Corrosion behavior of aluminum alloy 2024-T3 by 8-hydroxy-quinoline and its derivative in 3.5% chloride solution

The corrosion behavior of aluminum alloy 2024-T3 was studied in 3.5% NaCl solution with two fluorescence quinoline compounds named 8-hydroxy-quinoline(8HQ) and 8-hydroxy-quinoline-5-sulfonic acid(HQS). The open circuit potential(OCP) test result indicates that both compounds change the alloy corrosion potential by adsorbing on the electrode surface. Polarization measurements show that 8HQ is a mixed type inhibitor by blocking the active sites of the metal surface, while HQS is a corrosion accelerator by activating the cathodic reaction. Changes of the impedance parameters in the electrochemical impedance spectroscopy(EIS) are related to the adsorption of 8HQ on the metal surface, which leads to the formation of a protective layer. The impedance diagram in the solution with HQS is similar to the one without additional organic compounds. The morphology and composition of the protective layer were studied by using SEM/EDS. The result confirms the function of the additions that the effect of 8HQ is due to the insoluble aluminum chelate, Al(HQ)3, to prevent adsorption of chloride ion, while the effect of HQS is to break down the oxide film.

TD-DFT Calculation on the UV-Vis Spectra of Complex 8-((Trimethoxysilyl)methylthio)quinoline·SnCl_4

Electronic structures and absorption spectra properties of complex 8-（（trimethoxysilyl）methylthio）quinoline.SnCh in gas phase and MeCN media have been investigated by using DFT/TD-DFT method. The calculated lowest-energy absorption band shows different mechanisms under these two conditions, and it bears LMCT/LLCT/ILCT character in MeCN solution and LLCT/ILCT character in gas phase. The calculated absorption bands of the title complex in MeCN solvent are in good agreement with the experimental results, and calculation results indicate that the very weak experimentally observed lowest-energy absorption band of the title complex in MeCN solvent originates from the spin-forbidden singlet-triplet transitions.

A Novel Two-dimensional Lead(Ⅱ) Coordination Polymer Based on Dinuclear Lead(Ⅱ) Unit Containing(5-Chloro-quinolin-8-yloxy) Acetate

A novel two-dimensional lead（II） coordination polymer 1, [C11H7Cl2NO3Pb]n, has been prepared by solvothermal reaction of new bridging ligand（5-chloro-quinolin-8-yloxy）acetic acid（HL） with PbCl2, and its structure was characterized by IR, elemental analysis, TG-DTA and single-crystal X-ray diffraction analysis. The crystal is of monoclinic system, space group P21/c with a = 16.7603（7）, b = 8.6907（4）, c = 8.4745（3）A, β = 101.1110（11）°, C11H7Cl2NO3 Pb, Mr = 479.27, V = 1211.25（9）A3, Z = 4, Dc = 2.628 g/cm^3, F（000） = 880, μ = 14.367 mm^-1, R = 0.0173 and wR = 0.0508. The asymmetric unit contains one lead（II） cation, one（5-chloro-quinolin-8-yloxy）acetate（L） ligand and a chloride ion. The PbII center is hepta-coordinated in a distorted pentagonal bipyramidal geometry. The coordination sphere of the Pb atom is completed by two oxygen atoms and one nitrogen atom of the same L ligand, two bridging chloride ions and two bridging oxygen atoms of two adjacent L ligands. Two PbII centers are linked by the two L ligands to form a C2-symmetric dimer unit with a planar [Pb2O2] ring. Each dimer unit acts as a secondary building unit（SBU） and links adjacent four dimer units by the chloride atoms and oxygen atoms of carboxylate groups of L, forming a two-dimensional array. Such two-dimensional layers are packed through intermolecular C–H…Cl hydrogen bonds into a three-dimensional supramolecular structure. When the dimer unit is viewed as a 4-connected node, 1 is simplified as a 4-nodal 2-D network with square lattices of the diagonal lengths to be 6.079（1）A. The fluorescence emission peak of complex 1 appears near 407 nm.

Separation,preconcentration and determination of Pb(Ⅱ) in water samples using microcrystalline triphenylmethane loaded with quinolin-8-olate

This paper described a novel method for the preconcentration of Pb（II） using microcrystalline triphenylmethane loaded with quinolin-8-olate prior to the determination by flame atomic absorption spectrometry. Pb（II） could be enriched by controlling appropriate condition. The preconcentration factor could reach to 200 and the detection limit of Pb（II） was 0.074 μg/L. The recovery was in a range of 93.5-103% with relative standard deviation of 1.0-2.2%. The proposed method had been successfully applied to the determination of trace Pb（U） in various water samples with satisfactory result.

Synthesis, characterization and photophysical properties of quinolin-8-olato chelated osmium(II) organometallics bearing a pendant imine-phenol motif and electrogeneration of trivalent analogue

The reaction of Os(RL1)(PPh3)2(CO)Br, 1b, with qui-nolin-8-ol (HQ), 2, has furnished complexes of the type [Os(RL2)(PPh3)2(CO)(Q)], 3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p)-3-Me-5 and R is Me, OMe, Cl). In this process, quinolin-8-olato (Q) undergoes five-membered chelation, the iminium-phenolato function tautomerizing to the imine-phenol function. The trans geometry of the Os(PPh3)2 fragment is consistent with the occurrence of a single 31P resonance near –6.0 ppm in 3. In dichloromethane solution, 3 displays a quasireversible 3+/3 couple near 0.40 V vs. SCE (3+ is the osmium (III) analogue of 3). Coulometrically generated solutions of 3+ displays a strong absorption near 340 nm, 415 nm and 500 nm and are one-electron paramagnetic (low-spin d5, S = 1/2) and show rhombic EPR spectra in 1:1 dichloromethanetoluene solution at 77 K with g values near 2.44, 2.20, 1.83. Distortion parameters using the observed g values have been computed. Solutions of 3 absorb near 420 nm and emit near 510 nm at 298 K and 580 nm at 77 K. The fluorescence is believed to originate from the 3MLCT state.

Synthesis, Structure and Quantum Mechanical Calculations of Methyl 2-(5-((Quinolin-8-yloxy)-methyl)-1,3,4-oxadiazol-2-ylthio)-acetate

The title compound was synthesized by the base catalyzed reaction of 5-（（quinolin- 8-yloxy）methyl）-1,3,4-oxadiazole-2（3H）-thione with methyl chloroacetate. The structure was supported by the spectroscopic data and unambiguously confirmed by single-crystal X-ray diffraction studies. It crystallizes from a methanol solution in the triclinic space group Pi with unit cell dimensions a = 7.4509（9）, b = 10.2389（12）, c = 12.2299（15）A, a = 74.771（2）, β = 77.956（2）, 7 = 69.263（2）°, V = 834.98（17） A3 and Z = 2. In order to gain some valuable insights into the molecular structure, the quantum mechanical calculations were performed using both HF and time-dependent density functional theory at the B3LYP/6-31G（d,p） level. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock （HF） and density functional theory （DFT） with the 6-31G（d） basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound was examined using the B3LYP method with the 6-31G（d） basis set. The harmonic vibrational frequencies calculated have been compared with the experimental FTIR and FT-Raman spectra. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance （NMR） calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of the title compound. Moreover, molecular electrostatic potential and thermodynamic parameters of the title compound were investigated by theoretical calculations.

Catalyst Free One-Pot Synthesis of Chromeno Quinolines and Their Antibacterial Activity

An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-pot condensation method is described. The synthesized compounds are screened for further biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus using cut plate method and disc diffusion method.

Synthesis, Structural Study and Spectroscopic Characterization of a Quinolin-8-Yloxy Derivative with Potential Biological Properties

We have prepared the (5-chloro-quinolin-8-yloxy) acetic acid and characterized it by using infrared, Raman and multi-dimensional nuclear magnetic resonance spectroscopies. The density functional theory (DFT) together with the 6-31G* and 6-311++G** basis sets were used to study its structure and vibrational properties. Three stable conformations of the compound were theoretically determined in gas phase and probably these conformations are present in the solid phase. The harmonic vibrational wavenumbers for the optimized geometries were calculated at the same theory levels. For a complete assignment of the observed bands in the vibrational spectra, the DFT calculations were combined with Pulay’s scaled quantum mechanical force field (SQMFF) methodology in order to fit the theoretical wavenumber values to the experimental ones. Besides, the force constants of the three conformers of (5-chloro-quinolin-8-yloxy) acetic acid were calculated and compared with those obtained by us for the 2-(quinolin-8-yloxy) acetic acid. In addition, the characteristics of the electronic delocalization of those structures were performed by using natural bond orbital (NBO), while the corresponding topological properties of electronic charge density are analysed by employing Bader’s atoms in molecules theory (AIM).

Two Novel Mercury(Ⅱ) and Copper(Ⅱ) Complexes Based on(5-Chloro-quinolin-8-yloxy)acetic Acid

Two novel mononuclear complexes with 5-chloro-8-（methoxycarbonylmethoxy）quinoline ligand（L）, namely, HgLBr2 1 and CuL2Cl2 2, have been prepared by solvothermal reaction of（5-chloro-quinolin-8-yloxy）acetic acid with HgBr2 and CuCl2, respectively. Their structures were characterized by IR, elemental analysis, UV-Vis-NIR spectra, TG and single-crystal X-ray diffraction analysis. Interestingly,（5-chloro-quinolin-8-yloxy）acetic acid is changed as 5-chloro-8-（methoxycarbonylmethoxy）quinoline ligand（L） in complexes 1 and 2. Crystal data for 1： C12H10Br2 Cl Hg NO3, Mr = 612.07, triclinic, space group P1 with a = 8.5983（7）, b = 9.7726（6）, c = 10.1549（6） A, α = 66.355（6）, β = 77.067（8）, γ = 78.803（8）°, V = 756.6（9）A^3, Z = 2, Dc = 2.687 g/cm^3, F（000） = 560, μ = 15.633 mm^-1, R = 0.0351 and w R = 0.0504. Crystal data for 2： C24H20Cl4 Cu N2O6, Mr = 637.76, triclinic, space group P1 with a = 10.5324（9）, b = 11.2377（16）, c = 12.0143（12） ？, α = 83.413（11）, β = 64.475（9）, γ = 83.144（11）°, V = 1270.9（2） ？3, Z = 2, Dc = 1.667 g/cm3, F（000） = 646, μ = 1.324 mm-1, R = 0.0408 and wR = 0.0922. In 1, the HgII centre is a distorted trigonal planar geometry comprised of two Br atoms and one quinoline N atom of L. Intermolecular π-π, C–H…π stacking interactions and intermolecular C–H…Br hydrogen bonds are observed in the molecular packing of 1. In complex 2, each CuII center has a distorted octahedral geometry comprised of two chloride ions, two quinoline N atoms and two O atoms of two L ligands. Intermolecular C–H…Cl hydrogen bonds exist in the molecular packing of 2. The fluorescence emission peak of complexes 1 and 2 appears near 406 and 410 nm, respectively. Optical diffuse-reflection spectral results suggest complex 1 has the property of semiconductor.

双8-羟基喹啉-席夫碱-锌高分子配合物的制备及发光性能

将 5 甲酰基 8 羟基喹啉分别与对苯二胺、联苯二胺、4,4′ 二氨基二苯砜反应 ,得到了三种双 8 羟基喹啉 席夫碱配体 ,然后与锌离子配位 ,制得了一类新型的双 8 羟基喹啉 席夫碱 锌高分子配合物。利用红外光谱、紫外可见光谱、元素分析对配体和配合物的结构进行了表征 ,利用荧光光谱研究了高分子配合物的光致发光性能。

新试剂5-(4-氯苯基偶氮)-8-苯磺酰氨基喹啉光度法测定微量铜

在 p H 8.5的 Na2 B4 O7- HCl介质及有氯化十六烷基吡啶 ( CPC)存在时 ,室温下铜 ( )与 5 - ( 4 -氯苯基偶氮 ) - 8-苯基磺酰氨基喹啉 ( CPBSQ)迅速反应 ,生成络合比为 1∶ 3的有色络合物。研究了反应的最佳条件 ,建立了一个测定 Cu( )的光度分析新方法。Cu( )的浓度在 0～ 1 4.0 μg/2 5 m L 范围内符合比耳定律 ,其摩尔吸光系数为 8.1 2× 1 0 4 L· mol- 1· cm- 1。方法用于面粉、茶叶及奶粉中铜的测定 ,其相对标准偏差为 0 .5 8%～ 1 .2 % ,标准加入回收率为 95 .5 %～ 1 0 4 .5 %。

5-苯基偶氮-8-(4-羧基苯偶氮氨基)喹啉与铜(Ⅱ)显色反应研究

合成了5-苯基偶氮-8-(4-羧基苯偶氮氨基)喹啉(PACPAQ)。在pH8.2的硼砂缓冲介质中,在CTMAB存在下,铜(Ⅱ)与PACPAQ形成1:4紫红色络合物,λ_(max)为540nm,ε=6.9×10~4·L·mol^(-1)·cm^(-1),铜量在0～10μg/25ml范围内符合比尔定律.用于粗铅和水中铜的测定,结果满意。

5－（4－羧基苯偶氮）－8－（对甲苯磺酰氨基）－喹啉与金显色反应研究及应用

以８－氨基喹啉为母体，合成了新试剂５－（４－羧基苯偶氮）－８－（对甲苯磺酰氨基）－喹啉（ＣＰＴＳＱ），研究了它与Ａｕ的显色反应，在ＣＴＭＡＢ存在下，于ｐＨ１０～１３的ＮａＯＨ介质中，ＣＰＴＳＱ与Ａｕ形成２：１紫蓝色络合物，最大吸收峰位于６１０ｎｍ，摩尔吸光系数１．０×ｌ０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ａｕ含量在０～１．２ｍｇ／Ｌ内符合比尔定律。方法选择性好，灵敏度高，操作简便，已用于金矿石样品中Ａｕ的测定，结果满意。

试剂8Q5SA8Q5S的合成及其在铝(Ⅲ)荧光光度法测定中的应用

新试剂7-(8-β■喹啉-5-磺酸偶氮)-8-羟基喹啉-5-磺酸(8Q5SA8Q5S)的合成方法和鉴定,试剂的一些基本性能(酸解常数、吸收光谱和荧光光谱等)以及在 Al(Ⅲ)荧光分析中的应用。试剂与 Al 反应的最佳酸度为 pH4.86(NaAc/HAc 介质),线性范围为0～4.Oμg/25mL.栓出限达■.ppb。

含8-羟基喹啉类配体的新型钛配合物[O,N]CpTiCl_2的合成及其催化乙烯聚合研究

Synthesis of half metallocene complexes ([O,N]CpTiCl 2) containing 8 hydroxy quinoline ligand is described.The results indicate that [O,N]CpTiCl 2 is active for ethylene polymerization at 30℃ and 0.1?mPa with MAO activation,and exhibits much higher activity than CpTiCl\-3.The results show that when there is an electron donor substituent next to N,such as a methyl,the activity of [O,N]CpTiCl 2 increases greatly; however,if there is an electron acceptor substituent,such as nitro in the benzene ring,it is inactive.For the [O,N]CpTiCl 2/MAO system,the polymerization rate is “up and down” type with increasing the Al/Ti molar ratio.The activity reaches its maximum at molar ratio of Al/Ti = 500,which is over 1×10 5?gPE/molTi·h.The activity decreases as the polymerization time is longer.The polyethylene obtained is characteristic of narrow molecular distribution with molecular weight M w around 40×10 4 and molecular weight ratio M w/ M n=2 8.

5-(4-氯苯基偶氮)-8-苯磺酰氨基喹啉与钯(Ⅱ)的显色反应及其分析应用

研究了新显色剂 5 -(4 -氯苯基偶氮 ) -8-苯磺酰氨基喹啉 (CPBSQ )与钯的显色应反应。对 3 0多种常见离子进行了试验 ,发现没有离子对 Pd( )的测定产生严重干扰。用此法测定催化剂中钯的含量 。

新型荧光试剂5-(4-溴苯偶氮)-8-(8-喹啉重氮氨基)喹啉的合成及其分析应用

将具有荧光特性的8-氨基喹啉结构与具有良好特性的三氮烯结构相结合,首次合成了标题化合物。其结构经过元素分析、红外光谱、核磁共振谱证实。研究表明,在碱性介质中,该试剂在λex/λem=416 nm/512 nm处产生强荧光,并且能被Cu^2＋荧光增强。基于此,建立了BPAQAQ测定Cu^2＋的新型荧光分析法。该方法的线性范围为1.4×10^-8-1.0×10^-5mol/L,检测限为1.1×10^-8mol/L。将其应用于大米粉和小麦粉中Cu2＋的测定,结果满意。

8-羟基喹啉衍生物及其锌配合物的合成

自从1987年美国Kadak公司C.W.Tang及其合作者首次用8-羟基喹啉铝（Alq3）作为发光层,得到了在较低直流电压（约10V）驱动下高亮度（1000cd/m^2）的有机电致发光材料以来,以8-羟基喹啉为配体的有机金属电致发光材料的研究就一直成为人们重点关注的内容;近年来,人们不断对8-羟基喹啉配体进行化学修饰,在喹啉环结构上引入不同基团,改变分子轨道中HOMO和LUMO能级差,使配合物发光峰改变,成功合成出各种发不同荧光的有机电致发光材料。

新型荧光试剂1-(8-喹啉)-3-(2-吡啶)-三氮烯的合成及其分析应用

将具有荧光特性的8-氨基喹啉和吡啶类试剂结合,并引入杂环三氮烯结构,合成了新型荧光试剂1-(8-喹啉)-3-(2-吡啶)-三氮烯(QPyT).其结构经元素分析、红外光谱和核磁共振谱证实.研究结果表明,在碱性介质中,该试剂在λex/λem=216nm/343nm处产生强荧光,并且能被Pb(Ⅱ)猝灭.据此建立了QPyT测定Pb(Ⅱ)的新型荧光分析法.该方法的线性范围为1.6×10-7～1.2×10-5mol/L,检测限为9.0×10-8mol/L.将其应用于水中Pb(Ⅱ)的测定,结果令人满意.

5-(4-氯苯基偶氮)-8-苯磺酰氨基喹啉与钴(Ⅱ)的显色反应及其应用

本文用光度法研究了新显色剂 5 - (4-氯苯基偶氮 ) - 8-苯磺酰氨基喹啉 (CPBSQ)与钴的显色反应和最佳条件。结果表明 ,在 p H 9.5— 11.5范围内及有氯化十六烷基吡啶 (CPC)和硫脲 -酒石酸钾钠存在下 ,Co( )与 CPBSQ形成 1∶ 3的稳定配合物 ,其最大吸收波长为 5 90 nm。依此建立了一种测定 Co( )的新光度法。 Co( )的浓度在 0— 15 .0 μg/2 5 m L 范围内符合比耳定律 ,其摩尔吸光系数为 1.15× 10 5L·mol-1·cm-1。常见离子对 Co2 + 的测定均无严重干扰。本法具有灵敏度高、选择性好的特点。用于 VB12针剂中钴含量的测定 ,相对标准偏差为 0 .5 %— 0 .6 % ,标准加入回收率为 98%— 10 4 %。