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Low‐temperature Raman spectra of racemate DL ‐Alanine crystals
Author(s) -
Lima J. A.,
Freire P. T. C.,
Melo F. E. A.,
Filho J. Mendes,
De Sousa G. P.,
Lima R. J. C.,
Façanha Filho P. F.,
Bordallo H. N.
Publication year - 2010
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2507
Subject(s) - raman spectroscopy , alanine , chemistry , crystal structure , crystallography , wavenumber , crystal (programming language) , spectral line , space group , phase transition , stereochemistry , amino acid , x ray crystallography , diffraction , physics , optics , condensed matter physics , biochemistry , programming language , astronomy , computer science
Abstract Raman spectra of DL ‐Alanine crystals were investigated in the 50–3200 cm −1 spectral region for temperatures ranging from 15 to 295 K. The crystalline structure of DL ‐Alanine represents a rare example of an amino acid racemate crystallizing in a non‐centrosymmetric space group. From this study, we have observed changes in the wavenumber of modes associated with both rocking of CO 2 − and skeletal vibrations. On the other hand, neither changes in the modes associated to CH or CH 3 vibrations nor substantial modifications of the lattice modes of the crystal were observed. Such result indicates slight changes of the CO 2 group orientation without observation of a solid–solid phase transition in the DL ‐Alanine crystal. Copyright © 2009 John Wiley & Sons, Ltd.