Effects of partial charge-transfer solute -- solvent interactions in absorption spectra of aromatic hydrocarbons in aqueous and alcoholic solutions

TL;DR

This paper introduces a method to study charge-transfer interactions in aromatic hydrocarbons dissolved in water and alcohols by comparing spectral shifts, revealing interactions in higher electronic states.

Contribution

A new spectroscopic method is proposed to analyze charge-transfer interactions in molecules that do not alter their dipole moment upon excitation.

Findings

Charge transfer interactions are present in higher electronic states of aromatic hydrocarbons.

The method is applicable to molecules in inert solvents without changing their dipole moments.

Charge transfer effects vary with solvent type and molecular state.

Abstract

A method for study of charge-transfer interactions between solute molecules and solvent based on the comparison of the ratios of spectral shifts of different electronic transitions in solute molecules in chemically inert solvent is proposed. The method is applicable to molecules that do not change their dipole moment on excitation. As an example, a presence of charge transfer interactions in higher electronic states of aromatic hydrocarbons (benzene, phenanthrene, and naphthalene) dissolved in water and alcohols was demonstrated.