LIGHT SCATTERING STUDIES OF MOLECULAR LIQUIDS

In this review we focus attention primarily upon the depolarized Rayleigh and Raman scattering from liquids composed of small, rigid molecules; however, we also refer to the results of other experiments (NMR, IR, and molecular dynamics) that provide complementary infor­ mation. Even within this limited framework we do not provide a comprehensive review of the recent literature but rather we select certain topics that are of particular interest to us and where important changes have recently occurred. We have attempted to integrate the information from different sources and to provide a critical (and clearly personalized) analysis. Several excellent reviews of various aspects of this subject have appeared since the last review in this series (1). In particular the text on light scattering by Berne & Pecora (2), reviews on vibrational dephasing and energy relaxation by Oxtoby (3,4), the articles on rotational relaxation by Steele (5) and Griffiths (6), and the review of collision-induced scattering by Tabisz (7) discuss the techniques and physical principles involved. The up-to-date treatment of many topics in these sources has helped us restrict our choice of subject matter. The Raman and depolarized Rayleigh spectra monitor the fluctua­ tions in the polarizability density that arise from the modulation of the intrinsic (gas phase) and the interaction-induced polarizabilities of the molecules by the molecular motion. If there were no interaction-induced polarizability the shape of the depolarized Rayleigh spectrum (DRS)