Authors :
Shashikala Yalagi
Volume/Issue :
Volume 8 - 2023, Issue 2 - February
Google Scholar :
https://bit.ly/3IIfn9N
Scribd :
https://bit.ly/3JQsfyP
DOI :
https://doi.org/10.5281/zenodo.7623787
Abstract :
Raman and IR spectral measurements in the
3500 – 400 cm-1 have been carried out for the solid
sample of (R)-(+)-α-Methylvaline. The spectral features
indicated that the molecule is a zwitterion, as is true of
amino acids, and is involved in H-bonding, namely,
intermolecular –N-H···O bonding. To account for these
aspects, we have determined a zwitterionic stable
monomer structure in water as a solvent at B3LYP/6-
311++G(d,p) level, and from this monomer, a dimer
species with –N-H···O bonding is constructed. On the
basis of NBO analysis, it has been shown that the
delocalization of electron densities between lone pair
(LP) of Oxygen with the anti-bonding (σ*
) orbital of N-H
moiety is consistent with the geometrical structure of the
dimer. Molecular electrostatic potentials have been used
to demonstrate intermolecular donor (O) – acceptor (-NH) interaction. Predicted deformation modes for –NH3
+
and CO2¯ are in fair agreement with measured
frequencies than stretching modes.
Keywords :
(R)-(+)-α-Methylvaline; IR; Raman; DFT; NH···O Bonding
Raman and IR spectral measurements in the
3500 – 400 cm-1 have been carried out for the solid
sample of (R)-(+)-α-Methylvaline. The spectral features
indicated that the molecule is a zwitterion, as is true of
amino acids, and is involved in H-bonding, namely,
intermolecular –N-H···O bonding. To account for these
aspects, we have determined a zwitterionic stable
monomer structure in water as a solvent at B3LYP/6-
311++G(d,p) level, and from this monomer, a dimer
species with –N-H···O bonding is constructed. On the
basis of NBO analysis, it has been shown that the
delocalization of electron densities between lone pair
(LP) of Oxygen with the anti-bonding (σ*
) orbital of N-H
moiety is consistent with the geometrical structure of the
dimer. Molecular electrostatic potentials have been used
to demonstrate intermolecular donor (O) – acceptor (-NH) interaction. Predicted deformation modes for –NH3
+
and CO2¯ are in fair agreement with measured
frequencies than stretching modes.
Keywords :
(R)-(+)-α-Methylvaline; IR; Raman; DFT; NH···O Bonding
