Interaction of electron acceptors with bases part 14: Solvent effect on the optical transition of organic charge‐transfer complexes

Abstract

AbstractThe energies of the optical transitions for “non‐ionic” organic charge‐transfer complexes in a range of solvents have been measured. The solvents may be divided into those which can achieve an effective solvent cage and those which cannot. For the former class the Franck‐Condon principle applied to solvent re‐orientation results in a hypsochromic shift with increasing ionising ability of the solvent. For the latter class, which may be described as inert solvents, where there is no solvent cage, the dispersion forces and polarisation of the solvent cause bathochromic shifts as the ionising ability of the solvent increases.