MECHANISTIC INTERPRETATIONS OF VIBRATIONAL DEPHASING PROCESSES IN 1,1,1-TRICHLOROETHANE BY SPONTANEOUS RAMAN-SPECTROSCOPY

The Raman signals from modes ν1, ν2, ν3, 2ν2, and 2ν8, of 1,1,1‐trichloroethane have been examined by varying the concentration of this molecule in several solvents. In addition temperature studies were conducted, including data from the disordered solid phase of the neat sample. The results of these studies show that (a) the fundamentals (ν1, ν2, and ν3) are involved in a dephasing process controlled by the intramolecular potential function, (b) dephasing processes of the overtones are dominated by intermolecular processes and (c) the ν2 and ν3 modes of this molecule show very little dilution effects (some broadening), whereas the same modes of the structurally similar molecule CH3I show a definite narrowing in similar solvents. The theoretical model, proposed by Rothschild, is used to strengthen the interpretative case offered for the mechanistics of the dephasing processes of the fundamental modes. Copyright © 1979 Heyden & Son Ltd.