Anisotropic molecular polarizabilities of HCHO, CH3CHO, and CH3COCH3.: Rayleigh depolarization ratios of HCHO and CH3CHO and first and second Kerr virial coefficients of CH3COCH3

Available information in relation to the anisotropic electric dipole polarizabilities of HCHO, CH3CHO, and CH3COCH3 is complemented by measurements of the vapor-phase Rayleigh depolarization ratios of HCHO and CH3CHO and the temperature dependence of the vapor-phase electrooptical Kerr effect of CH3COCH3 at 632.8 nm. In the cases of HCHO and CH3CHO the polarizabilities remain incompletely defined by the experimental data; but in the case of CH3COCH3 the three principal polarizabilities are determinable from an analysis of the Kerr effect together with the previously reported mean polarizability and Rayleigh depolarization ratio of this species. The experimental polarizabilities of CH3COCH3, in conjunction with Rice and Handy's computed polarizabilities of HCHO and a simple group additivity model, allow the reliable prediction of the four components of the polarizability of CH3CHO. As well, the temperature dependence of the first Kerr virial coefficient of CH3COCH3 provides uncertain estimates of the first and second Kerr hyperpolarizabilities, which have not previously been reported. The temperature dependence of the second Kerr virial coefficient, which measures contributions from pairwise molecular interactions, is found to be explicable in terms of a recent statistical-mechanical theory of the effect.