摘要:

AbstractThe first thermodynamic dissociation constants of boric acid in aqueous solution of lithium chloride with borate at five different temperatures from 278.15 to 318.15 K were evaluated fromernfvalues of the cell without liquid junction potential with the improved extrapolation and polynomial approximation on the basis of Pitzer's theory. Values obtained from both methods are in good agreement with each other. Pitzer's parameters β(0)and β(1)of LiB(OH)4and other thermodynamic quantities of dissociation process of boric acid are obtained. Results have been discusse

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120201

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

年代:1994

数据来源: WILEY

摘要:

AbstractA new approach to the computation of the chemical potential of fluids is presented. In this method the particle‐insertion operation in the conventional test particle method is replaced by the growth of a specific particle. Application of the new technique to hard sphere and Lennard‐Jones fluids shows that it is capable of providing reliable estimates of the chemical potential, even at high density where the conventional test particle methods are difficult to ap

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120202

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

年代:1994

数据来源: WILEY

摘要:

AbstractLangmuir‐Blodgett (LB) films of Ar‐docosylpyridinium‐TCNQ (NDP‐TCNQ) were prepared in air. The films deposited at the room temperature showed in‐plane conductivity of 4·10−3S·cm−1and its absorption spectra in UV and IR regions resembled those for the films composed of mixed‐valence TCNQ salts of NDP‐(TCNQ)2rather than for the NDP‐TCNQ LB films preparaed under protection of nitrogen. In the case that the films left in a warm environment after each dipping cycle, the absorption in the corresponding region changed. Spectral analysis and XPS study revealed that more TCNQ molecules were produced. The oxidation of TCNQ: in air was considered to be the origin o

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120203

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe construction of adsorptive type Ceo modified electrode and its electrochemical reduction and oxidation behavior in aqueous solutions are described in this report. Four pairs of one‐electron transfer reduction and oxidation cyclic voltammetry is obtained in aqueous solution containing 30% CH3CN and 2% (C3H5)4NOH. It is reported in this paper that the Ceo modified electrode also catalyzes the electrochemical reduction of dissolved oxygen in 40% DMF and 2% (C2H5)4NOH aqueous solution and this might open a new field for the potential applications of C60in electrochemistry and electroanalytical chemistr

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120204

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

年代:1994

数据来源: WILEY

摘要:

AbstractTris)(η5‐cyclopentadienyl‐μ‐carbonyl‐iron)‐μ3‐nitrosyl cluster was obtained from the reaction of cyclopentadienyl dicarbonyliron dimer with nitrogen monoxide in xylane. The cluster was characterised by elemental analyses, IR, MS and1H NMR. The crystal structure of [(η5‐C5H5)(μ‐CO)Fe]3(μ3‐NO)·C4H8O was determined by X‐ray diffraction analysis. It crystallises in the orthorhombic space groupPnma, a=9.063(2),b=10.546(2),c=22.525(4) Å,V=2150.3(7) Å3,Z=4,Dc=1.68 g·cm−3; structure solution and refinement based on 1141 reflections withI≥ 3.0σ (I) (MoKα, λ=0.71073 Å) converged atR=0.0540. The infrared absorption band at 1325 cm−1of the μ3‐NO in the cluster, which is

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120205

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe study on retention behavior in supercritical fluid chromatography (SFC) is necessary to understand the mechanism of the various interactions in SFC. The retention of SFC in carboxylic acid methyl ester/polymethylsiloxane/CO2system was studied systematically and the retention behavior of this kind of compounds under various typical operation conditions was described using the method of an alternative unified theory of chromatographic retention. The results illustrated that expression: Ink =a+b/T + cp+dp/T+ep2/Tcan be used to describe quantitatively the retention behavior of carboxylic acid methyl ester/polymethylsiloxane/CO2system in the ranges of reduced density from 0.549 to 1.411. It was also found that the entropy of solute in stationary phase is dependent on the density of supercritical fluid (SF) under typical operating conditions of SFC.

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120206

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe electrochemical oxidation of diphenylamine in acetonitrile produces an adherent uniform polymer film which exhibits mutiple colour variation(yellow‐green‐blue) in a wide range of potential scan. The polymerization mechanism and the structure of the polymer were studied by cyclic voltammetry, FT‐IR andin situESR. The results indicate that the electrochemical polymerization of diphenylamine belongs to a cationic radical polymerization process. During electrolysis, only oligomers were initialy produced, then polymer film was formed on the electrode surface. The electropolymerization performs via the 4,4′ C‐C phenyl‐phenyl couplin

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120207

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

年代:1994

数据来源: WILEY

摘要:

AbstractDibromobiphenyl reacted with cynomethyl anion in ammonia under irradiation to form nucleophilic bis‐substituted product in high yield without substantial monosubstituted product. Quantum yields far the formations of bis‐ and monosubstituted products were found to be 85.6 and 2.3×10−5respectively while the corresponding pseudo‐first‐order rates were 6.9×10−3and 5.2×10−10mol·L−1·S−1. Block up the possible electron transfer of 4‐brome‐4′‐cyanomethyl‐biphenylyl radical anion to 4‐cyanomethyl

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120208

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

年代:1994

数据来源: WILEY

摘要:

AbstractUsing 2‐bromo‐1‐methylpyridimium iodide aa carbaxyl activating agent, 10 ansamacrolactams were prepared conveniently from the corresponding seco‐precursor ω‐aminoacids in the yields

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120209

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

年代:1994

数据来源: WILEY

摘要:

AbstractA homologous aeries of 4′‐methylphenyl 4″‐[(4‐alkoxy‐2,3,5,6‐tetrafluorophenyl)ethynyl]‐benzoates have been synthesized. Polarizing microscopic textural observation shows that such compounds exhibit enantiotropi

ISSN:1001-604X    

DOI:10.1002/cjoc.19940120210

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

年代:1994

数据来源: WILEY