摘要:

AbstractA series of 2‐benzyl‐1,3‐dicarbonyl derivatives was synthesized. Their insulin‐sensitizing activity was evaluated in 3T3‐L1 preadipocyte cells. Compounds 3, 26 and 27 were found to possess strong insulin‐sensitizing activityin vitroand were selected for further hypoglycemic evalua

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210402

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractA cyclic aryl thioester dimer was prepared by the reaction ofo‐phthaloyl dichloride and bis(4‐mercaptophenyl) sulfide in good yield under pseudo‐high dilution conditions via interfacial polycondensation. The structure of the cyclic dimer was confirmed by a combination of MALDI‐TOF‐MS, FITR, gel permeation chromatography and NMR analyses. The X‐ray diffraction study of the single crystal of cyclic thioester dimer obtained from two solutions reveals no severe internal strain on the cycli

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210403

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractThe catalytic performance of Ni(η5‐Ind)2complex in me dimerization of propylene was studied in combination with an organoaluminum co‐catalyst, eventually in the presence of a phosphine ligand. The effects of the type of aluminum co‐catalyst and its relative amount, the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined. The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum. It was likely to strongly modify the reactivity in the catalytic system when using phosphine ligand as additives, especially at the reaction temperature below 0 °C. The catalytic system based on Ni(η5‐Ind)2complex displayed an extremely high productivity (TOF up to 169000 h−1) and a good regioselectivity to 2,3‐dimethylbutenes (2,3‐DMB) in dimers (66.4%) under proper rea

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210404

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractTime‐dependent density‐functional theory (TDDFT) has been applied to calculate the electronic structure and second‐order nonlinear optical (NLO) properties of some organic molecules. The two‐dimensional (2‐D) charge transfer characteristics of calculated molecules were studied and compared with corresponding experimental results. All the theoretical results agree well with the measurement. For 2‐D molecule with two‐fold symmetry, the dominant charge transfer is off‐diagonal, while for three‐fold symmetry 2‐D molecule, the dominant charge transfer is not only between branches and central group but

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210405

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractNanocrystalline Ni‐Mo‐Fe alloy deposits were obtained by electrode‐position. The structures of the alloy deposits were analyzed by X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The XRD results of nanocrystalline Ni‐Mo‐Fe alloy deposit show that many diffraction lines disappear, and that there is only one diffraction peak at 44.0°. The XPS results of nanocrystalline Ni‐Mo‐Fe alloy deposits indicate that the nickel, molybdenum and iron of the deposits exist in metallic state, and that the binding energy of the alloyed elements increases to some extent. The nanocrystalline Ni‐Mo‐Fe alloy deposit electrode may offer better electrocatalytic activity than the polycrystalline nickel electrode and the nanocrystalline Ni‐Mo alloy electrode. The electrochemical impedance spectra from the nanocrystalline Ni‐Mo‐Fe alloy electrode indicate that hydrogen evolution in 30% (m/m) KOH at lower overpotential is in accordance with the Vohner‐Tafel mechanism, but with the Vohner‐Heyrovsky m

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210406

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractIn situphotochromic process in the monolayer of a photochromic spiropyran derivative without long alkyl chain, was investigated. The photochromism at the air/water interface under different surface pressures was studied by surface pressure‐area isotherms, surface pressure‐time curves, area‐time curves and Brewster angle microscopy. Both forms of the compound were found to form monolayers at the air/water interface although it does not have long alkyl chain. A large area expansion in the monolayer corresponding to a zerothorder reaction was found at the initial stage of the UV light irradiation. A series of dynamic investigations revealed that at high pressure after phase transition in the monolayer, the surface pressure changes greatly under alternative irradiation of UV and visible light An obvious morphological change accompanying with the photochromism was observedin

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210407

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

Abstract3‐Mercaptopropionic add monolayer protected gold nanoclusters (MPA‐MPCs) were synthesized and characterized by transmission electron microscopy, UV‐Vis spectroscopy, X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The exact value of quantized double‐layer capacitance of MPCs in aqueous media was obtained by differential pulse volt

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210408

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractThe heat capacities of the two complexes, [La2(Gly)6(H2O)4]‐(ClO4)6and [Ho2(Gly)4(H2O)4](ClO4)6·2H2O (Gly = glycine), were measured by adiabatic calorimetry in the temperature range from 78 to 375 K. A solid‐solid phase transition was found between 322.87 and 342.29 K for [Ho2(Gly)6(H2O)4](ClO4)6·2H2O, and the peak temperature, the enthalpy and the entropy of the transition were obtained to be 330.94 K, 11.65 kJ·mol−1and 35.20 J· K−1·mol−1, respectively. No indication of any phase transition or thermal anomaly was observed for [La2(Gly)6(H2O)4] (ClO4)6. Thermal stabilities of the two complexes were investigated by thermogravimetry in the temperature range of 40–800°C. The possible mechanisms for the thermal decompositions were proposed according to the

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210409

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractThe crystal growth process of Zn(Len)SO4·0.5H2O from water and acetone was investigated using a Calvet microcalorimeter. The heat and the rate of heat production during the crystal growth process at 293.15 K, 295.15 K, 298.15 K and 300.15 K were measured. On the basis of experimental and calculated results, the rate constant and the kinetic parameters (the activation energies, the pre‐exponential) during the crystal growth process were obtained. The results show that the crystal growth process accorded with the Burton‐Cabrera‐Frank dislocation

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210410

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY

摘要:

AbstractThe title complex, [La(btec)1/2(H2btec)1/2(H2O)]n(H4btec= 1, 2,4,5‐benzenetetracarboxylic acid) (1) was synthesized by the hydrothermal reaction of 1,2,4,5‐benzenetetracarboxylic dianhydride with La(NO3)3·6H2O in H2O, and crystallizes in the triclinic system, space groupP‐1 witha= 0.64403(3) nm,b= 0.94500(4) nm,c= 0.96380(5) nm,a= 88.535(2)°, β = 100.314(2)°, γ = 76.6470(10)°,V= 1.60968(10) nm3,Z= 2, and finalR= 0.0274,Rw= 0.0735. In 1, each La(m) ion is coordinated by eight oxygen atoms from six carboxylate groups and one coordinated water molecule. Two different coordination modes of H4btec were present in the structure, one of which contains two protonated carboxylate groups to balance

ISSN:1001-604X    

DOI:10.1002/cjoc.20030210411

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2003

数据来源: WILEY