PHOTOCHEMISTRY AND PHOTOINITIATION ACTIVITY OF NOVEL 1-SUBSTITUTED WATER-SOLUBLE DERIVATIVES OF 4-(2-HYDROXY-3-N,N,N-TRIMETHYL-AMMONIUMPROPOXY)THIOXANTHONE CHLORIDE SALT

The absorption, luminescence and photoreduction properties of four novel water soluble I-substituted thioxanthones is reported in this paper. The first singlet excited state was studied by fluorescence including fluorescence quantum yields, pH dependence and Stern-Volmer quenching by a tertiary amine. The lower triplet excited state has been characterized by examining the phosphorescence properties at 77 K and photoreduction by tertiary amines. The latter study includes the influence of amine concentration and the ionization potential of the amine on the photoreduction quantum yields. The photoinitiation effectiveness was studied by photocalorimetry for acrylamide photopolymerization in water solution irradiating at 365 nm in the presence of air.