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...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.展开更多
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...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.展开更多
A series of half-titanocene chloride 2-（benzimidazol-2-yl）quinolin-8-olates C1-C6 were synthesized by treating the lithium salts of the ligand with CpTiCI3. All the complexes were characterized by 1H-NMR, 13C-NMR an...A series of half-titanocene chloride 2-（benzimidazol-2-yl）quinolin-8-olates C1-C6 were synthesized by treating the lithium salts of the ligand with CpTiCI3. All the complexes were characterized by 1H-NMR, 13C-NMR and elemental analyses, and the crystal structure of C3 and C6 was measured by X-ray. These half-titanocene complexes showed moderate catalytic activities toward ethylene polymerization （up to 1840 kg·mol-1（Ti）·h-1） when activated with MMAO, affording the high molecular weight polymers. And they also exhibited good activity for copolymerization of ethylene and a-olefin with low content of co-monomer.展开更多
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 a...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.展开更多
A series of nickel halides bearing 2,4-di-t-butyl-6-（quinolin-8-yliminomethyl） phenolate ligands was synthesized and characterized by IR spectroscopy and elemental analysis. Molecular structures of C1 （R = H, X = B...A series of nickel halides bearing 2,4-di-t-butyl-6-（quinolin-8-yliminomethyl） phenolate ligands was synthesized and characterized by IR spectroscopy and elemental analysis. Molecular structures of C1 （R = H, X = Br） and C2 （R = H, X = C1） were further confirmed by single-crystal X-ray crystallographic studies, and revealed a distorted square planar geometry at nickel. Upon activation with diethylaluminum chloride （Et2AlCl）, all nickel pre-catalysts displayed good catalytic activity [up to 9.3 × 10^5 g mol-1（Ni） h-1] for ethylene oligomerization with major dimerization. In the presence of methylaluminoxane （MAO）, the nickel complex C1 was capable of ethylene polymerization under 3 MPa, and produced polyethylene products with narrow polydispersity （1.16-1.73） and molecular weights in the range of 2.6-4.95 kg/mol.展开更多
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-...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.展开更多
Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chr...Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chromatographic techniques including reversed-phase semipreparative HPLC from an ethanol extract of the stem bark of Fraxinus sielboldiana.Their structures were determined by spectroscopic methods including IR,MS,and 1D and 2D NMR experiments.This is the first report of sequiterpenes in the genus Fraxinus.展开更多
文摘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.
文摘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.
基金supported by NSFC (No. 20904059)Key Project of 863 Program of China(No. 2009AA034605)
文摘A series of half-titanocene chloride 2-（benzimidazol-2-yl）quinolin-8-olates C1-C6 were synthesized by treating the lithium salts of the ligand with CpTiCI3. All the complexes were characterized by 1H-NMR, 13C-NMR and elemental analyses, and the crystal structure of C3 and C6 was measured by X-ray. These half-titanocene complexes showed moderate catalytic activities toward ethylene polymerization （up to 1840 kg·mol-1（Ti）·h-1） when activated with MMAO, affording the high molecular weight polymers. And they also exhibited good activity for copolymerization of ethylene and a-olefin with low content of co-monomer.
文摘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.
文摘A series of nickel halides bearing 2,4-di-t-butyl-6-（quinolin-8-yliminomethyl） phenolate ligands was synthesized and characterized by IR spectroscopy and elemental analysis. Molecular structures of C1 （R = H, X = Br） and C2 （R = H, X = C1） were further confirmed by single-crystal X-ray crystallographic studies, and revealed a distorted square planar geometry at nickel. Upon activation with diethylaluminum chloride （Et2AlCl）, all nickel pre-catalysts displayed good catalytic activity [up to 9.3 × 10^5 g mol-1（Ni） h-1] for ethylene oligomerization with major dimerization. In the presence of methylaluminoxane （MAO）, the nickel complex C1 was capable of ethylene polymerization under 3 MPa, and produced polyethylene products with narrow polydispersity （1.16-1.73） and molecular weights in the range of 2.6-4.95 kg/mol.
文摘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.
基金Financial support from the National Natural Sciences Foundation of China(NNSFC,Grant nos.30825044 and 20932007)the National Science and Technology Project of China(Nos.2009ZX09311-004 and 2009ZX09301-003-4-1)is acknowledged.
文摘Two new ar-bisabol sequiterpenes,(+)-(7S,10S)-10-epi-7,10-epoxy-3-hydroxy-ar-bisabol-11-ol(1)and(+)-(7R,8R,10S)-10-epi-7,10-epoxy-8-hydroxy-ar-bisabol-11-ol(2),have been isolated by a combination of various column chromatographic techniques including reversed-phase semipreparative HPLC from an ethanol extract of the stem bark of Fraxinus sielboldiana.Their structures were determined by spectroscopic methods including IR,MS,and 1D and 2D NMR experiments.This is the first report of sequiterpenes in the genus Fraxinus.
