Theoretical Study
of Raman Intensities of p‑Nitroaniline in
Different Solvent Conditions by
Using a Reference Interaction Site Model Self-Consistent Field Explicitly
Including Constrained Spatial Electron Density Distribution
posted on 2023-12-15, 18:43authored byKayo Suda, Daisuke Yokogawa
Raman spectroscopy is one of the most powerful tools
to understand
and characterize the states and structures of systems in several environments.
To obtain highly accurate changes in Raman intensities of systems
in solution, theoretical treatment, which can deal with not only the
states and structures of systems but also the environment around molecules,
proves to be significant. Hence, in this study, we developed the calculation
of changes in Raman intensities of systems in different solvent conditions
by using the reference interaction site model self-consistent field
study explicitly including constrained spatial electron density distribution;
this model is designed based on elements from both quantum mechanics
and statistical mechanics. We showed that our calculation method could
reproduce the changes in Raman intensities of p-nitroaniline
(pNA) under different solvent conditions, including
supercritical water, which has been observed in previous experimental
studies. Based on the analysis of the calculation results, we observed
that the ratio of the Raman intensity change of pNA in different solvent conditions is strongly correlated with the
charge-transfer character of pNA.