Recent advances on pyrene-based photoinitiators of polymerization

Photoinitiators of polymerization activable under low light intensity and in the visible range are actively researched by both the academic and industrial communities. To efficiently harvest light and initiate a polymerization process, polyaromatic structures are ideal candidates. In this field, pyrene can be cited as a relevant example. Over the years, a wide range of Type I and Type II photoinitiators have been developed, ranging from push-pull dyes to polyaromatic structures, ferrocenium, ketones, chromones or acridinediones. In this review, an overview of the different pyrene-based photoinitiators reported to date is presented. Especially, a structure-performance relationship will be established with benchmark photoinitiators, evidencing all the interests of this polyaromatic structure.