Recent Progresses in Catalytic Polymerization of Alkynes

Twenty five years after the first report on catalytic polymerization of acetylene by Shirikawa, McDiarmid and Heeger [130], the Nobel prize has been awarded to these researchers for their contribution to the field of conducting polymers. Indeed, such polymers have promising applications such as low weight/high charge density batteries, polymer-modified electrodes, or capacitors to name only a few. Driven by these applications, different classes of polyacetylenes have been synthesized, starting from acetylene itself and from mono- or disubstituted acetylene derivatives. 

Most early transition metal complexes are considered to catalyze the polymerization through metal alkyl type intermediates. A typical example of such a catalyst, affording a high molecular weight polyacetylene [132], is Ti(O Bu)4/Et3Al [133]. 

Metals of Groups 5 and 6 (Nb, Ta, Mo and W) are known to form carbene complexes and are widely used in olefin metathesis [99, 100, 111]. Therefore, the polymerization of substituted alkynes with catalysts based on these metals is assumed 

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