Rotational correlation in chloroform

Abstract

We have measured the band shapes of the vibrational and low frequency features in the infrared and Raman spectra of liquid chloroform. The various measurements are analyzed to yield the appropriate orientational correlation functions. The dielectric corrections proposed by Klug et al. [J. Chem. Phys. 50, 3904 (1969)] provide the most consistent analysis of the far infrared band. Intensity comparisons for the depolarized Rayleigh wing show the need for ’’cavity’’ corrections to the polarizability anisotropy. The distinct correlation functions [such as Σ_ii≠j〈μ_i(o) ⋅μ_j(t) 〉] decay much more slowly than the total of self‐correlation functions in agreement with the theory of Keyes and Kivelson [J. Chem. Phys. 56, 1057 (1972)]. We compare our results with previous measurements and discuss a number of the difficulties involved in abstracting the desired correlation functions. Some results for chlorobenzene are also presented and for this molecule ’’cavity’’ corrections seem to be required even for explanation of the intensity of the far infrared band.