摘要:

The interstitial models of water put forward recently by Bell and Lavis and by Perram are compared. It is shown that the two-dimensional partition function of Bell and Lavis, and the three-dimensional one of Perram, are related by a simple transformation in the important limiting case in which both models are treated according to random mixing statistics.

ISSN:0026-8976    

DOI:10.1080/00268977100102231

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The coordination of the cupric ion to nitrogenous ligands differs in the three compounds: cupric protoporphyrin IX dimethyl ester, cupric benzoyl hydrazone, and cupric ortho-vanillin ethylene diamine. Electron paramagnetic resonance studies have been carried out to yield the spin-hamiltonian and bonding parameters of the cupric ion in these compounds. These parameters are compared with those from related compounds.

ISSN:0026-8976    

DOI:10.1080/00268977100102241

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The mechanism of direct spin-orbit coupling arising from electrostatic interaction of the electrons on the perturbed molecule with the nuclei of the perturber is investigated theoretically for the case of benzene in the presence of external heavy atoms. Matrix elements are evaluated using Slater-type orbitals and the von Neumann expansion, and by using gaussian-type orbitals. Results of the present calculation confirm the experimental evidence (from polarization studies by Giachino and Kearns and phosphorescence measurements by Hofeldt, Sahai and Lin) that mixing by the perturber of the triplet state of the molecule with its singlet states is not the mechanism for introducing intensity into the radiativeT1-S0transition.

ISSN:0026-8976    

DOI:10.1080/00268977100102251

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

as obtained from the anisotropic chemical shielding relaxation rate which is separated from the other contributions by its quadratic dependence on the Larmor frequency. Using thisτRthe intramolecular dipole-dipole relaxation rate is calculated. The contribution from the translational diffusion modulated intermolecular dipole-dipole interaction is calculated from the self-diffusion coefficient. When these contributions are subtracted from the observed relaxation rate, there remains a frequency-independent relaxation rate, proportional to 1/δR, which is attributed to the spin-rotational interaction. The latter is shown to be quantitatively consistent with large-angle reorientational jumps of the P4molecules by 120° about theirC3vaxes. The relaxation in the liquid phase is dominated by the spin-rotational interaction and the expression representing the spin-rotational relaxation rate is the same as the one derived in the plastic-crystalline phase. The mechanism of molecular reorientation in the liquid is therefore the same as in the plastic-crystalline phase.

ISSN:0026-8976    

DOI:10.1080/00268977100102261

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268977100102271

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268977100102281

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268977100102291

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor