Hexaarylbisimidazoles and ketocyanine dyes as effective electron transfer photoinitiating systems

Four different hexaarylbisimidazoles (HABIs) and 5 ketocyanine dyes (JAWs) have been synthetized. Chemical structures and basic spectroscopic properties of JAWs obtained have been characterized. Free energy changes (DeltaG(el)) of the process of electron transfer between HABIs and JAWs tested have been experimentally determined for 20 pairs of HABI + JAW. The dependence of the rate of 1,1,1-tri(acryloxymethyl)propane photopolymerization, initiated with HABI + JAW systems in the presence of mercaptobenzoxazole, on the DeltaG(el) value and on the radiation wavelength (488 nm and 355 nm or 365 nm, Fig. 1) has been determined. It was found that chemical structures of HABI and JAW do not affect considerably the rate of polymerization.