The synthesis of novel coumarin dyes and the study of their photoreaction properties

A series of novel coumarin derivatives linked with an N,N-dimethylaniline group via cyclopentanonediene on position 4 of the coumarin ring were synthesized and their two-photon absorbing (TPA) properties were investigated by femtosecond laser pulses. Compared to commercial coumarin dyes, novel compounds presented greatly enhanced TPA cross-sections around 100–400 GM. The photoreaction kinetic study showed that these dyes had fast electron transfer with commercial coinitiators, such as hexaarylbisimidazoles or iodonium salt. The dye/coinitiator combination can be used as highly efficient photoinitiating component in photopolymerization materials. In addition, a self-accelerating phenomenon was observed in the photoreaction process of the dye/iodonium salt.