A visible-light responsive zirconium metal-organic framework for living photopolymerization of methacrylates

Visible-light-induced controlled/living radical polymerization (C/LRP) mediated by photoactive zirconium metal-organic framework (Zr-MOF) NNU-28 has been explored. The photopolymerization is carried out at room temperature under 520 nm monochromatic light. The results show that anthracene-based NNU-28 is a promising heterogeneous sensitizer to initiate the photopolymerization where the robust Zr-MOF exhibits enhanced visible light absorption and characteristics of photoinduced charge generation. The NNU-28 mediated CRP relies on the in situ photoreduction of a Cu(II) complex deactivator to Cu(I) complex activator through an electron transfer process. The photopolymerization of methacrylates shows typical characteristics of controlled radical polymerization, where the as-prepared polymers have controlled molecular weights, narrow molecular weight distribution and high retention of chain-end groups. Besides, the NNU-28 mediated photopolymerization can be temporally and spatially controlled by light. The visible-light-induced polymerization investigated here suggests the promising application of photoactive MOFs for well-designed polymer synthesis.