ISSN:0005-9021    

DOI:10.1002/bbpc.19810850202

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

年代:1981

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850203

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe preparation process of initial quantum states for the relaxation in symmetrical molecular complexes is studied theoretically. It is shown that the possibility of preparing a definite quasistable molecular complex is drastically dependent on the magnitude of the minimal experimental error to detect this complex in real measurements. Consequences of the theory on the existence of classical and non classical structures of the 2‐norbornyl cation as intermediate complex in chemical reactions are discusse

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850204

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe thermodynamic data of formation of aromatic radical anions from nine different aromatic hydrocarbons and solvated electrons in ammonia are determined by potentiometric titration with a suitable electrochemical cell without diffusion potential. As expected a linear relationship is obtained between ΔHR0and ΔGR0of the electron attachment reaction and the energy parameter of the MO‐theory for the hydrocarbons — Via a Haber‐Born‐cycle the solvation enthalpy and solvation entropy of the electrons are obtained under the assumption that the solvation effects of the aromatic hydrocarbons and their radical anions can be estimated as the electrostatic effects of charging a spheric particle in the dielectricum ammonia. Due to the structure breaking action of the solvated electrons ΔH0 solv, e −= −89 ± 9 kj/mol ΔS0 solv, e −= 175 ± 25 J/mol · K are appreciable more positive than for norm

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850205

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

年代:1981

数据来源: WILEY

摘要:

AbstractInterfacial concentration values derived from overpotential measurements on the cation exchange membrane AMF C 100 are considered in relation to the corresponding current‐voltage curves. The concentration in the depleted layer was found to reach a limiting value as a function of current density which is still large compared to the H+and OH−ion concentration. The pHshift and the cation transport number were also determined as a function of current density. It appeared that water splitting did not contribute significantly to the conductivity in the high polarization regime and could not be correlated with the constant value of the interfacial concentration nor with the additional conductivity which appears beyond the polarographic plat

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850206

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe transport properties through a cation‐exchange membrane were investigated for ions of different valency, using an electric field as driving force. In agreement with theoretical considerations a distinct preference of the higher valent ions was foun

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850207

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe binary system H2SO4— H2O has been investigated.p,v, T‐data of the pure vapour phase including five concentrations (y) 19.94, 39.72, 61.07, 77.04, and 98.92 Mol‐% H2SO4, a density range (1/v) from 1.1 to 38.3 g/1, pressures (p) up to about 50 bar, temperatures (T) up to 823 K, have been determined experimentally. Besidep,T,x‐data of the liquid phase were measured in a range of concentration (x) between 30.0 and 98.39 Mol‐% H2SO4with pressures up to 50 bar and temperatures up to about 723 K. All experimental results are correlated using suitable

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850208

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe solid‐liquid equilibrium diagrams of following 11 binary systems were determined: benzene, toluene, ethylbenzene, n‐propylbenzene, and n‐butylbenzene + n‐heptane or n‐tetradecane and benzene + n‐dodecane. All these diagrams could be calculated accurately (maximum deviation ca. 1 K) in terms of the group‐contribution theory (in the random mixing approximation) developed by Kehiaian et al. [7], which is essentially the surface version of the Guggenheim‐Barker lattice theory. Most interchange parameters were identical to those derived previously [7, 31, 33]from experimental data (liquid‐vapor equilibria, excess enthalpies, excess heat capacities). Where experimental data were lacking, the parameters were estimated and finely adjusted to the observed equ

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850209

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe second‐order rate constants for the self‐termination reaction of the N‐hydro‐4‐acetylpyridinyl radical in propanol(‐2) and propanol(‐2) acetone have been measured by time‐resolved ESR during intermittent photolysis. The radical was generated from 4‐acetylpyridine via different photochemical reactions. The rate constants were measured in the temperature range ‐10 to 26°C. The frequency factor and the activation energy from the Arrhenius plot are (1.1 ± 0.4) · 1010M−1· s−1and 16.6 ± 0.6 kJ · mol−1, respectively. The Arrhenius parameters were independent of the solvent composition and the method of radical generation. The termination reaction is attributed to the formation of the respective pinacol by the combination of two radicals. The reaction rate is not diffusion‐controlled. Possible mech

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850210

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe13C NMR chemical shifts of n‐hexane, 2,3‐dimethylbutane, and 2,2,3,3‐tetramethylbutane solutions in cyclohexane and carbon tetrachloride were measured. The significant changes of chemical shifts were interpreted in terms of collision interactions, the nature of which was proposed to be the quantum mechanical exchange repu

ISSN:0005-9021    

DOI:10.1002/bbpc.19810850211

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

年代:1981

数据来源: WILEY