Spectral methods to estimate the strength of intermolecular interactions in liquids

Abstract

The spectrally active molecules in very small quantities are used as probes which measure the local field in liquids by the modifications induced in their electronic spectra. The energy levels of the molecules participating in the electronic transitions are stabilized in solvation process. When the solvation energy differs in the two states of the electronic transition, the spectral shifts of the electronic bands yield information about the strength of the solute-solvent interactions. The multi-linear dependences between the spectral shifts of the electronic bands and the solvent parameters are used to compute the contributions of each type of intermolecular interactions at the solvation energy. Both non-polar and polar spectrally active molecules are used in this study to evidence the intermolecular interactions in various solvents.