Visible-light-induced controlled radical polymerization of methacrylates mediated by a pillared-layer metal-organic framework

A novel visible light responsive metal-organic framework (MOF) with a pillared-layer structure has been constructed from photoactive anthracene derived bipyridine. The as-prepared MOF was studied by single crystal X-ray diffraction, steady-state fluorescence, and electron paramagnetic resonance and so on. Studies reveal the visible light induced free radical formation of the bipyridine pillars in the MOF structure. Consequently, the promising photocatalytic reaction of atom transfer radical polymerization for methacrylate monomers was performed upon the utilization of the MOF material as a photosensitizer to reduce the copper catalyst via electron transfer. It has been demonstrated that the reaction shows characteristics of controlled radical polymerization and the prepared polymers show narrow molecular weight distributions and high retention of chain-end activities. Moreover, the photopolymerization can be easily manipulated by light switching.