Manganese(iii) acetylacetonate initiated RAFT polymerizations: an alternative and versatile RAFT initiator

This work describes RAFT polymerization with manganese(III) acetylacetonate (Mn(acac)3) as an initiator. Initiated by Mn(acac)3, RAFT polymerization of poly(vinyl acetate) was achieved at 80 °C mediated by a xanthate, methyl 2-(ethoxycarbonothioylthio)propanoate. The polymerization manifested good control at a low concentration of Mn(acac)3 (approximately 157 ppm). The polymer was endowed with a high chain end fidelity (97%), which was comparable or even better in comparison with the azobisisobutyronitrile-initiated polymerization. The polymerization behavior was revealed to comply with the features of a typical RAFT process. Successful Mn(acac)3-initiated RAFT polymerization of methyl methacrylate at 25 °C with a typical dithioester as a RAFT agent, and styrene at 100 °C with a dithiocarbamate as a RAFT agent demonstrated that Mn(acac)3 was a versatile and superior RAFT initiator.