High temperature Raman spectra of L-leucine crystals

single crystal samples of l-leucine, c6h13no2, a fundamental aliphatic amino acid of the human body, have been studied by raman spectroscopy at temperatures from 300 to 430 k over the spectral range from 50 to 3100 cm -1. a tentative assignment of all bands is given. for high temperatures, several modifications on the raman spectra were observed at about 353 k, giving evidence that the l-leucine crystal undergoes a structural phase transition. an interpretation for this phase transition in terms of group theory analysis is given.