Effect of solvent fluctuation on the electronic transitions of formaldehyde in aqueous solution Available to Purchase

The absorption spectra of $nπ*$ and $ππ*$ transitions in formaldehyde aqueous solution were studied by the reference interaction site model self-consistent-field (RISM-SCF) method. The electrostatic potential fluctuations acting on the solute sites originating from the solvent fluctuations were obtained by calculating the derivative of the solute-solvent radial distribution function analytically, and these were utilized to estimate the spectral bandwidths. The contribution from the solute vibrations was also examined. As a result, a blue shift of 1998 with bandwidth of $2987 cm−1$ was obtained for the $nπ*$ transition. The $ππ*$ transition, on the other hand, showed a redshift of 1598 with the bandwidth of $5474 cm−1.$ The solvent fluctuation effect contributes to the bandwidths by 617 and $137 cm−1$ for the $nπ*$ and $ππ*$ transition, respectively. We further analyzed the simulated absorption band shapes using effective charges on the atoms and the charge response kernel calculated for each state.