Premium
High pressure Raman spectra of L ‐methionine crystal
Author(s) -
Lima J. A.,
Freire P. T. C.,
Melo F. E. A.,
Lemos V.,
Mendes Filho J.,
Pizani P. S.
Publication year - 2008
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.2005
Subject(s) - raman spectroscopy , chemistry , crystal (programming language) , spectral line , crystallography , analytical chemistry (journal) , crystal structure , phase transition , physics , optics , thermodynamics , organic chemistry , astronomy , computer science , programming language
Raman spectra of an L ‐methionine (C 5 H 11 NO 2 S) crystal were obtained in the spectral region between 50 and 3200 cm −1 for pressures up to 5 GPa. Pronounced changes of the Raman spectra were observed for bands associated to rocking of CO 2 − ; wagging of CO 2 − ; deformations of CO 2 − , CH 3 , and NH 3 + ; and stretching vibrations of SC, CC, CH, CH 2 , and CH 3 . Upon decompression to ambient pressure the original Raman spectrum prior to compression is recovered. These modifications were associated to a reversible phase transition undergone by the L ‐methionine crystal at about 2.2 GPa, with a hysteresis of ∼0.8 GPa. Pressure coefficients for most of the internal modes of the crystal are given. Copyright © 2008 John Wiley & Sons, Ltd.