Sunlight induced atom transfer radical polymerization by using dimanganese decacarbonyl

Abstract

A new photoredox catalyst system for atom transfer radical polymerization is developed on the basis of visible light photocatalysis using dimanganese decacarbonyl (Mn₂(CO)₁₀) that initiates and controls the polymerization at ambient temperature. The polymerization was performed by a Mn₂(CO)₁₀–alkyl halide system with visible- or sunlight in the presence of parts per million (ppm) copper catalysts. The photogenerated ˙Mn(CO)₅ radicals are not only able to abstract halogen atoms from alkyl halides to generate carbon centered radicals but also reduce the Cu^IIBr₂ to Cu^IBr directly, which was used as an activator in the Atom Transfer Radical Polymerization (ATRP) of vinyl monomers such as methyl methacrylate, methyl acrylate and styrene. The method was also used to synthesize graft copolymers from commercially available poly(vinyl chloride) without additional modification.