Vibrational relaxation in the group IVA trimethylmetal chlorides

The temperature dependence of the polarized and depolarized Raman spectra of the ν₂, ν₄, ν₆ and ν₇ modes were measured for t-butyl chloride and the analogous group IVA trimethylmetal chrlorides (silicon, germanium and tin). Analysis of the lineshapes revealed that isotropic second moments and vibrational relaxation times for a given mode remained approximately constant through the series. This tranferability of relaxation parameters between molecules extended to modulation times calculated from the Kubo formalism. The above results are in contrast to earlier studies on molecules of dissimilar structure. They provide some preliminary evidence that the mechanism of vibrational relaxation may be the same for equivalent modes in members of the series.