Michler's Ketone as an Interesting Scaffold for the Design of High-Performance Dyes in Photoinitiating Systems Upon Visible Light

International audienceFour new push-pull dyes derived from Michler's ketones are investigated. These dyes, based on a donor-π-acceptor (D-π-A) structure, exhibit a tunable character according to the electron- withdrawing ability of the acceptor used. The new proposed structures can be used in high-performance photoinitiating systems. Remarkably, two of them are characterized by an excellent reactivity to initiate the free-radical polymerization of acrylates, the ring-opening polymerization of epoxides, as well as the synthesis of interpenetrating polymer networks (IPNs) under exposure to a laser diode at 457 nm. The chemical mechanisms are investigated by steady-state photolysis, fl uorescence, and electron spin-resonance (ESR) experiment