Novel inorganic photoinitiators

摘要

Abstract: Thin films composed of the copolymer of glycidyl methacrylate-ethyl acrylate and a cobalt(III)-am(m)ine tetraphenylborate salt undergo crosslinking upon deep-UV irradiation and subsequent heating. The mechanism of this process involves the efficient photoredox decomposition of the cobalt salt with the release of multiequivalents of Lewis base. In a thermally activated step, the base then crosslinks the copolymer via nucleophilic attack on the epoxide rings. Near-UV irradiation of Pt(acac)$-2$/ (acac is the acetylacetonate anion) and Ru(Cp)$-2$/ (Cp is the cyclopentadienide anion) dissolved in ethyl $alpha@-cyanoacrylate initiates rapid anionic polymerization of the acrylate monomer. The active initiating species is acac in the former system, while the radical anion of the monomer is a likely candidate in the latter system. !10