Low frequency vibrational spectra of some amino acids

Far-IR absorption and reflection spectra, as well as laser andelshtam-Brillouin and Raman scattering spectra of beta-glycine, p-alanine, L-histidine, DL-tryptophane single crystals in the 0.2-400 cm(-1) range were investigated. it was revealed that the far-IR and Raman spectra of the amino acids under study contain more bands than predicted by factor-group analysis, thus indicating a possible contribution of low-energy intramolecular vibrations and overtones, as well as an emergence of forbidden vibrations. Some of the low-frequency bands have never, to our knowledge, been detected previously. (C) 1998 Elsevier Science B.V. All rights reserved.