicka, T; Kubán, V

    2007-11-01

    Conditions of a continuous flow extraction (CFE) of aluminium acetylacetonate in acetylacetone and aluminium 8-hydroxyquinolinate into methylisobutylketone (lengths of reaction and extraction coils, flow rates of aqueous and organic phases and their flow rate ratio, pH of aqueous phase, lengths of coils for transport of aqueous and organic phases and effect of salts) were studied. The analytical signal of the aluminium chelates present in the organic phase was measured at 309.3 nm using atomic absorption spectrometry with electrothermal atomization (ET-AAS) at the flow rate ratio F aq/F org=3 for aqueous and organic phases. The five points calibration curves were linear (R2 0.9973 and 0.9987) up to 21 microgl(-1) Al with the limits of detection of 0.3 microgl(-1) and the recovery 100+/-2% and precision of 3% at 2-10-fold dilution of the dialysis concentrates. The acetylacetonate method was applied to the determination of aluminium in real dialysis concentrates. Aluminium in concentrations 5-6 microgl(-1) (R.S.D.s 5-10% in real samples) were found and the results were in the very good agreement with those obtained by an ET-AAS using preconcentration of Al(III) on a Spheron-Salicyl chelating sorbent (absolute and relative differences were under 0.4 microgl(-1) and 8.2%, respectively). PMID:17897803

  7. Microextraction Methods for Preconcentration of Aluminium in Urine Samples

    Directory of Open Access Journals (Sweden)

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

    2016-07-01

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

  8. Alkali Metal Complexes: Mixed Ligand Complexes of Some Alkali Metal Salts of Some Organic Acids with Isonitroso-PMethylace to phenone

    Directory of Open Access Journals (Sweden)

    O.P. Gupta

    2016-02-01

    Full Text Available A number of mixed ligand complexes of alkali metal salts of o-nitrophenol,2,4-dinitrophenol, 2,4,6,- trinitrophenol, 1-nitroso-2- naphthol and 8- hydroxyquinoline with Insoniroso–p methylacetopheone have been synthesized in absolute ethanol & characterized by elemental analysis and I .B. spectral data. Their I.R spectral data indicate the presence of hydrogen bonding in them, which many be one of the dominant factors of their stability. Further appreciable shift in 1650 cm-1 band (possibly vC=O and 1600 cm-1 band (possibly vC=NSuggests their coordination behavior in these mixed ligand complexes The reactions that take place in natural systems are highly specific and selective. Alkali metal ions actively participate in most of the reaction occurring in the biological systems, which are dominated by mixed ligand complexes. Studies of such mixed ligand complexes of alkali metals can threw light in understanding the role and mechanism of selective absorption of alkali metals ions by plants Coordinating ability of alkali metal with isonitrosoacetophenone1-2 and transition metals with isonitrosoacetophenone3 and isonitroso-p-methylacetophenone4 have been reported earlier. In the present paper we report the mixed ligand complexes of alkali metal salts having the general formula ML.HL, ‘ where M=Li, Na & K and L=deprotonated o- nitrophenol, 2,4 dinitrophenol, 2, 4, 6- trinitrophenol, 1-nitroso-2-naphthol or 8- hydroxquinoline; HL’= p -MeHINAP (isonitroso-p-methylacetophenone.

  9. Monolayer Phases of a Dipolar Perylene Derivative on Au(111) and Surface Potential Build-Up in Multilayers.

    Science.gov (United States)

    Niederhausen, Jens; Kersell, Heath R; Christodoulou, Christos; Heimel, Georg; Wonneberger, Henrike; Müllen, Klaus; Rabe, Jürgen P; Hla, Saw-Wai; Koch, Norbert

    2016-04-19

    9-(Bis-p-tert-octylphenyl)-amino-perylene-3,4-dicarboxy anhydride (BOPA-PDCA) is a strongly dipolar molecule representing a group of asymmetrically substituted perylenes that are employed in dye-sensitized solar cells and hold great promise for discotic liquid crystal applications. Thin BOPA-PDCA films with orientated dipole moments can potentially be used to tune the energy-level alignment in electronic devices and store information. To help assessing these prospects, we here elucidate the molecular self-assembly and electronic structure of BOPA-PCDA employing room temperature scanning tunneling microscopy and spectroscopy in combination with ultraviolet and X-ray photoelectron spectroscopies. BOPA-PCDA monolayers on Au(111) exclusively form in-plane antiferroelectric phases. The molecular arrangements, the increase of the average number of molecules per unit cell via ripening, and the rearrangement upon manipulation with the STM tip indicate an influence of the dipole moment on the molecular assembly and the rearrangement. A slightly preferred out-of-plane orientation of the molecules in the multilayer induces a surface potential of 1.2 eV. This resembles the giant surface potential effect that was reported for vacuum-deposited tris(8-hydroxyquinoline)aluminum and deemed applicable for data storage. Notably, the surface potential in the case of BOPA-PDCA can in part be reversibly removed by visible light irradiation. PMID:26991048

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

    Directory of Open Access Journals (Sweden)

    Pabla Aguirre

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

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2013-12-15

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

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

    Science.gov (United States)

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

    2012-11-15

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

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

    Institute of Scientific and Technical Information of China (English)

    SUN Zhiguo; JIANG Guangzhi

    2011-01-01

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

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

    Science.gov (United States)

    Minagawa, Masahiro; Takahashi, Noriko

    2016-02-01

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

  18. White organic light-emitting diodes based on emission from DPVBi-doped 4,48-bis (2,28-diphenylvinyl)-1,18-biphenyl

    Institute of Scientific and Technical Information of China (English)

    SONG Rui-li; XU Yuan-zhe; CHEN Shu-fen; SONG Ji-bin; SONG Ji-cheng

    2006-01-01

    @@ White organic light-emitting diodes were fabricated by using 4,48-bis (2,28-diphenylvinyl) -1,18-biphenyl (DPVBi) as a dopant with a structure of ITO/4,4'-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl (NPB,50 nm)/NPB:DPVBi (molecular weight ratio 10∶1,30 nm)/tris-(8-hydroxyquinoline)aluminum(Alq3,20 nm)/LiF(1 nm)/Al.A broad emissive band with four major peaks of 438,464,496 and 520 nm was obtained by electroluminescence spectra,of which 438 nm-,464 nm- and 520 nm-peak come from emission of NPB,DPVBi and Alq3,respectively,and 496 nm-one resulted from the emissive superposition of three materials above.The emission from DPVBi was attributed to the charge trapping from NPB.The emission region was transferred partly from Alq3 to DPVBi-doped NPB by introducing the dopant DPVBi,which leads to emission of DPVBi and an enhanced emission from NPB.The maximum luminance and current efficiency were 4721 cd/m2 at 22 V and 0.80 cd/A at 5V,respectively.

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

    Directory of Open Access Journals (Sweden)

    Satyanarayana K.V.V.

    2013-01-01

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

  20. Study of various evaporation rates of the mixture of Alq{sub 3}: DCM in a single furnace crucible

    Energy Technology Data Exchange (ETDEWEB)

    Abedi, Zahra; Janghouri, Mohammad [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113 (Iran, Islamic Republic of); Mohajerani, Ezeddin, E-mail: e-mohajerani@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113 (Iran, Islamic Republic of); Alahbakhshi, Masoud; Azari, Amin [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113 (Iran, Islamic Republic of); Fallahi, Afsoon [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, 424 Hafez Avenue, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

    2014-03-15

    The emitting color for a new organic light emitting diode (OLED) structure is tuned by doping an appropriate amount of 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) orange dye into tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) emissive layer. Here, the blend of Alq{sub 3}:DCM is deposited in a single furnace crucible by various evaporation rates. The electro-optical behavior of organic light emitting diode devices is greatly influenced by varying the Alq{sub 3}:DCM film composition. It is investigated that when the deposition rate increased from 0.6 to 5 Å/s, complete energy transfer occurred from Alq{sub 3} to DCM and Electroluminescence (EL) peak shifted to higher wavelength regions. The device with evaporation rate of 0.6 Å/s shows a luminance of 3532 cd/m{sup 2} and maximum efficiency of 0.82 cd/A at 20 V. These blends show excellent orange emission host–guest system properties with easier deposition rate control. -- Highlight: • We fabricated light emitting layer by dissolving dyes in common solvent followed by thermal evaporation of dyes. • Achieving orange emissions with a single furnace. • We investigated for the first time Alq{sub 3}:DCM evaporation rate by using single furnace.

  1. Red organic light emitting device based on TPP and a new host material

    Science.gov (United States)

    Janghouri, Mohammad; Mohajerani, Ezeddin; Amini, Mostafa M.; Najafi, Ezzatollah

    2014-02-01

    A novel coating method for fabrication of red OLEDs by using a new host material has been developed with the aid of a single furnace. The host material, zinc complex, was prepared from the reaction of zinc acetate and 2-methyl-8-hydroxyquinoline and after characterization by UV-vis, FT-IR, and 1H NMR spectroscopes was used as an emitting material in the fabrication of OLEDs. Since meso-tetraphenylporphyrin (TPP) and zinc complex have a close molecular weight, both materials were evaporated from a single furnace. Devices with TPP and structures of ITO/PEDOT:PSS (55 nm)/PVK (90 nm)/zinc complex:TPP (65 nm)/Al (180 nm) were fabricated; Without TPP green and with TPP red emission was achieved. The device with 2 % TPP that doped into the zinc complex showed the purest red emission among all devices. The device showed the CIE coordinates of 0.70 and 0.28 at 14 V and a maximum luminance of about 94.2 cd/m2. This new method is a promising candidate for fabrication of low cost red OLEDs with a more homogeneous layer.

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

    Directory of Open Access Journals (Sweden)

    A. M. Rahatgaonkar

    2008-01-01

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

  3. Effects of doping dyes on the electroluminescent characteristics of multilayer organic light-emitting diodes

    Science.gov (United States)

    Suzuki, Hiroyuki; Hoshino, Satoshi

    1996-06-01

    We report the effects of dyes doped in the emitting layer on the electroluminescent characteristics of multilayer organic light-emitting diodes (LEDs) using a polysilane polymer, poly(methylphenylsilane) (PMPS), as the hole transporting material. We formed the emitting layer by dispersing in poly(styrene) (PS), one of four dyes whose fluorescence ranged from blue to orange. Two- or three-layer LEDs were prepared by combining PMPS and dye doped PS layers with the indium tin oxide and aluminum used for the hole and electron injecting electrodes, respectively. The three-layer LEDs had an additional vacuum-deposited tris-(8-hydroxyquinoline) aluminum layer. The electroluminescent (EL) characteristics of these multilayer organic LEDs, such as the current-voltage-EL intensity curve, the relative EL efficiency, and the EL emitting species, exhibit a marked dependence on the emitting dye. The observed dependence can be described consistently in terms of the dependence of the charge carrier trapping efficiency on the emitting dyes.

  4. Light Emitting Heterojunctions Based on Fully Conjugated Heterocyclic Aromatic Rigid-rod Polymer PBT

    Science.gov (United States)

    Bai, S. J.; Wu, C. C.; Cheng, H. Y.; Wang, W.

    2003-03-01

    Poly(p-phenylenebenzobisthiazole), PBT, is a heterocyclic aromatic rigid-rod polymer having a fully conjugated backbone, excellent stabilities and opto-electronic properties. We investigated multi-layer heterojunctions of PBT and low molar compounds of 3-(2-benzothiazoly)-7-(diethylamino), C6, and tris-(8-hydroxyquinoline) aluminum, Alq3, using PBT as a hole injecting and transporting material. A PBT polymer with an intrinsic viscosity of 18.0 dL/g was dissolved in Lewis acid and spin-coated onto an indium-tin-oxide (ITO) substrate. The acid was removed via coagulation. The low molar compounds were evaporated onto the ITO substrate or the thin PBT film on the ITO substrate. UV-Vis absorption spectra over 200 to 800 nm revealed different band gaps for PBT, C6 and Alq3. Scanning electron microscopy determined that the resultant PBT and low molar compound layer thicknesses were about 23 nm and 50 nm, respectively. Aluminum was evaporated onto the multilayer heterojunction as an electron injector for electroluminescence response leading to a lower I-V threshold voltage and a higher emission brightness. This was mainly because of significant balance in the numbers of the hole and the electron injected and transported in the heterojunctions.

  5. Molecular light emitting heterojunctions based on fully conjugated heterocyclic aromatic rigid-rod polymer poly-p-phenylenebenzobisthiazole

    International Nuclear Information System (INIS)

    Poly-p-phenylenebenzobisthiazole, PBT, is a heterocyclic aromatic polymer having a fully conjugated rigid-rod backbone, excellent stabilities and opto-electronic properties. Multilayer heterojunctions of PBT and conjugated dyes of 3-(2-benzothiazoly)-7-(diethylamino), Coumarin 6 (or C6), and tris-(8-hydroxyquinoline) aluminum, Alq3, were processed using PBT as a hole injection and transport layer. A PBT with an intrinsic viscosity of 18.0 dL/g was dissolved in acids and spun onto an indium-tin-oxide (ITO) substrate followed by coagulation to remove the acid. The low molar dyes were evaporated directly to, or onto the PBT film adhered to the ITO substrate. UV-Vis absorption spectra showed direct band gaps for PBT, C6 and Alq3 at correspondingly 2.6, 2.4, and 2.9 eV. Scanning electron microscope revealed that the heterojunction layer for PBT and the dyes were, respectively, about 23 and 50 nm in thickness. Aluminum was evaporated onto the heterojunction as electron injector for light-emitting diode (LED). By varying the layer ordering and composition, it was evidenced that PBT was a p-type material of high hole mobility; both C6 and Alq3 were n-type materials of a low and a high electron mobility, respectively. Significantly reduced LED threshold voltage and enhanced electroluminescence intensity were resulted from the dyes by introducing a PBT layer showing that the holes were the minority carrier for the heterojunction LEDs

  6. Behavior of charge carriers and excitons in multilayer organic light-emitting diodes made from a polysilane polymer as monitored with electroluminescence

    Science.gov (United States)

    Suzuki, Hiroyuki; Hoshino, Satoshi

    1996-01-01

    Using electroluminescence (EL) as a monitor, we have investigated the behavior of charge carriers injected from electrodes and excitons generated by the recombination of charge carriers in multilayer organic light-emitting diodes (LEDs) using poly(methylphenylsilane) (PMPS) as a hole transporting material. Our multilayer LEDs have two or three functional organic layers including Coumarin 6 [3-(2'-benzothiazolyl)-7-diethylaminocoumarin, abbreviated as C6] and/or tris-(8-hydroxyquinoline) aluminum layers as well as a PMPS layer. When the LEDs were fabricated, two parameters of the C6 layer were changed, the layer thickness (30-120 nm) and the dye concentration (1-100 wt %). We employed a combined analysis of the dependence of the EL spectra on the thickness and dye concentration of the C6 layer, the dye-selective fluorescence spectra and the current-voltage-EL characteristics, to reveal the thickness of the electron-hole capture zone and the behavior of charge carriers and excitons during operation in these LEDs.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1980-06-01

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

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

    Science.gov (United States)

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

    2015-08-24

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-12

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

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

    Institute of Scientific and Technical Information of China (English)

    张秀丽

    2011-01-01

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

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

    Science.gov (United States)

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

    2015-11-16

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

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

    Science.gov (United States)

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

    2004-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Agata Jedrzejuk

    2012-01-01

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

  15. Determination of some trace metals in elsaraf dam (GEDAREF)

    International Nuclear Information System (INIS)

    In this study the part of the plant analyzed was the root, while by the soil we mean the soil which is in direct contact with the plant root. This analysis was carried to find the relation between the concentrations of the free ions in water, the mobile ions in the soil in contact with the root of the plant and the ions uptake by the plant as well as the movement of these ions between different reservoirs. The nutrient elements, (Fe, Mn, Zn, Cu, Co) showed higher concentrations than toxic elements (Cr, Ni, Cd). Because of its natural abundance, iron has the highest concentration (54900/56600, 33580/36800), manganese has shown the second highest concentration, followed by nickel and zinc. Copper, cobalt and chromium have shown relatively similar concentrations, while cadmium has shown the lowest concentration. In general, almost for all elements the soils have shown higher concentration followed by the plant and then water. Cyperus rotandus has shown high affinity towards most of the metal ions, while the rest of plants have shown almost similar affinity. Because of the generally low concentration of metal ions in water, preconcentration was used using 8-hydroxyquinoline (oxine) and ammonium pyrolidine dithiocarbamate APDC to extract (pre concentrate) the metal ions at the optimum parameters before measurement in AAS.(Author)

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

    Science.gov (United States)

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

    2015-01-27

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

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

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2015-09-01

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

  18. White electrophosphorescent devices based on tricolour emissive layers

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Hua Yulin [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Wu Xiaoming [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Zhang Guohui [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Hui Juanli [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Zhang Lijuan [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Liu Qian [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Ma Liang [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Yin Shougen [Institute of Physical Materials, Tianjin University of Technology, Tianjin, 300384 (China); Petty, M C [School of Engineering, University of Durham, Durham DH1 3LE (United Kingdom)

    2008-01-21

    We demonstrate high efficiency, white organic light-emitting devices based on a structure using multiple emissive layers and fabricated without a hole-injecting layer. 2,5,8,11-tetra-tertbutylperylene (TBPe) was used as the blue fluorescent layer and the overall device configuration was indium tin oxide (ITO)/N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB)/4,4'-N, N'-dicarbazole-biphenyl (CBP): bis[1-(phenyl)isoquinoline] iridium (III) acetylanetonate [Ir(piq){sub 2}(acac)]/CBP:fac-tris(2-phenylpyridine) iridium [Ir(ppy){sub 3}]/CBP: TBPe/2, 9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/(8-hydroxyquinoline) aluminium (Alq{sub 3})/LiF/Al. This structure possessed a maximum luminous efficiency of 14.2 cd A{sup -1} at a current density of 4 mA cm{sup -2} and a maximum brightness of 40 520 cd m{sup -2} at 25 V. The Commission Internationale de L'Eclairage coordinates changed only from (0.27, 0.38) to (0.33, 0.38), with the brightness varying from 100 to 25 640 cd m{sup -2}, as the applied voltage was increased from 10 to 23 V.

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

    Directory of Open Access Journals (Sweden)

    MÓNICA MOURA

    2009-01-01

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

  20. Anion-directed self-assembly of two half-sandwich ruthenium-based metallamacrocycles as catalysts for water oxidation.

    Science.gov (United States)

    Yu, Wei-Bin; He, Qing-Ya; Shi, Hua-Tian; Yuan, Guozan; Wei, Xianwen

    2015-01-01

    The binuclear [η(6) -(cymene)Ru(L)]2 (OTf)2 (TfO(-) =trifluoromethanesulfonate) and tetranuclear [η(6) -(cymene)Ru(L)]4 (NO3 )4 metallacycles were prepared by treating the pyridyl-substituted 8-hydroxyquinoline ligand (E)-2-[2-(pyridin-3-yl)vinyl]quinolin-8-ol (HL) with [(p-cymene)Ru(μ-Cl)Cl]2 in the presence of AgOTf or AgNO3 . The molecular structures of these complexes were confirmed by single-crystal X-ray diffraction, which revealed that both complexes have macrocycle frameworks induced by the TfO(-) and NO3 (-) counteranions, respectively. The electrochemical properties of the two metallacycles were investigated by cyclic voltammetry, which showed that they have great potential as catalysts for water oxidation. Good efficiency was obtained by utilizing the nitrate complex as a water oxidation catalyst in the presence of a Ce(IV) salt as an oxidant at high pH values. PMID:25303729

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

    Directory of Open Access Journals (Sweden)

    Jayamohan Subramanian

    2014-09-01

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

  2. The solution structure of the copper clioquinol complex.

    Science.gov (United States)

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

    2014-04-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

  4. Investigation on internal electric field distribution of organic light-emitting diodes (OLEDs) with Eu{sub 2}O{sub 3} buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Shengwei; Ma, Dongge [State Key Laboratory of Polymer Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022 Changchun (China)

    2009-11-15

    We have found that organic light-emitting diode (OLED) performance was highly improved by using europium oxide (Eu{sub 2}O{sub 3}) as a buffer layer on indium tin oxide (ITO) in OLEDs based on tris-(8-hydroxyquinoline) aluminium (Alq{sub 3}), which showed low turn-on voltage, high luminance, and high electroluminescent (EL) efficiency. The thickness of Eu{sub 2}O{sub 3} generally was 0.5-1.5 nm. We investigated the effects of Eu{sub 2}O{sub 3} on internal electric field distributions in the device through the analysis of current-voltage characteristics, and found that the introduction of the buffer layer balanced the internal electric field distributions in hole transport layer (HTL) and electron transport layer (ETL), which should fully explain the role of the buffer layer in improving device performance. Our investigation demonstrates that the hole injection is Fowler-Nordheim (FN) tunnelling and the electron injection is Richardson-Schottky (RS) thermionic emission, which are very significant in understanding the operational mechanism and improving the performance of OLEDs. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

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

    Directory of Open Access Journals (Sweden)

    Sachin R. Joshi

    2014-09-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Lu Fei-Ping; Wang Qian; Zhou Xiang

    2013-01-01

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

  7. Polymetallic lanthanide (III) complexes for the design of new luminescent materials

    International Nuclear Information System (INIS)

    The incorporation of f elements in highly organized polymetallic complexes is of great interest in supramolecular chemistry and allows the combination of their nano-scopic size with the magnetic or optical properties of the metal ions. However due to the difficulty in controlling the coordination environment of these ions, the assembly of lanthanide-based polynuclear architectures has lagged behind that of other systems. These factors make the rational design for the construction of supramolecular lanthanide complexes quite challenging. In order to better understand the factors determining the assembly of lanthanide-based polymetallic arrays, we designed two different types of organic ligands, which favor, in one case, formation of infinite polymetallic complexes (coordination polymers), and in the case the assembly of discrete polymetallic architectures. Thus, we show that the use of flexible and multi-dentate picolinate-derivative ligands enables the formation of infinite and luminescent infinite frameworks which display very interesting luminescent properties. Geometry of the ligand has a great influence on the final network architecture. Particularly, implementation of four picolinate units within a tetrapodal ligand results in the controlled assembly of 1-D coordination polymers. Conversely to favor the controlled assembly of discrete polymetallic arrays we use dissymmetric ligands which displays low denticity. Complexation studies of a tridentate 8- hydroxyquinoline-derivative ligand as well as a tetradentate ligand possessing an oxazoline ring are presented. (author)

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

    Science.gov (United States)

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

    2016-03-01

    Copper is a catalytic cofactor required for the normal function of many enzymes involved in fundamental biological processes but highly cytotoxic when in excess. Therefore its homeostasis and distribution is strictly regulated by a network of transporters and intracellular chaperones. ATOX1 (antioxidant protein 1) is a copper chaperone that plays a role in copper homeostasis by binding and transporting cytosolic copper to ATPase proteins in the trans-Golgi network. In the present study the Caco-2 cell line, a colon carcinoma cell line, was used as an in vitro model to evaluate if ATOX1 deficiency could affect sensitivity to experimentally induced copper dyshomeostasis. Silencing of ATOX1 increased toxicity of a short treatment with a high concentration of Cu(2+). Copper ionophores, such as 5-chloro-8-hydroxyquinoline, induced a copper-dependent cell toxicity which was significantly potentiated after ATOX1 silencing. The copper chelator TPEN (N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine) produced a form of cell toxicity that was reversed by the addition of Cu(2+). ATOX1 silencing increased Caco-2 cell sensitivity to TPEN toxicity. Our results suggest the possibility of a therapy with copper-chelating or ionophore drugs in subtypes of tumors showing specific alterations in ATOX1 expression. PMID:26784148

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

    Science.gov (United States)

    Gregusova, Michaela; Docekal, Bohumil

    2011-01-17

    A new resin gel based on Spheron-Oxin(®) chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin(®) functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10(2) mg L(-1). The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel. PMID:21167996

  10. Segmented sediment probe for diffusive gradient in thin films technique.

    Science.gov (United States)

    Docekal, Bohumil; Gregusova, Michaela

    2012-01-21

    A new modification of a constrained sediment probe was tested for application in the diffusive gradient in thin films technique (DGT). The sediment probes packed with agarose based resin and diffusive gels were exposed under laboratory conditions to well-mixed test solutions of cadmium and nickel as model elements. The reproducibility of metal uptake in segments (strips) of resin gel with anchored 8-hydroxyquinoline functional groups (Spheron-Oxin® ion exchanger) was studied. The relative yield of uptake of metals in resin gel strips, determined as the ratio of the time-averaged DGT-measured metal concentration and the concentration of a metal in the test solution, showed that the effective sampling area was larger than the geometric area of the resin gel strip. This relative yield is in very good agreement with the theoretical value obtained by the Finite Element Method (FEM) in calculation of diffusion processes. The performance of the modified constrained probe is demonstrated by an example of uranium, iron and manganese depth profiling in a spiked sediment core. Utilization of the new segmented sediment probe in the DGT technique is very simple. Its application does not require special devices and labor-intensive procedures. It can provide sediment depth profiles of metals with the resolution down to the millimetre level. PMID:22116834

  11. Preparation of gallium-68 radiopharmaceuticals for positron tomography. Progress report, November 1, 1980-December 31, 1981

    International Nuclear Information System (INIS)

    Although the germanium-68 → gallium-68 generator is probably the only source of positron-emitting radionuclides that could enable the widespread application of positron tomography, the commercially available 68Ga/68Ge generator system suffers from several major disadvantages. The most important of these is that the generator is eluted with EDTA, which forms a very strong chelate with gallium. In order to produce radiopharmaceuticals other than 68Ga-EDTA, it is first necessary to break the stable EDTA complex and remove all traces of EDTA. This procedure adds several steps and a significant amount of time to procedures for preparing 68Ga-radiopharmaceuticals. Several years ago, we developed a new generator using a solvent extraction system which produces 68Ga-oxine (8-hydroxyquinoline), a weak chelate. We have also carried out studies to compare generator systems which produce 68Ga in an ionic form. Using the gallium-68 eluted from these various generator systems, several 68Ga-labeled radiopharmaceuticals have been synthesized and tested in vitro and in vivo. In addition, attempts have been made to design and synthesize a lipophilic ligand for gallium-68. The stability of radiogallium complexed with a series of potentially lipophilic complexing agents has been studied using chromatographic techniques and in vivo distribution data. The potential of these complexing agents for altering the biodistribution of gallium radiopharmaceuticals has also been investigated

  12. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Irina ČERNIUKĖ

    2013-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-03

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-24

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

  17. Characterization of amorphous organic thin films, determination of precise model for spectroscopic ellipsometry measurements

    International Nuclear Information System (INIS)

    The optical properties of tris(8-hydroxyquinoline) aluminum (Alq3), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1-1'biphenyl-4,4''diamine (α-NPD) and other amorphous organic materials for OLEDs application, e.g. 4,4-bis(2,2-diphenyl vinyl)-1,1-biphenyl (DPVBI) and Spiro-DPVBI have been studied by multi-angle spectroscopic ellipsometry (SE). The thin films of these materials have been deposited by organic vapor phase deposition (OVPD). The structural characterization has been performed using atomic force microscopy (AFM) and X-ray reflectometry (XRR). Comparison of the measurements using these different independent techniques enables the precise determination of the optical model for dielectric function of these thin films. The detail analyses on Alq3 and α-NPD show that the Kim model with Gaussian broadening provides a significantly better fit to the ellipsometry data than the frequently used harmonic oscillator model. This conclusion is further proved by performing similar measurements on other amorphous organic samples for OLEDs application, e.g. DPVBI and Spiro-DPVBI. This result can be explained by the characteristic features of electronic states in organic molecules.

  18. Aryl end-capped quaterthiophenes applied as anode interfacial layers in inverted organic solar cells

    International Nuclear Information System (INIS)

    Four aryl end-capped quaterthiophene derivatives were synthesized and their material properties were studied by computational, spectroscopic, electrochemical, and thermoanalytical methods. Compounds were applied as interfacial layers between the bulk heterojunction active layer and Ag anode in inverted organic solar cells. Results show that p-cyanophenyl end-capped quaterthiophene with hexyl side chains increases both the short circuit current density and power conversion efficiency notably compared to reference interlayer material, tris-(8-hydroxyquinoline)aluminum. The improved cell performance was attributed to the optimal positions of the highest occupied molecular orbital and the lowest unoccupied molecular orbital (LUMO) of this material, relative to those of the photoactive electron donor poly(3-hexylthiophene) and Ag anode, and evenly distributed LUMO. In addition, the use of these materials as an anode interfacial layer increases the absorption of the solar cell, which could contribute to the formation of excitons and additional current production by the cell. - Highlights: • Aryl end-capped oligothiophenes were synthesized in good overall yields. • Materials could be applied as anode interfacial layers in organic solar cells. • Computational, spectroscopic, and electrochemical analyses support conclusions. • Substitution patterns determine HOMO and LUMO levels of interfacial material. • Improved cell performance was attributed mainly to optimal HOMO and LUMO levels

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

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jim Geiser

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

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

    Directory of Open Access Journals (Sweden)

    Celeste A. Roney

    2009-01-01

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

  2. Occurrence of blockage in cut stems of Clematis L.

    Directory of Open Access Journals (Sweden)

    Agata Jędrzejuk

    2013-04-01

    Full Text Available During vase life of cut flowers obstructions in stem xylem vessels develop. Such obstructions may restrict water uptake in stems and its transport towards flowers, thus lowering their ornamental value and longevity. Clematis is a very attractive plant which can be used as a cut flower in floral compositions. However, nothing is known about the histochemical or cytolo- gical nature of xylem blockages occurring in cut stems of this plant. Observations carried out on Clematis cv. 'Solidarność' proved that tyloses appeared as a principal source of xylem blockage in cut stems. The preservative composed of 200 mg × dm-3 8-HQC (8-hydroxyquinolin citrate and 2% sucrose arre-sted development of xylem blockage, while the vessels in stems kept in water were filled with tyloses or an amorphic substance. PAS reaction proved that polysaccharides were present in the xylem occlusions, whereas no homogalacturonans were immunolocalized in tyloses using JIM 5 and JIM 7 antibodies. The present study provides new information on the origin of xylem occlusions in clematis and their development in two different vase solutions. Such information can be useful to develop pro- per postharvest treatments aiming to improve keeping qualities of this new cut flower.

  3. Identification of xylem occlusions occurring in cut clematis (Clematis L., fam. Ranunculaceae Juss.) stems during their vase life.

    Science.gov (United States)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-04-15

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

  5. Mono- and binuclear copper(II) complexes of new hydrazone ligands derived from 4,6-diacetylresorcinol: Synthesis, spectral studies and antimicrobial activity

    Science.gov (United States)

    Shebl, Magdy; El-ghamry, Mosad A.; Khalil, Saied M. E.; Kishk, Mona A. A.

    Two new hydrazone ligands, H2L1 and H2L2, were synthesized by the condensation of 4,6-diacetylresorcinol with 3-hydrazino-5,6-diphenyl-1,2,4-triazine and isatin monohydrazone, respectively. The structures of the ligands were elucidated by elemental analyses, IR, 1H NMR, electronic and mass spectra. Reactions of the ligands with several copper(II) salts, including AcO-, NO3-, SO42-, Cl- and Br- afforded mono- and binuclear metal complexes. Also, the ligands were allowed to react with Cu(II) ion in the presence of a secondary ligand (L‧) [N,O-donor; 8-hydroxyquinoline, N,N-donor; 1,10-phenanthroline or O,O-donor; benzoylacetone]. Characterization and structure elucidation of the prepared complexes were achieved by elemental and thermal analyses, IR, electronic, mass and ESR spectra as well as conductivity and magnetic susceptibility measurements. The ESR spin Hamiltonian parameters of some complexes were calculated. The spectroscopic data showed that the H2L1 ligand acts as a neutral or monobasic tridentate ligand while the H2L2 ligand acts as a bis(monobasic tridentate) ligand. The coordination sites with the copper(II) ion are phenolic oxygen, azomethine nitrogen and triazinic nitrogen (H2L1 ligand) or isatinic oxygen (H2L2 ligand). The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. The ligands and some metal complexes showed antimicrobial activity.

  6. Sensitive imaging and effective capture of Cu(2+): Towards highly efficient theranostics of Alzheimer's disease.

    Science.gov (United States)

    Cui, Zhaowen; Bu, Wenbo; Fan, Wenpei; Zhang, Jiawen; Ni, Dalong; Liu, Yanyan; Wang, Jing; Liu, Jianan; Yao, Zhenwei; Shi, Jianlin

    2016-10-01

    As a distinct feature of Alzheimer's disease (AD), the presence of excess metal ions in the brain is most probably one of the main causative factors for the aggregation of β-Amyloid (Aβ) proteins. The design of nanoprobes for detection and control of ion concentrations will be of great importance in predicting the progression of AD and simultaneously providing effective treatments. Herein, we report the design and synthesis of a novel yet smart nanoprobe that can sensitively detect the Cu(2+) concentration and concurrently capture Cu(2+) both in vitro and in vivo. The designed nanoprobe (UCHQ) combines two main components: upconversion nanoparticles (UCNPs) used for the detection and upconversion luminescence (UCL) imaging of Cu(2+) upon 980 nm exposure and the chelator 8-hydroxyquinoline-2-carboxylic acid (HQC) used for chelating Cu(2+) and AD therapy. The results show that the emission intensity of UCHQ is highly dependent on the Cu(2+) concentrations due to the luminescence resonance energy transfer (LRET) from UCNPs to HQC-bonded Cu(2+). Fascinatingly, the as-constructed UCHQs could be used for UCL imaging of Aβ both in cells and AD mice. Most importantly, UCHQs could not only inhibit the Aβ aggregation-induced apoptosis via capturing overmuch Cu(2+) but also accelerate the nontoxic structural transformation of Aβ. PMID:27454062

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

    Science.gov (United States)

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

    2000-09-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  9. Synthesis and characterization of copper-64- thiosemicarbazone complexes for radionuclide cancer therapy: biodistribution study in mice by microPET imaging

    International Nuclear Information System (INIS)

    Full text: Multiple copper-thiosemicarbazone complexes of strong anticancer activity were reported in the literature. We hypothesize that a radioactive copper -thiosemicarbazone complex prepared with a radioactive copper radionuclide, such as copper-64 or copper-67, may have enhanced therapeutic efficiency combining cytotoxicity of the copper complex itself and radiotherapeutic effects of the copper radionuclide. Furthermore, a copper-64 thiosemicarbazone complex is especially attractive for targeted radionuclide cancer therapy because tumor localization of the radioactive copper complexes may be non-invasively monitored by position emission tomography (PET) when positron emitting copper isotopes, such as copper-64, are used to prepare the copper complexes. Methods: 8- hydroxyquinoline was coupled to 2-carboxaldehydethiosemicarbazide to make 8-hydroxyquinoline-2- carboxaldehydethiosemicarbazide (HQTS) holding a unique ONNS quadridentate system. Copper complex of HQTS (CuHQTS) was prepared through directly reacting copper chloride with HQTS in enthanolic solution. Anticancer activity of the CuHQTS complex was tested on human prostate cancer, neuroblastoma, and malignant glioblastoma cells by MTT assay, cell cycle arrest analysis, and FITC-Annexin V/PI FACS analysis of apoptosis. To assess bio-distribution in vivo, the HQTS ligands were radiolabeled with copper-64 at 500C for 50 min, and intravenously injected to the mice after removal of nonconjugated copper-64 radionuclides by spin column. Subsequently, the mice were subjected to whole body imaging using a Concorde microPET R4 tomograph, at 1 and 24-hour post injection of the conjugates. Upon completion of the imaging study, the mice were euthanized and the postmortem tissues were harvested, weighted and counted for radioactivity using a gamma counter (%ID/g). The mice injected with copper-64 chlorides were used as control. Results and Discussion: The CuHQTS complexes were synthesized and characterized by IR

  10. Porous dimanganese trioxide microflowers derived from microcoordinations for flexible solid-state asymmetric supercapacitors

    Science.gov (United States)

    Pang, Huan; Li, Xinran; Li, Bing; Zhang, Yizhou; Zhao, Qunxing; Lai, Wen-Yong; Huang, Wei

    2016-06-01

    Dimanganese trioxide microflowers are easily obtained from a Mn(ii) 8-hydroxyquinoline microcoordination after calcination in air. We also look into the possible formation mechanism of the flower-like morphology, and find that the reaction time affects the morphology of the coordination. Furthermore, the as-prepared porous Mn2O3 microflowers are made of many nanoplates which form many nanogaps and nanochannels. Interestingly, the assembled electrode based on the as-prepared porous Mn2O3 microflowers proves to be a high-performance electrode material for supercapacitors. The electrode shows a specific capacitance of 994 F g-1, which can work well even after 4000 cycles at 0.75 A g-1. More importantly, the porous Mn2O3 microflowers and activated carbons are assembled into a high-performance flexible solid-state asymmetric supercapacitor with a specific capacitance of 312.5 mF cm-2. The cycle test shows that the device can offer 95.6% capacity of the initial capacitance at 2.0 mA cm-2 after 5000 cycles with little decay. The maximum energy density of the device can achieve 6.56 mWh cm-3 and the maximum power density can also achieve 283.5 mW cm-3, which are among the best results for manganese based materials.Dimanganese trioxide microflowers are easily obtained from a Mn(ii) 8-hydroxyquinoline microcoordination after calcination in air. We also look into the possible formation mechanism of the flower-like morphology, and find that the reaction time affects the morphology of the coordination. Furthermore, the as-prepared porous Mn2O3 microflowers are made of many nanoplates which form many nanogaps and nanochannels. Interestingly, the assembled electrode based on the as-prepared porous Mn2O3 microflowers proves to be a high-performance electrode material for supercapacitors. The electrode shows a specific capacitance of 994 F g-1, which can work well even after 4000 cycles at 0.75 A g-1. More importantly, the porous Mn2O3 microflowers and activated carbons are

  11. Multi-Target Directed Donepezil-Like Ligands for Alzheimer's Disease.

    Science.gov (United States)

    Unzeta, Mercedes; Esteban, Gerard; Bolea, Irene; Fogel, Wieslawa A; Ramsay, Rona R; Youdim, Moussa B H; Tipton, Keith F; Marco-Contelles, José

    2016-01-01

    HIGHLIGHTS ASS234 is a MTDL compound containing a moiety from Donepezil and the propargyl group from the PF 9601N, a potent and selective MAO B inhibitor. This compound is the most advanced anti-Alzheimer agent for preclinical studies identified in our laboratory.Derived from ASS234 both multipotent donepezil-indolyl (MTDL-1) and donepezil-pyridyl hybrids (MTDL-2) were designed and evaluated as inhibitors of AChE/BuChE and both MAO isoforms. MTDL-2 showed more high affinity toward the four enzymes than MTDL-1.MTDL-3 and MTDL-4, were designed containing the N-benzylpiperidinium moiety from Donepezil, a metal- chelating 8-hydroxyquinoline group and linked to a N-propargyl core and they were pharmacologically evaluated.The presence of the cyano group in MTDL-3, enhanced binding to AChE, BuChE and MAO A. It showed antioxidant behavior and it was able to strongly complex Cu(II), Zn(II) and Fe(III).MTDL-4 showed higher affinity toward AChE, BuChE.MTDL-3 exhibited good brain penetration capacity (ADMET) and less toxicity than Donepezil. Memory deficits in scopolamine-lesioned animals were restored by MTDL-3.MTDL-3 particularly emerged as a ligand showing remarkable potential benefits for its use in AD therapy. Alzheimer's disease (AD), the most common form of adult onset dementia, is an age-related neurodegenerative disorder characterized by progressive memory loss, decline in language skills, and other cognitive impairments. Although its etiology is not completely known, several factors including deficits of acetylcholine, β-amyloid deposits, τ-protein phosphorylation, oxidative stress, and neuroinflammation are considered to play significant roles in the pathophysiology of this disease. For a long time, AD patients have been treated with acetylcholinesterase inhibitors such as donepezil (Aricept®) but with limited therapeutic success. This might be due to the complex multifactorial nature of AD, a fact that has prompted the design of new Multi-Target-Directed Ligands

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

    International Nuclear Information System (INIS)

    The photophysical properties of adduct of a novel nonadentate tripodal ligand, 5,5′-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1, 3-diyl)bis(azanediyl)bis(methylene diquinolin-8-ol, (TAME5OX), with Eu3+ and Tb3+ metal ions have been probed for photonics applications. The absorption spectroscopy of these complexes show remarkable spectral changes due to characteristic lanthanide transitions, which support the use of TAME5OX as a sensitive optical pH based sensor to detect Ln3+ metal ions in biological systems. In addition, these complexes have also been shown to exhibit strong green fluorescence allowing simultaneous sensing within the visible region under physiological pH in competitive medium for both Eu3+ and Tb3+ ions. The intense fluorescence from these compounds were revealed to intermittently get quenched under acidic as well as basic conditions due to the photoinduced intramolecular electron transfer from excited 8-hydroxyquinoline (8-HQ) moiety to metal ion, just an opposite process. This renders these compounds the OFF–ON–OFF type of pH-dependent fluorescent sensor. The thermodynamic stability and aqueous coordination chemistry of the chelator with the said lanthanide ions have also been probed by potentiometric, UV–visible and fluorescence spectrophotometric method. TAME5OX has been found to form two protonated complexes [Ln(H5L)]5+ and [Ln(H4L)]4+ below pH 2.5 with both metal ions, which consecutively deprotonates through one proton process with rise of pH. The formation constants (log β11n) of neutral complexes have been determined to be 33.51 and 32.16 with pLn (pLn=−log[Ln3+]) values of 16.14 and 19.48 for Eu3+ and Tb3+ ions, respectively, calculated at pH 7.4, indicating TAME5OX is a good lanthanide synthetic chelator. The emission lifetimes of the Eu3+ and Tb3+ complexes recorded in D2O and H2O suggest the presence of water molecules in the first coordination sphere of the metal ions. NMR titrations were carried out

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  14. Rare earth(III) complexes for the development of new magnetic and luminescent probes

    International Nuclear Information System (INIS)

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

  15. Determination of manganese- and manganese-containing fungicides with lucigenin-Tween-20-enhanced chemiluminescence detection.

    Science.gov (United States)

    Yaqoob, Mohammad; Asghar, Mohammad; Nabi, Abdul

    2015-11-01

    A flow-injection (FI) method is reported for the determination of Mn(II), maneb and mancozeb fungicides based on the catalytic effect of Mn(II) on the oxidation of lucigenin and dissolved oxygen in a basic solution. The Tween-20 surfactant has been reported for first time to enhance lucigenin chemiluminescence (CL) intensity in the presence of Mn(II) (53%) and maneb and mancozeb (89%). The calibration graphs were linear in the concentration range of 0.001-1.5 mg L(-1) (R(2) = 0.9982 (n = 11) with a limit of detection (S/N = 3) of 0.1 µg L(-1) for Mn(II) and 0.01-3.0 mg L(-1) [R(2) = 0.9989 and R(2) = 0.9992 (n = 6)] with a limit of detection (S/N =3) of 1.0 µg L(-1) for maneb and mancozeb respectively. Injection throughputs of 90 and 120 h(-1) for Mn(II) and maneb and mancozeb respectively, and relative standard deviations of 1.0-3.4% were obtained in the concentration range studied. The experimental variables, e.g., reagents concentrations, flow rates, sample volume, and photomultiplier tube voltage, were optimized and potential interferences were investigated. The analysis of Mn(II) in river water reference materials (SLRS-4 and SLRS-5) showed good agreement with the certified values incorporating an on-line 8-hydroxyquinoline chelating column in the manifold for removing interfering metal ions. Recoveries for maneb and mancozeb were in the range of 92 ± 5 to 104 ± 3% and 91 ± 2 to 100 ± 4% (n = 3) respectively. The effect of 30 other pesticides (fungicides, herbicides and insecticides) was also examined in the lucigenin-Tween-20 CL system. PMID:25640332

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

    Science.gov (United States)

    Burrows, Hugh D; Costa, Telma; Ramos, M Luisa; Valente, Artur J M; Stewart, Beverly; Justino, Licinia L G; Almeida, Aline I A; Catarina, Nathanny Lessa; Mallavia, Ricardo; Knaapila, Matti

    2016-06-22

    We have studied the interaction of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the metal ions Al(iii) and Zn(ii) in aqueous solution in the presence of tetraalkylammonium surfactants using UV/vis absorption, fluorescence, NMR spectroscopy and electrical conductivity measurements, complemented by DFT calculations and molecular dynamics (MD) simulations. Under appropriate conditions, complexes between 8-HQS and metal ions form rapidly, and have similar electronic, spectroscopic and photophysical properties to the corresponding metal quinolates, such as Alq3. These interact with the cationic surfactants, leading to marked increases in fluorescence intensity. However, significant differences are seen in the behavior of the two metal ions. With aluminium, a stable [Al(8-QS)3](3-) anion is formed, and interacts, predominantly through electrostatic interactions, with the surfactant, without disrupting the metal ion coordination sphere. In contrast, with Zn(ii), there is a competition between the metal ion and surfactants in the interaction with 8-HQS, although the [Zn(8-QS)2(H2O)2](2-) species is stable at appropriate pH and surfactant concentration. The studies are extended to systems with the conjugated polyelectrolyte (CPE) poly-(9,9-bis(6-N,N,N-trimethylammonium)hexyl)-fluorene-phenylene bromide (HTMA-PFP), which has a similar alkylammonium chain to the surfactants. Mixing metal salt, 8-HQS and HTMA-PFP in the presence of a nonionic surfactant leads to the formation of a metal complex/CPE supramolecular assembly between the conjugated polyelectrolyte and the metal/8-HQS complex, as demonstrated by electronic energy transfer. The potential of these systems in sensing, light harvesting, and electron injection/transport layers in organic semiconductor devices is discussed. PMID:26817700

  17. Electrophotometric determination of molybdenum after separation from its pyrrolidinedithiocarbamte by adsorption of naphthalene

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, R.K.; Kumar, A. [D.A. Univ., Indore (India)

    1992-05-10

    Various reagents, namely thiosemicarbazone 2,2{sup prime}-dihydroxybenzophenone, imidoylphenhydrazine, 2-thiopyrogallol, 5,7-dibro-8-hydroxyquinoline, 1,10-phenanthromine + bromopyrogallol, Alizarine Blue, benzohydroxamic acid, benzoylacetone, and 2,4-dihydroxyacetophenone oxime, are used for the determination of molybdenum. In most cases, tungsten interferes significantly, or the method requires strict monitoring of the concentration, calculation, and boiling time. In some cases, molybdenum has been determined only in alloys with high molybdenum content and with reduction of Mo(VI) to Mo(V). The authors have developed a method using solid-liquid separation extraction after liquid-liquid extraction into molten naphthalene. Although this method has a number of advantages in ordinary liquid-liquid extraction, it cannot be used for extraction of thermally unstable complexes. Recently, the authors observed that most complexes of metals in aqueous solutions can be precipitated with microcrystalline naphthalene. This method is convenient (it is carried out at room temperature), rapid (it requires no time for heating of naphthalene), and economical (only 0.4 g of naphthalene is required). The method is especially convenient for metal complexes insoluble in nonaqueous organic solvents. In this article, ammonium pyrrolidinedithiocarbamate is recommended for determination of molybdenum after coprecipitation of molybdenum pyrrolidinedithiocarbamate with microcrystalline naphthalene. The role of various parameters (pH, concentration of the reagent and naphthalene, time of separation and shaking, and volume of the aqueous phase) was established, and conditions were found for determination of molybdenum in some alloys. Because molybdenum can be adsorbed from an acid solution (pH {le} 2.5), the method is more selective than many other names described in the literature. 14 refs., 2 tabs.

  18. Fast detection and quantification of Escherichia coli using the base principle of the microbial fuel cell.

    Science.gov (United States)

    Kim, Taegyu; Han, Jong-In

    2013-11-30

    Escherichia coli is an important microbial indicator of fecal contamination, making accurate quantitative detection of E. coli a key to ensuring public health. In this study, a microbial fuel cell (MFC) was used as a detection unit of an E. coli sensor, and specific enzymes expressed in E. coli, such as β-D-galactosidase (GAL) and β-D-glucuronidase (GUS), were exploited as biological detection elements. As substrates, 4-aminophenyl-β-D-galactopyranoside (4-APGal) were used for GAL detection, whereas 8-hydroxyquinoline glucuronide (8-HQG) and 4-nitrophenyl β-D-glucuronide (PNPG) were used for GUS detection. Once these substrates were hydrolyzed by GAL or GUS, they became electrochemically active products, which were, in turn, oxidized on the anode of the MFC reactor. The power output of the MFC reactor increased sharply when E. coli in the reactor reached the critical concentration. Accordingly, the time required to reach the highest voltage output was recorded as a detection time (DT), and a negative linear relationship was established between DT and the logarithm of the initial concentration of E. coli in the samples studied. The DTs of laboratory samples were 140 min and 560 min for initial concentrations of 1.9 × 10(7) CFU/mL and 42 CFU/mL at 44.5 °C. Moreover, the DTs for GUS assays were further shortened by induction with methyl β-D-glucuronide sodium salt (MetGlu). The quantitative relationship between DTs and initial E. coli concentrations established from replicate laboratory sample assays allowed estimation of the E. coli concentration in environmental samples, but with approximately 100 min of lag time. The lag time was also observed with E. coli samples that were prepared by starving cells in a laboratory. PMID:24095789

  19. Highly luminescent material based on Alq3:Ag nanoparticles.

    Science.gov (United States)

    Salah, Numan; Habib, Sami S; Khan, Zishan H

    2013-09-01

    Tris (8-hydroxyquinoline) aluminum (Alq3) is an organic semiconductor molecule, widely used as an electron transport layer, light emitting layer in organic light-emitting diodes and a host for fluorescent and phosphorescent dyes. In this work thin films of pure and silver (Ag), cupper (Cu), terbium (Tb) doped Alq3 nanoparticles were synthesized using the physical vapor condensation method. They were fabricated on glass substrates and characterized by X-ray diffraction, scanning electron microscope (SEM), energy dispersive spectroscopy, atomic force microscope (AFM), UV-visible absorption spectra and studied for their photoluminescence (PL) properties. SEM and AFM results show spherical nanoparticles with size around 70-80 nm. These nanoparticles have almost equal sizes and a homogeneous size distribution. The maximum absorption of Alq3 nanoparticles is observed at 300 nm, while the surface plasmon resonant band of Ag doped sample appears at 450 nm. The PL emission spectra of Tb, Cu and Ag doped Alq3 nanoparticles show a single broad band at around 515 nm, which is similar to that of the pure one, but with enhanced PL intensity. The sample doped with Ag at a concentration ratio of Alq3:Ag = 1:0.8 is found to have the highest PL intensity, which is around 2 times stronger than that of the pure one. This enhancement could be attributed to the surface plasmon resonance of Ag ions that might have increased the absorption and then the quantum yield. These remarkable result suggest that Alq3 nanoparticles incorporated with Ag ions might be quite useful for future nano-optoelectronic devices. PMID:23653126

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

    Science.gov (United States)

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

    2016-06-22

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

  1. Optical properties of organic films, multilayers and plasmonic metal-organic waveguides fabricated by organic molecular beam deposition

    Science.gov (United States)

    Wickremasinghe, Niranjala D.

    In this thesis, the optical properties of tris (8-hydroxyquinoline) aluminum (Alq3) and 3,5,9,10-perylentetracarboxylic dianhydride (PTCDA) organic films, PTCDA/ Alq3 multilayers and plasmonic Alq3 -metal waveguides are investigated. The organic films and heterostructures used for this work were fabricated by organic molecular beam deposition (OMBD). We investigated the quenching of the light emission in Alq3 films grown on a Si substrate as a function of cw laser excitation intensity at varying temperatures from 15 to 300 K. The saturation of the singlet-singlet annihilation coefficient was measured with spectrally-integrated (SI) photoluminescence (PL) using a photodiode. The bimolecular quenching coefficient was further studied with time-resolved (TR) PL as a function of 100 fs pulse fluences. The PL quenching is attributed to the annihilation of trapped excitons at Alq3 nanocrystal grain boundaries. The saturation is explained by the limited density of available trapping states at the grain boundaries. Our interpretation is supported by structural investigations of ultrathin Alq3 films with atomic force microscopy (AFM), scanning electron microscopy (SEM) and by comparing the experimental data with calculations using a coupled rate equation model. The wavelength dispersion of the refractive indices of PTCDA and Alq 3 layers and of PTCDA/Alq3 multilayer waveguides grown on Pyrex substrates was investigated. The m-line technique, an evanescent prism coupling technique, was used to determine the layers' thickness and the in-plane (TE modes) and normal (TM modes) refractive indices. The potential for controlling the refractive index dispersion and anisotropy by tailored organic multilayer waveguides is discussed.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  3. A Novel Structure Organic White-light Device with DPVBi as Emitting Layers%基于DPVBi发光的新结构有机白光器件

    Institute of Scientific and Technical Information of China (English)

    姜文龙; 王静; 丁桂英; 汪津; 王洪梅

    2007-01-01

    介绍了结构为ITO/4,4',4"-tris{N,-(3-methylphenyl)-N-phenylamino}tripheny-lamine(m-MTDATA,40 nm)/N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine(NPB,5 nm)/4,4'-bis(2,2'diphenyl vinyl)-1,1'-biphenyl(DPVBi,x nm)/5,6,11,12,-tetraphenylnaphthacene(Rubrene,0.5 nm)/DPVBi(20 nm)/tris(8-hydroxyquinoline)aluminum(Alq,45-x nm)/LiF(0.5 nm)/Al的白光器件.采用了2个DPVBi层中间夹1个Rubrene的薄层,这种结构充分利用了DPVBi的空穴阻挡特性和发光特性,有力地平衡了来自于DPVBi的蓝光和Rubrene的黄光,从而使器件发出性能较好的白光.器件保持第2层DPVBi的厚度为20 nm,第1层的DPVBi的厚度按照5、8、11和14 nm的规律进行变化,相应改变Alq的厚度,使得这两者的总厚度为45 nm保持不变.当第1层DPVBi的厚度是8 nm、Alq的厚度是37 nm和其它层的厚度保持不变时,在13 V的电压下,器件的最大亮度为18 710 cd/m2,对应的效率为2.06 cd/A,色坐标为(0.29,0.30),属于白光发射.

  4. Effect of Voltage on Electroluminescent Spectrum of Blue Organic Light-emitting Devices%电压对有机蓝光器件发光光谱的影响

    Institute of Scientific and Technical Information of China (English)

    姜文龙; 王静; 丁桂英; 汪津; 王立忠; 韩强; 王洪梅; 赵晓红

    2007-01-01

    介绍了结构为ITO/40 nm 4,4',4"-tris[N,-(3-methylphenyl)-N-phenylamino]triphenylamine(m-MTDATA)/5 nm N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine(NPB)/x nm 4,4-bis(2,2-diphenyl vinyl)-1,1-biphenyl(DPVBi)/y nm 6,11,12,-tetraphenylnaphthacene(Rubrene)/40 nm tris(8-hydroxyquinoline)aluminum(Alq)/0.5 nm LiF/Al的器件,其发光光谱的半峰宽在电压由2 V变为12 V时,由140 nm变为70 nm,器件发光的峰值波长由456 nm变为444 nm的规律.半峰宽变窄是由于随着电压的升高,被Rubrene俘获的电子获得了足够的能量,越过Rubrene层,在DPVBi中与注入的空穴形成激子而复合发光的概率的逐步增加所造成的.峰值波长蓝移是由于激子的形成区域随着电压的增加逐渐由DPVBi层移向NPB层造成的.器件峰值波长的这种变化对器件的色度改善有着很大的影响.

  5. New double graded structure for enhanced performance in white organic light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Peng Yu Chen [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan (China); Herng Yih Ueng, E-mail: hueng@ee.nsysu.edu.t [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan (China); Yokoyama, Meiso [Department of Electronic Engineering, I-Shou University, Kaohsiung County, Taiwan (China)

    2010-10-15

    This study presents a new design that uses a combination of a graded hole transport layer (GH) structure and a gradually doped emissive layer (GE) structure as a double graded (DG) structure to improve the electrical and optical performance of white organic light-emitting diodes (WOLEDs). The proposed structure is ITO/m-MTDATA (15 nm)/NPB (15 nm)/NPB: 25% BAlq (15 nm)/NPB: 50% BAlq (15 nm)/BAlq: 0.5% Rubrene (10 nm)/BAlq: 1% Rubrene (10 nm)/BAlq: 1.5% Rubrene (10 nm)/Alq{sub 3} (20 nm)/LiF (0.5 nm)/Al (200 nm). (m-MTDATA: 4,4',4'' -tris(3-methylphenylphenylamino)triphenylamine; NPB: N,N'-diphenyl-N,N'-bis(1-naphthyl-phenyl)-(1,1'-biphenyl)-4,4'-diamine; BAlq: aluminum (III) bis(2-methyl-8-quinolinato) 4-phenylphenolate; Rubrene: 5,6,11,12-tetraphenylnaphthacene; Alq{sub 3}: tris-(8-hydroxyquinoline) aluminum). By using this structure, the best performance of the WOLED is obtained at a luminous efficiency at 11.8 cd/A and the turn-on voltage of 100 cd/m{sup 2} at 4.6 V. The DG structure can eliminate the discrete interface, and degrade surplus holes, the electron-hole pairs are efficiently injected and balanced recombination in the emissive layer, thus the spectra are unchanged under various drive currents and quenching effects can be significantly suppressed. Those advantages can enhance efficiency and are immune to drive current density variations.

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  8. Comparison of kinetic properties of amine oxidases from sainfoin and lentil and immunochemical characterization of copper/quinoprotein amine oxidases.

    Science.gov (United States)

    Zajoncová, L; Frébort, I; Luhová, L; Sebela, M; Galuszka, P; Pec, P

    1999-01-01

    Kinetic properties of novel amine oxidase isolated from sainfoin (Onobrychis viciifolia) were compared to those of typical plant amine oxidase (EC 1.4.3.6) from lentil (Lens culinaris). The amine oxidase from sainfoin was active toward substrates, such as 1,5-diaminopentane (cadaverine) with K(m) of 0.09 mM and 1,4-diaminobutane (putrescine) with K(m) of 0.24 mM. The maximum rate of oxidation for cadaverine at saturating concentration was 2.7 fold higher than that of putrescine. The amine oxidase from lentil had the maximum rate for putrescine comparable to the rate of sainfoin amine oxidase with the same substrate. Both amine oxidases, like other plant Cu-amine oxidases, were inhibited by substrate analogs (1,5-diamino-3-pentanone, 1,4-diamino-2-butanone and aminoguanidine), Cu2+ chelating agents (diethyltriamine, 1,10-phenanthroline, 8-hydroxyquinoline, 2,2'-bipyridyl, imidazole, sodium cyanide and sodium azide), some alkaloids (L-lobeline and cinchonine), some lathyrogens (beta-aminopropionitrile and aminoacetonitrile) and other inhibitors (benzamide oxime, acetone oxime, hydroxylamine and pargyline). Tested by Ouchterlony's double diffusion in agarose gel, polyclonal antibodies against the amine oxidase from sainfoin, pea and grass pea cross-reacted with amine oxidases from several other Fabaceae and from barley (Hordeum vulgare) of Poaceae, while amine oxidase from the filamentous fungus Aspergillus niger did not cross-react at all. However, using Western blotting after SDS-PAGE with rabbit polyclonal antibodies against the amine oxidase from Aspergillus niger, some degree of similarity of plant amine oxidases from sainfoin, pea, field pea, grass pea, fenugreek, common melilot, white sweetclover and Vicia panonica with the A. niger amine oxidase was confirmed. PMID:10092944

  9. Push-pull effect on the geometrical, optical and charge transfer properties of disubstituted derivatives of mer-tris(4-hydroxy-1,5-naphthyridinato aluminum (mer-AlND3

    Directory of Open Access Journals (Sweden)

    Rao Joshi Laxmikanth

    2016-12-01

    Full Text Available To design innovative and novel optical materials with high mobility, two kinds of disubstituted derivatives for mer-tris(4-hydroxy-1,5-naphthyridinato aluminum (mer-AlND3 with push (EDG–pull (EWG substituents have been designed. The structures of mer-tris(8-EDG-2-EWG-4-hydroxy-1,5-naphthyridinato aluminum (type I and mer-tris(8-EWG-2-EDG-4-hydroxy-1,5-naphthyridinato aluminum (type II in the ground and first excited states have been optimized at the B3LYP/6-31G(D and CIS/6-31G(D level of theory, respectively. It can be seen from frontier molecular orbitals analysis, in all these complexes, the highest occupied molecular orbital (HOMO is localized on the pyridine-4-ol ring of A-ligand while lowest unoccupied molecular orbital (LUMO is on the pyridyl ring of B-ligand in ground state irrespective of electron donor/acceptor substitution present on the ligands similar to that of mer-tris(8-hydroxyquinoline aluminum (mer-Alq3 and parent mer-AlND3.The absorption and emission wavelengths have been evaluated at the TD-PBE0/6-31G(D level and it can be see that all the type I derivatives show blue shift while most of the type II derivatives show red shift compared to mer-AlND3. All the disubstituted complexes have showed hypsochromic shifts in both the absorption and emission spectra when compared with the calculated absorption and emission spectra respectively of mer-Alq3. It can be seen that the reorganization energies of some of the disubstituted derivatives are comparable with mer-Alq3 and these derivatives might be good candidates for emitting materials in OLED.

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

    Science.gov (United States)

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

    2016-06-22

    Copper is an essential nutrient for life, but at the same time, hyperaccumulation of this redox-active metal in biological fluids and tissues is a hallmark of pathologies such as Wilson's and Menkes diseases, various neurodegenerative diseases, and toxic environmental exposure. Diseases characterized by copper hyperaccumulation are currently challenging to identify due to costly diagnostic tools that involve extensive technical workup. Motivated to create simple yet highly selective and sensitive diagnostic tools, we have initiated a program to develop new materials that can enable monitoring of copper levels in biological fluid samples without complex and expensive instrumentation. Herein, we report the design, synthesis, and properties of PAF-1-SMe, a robust three-dimensional porous aromatic framework (PAF) densely functionalized with thioether groups for selective capture and concentration of copper from biofluids as well as aqueous samples. PAF-1-SMe exhibits a high selectivity for copper over other biologically relevant metals, with a saturation capacity reaching over 600 mg/g. Moreover, the combination of PAF-1-SMe as a material for capture and concentration of copper from biological samples with 8-hydroxyquinoline as a colorimetric indicator affords a method for identifying aberrant elevations of copper in urine samples from mice with Wilson's disease and also tracing exogenously added copper in serum. This divide-and-conquer sensing strategy, where functional and robust porous materials serve as molecular recognition elements that can be used to capture and concentrate analytes in conjunction with molecular indicators for signal readouts, establishes a valuable starting point for the use of porous polymeric materials in noninvasive diagnostic applications. PMID:27285482

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

    Science.gov (United States)

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

    2016-04-01

    A simple and rapid dispersive liquid-liquid microextraction procedure based on ionic liquid assisted microemulsion (IL-µE-DLLME) combined with cloud point extraction has been developed for preconcentration copper (Cu(2+)) in drinking water and serum samples of adolescent female hepatitits C (HCV) patients. In this method a ternary system was developed to form microemulsion (µE) by phase inversion method (PIM), using ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and nonionic surfactant, TX-100 (as a stabilizer in aqueous media). The Ionic liquid microemulsion (IL-µE) was evaluated through visual assessment, optical light microscope and spectrophotometrically. The Cu(2+) in real water and aqueous acid digested serum samples were complexed with 8-hydroxyquinoline (oxine) and extracted into IL-µE medium. The phase separation of stable IL-µE was carried out by the micellar cloud point extraction approach. The influence of of different parameters such as pH, oxine concentration, centrifugation time and rate were investigated. At optimized experimental conditions, the limit of detection and enhancement factor were found to be 0.132 µg/L and 70 respectively, with relative standard deviation <5%. In order to validate the developed method, certified reference materials (SLRS-4 Riverine water) and human serum (Sero-M10181) were analyzed. The resulting data indicated a non-significant difference in obtained and certified values of Cu(2+). The developed procedure was successfully applied for the preconcentration and determination of trace levels of Cu(2+) in environmental and biological samples. PMID:26761783

  12. Synthesis, magnetic, spectral, and antimicrobial studies of Cu(II), Ni(II) Co(II), Fe(III), and UO 2(II) complexes of a new Schiff base hydrazone derived from 7-chloro-4-hydrazinoquinoline

    Science.gov (United States)

    El-Behery, Mostafa; El-Twigry, Haifaa

    2007-01-01

    A new hydrazone ligand, HL, was prepared by the reaction of 7-chloro-4-hydrazinoquinoline with o-hydroxybenzaldehyde. The ligand behaves as monoprotic bidentate. This was accounted for as the ligand contains a phenolic group and its hydrogen atom is reluctant to be replaced by a metal ion. The ligand reacted with Cu(II), Ni(II), Co(II), Fe(III), and UO 2(II) ions to yield mononuclear complexes. In the case of Fe(III) ion two complexes, mono- and binuclear complexes, were obtained in the absence and presence of LiOH, respectively. Also, mixed ligand complexes were obtained from the reaction of the metal cations Cu(II), Ni(II) and Fe(III) with the ligand (HL) and 8-hydroxyquinoline (8-OHqu) in the presence of LiOH, in the molar ratio 1:1:1:1. It is clear that 8-OHqu behaves as monoprotic bidentate ligand in such mixed ligand complexes. The ligand, HL, and its metal complexes were characterized by elemental analyses, IR, UV-vis, mass, and 1H NMR spectra, as well as magnetic moment, conductance measurements, and thermal analyses. All complexes have octahedral configurations except Cu(II) complex which has an extra square-planar geometry, while Ni(II) mixed complex has also formed a tetrahedral configuration and UO 2(II) complex which formed a favorable pentagonal biprymidial geometry. Magnetic moment of the binuclear Fe(III) complex is quite low compared to calculated value for two iron ions complex and thus shows antiferromagnetic interactions between the two adjacent ferric ions. The HL and metal complexes were tested against one stain Gram positive bacteria ( Staphylococcus aureus), Gram negative bacteria ( Escherichia coli), and fungi ( Candida albicans). The tested compounds exhibited higher antibacterial acivities.

  13. Study on the electrical conductive mechanism in the five-layered structure of organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Jong; Choi, Hyun-Min; Hong, Jin-Woong [Kwangwoon University, Seoul (Korea, Republic of); Shin, Jong-Yeol [Sahmyook University, Seoul (Korea, Republic of); Kim, Tae-Wan [Hongik University, Seoul (Korea, Republic of)

    2010-12-15

    The Electrical conductive mechanism was studied using a five-layered structure of organic light emitting diodes. The manufactured device structure was ITO/2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole (AF)/N,N'-diphenyl-N,N'bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/ tris(8-hydroxyquinoline)aluminum (Alq{sub 3})/(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/LiF/Al. From the analysis of the current density-luminance-voltage characteristics of the five-layered device, four conductive mechanisms depending on the applied voltage region were found. In the Schottky region, where the electric field E is below 1.6 x 10{sup 5} V/cm, the obtained Schottky coefficient {beta}{sub ST} is 3.98 x 10{sup -24} JV{sup -1/2}m{sup 1/2}. In the negative-resistance region, where the electric field is below 3.7 x 10{sup 5} V/cm, the current density J is proportional to E{sup -2.41}. In the Poole-Frenkel region, where the electric field is below 6.4 x 10{sup 5} V/cm, the obtained Poole-Frenkel coefficient {beta}{sub PF} is 7.80 x 10{sup -24} JV{sup -1/2}m{sup 1/2}. The experiment obtained value of {beta}{sub PF} corresponds to 1.96 times that of {beta}{sub ST} , which is theoretically expected because {beta}{sub PF} = 2{beta}{sub ST} . In the Folwer-Nordheim region, where the electric field is above 8.30 x 10{sup 5} V/cm, the obtained potential barrier {Phi}{sub FN} is 0.42 eV.

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

    Zheng, Yan-Qiong; J. Potscavage, William, Jr.; Zhang, Jian-Hua; Wei, Bin; Huang, Rong-Juan

    2015-02-01

    In order to explore the novel application of the transparent hole-transporting material 5,10,15-tribenzyl-5H-diindolo[3,2-a:3‧,2‧-c]-carbazole (TBDI), in this article TBDI is used as an active layer but not a buffer layer in a photodetector (PD), organic light-emitting diode (OLED), and organic photovoltaic cell (OPV) for the first time. Firstly, the absorption and emission spectra of a blend layer comprised of TBDI and electron-transporting material bis-(2-methyl-8-quinolinate) 4-phenylphenolate (BAlq) are investigated. Based on the absorption properties, an organic PD with a peak absorption at 320 nm is fabricated, and a relatively-high detectivity of 2.44 × 1011 cm·Hz1/2/W under 320-nm illumination is obtained. The TBDI/tris (8-hydroxyquinoline) aluminum (Alq3) OLED device exhibits a comparable external quantum efficiency and current efficiency to a traditional 4, 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD)/Alq3 OLED. A C70-based Schottky junction with 5 wt%-TBDI yields a power conversion efficiency of 5.0%, which is much higher than 1.7% for an α-NPD-based junction in the same configuration. These results suggest that TBDI has some promising properties which are in favor of the hole-transporting in Schottky junctions with a low-concentration donor. Project supported by the Funding Program for World-Leading Innovative R & D on Science and Technology (FIRST) from JSPS, the Fund from the Science and Technology Commission of Shanghai Municipality, China (Grant Nos. 14DZ2280900 and 14XD1401800), and the Natural Science Foundation of Shanghai (Grant No. 15ZR1416600).

  16. New Opportunities for Lanthanide Luminescence

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    宋希强; 李育容; 罗冠勇; 杨福孙; 徐诗涛

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  19. Speciation analysis of chromium by separation on a 5-palmitoyl oxine-functionalized XAD-2 resin and spectrophotometric determination with diphenylcarbazide.

    Science.gov (United States)

    Filik, Hayati; Doğutan, Melek; Apak, Reşat

    2003-07-01

    The method developed in this work for the separation and preconcentration of Cr(III) is based on its retention by an Amberlite XAD-2 copolymer resin functionalized with 5-palmitoyl-8-hydroxyquinoline (oxine), abbreviated XAD-POx, with the ligand covalently bound to the copolymer. Cr(III) sorption was quantitative within the pH range 4.5-7.0 and Cr(VI) was not retained. The Cr(III) held by the resin column was eluted with a hot solution of H(2)O(2) in pH>or=9.0 aqueous NH(3)-NH(4)Cl buffer, and Cr oxidized to CrO(4)(2-) was rejected by the chelating cation-exchanger column. Any Cr(VI) originally present with Cr(III) could be reduced with an acidic solution of H(2)O(2), and retained by the column yielding total Cr results, Cr(VI) being determined from the difference. The resin showed a maximal preconcentration factor of 60 for Cr(III), the LOD and LOQ being 9.3 and 30.1 nmol L(-1), respectively. The developed preconcentration-speciation analysis was finished with a diphenylcarbazide (DPC) spectrophotometric procedure suitable for conventional laboratories. The resin showed excellent salt tolerance, enabling Cr analysis in seawater, and was stable over extended use. All the interferents of this procedure that normally occur in an electroplating effluent, a blended coal CRM, and a standard steel sample could be removed by the recommended procedure, by use of partial and total selectivity at the adsorption and desorption stages, respectively, enabling preconcentration and colorimetric determination of chromium in various complex matrices. PMID:12819851

  20. The role of heavy metal ions on spin transport in organic semiconductors

    Science.gov (United States)

    Chen, B. B.; Wang, S.; Jiang, S. W.; Yu, Z. G.; Wan, X. G.; Ding, H. F.; Wu, D.

    2015-01-01

    It is generally believed that spin-orbit coupling (SOC) strength and the associated spin relaxation can be enhanced by introducing heavy metal ions in organic semiconductors. Here, we systematically study the spin transport in two organic semiconductors, tris(2-phenylpyridine)iridium (Ir(ppy)3) and tris-(8-hydroxyquinoline) aluminum (Alq3), which have similar chemical structures except that Ir(ppy)3 contains a heavy metal ion Ir. As expected, the photoluminescence spectroscopy measurements show that the SOC strength in Ir(ppy)3 is several orders of magnitude larger than in Alq3. Surprisingly, the spin diffusion length in Ir(ppy)3, deduced from magnetoresistance measurements in Ir(ppy)3-based organic spin valves, is longer than in Alq3. Considering the lower carrier mobility in Ir(ppy)3, the spin relaxation time in Ir(ppy)3 is much longer than in Alq3, implying that the SOC strength in Ir(ppy)3 is weaker than in Alq3. The seemingly contradictory results of photoluminescence spectroscopy and magneto-transport can be explained by the SOC strength depending on the electronic states of a material. The weak SOC strength in Ir(ppy)3 observed in magneto-transport measurements is due to the strong ligand field induced orbital moment quenching for Ir3+ and the polarons transporting in the ligands. However, the excitons involved in photoluminescence spectroscopy overlap with the Ir ion and transforms Ir3+ to Ir4+, which has non-zero spin and orbital moments and hence results in high SOC strength.

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

    Institute of Scientific and Technical Information of China (English)

    CHENSIXUE; CHICHIONGYEN; 等

    1996-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mercedes eUnzeta

    2016-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nonat, A

    2007-10-15

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

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

    Science.gov (United States)

    Basel, Tek Prasad

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  7. Differential modulation of Alzheimer's disease amyloid beta-peptide accumulation by diverse classes of metal ligands.

    Science.gov (United States)

    Caragounis, Aphrodite; Du, Tai; Filiz, Gulay; Laughton, Katrina M; Volitakis, Irene; Sharples, Robyn A; Cherny, Robert A; Masters, Colin L; Drew, Simon C; Hill, Andrew F; Li, Qiao-Xin; Crouch, Peter J; Barnham, Kevin J; White, Anthony R

    2007-11-01

    Biometals have an important role in AD (Alzheimer's disease) and metal ligands have been investigated as potential therapeutic agents for treatment of AD. In recent studies the 8HQ (8-hydroxyquinoline) derivative CQ (clioquinol) has shown promising results in animal models and small clinical trials; however, the actual mode of action in vivo is still being investigated. We previously reported that CQ-metal complexes up-regulated MMP (matrix metalloprotease) activity in vitro by activating PI3K (phosphoinositide 3-kinase) and JNK (c-jun N-terminal kinase), and that the increased MMP activity resulted in enhanced degradation of secreted Abeta (amyloid beta) peptide. In the present study, we have further investigated the biochemical mechanisms by which metal ligands affect Abeta metabolism. To achieve this, we measured the effects of diverse metal ligands on cellular metal uptake and secreted Abeta levels in cell culture. We report that different classes of metal ligands including 8HQ and phenanthroline derivatives and the sulfur compound PDTC (pyrrolidine dithiocarbamate) elevated cellular metal levels (copper and zinc), and resulted in substantial loss of secreted Abeta. Generally, the ability to inhibit Abeta levels correlated with a higher lipid solubility of the ligands and their capacity to increase metal uptake. However, we also identified several ligands that potently inhibited Abeta levels while only inducing minimal change to cellular metal levels. Metal ligands that inhibited Abeta levels [e.g. CQ, 8HQ, NC (neocuproine), 1,10-phenanthroline and PDTC] induced metal-dependent activation of PI3K and JNK, resulting in JNK-mediated up-regulation of metalloprotease activity and subsequent loss of secreted Abeta. The findings in the present study show that diverse metal ligands with high lipid solubility can elevate cellular metal levels resulting in metalloprotease-dependent inhibition of Abeta. Given that a structurally diverse array of ligands was assessed, the

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

    Science.gov (United States)

    Starko-Bowes, Ryan; Pramanik, Sandipan

    2013-01-01

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

  9. Effect of Rubrene Position on the EL Performance of the Device and Analysis of the Exciton Recombination Zone%Rubrene薄层的位置对器件发光性能的影响及器件内激子复合区域的分析

    Institute of Scientific and Technical Information of China (English)

    徐登辉; 李熊; 王秀娥; 赵慈; 赵佳; 邓振波; 吕昭月; 陈征

    2011-01-01

    通过在主体材料上蒸镀一层荧光染料超薄层的方法,研究了有机小分子5,6,11,12-tetraphenyl-naphthacene(rubrene)薄层在器件中不同位置时,有机电致发光器件(OLED)的电致发光光谱及发光性能.实验发现当rubrene薄层位于NPB/AlQ界面处时,器件的发光几乎都来自rubrene的发光;当薄层位置远离界面时,器件的发光则同时来自rubrene和AlQ的发光.通过对器件电致发光光谱的分解,研究了ru-brene薄层在不同位置时器件发射光谱的变化,并确定了rubrene和A1Q两种材料各自埘器件电致发光的贡献,进一步分析了rubrene发光强度与该薄层位置之间的关系.通过分析,得到激子在AIQ层中的迁移长度约在15~20 nm之间.此外,还进一步探讨了该器件中激子复合及传输的特点.%By using an ultrathin 5,6,11,12-tetraphenylnaphthacene (rubrene) layer deposited on the top of host materials, the influence of rubrene layer position on the electroluminescence (EL) spectra of organic light-emitting devices (OLEDs) was studied. When the rubrene layer is located at the interface between N,N,-diphenyl-N,N'-bis( 1-naphthyl)-(1,18-biphenyl)-4,4 ,-diamine (NPB) and tris(8-hydroxyquinoline) aluminum (AIQ) layer, EL luminescence of the device is nearly coming from rubrene emission. From the analysis of the EL spectra of the devices with different rubrene layer position, the solely contribution of rubrene and AlQ, respectively, to the luminescence of the devices is determined by spectra unmixing. Based on the analysis, the exciton length in AlQ layer is determined to be about 15-20 nm. The exciton transport and recombination characteristics are also discussed in this work.

  10. 红荧烯衍生物的红光电致发光器件及其在照明中的应用%Red electroluminescent devices based on rubrene derivativedopant and its lighting application

    Institute of Scientific and Technical Information of China (English)

    李天乐; 李晓; 李文连

    2012-01-01

    我们合成了一种红荧烯的衍生物,2-甲酰基红荧烯,作为一种红光掺杂剂,掺杂在N,N-diphenyl-N,N-bis1-naphthyl–1,1-biphenyl-4,4-diamine(NPB)中制备的电致发光器件,发射峰位于598nm,电流效率为2.1cd/A。用这个红光掺杂系统制备了一个白光电致发光器件,在白光器件中,2-甲酰基红荧烯,八-羟基喹啉铝(Alq3),以及NPB分别组成了白光中的红、绿以及蓝的发光成分,获得了一个白光器件,该器件显色指数高达89.8,在11V的时候,色坐标达(0.33,0.33)、最大亮度为5000cd/m2以及最大发光效率为4.7cd/A。这些性能参数表明这个白光器件具有潜在的照明应用。另外,还讨论了器件的结构设计以及电致发光过程及机理。%A rubrene (Ru) derivative, 2-formyl-rubrene was synthesized and was used as reddopant in N,N'-bis- (1-naphthyl)-N, N '-diphenyl-1, 1'-biphenyl- 4, 4 '-diamine (NPB) host in organic light-emitting devices (OLEDs) that offers an emission peak at about 598nm and a current efficiency of 2. lcd/A. The red emitter was also used to fabricate a white OLED (WOLED), in which 2-formyl-rubrene, tris (8-hydroxyquinoline) alumi- num (Alq3) and NPB contribute to the red, green and blue emissive components respectively. As a result, a high color rendering index of 89.8, CIE coordinates of (0.33, 0.33) at llV as well as a maximum luminance of 5000cd/m2 and a luminance efficiency of 4.7cd/A were obtained. The performances suggest its potential appli- cations for solid-state lighting. Also, the design and electroluminescent processes of the WOLED based on 2- formyl-rubrene were also discussed.

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

    Institute of Scientific and Technical Information of China (English)

    黄海霞; 谭雪晴

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-15

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

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

    Institute of Scientific and Technical Information of China (English)

    劳世辉; 魏岳荣; 盛鸥; 梁国鲁

    2011-01-01

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

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Science.gov (United States)

    Zheng, Fei; Hu, Bin

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    A novel bimodal porous N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS)-silica monolithic capillary was prepared by sol-gel technology, and used as capillary microextraction (CME) column for aluminum fractionation by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV)-ICP-MS with the use of polytetrafluoroethylene (PTFE) slurry as fluorinating agent. The extraction behaviors of different Al species were studied and it was found that in the pH range of 4-7, labile monomeric Al (free Al3+, Al-OH and Al-F) could be retained quantitatively on the monolithic capillary, while non-labile monomeric Al (Al-Cit and Al-EDTA) passed through the capillary directly. The labile monomeric Al retained on monolithic capillary was eluted with 10 μL 1 mol L-1 HCl and the elution was introduced into the ETV for fluorination assisted ETV-ICP-MS determination. The total monomeric Al fraction was also determined by AAPTS-silica monolithic CME-fluorination-assisted electrothermal vaporization (FETV)-ICP-MS after the sample solution was adjusted to pH 8.8. Non-labile monomeric Al was obtained by subtracting labile monomeric Al from the total monomeric Al. Under the optimized conditions, the relative standard deviation (R.S.D) was 6.2% (C = 1 μg L-1, n = 7; sample volume, 5 mL), and the limit of detection was 1.6 ng L-1 for Al with an enrichment factor of 436 fold and a sampling frequency of 9 h-1. The prepared AAPTS-silica monolithic capillary showed an excellent pH tolerance and solvent stability and could be used for more than 250 times without decreasing adsorption efficiency. The developed method was applied to the fraction of Al in rainwater and fruit juice, and the results demonstrated that the established system had advantages over the existing 8-hydroxyquinoline (8-HQ) chelating system for Al fractionation such as wider pH range, higher tolerance of interference and better regeneration

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

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Fei [Department of Chemistry, Wuhan University, Wuhan 430072 (China); HuBin [Department of Chemistry, Wuhan University, Wuhan 430072 (China)], E-mail: binhu@whu.edu.cn

    2008-01-15

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

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

    Science.gov (United States)

    Wendt, Franziska; Näther, Christian; Tuczek, Felix

    2016-09-01

    Four new imidazole-based ligands, 4-((1H-imidazol-4-yl)methyl)-2-phenyl-4,5-dihydrooxyzole (L OL 1), 4-((1H-imidazol-4-yl)methyl)-2-(tert-butyl)-4,5-dihydrooxyzole (L OL 2), 4-((1H-imidazol-4-yl)methyl)-2-methyl-4,5-dihydrooxyzole (L OL 3), and N-(2,2-dimethylpropylidene)-2-(1-trityl-1H-imidazol-4-yl-)ethyl amine (L imz 1), have been synthesized. The corresponding copper(I) complexes [Cu(I)(L OL 1)(CH3CN)]PF6 (CuL OL 1), [Cu(I)(L OL 2)(CH3CN)]PF6 (CuL OL 2), [Cu(I)(L OL 3)(CH3CN)]PF6 (CuL OL 3), [Cu(I)(L imz 1)(CH3CN)2]PF6 (CuL imz 1) as well as the Cu(I) complex derived from the known ligand bis(1-methylimidazol-2-yl)methane (BIMZ), [Cu(I)(BIMZ)(CH3CN)]PF6 (CuBIMZ), are screened as catalysts for the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC-H2) to 3,5-di-tert-butylquinone (3,5-DTBQ). The primary reaction product of these oxidations is 3,5-di-tert-butylsemiquinone (3,5-DTBSQ) which slowly converts to 3,5-DTBQ. Saturation kinetic studies reveal a trend of catalytic activity in the order CuL OL 3 ≈ CuL OL 1 > CuBIMZ > CuL OL 2 > CuL imz 1. Additionally, the catalytic activity of the copper(I) complexes towards the oxygenation of monophenols is investigated. As substrates 2,4-di-tert-butylphenol (2,4-DTBP-H), 3-tert-butylphenol (3-TBP-H), 4-methoxyphenol (4-MeOP-H), N-acetyl-L-tyrosine ethyl ester monohydrate (NATEE) and 8-hydroxyquinoline are employed. The oxygenation products are identified and characterized with the help of UV/Vis and NMR spectroscopy, mass spectrometry, and fluorescence measurements. Whereas the copper complexes with ligands containing combinations of imidazole and imine functions or two imidazole units (CuL imz 1 and CuBIMZ) are found to exhibit catalytic tyrosinase activity, the systems with ligands containing oxazoline just mediate a stoichiometric conversion. Correlations between the structures of the complexes and their reactivities are discussed. PMID:27333775

  19. 功能层厚度对叠层有机电致发光器件出光性能影响的数值研究%Influence of the functional layer thickness on the light output property of tandem organic light emitting diode:a numerical study

    Institute of Scientific and Technical Information of China (English)

    路飞平; 李建丰; 孙硕

    2013-01-01

    Based on the principle of thin film optics, the theory of electric dipole radiation, and the principle of Fabry-P ´erot microcavity, an optical model is built for the tandem organic light emitting diode (OLED) with the structure of Glass/ITO/N, N0-bis(naphthalen-1-yl)-N, N0-bis (phenyl)-benzidine(NPB)/tris(8-hydroxyquinoli-ne) aluminum (Alq3)/molybdenum trioxide (MoO3)/NPB/Alq3/LiF/Al. The influence of the functional layer thickness on the light output intensity of device is systematically studied, the laws of light output intensity for tandem OLEDs under different thickness values of functional layer are obtained. This model and the results obtained in this paper can present an in-depth understanding of the working mechanism of tandem OLED and help ones fabricate high efficiency OLED.%功能层厚度是影响有机电致发光器件出光效率的主要因素之一,故获得不同功能层厚度对器件出光特性的影响规律是制备高性能器件的重要基础。本文基于薄膜光学原理、电偶极子辐射理论及Fabry-P´erot 微腔原理,建立了结构为glass/ITO/N, N0-bis(naphthalen-1-yl)-N, N0-bis(phenyl)-benzidine(NPB)/tris(8-hydroxyquinoline) aluminum(Alq3)/molybdenum trioxide(MoO3)/NPB/Alq3/Al的叠层有机电致发光器件的光学模型,系统地研究了各个功能层厚度对叠层有机电致发光器件出光强度的影响,得到了功能层厚度对器件出光强度影响的规律。该模型的建立与所获得的结果可对深入了解叠层有机电致发光器件的工作机理以及制备高性能的器件提供一定的帮助。

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

    Institute of Scientific and Technical Information of China (English)

    王荣华; 郑兴峰; 徐小林; 王红燕

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-08

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

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

    Directory of Open Access Journals (Sweden)

    Hsi-Kang Shih

    2015-04-01

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

  3. Charge transport in amorphous organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Lukyanov, Alexander

    2011-03-15

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

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

    Directory of Open Access Journals (Sweden)

    Chan-on W

    2015-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Mehrdad Jafarpour

    2015-06-01

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

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

    Institute of Scientific and Technical Information of China (English)

    洪培培; 杨建玉; 陈洪伟; 刘克锋; 王红利; 智利婷

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    林秀琴; 蔡青; 陆鑫; 应雄美; 毛钧; 苏火生

    2011-01-01

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

  8. White organic light-emitting devices based on blue fluorescent dye combined with dual sub-monolayer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huishan, E-mail: yanghuishan1697@163.com

    2013-10-15

    White organic light-emitting devices have been realized by using highly blue fluorescent dye 4,4′-Bis(2,2-diphenyl-ethen-1-yl)-4,4′-di-(tert-butyl)phenyl(p-TDPVBi) and [2-methyl-6-[2-(2, 3,6,7-tetrahydro-1H, red fluorescent dye 5H-benzo[ij] quinolizin-9-yl) ethenyl]-4H-pyran-4-ylidene] propane-dinitrile(DCM2), together with well known green fluorescent dye quinacridone (QAD). The fabrication of multilayer WOLEDs did not involve the hard-to-control doping process. The structure of the device is ITO/m-MTDATA (45 nm)/NPB(8 nm)/p-TDPVBi(15 nm)/DCM2(x nm)/Alq{sub 3} (5 nm)/QAD(y nm)/Alq{sub 3}(55 nm)/LiF(1 nm)/Al, where 4,4′,4′′-tris{N,-(3-methylphenyl)-N-phenylamine}triphenylamine (m-MTDATA) acts as a hole injection layer, N,N′-bis-(1-naphthyl)-N, N′-diphenyl-1, 1′-biph-enyl-4, 4′-diamine (NPB) acts as a hole transport layer, p-TDPVBi acts as a blue emitting layer, DCM2 acts as a red emitting layer, QAD acts as a green emitting layer, tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) acts as an electron transport layer, and WOLEDs of devices A, B, C and D are different in layer thickness of DCM2 and QAD, respectively. To change the thickness of dual sub-monolayer DCM2 and QAD, the WOLEDs were obtained. When x, y=0.05, 0.1, the Commission Internationale de 1’Eclairage (CIE) coordinates of the device change from (0.4458, 0.4589) at 3 V to (0.3137, 0.3455) at 12 V that are well in the white region, and the color temperature and color rendering index were 5348 K and 85 at 8 V, respectively. Its maximum luminance was 35260 cd/m{sup 2} at 12 V, and maximum current efficiency and maximum power efficiency were 13.54 cd/A at 12 V and 6.68 lm/W at 5 V, respectively. Moreover, the current efficiency is largely insensitive to the applied voltage. The electroluminescence intensity of white EL devices varied only little at deferent dual sub-monolayer. Device D exhibited relatively high color rendering index (CRI) in the range of 88–90, which was essentially

  9. 去壁低渗法制备无融合生殖甜菜M14染色体标本%Preparation of Apomixes Sugarbeet M14 Chromosome Samples Using Wall Degaradation Hypotonic Method

    Institute of Scientific and Technical Information of China (English)

    刘丽萍; 王艳

    2013-01-01

    无融合生殖甜菜M14单体附加系为19条染色体甜菜,其中附加l条白花甜菜第9号染色体.为了探明无融合生殖甜菜M14的细胞及胚胎学机理,介绍了一种快速、简便观察分析无融合生殖甜菜染色体标本的制片方法及操作流程.取甜菜根尖分生区部位用0.2 mmol/L8-羟基喹啉预处理,经前低渗的材料需先用甲醇∶冰醋酸(3∶1)固定4h,再酶解去壁、后低渗,酶解时间大约0.5 ~2.0h 利用滴片或徐片法通过荧光显微技术观察染色体标本,可以更加清晰地观察到染色体的自然裸露状态,附加的l条白花甜菜染色体游离于栽培甜菜染色体之外,更易于识别.此方法适用于无融合生殖甜菜,可为后续的染色体微分离及Fish荧光原位杂交等提供前提条件和技术保障.%The monosomic addition line ofapomixes sugarbeet M14 has 19 chromosomes, one of them is the additional chromosome of ninth corollifiora zoss. In order to study the mechanism of cytology and Embryology, the wall degaradation hypotonic method of preparing samples has been Practiced in apodictic monosomic line named sugarbeet M14 line ( Beta vulgaris. , L, , VV + 1C 、 2n = 18 + 1 ). The root meristem of Apomixes Sugarbeet was pre-treated with 0.2 mmol/L 8-hydroxyquinoline and fixed with methanol and acetic acid ( 3 : 1 ) for 4 h, the time of Enzymatic hydrolysis was about 0.5 -2 h. During the preparation of the chromosomes in sugarbeet M14 line, the native nudity of the alien chromoso me had also been observed. The results were as follows; The Examination of the generations M14 revealed that the genomes of its plants (VV+1C、2n = 18 + 1), these indicated that the monosomic addition line M14 was a faeultative apomicts and was easy to observe. This method is adoptable to apomixes Sugarbeet, and also can provide technical support for the study of chromosome micro dissection and Fish fluorescence in situ hybridization.

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

    Directory of Open Access Journals (Sweden)

    Pedro Alberto Bolívar Chávez

    2005-12-01

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

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

    Science.gov (United States)

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

    2015-01-01

    A compact photometric detector was constructed from an organic light emitting diode (OLED) based on a europium complex, europium(diben-zoylmethanato)3(bathophenanthroline) (Eu(DBM)3bath), as the light source and an organic photodiode (OPD) fabricated from a hetero-junction of two layers of copper phthalocyanine (CuPc)/fullerene (C60) as the photo-detector on a microchip prepared from poly(dimethylsiloxan) (PDMS) and was applied to the determination of phosphate. The OLED and the OPD were fabricated by a vapor deposition method on an indium tin oxide (ITO) coated glass substrate with the following layered structure; Glass (0.7 mm)/ITO (110 nm)/4,4'-bis[N-(1-naphthyl)-N-phenyl amino]-biphenyl (α-NPD) (30 nm)/4,4'-di(N-carbazolyl)biphenyl (CBP): Eu(3+) (8 wt%, 30 nm)/bathocuproine (BCP) (30 nm)/aluminum tris(8-hydroxyquinoline) (Alq3) (25 nm)/magnesium and silver (MgAg) (100 nm)/Ag (10nm) and Glass (0.7 mm)/ITO (110 nm)/CuPc (35 nm)/C60 (50 nm)/BCP (10 nm)/Ag (50 nm), respectively. The OLED based on the europium complex emitted a sharp light at the wavelength of 612 nm with a full width at half maximum (FWHM) of 8 nm. The performance of the photometric detector assembled was evaluated based on measurements of the absorbance of different concentrations of malachite green (MG) solutions for a batch system with 1cm long path length. The molar absorptive coefficient of the MG solution, calculated from the photocurrent of the OPD, was in good agreement with the value reported in the literature. A microchip with two inlets and one outlet U-shaped channel was prepared by a conventional photolithograph method. The OLED and the OPD were configured so as to face each other through the PDMS microchip in parallel in order to align the light axis of the OLED and the OPD with the flow cell (optical path length of 5mm), which was located at the end of outlet. For the determination of phosphate, an ion-association reaction between MG and a molybdenum-phosphate complex was utilized

  12. Spectrophotometric Determination of Lead in Food with Meso-4-(3-5-Dibromo-4-hydroxyphenyl) Porphyrin [ T(DBHP) P ]%Meso-四-(3-5-二溴4-羟基苯)卟啉分光光度法测食品中铅含量

    Institute of Scientific and Technical Information of China (English)

    陈莉; 彭惠琦

    2011-01-01

    Reaction of Meso-4-(3-5-Dibromo-4-hydroxyphenyl) porphyrin [T(DBHP)P] and the lead in the foods,and the impact of heating time, pH, dosage of the surfactants and reagent on the formation and stability of the complex are studied,and the best reaction conditions are determined. With the presence of 8-hydroxyquinoline, lead can create 1: 2 orange compounds with T(DBHP)P. Which has strong absorption of 479 nm. When the lead content is in the range of 0 ~ 12 (xg/mL,the measured curve is linear. The results showed that the method used is simple,safe,more environmental friendly with higher sensitivity and better selectivity. There is no need to separate the interfering ions in the sample. Simply by adding a masking agent, the calcium and iron effects can be eliminated. The spectrophotometer measures absorbance and the standard curve to calculate the lead content. This method can be used to measure the lead in foods with ease.%以食品为对象,研究了铅与Meso-四-(3-5-二溴-4-羟基苯)卟啉[T(DBHP)P]的配合反应,并对于溶液pH值、加热时间、表面活性剂用量、显色剂用量等对配合物的生成及稳定性的影响进行了探究,确定反应的最佳条件.经试验,当8-羟基喹啉存在时,铅在碱性条件下可与T(DBHP)P反应生成1:2的橙黄色化合物.该化合物在479 nm处有较强的吸收,当铅含量在0~12 μg/mL时,测得的曲线呈线性关系,服从比尔定律,重复性较好.经分光光度计测出其吸光度,绘制标准工作曲线,计算出铅的含量.结果表明:本实验所采用方法简便快速、安全,对环境污染小,且灵敏度较高,选择性较好,样品不需要分离出干扰离子,只需加入掩蔽剂即可消除钙离子和铁离子的影响.将该方法用于测定食品中铅的含量,取得了较满意的效果.

  13. 基于面式-三(2-(4-三氟甲基苯基)吡啶)合铱配合物为发光中心的高效绿光有机电致发光器件%Efficient Green Organic Light-Emitting Diodes with fac-Tris(2-(4-trifluoromethylphenyi)pyridine)iridium Complex as Emitter

    Institute of Scientific and Technical Information of China (English)

    滕明瑜; 王铖铖; 荆一铭; 郑佑轩; 林晨

    2013-01-01

    with 6% dopant concentration exhibits a maximum power efficiency of 27.29 cd·A-1 at 1 981 cd·m-2,a maximum brightness of 33 071 cd·m-2 at 9.6 V.The electron mobility of Ir(ffmppy)3 is 4.24× 10-6 cm2· (V·s)-1 under electric field of 1 300 (V· cm-1)1/2 via transient electroluminescence (TEL) method,which is close to that of Alq3 (tri(8-hydroxyquinoline)aluminum) emitter.CCDC:887658.

  14. Manutenção da qualidade e aumento da longevidade floral de crisântemo cv. White polaris Keeping quality and prolonging the postharvest longevity of spray chrysanthemum cv. White polaris

    Directory of Open Access Journals (Sweden)

    Victor Julio Flórez-Roncancio

    1996-01-01

    changes associated with individual flowers. The flowers were held during 24 hours (pulsing treatment period at 25 ± 2°C and 60 to 90% of air relative humidity under continuous cool white fluorescent light at 1.5 KLx. At the end of the treatment, the flowers were transferred to distilled water, under daily 10 hours of continuous fluorescent light and at the same laboratory conditions already described. At the first experiment, it was tested the efficiency of 8-hydroxyquinoline (8-HQ and thiabendazole (TBZ, as germicides, in three concentrations each one. Furthermore, two growth regulators were applied in order to keep the green color and the turgidity of leaves: gibberellic acid (GA3, 6-benzylaminopurine (6-BA and a mix of them. At the second experiment, in order to extend the vase-life by inhibition of ethylene production, it was tested the effect of silver nitrate (AgNO3, anionic silver thiosulphate complex (STS and cobalt chloride (CoCl2 into pulsing solutions in three concentrations each one. The results of experiments showed that pulsing treatment with distilled water + 0.52 mol/m³ citric acid + 58.43 mol/m³ sucrose + 0.69 mol/m³ 8-HQ + 2.9 or 4.4 mol/m³ AgNO3, combined with foliar treatment of 0.058 mol/m³ GA3, improved the foliar quality and extended the flower vase life.

  15. 六出花切花瓶插生理和保鲜效应研究%Study on Vase-physiological and Fresh-keeping Effect of Cut-flower Alstroemeria

    Institute of Scientific and Technical Information of China (English)

    张瑜瑜; 李晶; 吴旭; 姚丽媛; 华金珠

    2013-01-01

    the preservation experiment of cut flower A lstroemeria ,the mixture of 8-hydroxyquinoline citrate(200 mg・L-1 )and sucrose solution(5% )could produce the best preservation effect . The preservative solution could prolong the life of cut flower 9 days more than CK ;3 days delayed to bloom stage ;fresh weight increased 24 g more than CK at the 21th day after vasing ;Moisture balance was 1 .9 g higher than CK .Anthocyanin content was 0 .568 5 than CK at the 21th day after vasing ;In the aspect of the change of cell membrane permeability ,conductivity was 73 .4% ,which was 22 .8% less than CK ,maximum value of solu-ble sugar content was 0 .249 g・kg-1 higher than CK and the content of vitamin C was 5 .072 59 mg・kg-1 higher than CK ,at the 21th day after vasing .

  16. 不对称三苯胺-锌酞菁的合成及性能研究%Synthesis and Study of Properties for Asymmetric Triphenylamine-Zinc Phthalocyanine

    Institute of Scientific and Technical Information of China (English)

    毛利军; 谭青龙; 辛冠琼; 韩明亮; 张学俊

    2012-01-01

    以对氨基酚、对硝基氯苯、8-羟基喹啉、4-硝基邻苯二甲腈以及醋酸锌为主要原料,合成了不对称2(3)-[二(对硝基苯基)氨基苯氧基]-9(10),16(17),23(24)-三(8-喹啉氧)锌酞菁(TQPc).用核磁、红外、元素分析等表征TQPc以及前驱化合物结构,TQPc的电子吸收光谱表现出了强烈的π-π*跃迁现象.利用紫外光谱研究了其N,N-二甲基甲酰胺(DMF)和CH2Cl2溶液的吸收光谱性质,结果表明在DMF中主要以单体的形式存在,浓度在0.223×10-5~2.587×10-5 mol/L时,TQPc在CH2Cl2溶液中有二聚体的存在,经计算得到平衡常数为0.24×105 L/mol.用循环伏安法研究了TQPc的氧化还原行为,结合差分伏安数据计算了能级结构,LUMO(-1.04 V vs SCE)和HOMO (0.78 V vs SCE)与纳米TiO2导带能级匹配,可作为性能较好的电荷传输材料用于染料敏化太阳能电池.%Triphenylamine-zinc phthalocyanine (TQPc) that contains a bulky triphenylamine group and three 8-oxy-quinoline groups has been found to exhibit preferable performance. The first example of TQPc has been synthesized. Its zinc complexes of the well-known electron transport material displays enhanced electron-accepting ability relative to free- metallophthalocya-nines, and can also be used as chemical sensors, liquid crystals, photodynamic therapy, data storage and non-linear optics. The triphenylamine-zinc phthalocyanine is synthesized by statistical condensation. The main chemicals are aminophenol, p-chloronitrobenzene, 8-hydroxyquinoline, 4-nitrophthalonitrile and zinc acetate. The fragment 4,4'-dinitro-4"-hydroxy-triphenylamine is synthesized by the reacting from aminophenol with p-chloronitrobenzene at the catalysis of anhydrous potassium carbonate. The gross yield is 27.5%, and its purity is 96.6%. In comparison with other methods, there are some advantages in this method: the materials are cheap and easily available, and the product can be used as a substituent for phthalocyanine. All