摘要:

Measurements have been made of the electron spin resonance spectrum of aγ-irradiated single crystal of glycollic acid as a function of crystal orientation. These confirm that the trapped radicals are carboxy hydroxy methyl radicals, HOCHCOOH. The results are expressed in the form of a spin Hamiltonian which includes a coupling tensor for the hydrogen attached to the central carbon atom and a tensor for the hydroxyl hydrogen. A special feature of the spectra is that the relative intensities of the hyperfine lines are non-integral, and this is explained by a derivation of the transition moments which shows that the usual selection rule ΔMI= 0 is inapplicable to the solid state. The anisotropicgtensor is also evaluated. The tensors are briefly discussed in relation to the orientation of the radicals in the crystal and their electronic structure.

ISSN:0026-8976    

DOI:10.1080/00268976000100011

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The Renner theory of vibrational-electronic interaction in linear triatomic molecules in Π electronic states is extended to take account of coupling between an odd electron spin and the electron orbital angular momentum. Perturbation expressions for the splittings and shifts of energy levels are obtained on the assumption that the Renner splittings and the spin-orbit coupling energy are of the same order of magnitude, but less than the energy quantum of the bending vibrations.

ISSN:0026-8976    

DOI:10.1080/00268976000100021

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The temperature variations of the total intensity and of the mean energy of optical absorption in hydrated paramagnetic salts are calculated on the assumption that the absorbing ion and its coordinated ligands form an isolated complex. These calculations take into account the anharmonicities in the vibrational motion of the ligands. Comparison with experimental data indicates a rather large amount of anharmonicity.

ISSN:0026-8976    

DOI:10.1080/00268976000100031

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

can be related exactly to configurational thermodynamic properties and the repulsion exponentn. The condition that the discriminant is essentially positive (Schwarz's inequality) provides an experimental lower bound forn.

ISSN:0026-8976    

DOI:10.1080/00268976000100041

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

A comprehensive theory is given for all observed optical absorptions which do not involve a spin-change in the paramagnetic ion. Except for the anomalous behaviour of the vanadous ion, good agreement is found between the calculated and the observed oscillator strengths. The operative mechanism in the absorption is the vibrational motion of the ligands, enabling virtual transitions to odd-parity charge transfer states to take place. In these states the central ion loses an electron to the ligands; this situation is also analysed in the paper.

ISSN:0026-8976    

DOI:10.1080/00268976000100051

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Measurements have been made of the heat capacityCpfrom ∼13 to ∼ 298°Kof three clathrates of methane andβ-quinol, in which 75·5, 45·7 and 16·5 per cent of the cavities were occupied by methane. Over the entire temperature rangeCpis found to be a linear function of composition. The contribution made to the heat capacity by a mole of methane has been analysed with the aid of the theory of J. H. van der Waals, and the rotational contribution found to be 3/2R, within experimental error, from about 150°kupwards, showing that rotation of the methane molecules is almost unrestricted.

ISSN:0026-8976    

DOI:10.1080/00268976000100061

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

It is shown that singlet-triplet transitions may obtain a finite probability when exchange interaction occurs between the absorbing molecule and a paramagnetic molecule.

ISSN:0026-8976    

DOI:10.1080/00268976000100071

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The dependence of fluorescence intensity on the wavelength of exciting radiation has been recorded for anthracene vapour at 0·09 mm and 170°Cover the range 230–366 mμ. It is shown that whereas the photon cascade theory cannot account for the much higher intensity excited in the 250 mμband than excited in the band at 363 mμ, this behaviour is precisely that expected if the fluorescent state is populated by internal conversion following excitation in the short-wave band.

ISSN:0026-8976    

DOI:10.1080/00268976000100081

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

It is shown that second-order perturbation theory leads to the usual quadratic and bilinear terms in the spin-Hamiltonian for a spatially non-degenerate state even when excited states differing in multiplicity from the ground states are included. The form of the spin-Hamiltonian adequate to represent arbitrary splittings of the ground manifold is considered and explicit results given for the fine structure and for those interactions with nucleus and external magnetic field which are linear inIandHrespectively.

ISSN:0026-8976    

DOI:10.1080/00268976000100091

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Spectrophotometric evidence for the formation of contact ion-pairs in solutions of tetra-alkylammonium iodides in certain solvents of poor ion-solvating power, such as carbon tetrachloride, is presented.

ISSN:0026-8976    

DOI:10.1080/00268976000100101

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor