The LAM-1 band in the low-frequency Raman spectra of even and odd monosubstituted n-alkanes

Abstract

Low-frequency Raman spectra of even and odd monosubstituted n-alkanes have been recorded. Longitudinal acoustic modes (LAM) arising from whole-chain vibrations are described. Effects of chain length, end-group mass and temperature on the frequencies of these vibrations are discussed. The single-node LAM-1 frequencies are interpreted in terms of the chain model of Minoni and Zerbi, and are correlated with the crystal structures indicated by the high-frequency Raman spectra of the compounds.