Synthesis and characterization of a ruthenium-containing copolymer for use as a photoredox catalyst

Herein, we report the synthesis and characterization of a PMMA-functionalized copolymer bearing a photoredox-active Ru(ii) polypyridyl moiety and pyrene pendant groups. The integration of both the Ru(ii) polypyridyl and pyrene pendant groups enabled a photoredox-catalyzed reaction through energy transfer. The effective energy transfer process was evidenced through the polymer's ability to serve as a reductive catalyst toward the formation of carbon-carbon bonds using C-H arylation, wherein product yields ranging from 37-71% were observed. The copolymer design also exhibited solvent-dependent size and catalyst activity, wherein the use of DMSO promoted aggregation of the pyrene groups that led to higher product yield, likely owing to achieving a more confined structure that enables more efficient energy transfer between Ru(ii) and pyrene pendant units. We present a [Ru(bpy)2(dmbpy)]2+- and pyrene-based photocatalytic PMMA that enables photoredox-energy transfer to achieve the C-H arylation of electron deficient aryl bromides.