A facile one-pot-synthesis of polyphenylacetylene with Group VI metal carbonyls as catalysts

Abstract

It is quite well-known that polymerisation of phenylacetylene can be effected catalytically by using Group VI metal carbonyls (or metal carbenes) under photolytic conditions or by employing derivatives of these metal carbonyls in the form of arene complexes under thermal conditions. This study shows that neither photolytic conditions nor a preformed arene complex are necessary to obtain polyphenylacetylene from phenylacetylene. This technique involves generation of the appropriate arene metal complex in situ by refluxing a slurry of the metal carbonyl and the arene followed by addition of the monomer. The polymerisation is carried out in refluxing conditions and the product is isolated in high yield and purity by addition of excess methanol. Various combinations of arenes and Group VI metal carbonyls were tried with and without cocatalyst such as NaOH. The relative efficiency of the various catalyst precursors employed is discussed in this paper. Also discussed are the conductivity and optical properties of the polymers obtained by this technique.