Nickel(II)-catalyzed living polymerization of diazoacetates toward polycarbene homopolymer and polythiophene-block-polycarbene copolymers

Abstract

Diazoacetate polymerization has attracted considerable research attention because it is an effective approach for fabricating carbon–carbon (C–C) main chain polymers. However, diazoacetate polymerization based on inexpensive catalysts has been a long-standing challenge. Herein, we report a Ni(II) catalyst that can promote the living polymerization of various diazoacetates, yielding well-defined C–C main chain polymers, polycarbenes, with a predictable molecular weight (Mn) and low dispersity (Mw/Mn). Moreover, the Ni(II)-catalyzed sequential living polymerization of thiophene and diazoacetate monomers affords interesting π-conjugated poly(3-hexylthiophene)-block-polycarbene copolymers in high yields with a controlled Mn, variable compositions, and low Mw/Mn, although the structure and polymerization mechanism of the two monomers differ. Using this strategy, amphiphilic block copolymers comprising hydrophobic poly(3-hexylthiophene) and hydrophilic polycarbene blocks are facilely prepared, which were self-assembled into well-defined supramolecular architectures with tunable photoluminescence.