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, CH 3 CHO, and CH 3 COCH 3 is complemented by measurements of the vapor-phase Rayleigh depolarization ratios of HCHO and CH 3 CHO and the temperature dependence of the vapor-phase electrooptical Kerr effect of CH 3 COCH 3 at 632.8 nm. In the cases of HCHO and CH 3 CHO the polarizabilities remain incompletely defined by the experimental data; but in the case of CH 3 COCH 3 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 CH 3 COCH 3, 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 CH 3 CHO. As well, the temperature dependence of the first Kerr virial coefficient of CH 3 COCH 3 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.