Triplet—Singlet Luminescence from Methylated Benzenes in the Crystalline State and in Rigid Glass Solutions

Publisher Website
Google Scholar
Abstract
In continuation of earlier studies, triplet—singlet emission of the following methylated benzenes is reported in their solid phases: mesitylene, durene, hexamethylbenzene. The spectra were obtained in rigid EPA solutions at 77°K, and in the crystalline state at 77° and at 4°K. Two different spectra were found for mesitylene and durene crystals, one at shorter wavelengths representing the genuine triplet—singlet emission of the substance, and the other at longer wavelengths belonging to the lowest phosphorescence of an oxidation product. Hexamethylbenzene crystal apparently exhibits only one spectrum at any temperature. No solution spectrum was obtained for it because of its poor solubility. For an interpretation of the observations, various processes which take place in these crystals upon light illumination are discussed.
Keywords