High‐pressure Raman spectra of deuterated L‐alanine crystal |
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Authors: | R. O. Gonç alves,P. T. C. Freire,H. N. Bordallo,J. A. Lima,F. E. A. Melo,J. Mendes Filho,D. N. Argyriou,R. J. C. Lima |
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Abstract: | Raman spectra of deuterated L ‐alanine have been obtained at high‐pressure conditions. A phase transition at ∼1.5 GPa associated with the splitting of some internal modes and increase of the wavenumber of the external modes was observed. Similarly to the hydrogenated L ‐alanine crystal, this first transition was related to a symmetry change. Moreover, further modifications of the Raman spectra were observed at 4.4 GPa, which may be associated to conformational changes of the molecule. To give further support to such a hypothesis, neutron powder diffraction measurements were performed. Information about the cell parameter at atmospheric pressure gave valuable information about the N D distances, shedding light on the behavior of the torsional vibration of ND3+. Copyright © 2009 John Wiley & Sons, Ltd. |
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Keywords: | deuterated crystal high pressure phase transition |
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