Organic Photocatalysts Based on Dithieno[3,2-b:2′,3′-d]pyrrole for Photoinduced Metal-Free Atom Transfer Radical Polymerization

In this research, three organic photocatalysts, 4-(4H-dithieno[3,2-b:2 ',3 '-d]pyrrol-4-yl)-N,N-diphenylaniline, 4-(pyren-1-yl)-4H-dithieno[3,2-b:2 ',3 '-d]pyrrole and 4-(6b,10-dihydroperylen-3-yl)-4H-dithieno[3,2-b:2 ',3 '-d]pyrrole have been successfully synthesized through C-N coupling reactions. The chemical structures and the optical properties of the obtained organic photocatalysts have been characterized via(1)H NMR, C-13 NMR, elemental analysis, and UV-Vis spectroscopy. Next, these dithieno[3,2-b:2 ',3 '-d]pyrrole-based photocatalysts have been used for the polymerization of methyl methacrylate, 2-(dimethylamino)ethyl methacrylate and tert-butyl methacrylate monomers under 365 nm UV irradiation, resulting in (meth)acrylate polymers with controlled molecular weights and low polydispersity indexes.