Flash photolysis of the water-sol. title compound, p-C6H5C(O)C6H4O(CH2)3N+(CH3)3-O3SCH3 (I) leads to the excited n-p triplet state, which abstrs. an electron from a tertiary amine via an excited triplet exciplex. The I radical anion then induces H atom abstraction to give a ketyl radical and an alkylamino radical. This mechanism is confirmed through a detailed study of the effects of O, pH, and the ionization potential of various amines used in the study.

Key words: REACTION MECHANISM, DIPHENYLMETHANONE P, WATER SOLUBILITY, EXCITED STATE, FREE RADICAL, METHANESULFONIC ACID, PHOTOSENSITIZER, METHONIUM COMPOUNDS, FLASH PHOTOLYSIS