Excited state interactions of thiopyrylium salts

Abstract

The photophysics and photochemistry of thiopyrylium salts have been investigated by UV–VIS absorption spectroscopy and nanosecond laser absorption spectroscopy. The effect of substituents of the heterocycle on the photophysical properties was analysed. Dissociation of peroxidic compounds photosensitized by these salts was studied. The interaction with monomers and many other additives has also been investigated. A mechanism is proposed for the initiation of acrylic photopolymerization reactions.