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191.
A series of mononuclear organoruthenium complexes of the type [RuX(PPh3)2(L)] (X = Cl or Br; L = 2-(arylazo)phenolate ligand) have been synthesized from the reaction of five 2-(arylazo)phenol ligands with ruthenium(III) precursors, viz. [RuCl3(PPh3)3] and [RuBr3(PPh3)2(CH3OH)] in benzene under reflux. In all these reactions, the 2-(arylazo)phenolate ligand replaces one triphenylphosphine molecule, two chlorides or bromides and one methanol from the precursors leading to five-membered cyclometallated species. The 2-(arylazo)phenol ligands behave as dianionic tridentate C, N, O donors and coordinated to ruthenium by dissociation of the phenolic proton and the phenyl proton at the ortho position of the phenyl ring. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-Vis and EPR spectral data. These complexes are paramagnetic and shows intense d-d and charge transfer transitions in chloroform. The solution EPR spectrum of the complex 7 in dichloromethane at 77 K shows rhombic distortion around the ruthenium ion. The structural conformation of the complex 1 has been carried out by X-ray crystallography. The redox behavior of the complexes has been investigated by cyclic voltammetry and the potentials are observed with respect to the electronic nature of substituents (R) in the 2-(arylazo) phenolate ligands. These complexes catalyze transfer hydrogenation of benzophenone to benzhydrol with up to 99.5% in the presence of i-prOH/KOH. Further, these complexes have shown great promise in inhibiting the growth of both Gram +ve and Gram −ve bacteria, viz. Staphylococcus aureus NCIM 2079 and Escherichia coli NCIM 2065 and fungus Candida albicans NCIM 3102. 相似文献
192.
The freezing points, conductivities, and densities of NaI, KI, CsI, Bu4NCl, Bu4NBr, Bu4NI, Et4NBr, and Pr4NBr (where Et = ethyl, Pr = propyl, and Bu =n-butyl) in ethylene carbonate have been measured. Osmotic and activity coefficients were calculated from the results. All of the salts studied are strong electrolytes. The trends in the osmotic coefficients of the alkali metal iodides are NaI>KI>CsI, showing that Na+ is more solvated by ethylene carbonate than Cs+. For the tetraalkylammonium halides, the order of osmotic coefficients are Et4NBrPr4NBrBu4NCl>Bu4NBr>Bu4NI. This is the same order as observed in two other high-dielectric-constant solvents, water andN-methylacetamide. The results indicate that the smaller anions are more solvated than the larger anions in ethylene carbonate in contrast to the usual behavior of dipolar aprotic (basic) solvents, such as dimethyl sulfoxide. 相似文献
193.
S. Goto 《Catalysis Surveys from Asia》2004,8(4):241-247
Phase transfer catalysis, a technique to bring the reactants in two immiscible phases together by adding a phase transfer agent, has been employed in the production of fine chemicals and pharmaceuticals in the last few decades. The third liquid phase (catalytic phase) may be formed when phase transfer catalysts (PTC), cannot be dissolved in either organic or aqueous phase. The third phase catalytic systems have the following three advantages, that is, (1) high activity (2) repeated use and (3) separation between the organic phase and the aqueous phase. It is expected that simple new processes can be constructed by applying these three advantages. 相似文献
194.
Hai‐Yang Liu Shi‐Jin Li Yi Zhao Wei Ni Xiao‐Jiang Hao Jun‐Zhu Li Yan Hua Bai‐Bo Xie Chen Qing Chang‐Xiang Chen 《Helvetica chimica acta》2007,90(10):2017-2023
Four new podocarpane‐type trinorditerpenenes, (5β,10α)‐12,13‐dihydroxypodocarpa‐8,11,13‐trien‐3‐one ( 1 ), (5β,10α)‐12‐hydroxy‐13‐methoxypodocarpa‐8,11,13‐trien‐3‐one ( 2 ), (5β,10α)‐13‐hydroxy‐12‐methoxypodocarpa‐8,11,13‐trien‐3‐one ( 3 ), and (3α,5β,10α)‐13‐methoxypodocarpa‐8,11,13‐triene‐3,12‐diol ( 4 ), together with four known diterpenes, 12‐hydroxy‐13‐methylpodocarpa‐8,11,13‐trien‐3‐one ( 5 ), spruceanol ( 6 ), ent‐3α‐hydroxypimara‐8(14),15‐dien‐12‐one ( 7 ), and ent‐3β,14α‐hydroxypimara‐7,9(11),15‐triene‐12‐one ( 8 ), were isolated from the twigs and leaves of Aleurites moluccana. Their structures were elucidated by means of comprehensive spectroscopic analyses, including NMR and MS. Except 8 , all compounds were evaluated for their cytotoxicity; compound 4 exhibited moderate inhibitory activity against Raji cells with an IC50 value of 4.24 μg/ml. 相似文献
195.
3-芳基-6-对甲苯甲酰氨基均三唑并[3,4-b]-1,3,4-噻二唑的合成及生物活性 总被引:2,自引:0,他引:2
利用3-芳基-4-氨基-5-巯基-1,2,4-均三唑和对甲苯甲酰异硫氰酸酯在乙腈中反应, 得到一系列3-芳基-6-对甲苯甲酰氨基均三唑并[3,4-b]-1,3,4-噻二唑, 用1H NMR, IR, MS和元素分析确定了其结构, 并对其进行了抗菌活性测试. 相似文献
196.
Simple two-parameter Hückel and Pitzer equations were used for the calculation of the activity coefficients of aqueous hydrochloric acid at temperatures 0–60°C up to a molality of 2.0 mol-kg–1. The data obtained by Harned and Ehlers(2,3) on galvanic cells without a liquid junction were used in the parameter estimations of these equations. These data consist of sets of measurements at the temperature intervals of 5°C. It was observed that all estimated parameters follow very simple equations with respect to temperature. They are either constant or depend linearly on the temperature. The values for the activity coefficient parameters calculated by these simple equations are recommended here. The recommended parameter values were tested by predicting the data of Gupta, Hills, and Ives,(5) consisting of cell measurements from 5 to 45°C and molalities up to 1.0 mol-kg–1, and the data of Bates and Bower,(4) which extend to 95°C but measurements were only made on molalities less than about 0.1 mol-kg–1. The activity coefficients obtained by the new equations were also compared to those calculated by the Pitzer equations with the parameter values determined by Saluja, Pitzer, and Phutela(6) from calorimetric data. The agreement observed was excellent up to a molality of 1.5 mol-kg–1 at temperatures from 0 to 60°C. 相似文献
197.
Synthesis and properties of chiral ammonium-based ionic liquids 总被引:1,自引:0,他引:1
New chiral ammonium-based ionic liquids containing the (1R,2S,5R)-(-)-menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air- and moisture-stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single-crystal X-ray structure of butyldimethyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride has been determined. The chiral, room-temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities. 相似文献
198.
Trihalogermyl-furans and -thiophenes were prepared by inserting germanium dibromide (GeBr2) generated from the dibromogermane(II) dioxanate complex into the carbon-halogen bond of halo-furans and -thiophenes. Their ethanolysis and transesterification by triethanolamine yielded the germatranes which were subjected to psychotropic activity assays. The psychotropic properties of germatranes were found to depend on the type of the heterocycle and on the position of the germatrane moiety. 相似文献
199.
Won Young Jung Seung Hee Baek Seong Soo Park Gun-Dae Lee Euh Duck Jeong Hyun Gyu Kim Seong-Soo Hong 《Reaction Kinetics and Catalysis Letters》2007,91(2):233-240
The nanosized titania and TiO2/SiO2 particles were prepared by the microwave-hydrothermal method. The effect of physical properties TTIP/TEOS ratio and calcination
temperature has been investigated. The major phase of the pure TiO2 particle is of the anatase structure, and a rutile peak was observed above 800°C. In TiO2/SiO2 particles, however, no significant rutile phase was observed, although the calcination temperature was 900°C. No peaks for
the silica crystal phase were observed at either silica/titania ratio. The crystallite size of TiO2/SiO2 particles decreases as compared to pure TiO2 at high calcination temperatures. The TiO2/SiO2 particles show higher activity on the photocatalytic decomposition of orange II as compared to pure TiO2 particles. 相似文献
200.
Nebojša Banjac Gordana Ušćumlić Nataša Valentić Dušan Mijin 《Journal of solution chemistry》2007,36(7):869-878
Absorption spectra of eight 3-substituted-5,5-diphenylhydantoins have been recorded in fourteen solvents in the range 200–400 nm.
The effect of solvent dipolarity/polarizability and solvent/solute hydrogen bonding interactions are analyzed by means of
the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The lipophilic activity of the investigated
hydantoins was estimated by the calculation of log 10
P values with the Advanced Chemistry Development Software. The calculated values of log 10
P were correlated with the ratio of the contributions of specific solvent interactions, and, by employing the linear dependence
thus obtained, the pharmacological activity of the studied hydantoin derivatives is discussed. 相似文献