Charge Transfer Complexes (CTCs) with Pyridinium Salts: Toward Efficient Dual Photochemical/Thermal Initiators and 3D Printing Applications.

In both organic and polymer synthesis, photochemistry of charge transfer complexes (CTCs) is considered as a powerful approach to expand visible-light-driven radical chemistry reaction. One reports herein on the development of a class of useful CTCs using pyridinium salts as efficient electron acceptors (combined with N, N, 3,5-tetramethylaniline, TMA) to achieve a multiwavelength (375-560 nm) metal-free LED photopolymerization process under mild conditions (open to air, without monomer purification and inhibitor removal). The UV-vis absorption spectra and molecular modeling simultaneously verify its potential blue-green absorbing wavelength range.