Investigation of pyrene vs Anthracene-based oxime esters: Role of the excited states on their polymerization initiating abilities

In this work, two series of oxime esters (OXE) based on Pyrene and Anthracene chromophores were synthesized tested as Type ? photoinitiators for the Free Radical Photopolymerization (FRP) under visible irradiation at 405 nm using light-emitting diodes (LED) source. Interestingly, only differ by nature substituents connected to ester functional group. As a result modification, reactivity different compounds depends rate decomposition from their excited states well generated radicals. Remarkably, 18 Pyrene-based OXEs (Py-OXE) 17 Anthracene-based (An-OXE) never prior work. selected benchmark structures reacting mainly first singlet (S1) triplet (T1) states, respectively. This will allow shed some light responsible cleavage OXEs. Therefore, originality study relies in difference initiation ability between these families. fact, results showed that Py-OXEs (0.5 % w) are most efficient systems compared An-OXEs, so higher final conversions rates polymerization could be obtained with Py-OXEs. Influence OXE structure (both leaving groups) is discussed basis characterization techniques such as: UV–visible absorption spectroscopy, photolysis experiments, real-time Fourier transform infrared spectroscopy (RT-FTIR), stationary fluorescence time-resolved fluorescence. global mechanism finally provided complementary data. Oxime derivatives also air generation 3D patterns (by Direct Laser Write DLW) diode laser nm.