Response of Scalar Fields and Hydrogen Bonding to Excited-State Molecular Solvation of Carbonyl Compounds.

An attempt has been made to understand the mechanism of excited-state molecular solvation and its effect on hydrogen bonding in carbonyl compounds in aqueous solution. The correlation between solvation and electronic transitions has been investigated by comparing results obtained either with a supermolecular description in terms of hydrogen-bonded clusters or with a combined method embedding such clusters with a polarizable continuum dielectric mimicking the bulk water. Popular scalar fields such as molecular electrostatic potential and molecular electron density have been used as useful tools to probe the changes in the hydrogen bonding passing from ground to excited states in the gas as well as solvent phase.