摘要:

The absorption spectra of ReF6, OsF6, IrF6and PtF6have been obtained between 2500 and 40 000 cm-1in the gas phase. The interesting band systems have been assigned on the basis of ligand field theory, and some predictions have been made as to magnetic properties.

ISSN:0026-8976    

DOI:10.1080/00268975900100101

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The method, previously developed by the authors, for calculating the intensity of dnelectronic transitions in inorganic complexes is extended to include electronic systems which exhibit configuration interaction. The oscillator strengths of both the spin-allowed and spin-forbidden spectral transitions of divalent nickel and trivalent vanadium complex salts are computed and compared with experiment. Fair agreement is found. Some critical comments concerning the relative merit of such calculations are presented. The envelope of the Ni(II) red band is elucidated in terms of the spin-orbit fine structure of the3T1gelectronic state.

ISSN:0026-8976    

DOI:10.1080/00268975900100111

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Anisotropic proton hyperfine interactions inπ-electron radicals are approximated by a magnetic dipole interaction between each proton and an electron spin magnetization that is distributed in 2s and 2p Slater atomic orbitals centred on carbon atoms.

ISSN:0026-8976    

DOI:10.1080/00268975900100121

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Self-consistent field (SCF) calculations have been carried out for hydrogen fluoride at the experimental internuclear distance using a single determinantal wave function composed of molecular orbitals (MO's) expressed as linear combinations of atomic orbitals (LCAO's). The AO's used are of Slater-type in which the parameters have been varied within the framework of the variational method. The improvement in the energy and other physical quantities brought about by the variation of the Slater parameters has been discussed in relation to the results of other methods of obtaining improved wave functions for this molecule.

ISSN:0026-8976    

DOI:10.1080/00268975900100131

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Theπ-electron systems in four electron-rich heterocyclic nitrogen compounds of a new type were studied by the simple molecular-orbital method. Resonance energies,π-electron densities and energies of excited states were studied as a function of the nitrogen electronegativity parameter. Although only one of the compounds has yet been synthesized, the present results suggest that all would be stable once formed. Definite predictions of the positions of highest chemical reactivity towards electrophils can be made in the case of the two tricyclic compounds (I) and (II).

ISSN:0026-8976    

DOI:10.1080/00268975900100141

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268975900100151

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The approach to equilibrium of a particle interacting with the vibrations of an equilibrium lattice is studied using the methods developed by Prigogine and co-workers. For a low energy particle it is found that the approach to equilibrium is characterized by a relaxation time which is proportional to the square of the mass of the particle, and that the autocorrelation function is a simple exponential function. For a high energy particle no ordinary relaxation time exists, and the apparent relaxation time increases proportionally to the three halves power of the energy of the particle, and is inversely proportional to the square root of its mass. The fact that it depends on the energy is understood when one considers the number of phonons with frequencies high enough to make interaction possible.

ISSN:0026-8976    

DOI:10.1080/00268975900100161

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The terms of the expression previously obtained by Friedman for the cluster integral sum in Mayer's theory are examined as to order in total ion concentration,c, at the limit,c= 0. The order of the singularity atc= 0 is calculated for several of those terms of the irreducible cluster integrals that correspond to graphs of low connectivity but with an arbitrary number of vertices. On the basis of these calculations and two postulates concerning the relation of the singularities of these integrals to others, it is concluded that the terms of the cluster integral sum, when arranged in order of increasing index, are also in increasing order of concentration, and that the first term,κ3/12π, has a lower order than any other. The order in concentration of the higher terms depends on whether the third moment of the concentration of charge types, σc8z83, vanishes, as it does in solutions of electrolytes of symmetrical charge type.

ISSN:0026-8976    

DOI:10.1080/00268975900100171

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

A calculation of vibrational relaxation times in gaseous cyanogen at 300°K is presented. It is suggested that two well separated dispersion regions should be found in sound velocity measurements at ultrasonic frequencies, the higher frequency region being associated with the relaxation of the combined vibrational specific heat contributions of the two lowest modes and the lower frequency region being associated with the relaxation of the corresponding contribution of the next highest mode.

ISSN:0026-8976    

DOI:10.1080/00268975900100181

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Measurements have been made of the heat capacityCpfrom ∼ 13°kto ∼ 273°kof five clathrates of argon andβ-quinol. The argon content ranged from ∼ 20 per cent to ∼ 80 per cent of the maximum possible amount. Over much of the temperature range studied,Cpproved to be a linear function of the argon content, but from 13°kto 20°k, and from 50°kto 100°kthe relation betweenCpand argon content is obscure, and may, in fact, be non-linear. Estimates have been made of the contribution toCpmade by a mole of argon in the temperature region whereCpis a linear function of composition, and these experimental values have been compared with those calculated according to the theory of J. H. van der Waals, which is based on the cell model of Lennard-Jones and Devonshire. The agreement between theory and experiment is satisfactory.

ISSN:0026-8976    

DOI:10.1080/00268975900100191

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor