Red-Light-Induced, Copper-Catalyzed Atom Transfer\nRadical Polymerization

Abstract

Despite\nadvances in photochemical atom transfer radical polymerization\n(photoATRP), these systems often rely on the use of UV light for the\nactivation/generation of the copper-based catalytic species. To circumvent\nthe problems associated with the UV light, we developed a dual photoredox\ncatalytic system to mediate photoinduced ATRP under red-light irradiation.\nThe catalytic system is comprised of a Cu catalyst to control the\npolymerization via ATRP equilibrium and a photocatalyst, such as zinc­(II)\ntetraphenylporphine or zinc­(II) phthalocyanine, to generate the activator\nCu^I species under red-light irradiation. In addition, this\nsystem showed oxygen tolerance due to the consumption of oxygen in\nthe photoredox reactions, yielding well-controlled polymerizations\nwithout the need for deoxygenation processes.