Raman and neutron scattering study of partially deuterated l-alanine: Evidence of a solid-solid phase transition

TY - JOUR

T1 - Raman and neutron scattering study of partially deuterated l-alanine

T2 - Evidence of a solid-solid phase transition

AU - De Souza, Joelma M.

AU - Freire, Paulo T.C.

AU - Argyriou, Dimitri N.

AU - Stride, John A.

AU - Barthès, Mariette

AU - Kalceff, Walter

AU - Bordallo, Heloisa N.

PY - 2009/12/21

Y1 - 2009/12/21

N2 - Raman and neutron experiments using specific isotope labeling were combined in order to study the dynamics and structure of l-alanine. Inelastic neutron and Raman scattering data of C 2H 4(ND 2)CO 2D are discussed in relation to the doubling of the lattice parameter a observed by means of neutron powder diffraction in C 2D 4 (NH 2)CO 2H. The major changes accompanying the phase transition are found in the vibrational frequencies involving the torsional vibration τ(CO 2 -), which is clearly affected by the hydrogen bonds between the protons of the ammonium group and the oxygen atoms of the carboxylate group. At lower temperatures the rearrangement of identifiable hydrogen bonds induces changes in the bending vibration δ(ND 3), confirming some orientational disorder.

AB - Raman and neutron experiments using specific isotope labeling were combined in order to study the dynamics and structure of l-alanine. Inelastic neutron and Raman scattering data of C 2H 4(ND 2)CO 2D are discussed in relation to the doubling of the lattice parameter a observed by means of neutron powder diffraction in C 2D 4 (NH 2)CO 2H. The major changes accompanying the phase transition are found in the vibrational frequencies involving the torsional vibration τ(CO 2 -), which is clearly affected by the hydrogen bonds between the protons of the ammonium group and the oxygen atoms of the carboxylate group. At lower temperatures the rearrangement of identifiable hydrogen bonds induces changes in the bending vibration δ(ND 3), confirming some orientational disorder.

KW - Amino acids

KW - Hydrogen bonds

KW - Neutron scattering

KW - Raman spectroscopy

KW - Selective deuteration

UR - http://www.scopus.com/inward/record.url?scp=77449099190&partnerID=8YFLogxK

U2 - 10.1002/cphc.200900482

DO - 10.1002/cphc.200900482

M3 - Journal article

C2 - 19937663

AN - SCOPUS:77449099190

SN - 1439-4235

VL - 10

SP - 3337

EP - 3343

JO - ChemPhysChem

JF - ChemPhysChem

IS - 18

ER -