Photoreduction of benzophenone by 2,4,6-trimethyl-1,3,5-trithiane in solution. Laser flash photolysis study

The role of 2,4,6-trimethyl-1,3,5-trithiane (TMT) in accelerating the initiation of polymerization induced by benzophenone (BP) was pursued by studying the primary photochemical reactions occurring between BP and TMT. Kinetic aspects of the quenching of the BP triplet by TMT were followed by laser flash photolysis. Triplet quenching rate constants and quantum yields for electron-transfer products were measured. In addition the mechanism of the photoreduction of BP by organic sulfides in acetonitrile and mixed acetonitrile/water solutions is discussed. Photoinitiated polymerizations with a model monomer were carried out with some of the sulfide co-initiators investigated, and the polymerization behavior was correlated with the kinetic results.