Structural isotopic effects in the smallest chiral amino acid: Observation of a structural phase transition in fully deuterated alanine
Research output: Contribution to journal › Journal article › Research › peer-review
A first study of possible changes instigated by deuteration in amino acids was carried out using neutron diffraction, inelastic neutron scattering, and Raman scattering in L-alanine, C2H4(NH2)COOH. Careful analysis of the structural parameters shows that deuteration of L-alanine engenders significant geometric changes as a function of temperature, which can be directly related to the observation of new lattice vibration modes in the Raman spectra. The combination of the experimental data suggests that C2(ND4)COOD undergoes a structural phase transition (or a structural rearrangement) at about 170 K. Considering that this particular amino acid is a hydrogen-bonded system with short hydrogen bonds (O⋯H ∼ 1.8 A), we evoke the Ubbelohde effect to conclude that substitution of hydrogen for deuterium gives rise to changes in the hydrogen-bonding interactions. The structural differences suggest distinct relative stabilities for the hydrogenous and deuterated L-alanine.
Original language | English |
---|---|
Journal | Journal of Physical Chemistry B |
Volume | 111 |
Issue number | 19 |
Pages (from-to) | 5034-5039 |
Number of pages | 6 |
ISSN | 1520-6106 |
DOIs | |
Publication status | Published - 17 May 2007 |
Externally published | Yes |
ID: 209601039