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The coefficients C, and D are not independent; an expansion of this form was used only for purposes of convenience and was subsequently converted to a more simplified form. (17) Functions of this form to represent the calculated values of coupling constants (EHT method) were proposed previously: K.

The complex permittivity of 0.05 M L1CIO4 in tetrahydrofuran (THF) at 25°in the frequency range 0.3-8.5GHz has been measured. An admittance bridge was used in the frequency range 0.3-1.5 GHz and a power reflection method in the range 2-8.5 GHz. The real and imaginary parts of the permittivity follow a Cole-Davidson distribution of relaxation times with an average relaxation frequency /r = 1.5 GHz and a distribution parameter ß = 0.8. Including data reported in the literature the relaxation amplitude «o -of the solute is found to be a linear function of the concentration of ion pairs. The Cole-Davidson distribution parameter, ß, is calculated by a modified Glarum theory which postulates that the diffusion-controlled collision between ion-pair dipoles couples with the diffusional rotational relaxation. The calculated value of ß approximates the experimental distribution parameters including those for LiC104-THF-benzene mixtures.

Audiofrequency electrical conductivity, Raman spectra, radiofrequency ultrasonic absorption, and microwave dielectric permittivity of LiAsFg in the solvent 1,2-dimethoxyethane (DME) are reported. An analysis of the electrical conductivity data reveals the electrolyte to be associated to ion pairs (KA = 1 X 105 M"1). Raman spectra of the symmetrical stretching mode of AsFg" suggest the ion to be "spectroscopically free", namely, either unpaired or solvent separated from the cation. Ultrasonic relaxation data are interpreted in terms of the equilibrium Li+, S, AsFg" <=* LiAsFg, (S being a solvent molecule). The equilibrium appears to be heavily shifted toward solvent-separated ion pairs in accord with the information obtained from Raman spectra. In other words, the majority of the electrolyte is associated in the form of a solvent-separated ion pair symbolized by Li+, S, AsFg". Microwave dielectric relaxation data can be interpreted as due to the diffusion rotation relaxation of ion pairs. The estimate of the charge-to-charge distance in the ion pairs reinforces the model that the solvent resides between the cation and the anion in the majority of the pairs. The equilibrium is shifted to increase contact pairs, by increasing the electrolyte concentration, in accordance with the law of mass action.

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