The near ultraviolet spectra of benzene in inert solid solutions

Abstract

The near ultraviolet absorption and phosphorescence spectra of benzene in solid solutions in argon, krypton, xenon, nitrogen, carbon dioxide, and methane have been recorded. The spectra exhibit multiplet structure in most solid solution systems but consist of sharp single lines in solid nitrogen as solvent. Experiments were carried out at liquid helium (4.2°K) and liquid hydrogen (20.4°K) temperatures in order to determine the physical origin of the multiplets. It was concluded that the multiplet components arise from solute molecules having sharply defined but different environments in the host lattices. The possibility of the coexistence of two crystalline phases, cubic and hexagonal, of the host solid in the presence of the benzene impurity is discussed as a possible cause for the observations.