Structural isotopic effects in the smallest chiral amino acid: Observation of a structural phase transition in fully deuterated alanine
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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.
Originalsprog | Engelsk |
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Tidsskrift | Journal of Physical Chemistry B |
Vol/bind | 111 |
Udgave nummer | 19 |
Sider (fra-til) | 5034-5039 |
Antal sider | 6 |
ISSN | 1520-6106 |
DOI | |
Status | Udgivet - 17 maj 2007 |
Eksternt udgivet | Ja |
ID: 209601039