Temperature effects in solvatochromic shifts

Abstract

The shifts of absorption bands of a few polar molecules have been measured as a function of temperature in several non-polar and polar solvents. These shifts can be described adequately with the Onsager model of dielectrics provided both solute–solvent dipole–dipole interactions and dipole–induced-dipole interactions are included.

Thermochromic shifts can be used to obtain excited state dipole moments in a way similar to constant temperature solvatochromic shifts; the two methods appear to be in general agreement.