Red-Light-Induced Cationic Photopolymerization: Perylene Derivatives as Efficient Photoinitiators

Nine different perylene derivatives are prepared and their ability to initiate, when combined with an iodonium salt (and optionally N‐vinylcarbazole), a ring‐opening cationic photopolymerization of epoxides under very soft halogen lamp irradiation is investigated. One of them is particularly efficient under a red laser diode exposure at 635 nm and belongs now to the very few systems available at this wavelength. The photochemical mechanisms are studied by steady‐state photolysis, electron spin resonance spin trapping, fluorescence, cyclic voltammetry, and laser flash photolysis techniques. A newly synthesized perylene derivative in combination with an iodonium salt and N‐vinylcarbazole can efficiently initiate the free radical promoted cationic photopolymerization of EPOX under a red laser diode (635 nm). Per1 is one of the rare compounds described so far that can operate in red light.