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

摘要

Diazoacetate polymerizations using inexpensive catalysts has been a long-standing challenge to achieve. Here the authors report a Ni(II) catalyst that can promote living polymerization of various diazoacetates, yielding well-defined carbon-carbon main chain polymers, polycarbenes. @@@ 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 (M-n) and low dispersity (M-w/M-n). Moreover, the Ni(II)-catalyzed sequential living polymerization of thiophene and diazoacetate monomers affords interesting pi-conjugated poly(3-hexylthiophene)-block-polycarbene copolymers in high yields with a controlled M-n, variable compositions, and low M-w/M-n, 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.

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