Synthesis and Reactivity of Metallocarbene-Containing Polymers

Abstract

Metallopolymers are an emerging class of materials with potential utility as semiconductors, catalysts, optical device components, and stimuli responsive networks. While polymer frameworks have been decorated with an array of organometallic moieties, the incorporation of metallocarbenes has been largely overlooked. Here, we report ring-opening metathesis polymerization as a strategy for the synthesis of Fischer carbenecontaining polymers. High degrees of polymerization were observed (>800 repeats), and the isolated materials exhibited exceptional solubility and thermal stability. The tungsten carbene subunits were readily incorporated into block copolymers and could be modified through subsequent transformations. Moreover, the metallocarbene polymers were found to release carbon monoxide upon exposure to light or oxygen, which is unusual for tungsten carbene complexes. These metallocarbenecontaining polymers could represent new platforms for the development of functional materials.

Metallopolymers in minutes via organocatalysis at room temperature

“…8 The best main-chain metallopolymer synthetic strategies arguably continue to be the ring-opening polymerization (ROP) of strained metallocenophanes, as developed by Manners, because of their good speed and control. [9][10][11][12] Syntheses of diverse metallopolymers with pendant metal groups tethered to the polymer backbone have been accomplished by many strategies, including polymerization of vinyl, acrylate, or epoxy monomers bound to metal complexes, [13][14][15][16][17][18][19][20][21] ring-opening metathesis polymerization (ROMP) of norbornyl-substituted metal complexes, 22,23 and post-polymerization metalation of polymers with metal binding sites. 14,24 Despite these successes, metallopolymer synthesis remains notoriously difficult, and new synthetic strategies are needed that are fast, controlled, and compatible with existing monomer classes.…”