RAMAN STUDIES OF THE C-H STRETCHING MODES IN VARIOUS CHOLESTERYL ALKANOATES

In this work, we present Raman spectroscopy studies of the C-H stretch ing modes for various cholesteryl alkanoates in the polycrystalline st ate, in the spectral range 2800-3200 cm(-1). Our experiments lead us t o remove the ambiguity of some assignments of different C-H stretching modes considering the alkyl chain length variations and the polarizat ion effects. The C-H stretching modes are common to all the studied sa mples of the cholesteryl alkanoate family. The spectra shape reflects the alkyl chain length and the local symmetry of the CH2 and CH3 group s: the observed intensity variations for some modes are strongly corre lated with these parameters. (C) 1998 Elsevier Science B.V. All rights reserved.