Photochemical reactions of 4,4′-di-t-butylbenzophenone in isopropyl alcohol

Abstract

The photoreduction of 4,4′-di-t-butylbenzophenone in deaerated isopropyl alcohol was investigated by (a) monitoring absorption spectra following short intervals of irradiation, (b) successive determinations of absorption spectra throughout the dark period following irradiation, and (c) periodic recording of emission and excitation spectra during or after irradiation. The reactions taking place in the dark were examined separately from those during irradiation, and the second intermediate was allowed to react with sodium isopropoxide and sulphuric acid. Quantitative kinetic calculations were used to determine the orders of reaction for the individual steps and their rate constants. Extinction coefficients for the intermediates were likewise calculated, although their structures were not identified.