New Approach to Organometallic Polymers

Conjugated organometallic polymers are materials with potentially desirable electronic and mechanical properties, but synthesizing such polymers generally requires factors such as inert atmospheres and anhydrous conditions, which make the process difficult. Christopher W. Bielawski and coworkers at the University of Texas, Austin, have now developed a synthetic approach to conjugated organometallic polymers that overcomes these restraints (J. Am. Chem. Soc. 2005, 127, 12496). The technique uses N-heterocyclic carbenes to integrate metals into conjugated arene-based organic polymers. Polymerization and metal incorporation are carried out by mild heating of bis(imidazolium) bromides with a palladium or platinum complex in dimethyl sulfoxide and subsequent precipitation of products. In the product structure shown, large circles represent arenes, X is a halogen, M is palladium or platinum, and R is benzyl or butyl. Bielawski and coworkers are currently studying the electronic and physical characteristics of the polymers, noting that they "should open new opportunities in polymer synthesis, conductive polymers, nonlinear optics, and electronic devices."