Reorientational dynamics of liquid CH₃CCl₃ by Raman spectroscopy

Abstract

Spontaneous Raman spectra of the 2940 em-' signal of liquid l,l,l-trichloroethane (TCE) were studied in order to obtain information concerning the molecular reorientation process. The reorientational correlation time was measured as a function of temperature between 255 and 298K giving an activation energy of 2.6 cal mol-' for the tumbling motion of neat liquid TCE. Experimental results were compared with those from extended &diffusion model, microviscosity theory and previous work. It was found that the TCE molecules underwent small-step rotational diffusion. The large variation of the reorientational correlation functions and rotational correlation times of TCE in dilute solutions of CCI,, CDCI3 and CD3CN suggested that the dipole moment contribution is an important factor in molecular reorientation in solutions as suggested by Larkin.