The Behavior of the Deformation Vibration of NH3 in Semi-Organic
Crystals under High Pressure Studied by Raman Spectroscopy
CRYSTALS, (2018)DOI: 10.3390/cryst8060245
Abstract
Single-crystal samples of the semi-organic compounds mono-l-alaninium
nitrate and monoglycine nitrate have been studied by Raman spectroscopy
in a diamond-anvil cell up to 5.5 GPa, in order to observe the behavior
of the deformation mode of NH3 units. It was observed for these
semi-organic crystals that increasing pressure produces a decrease in
the wavenumber of the band associated with the deformation vibration,
differently from most of the modes. Comparatively, mono-l-alaninium has
a higher d/dP than monoglycine nitrate, for the band associated with the
deformation vibration. The anomalous behavior is explained in terms of
the effect of high pressure in the short and linear intermolecular
hydrogen bonds.