Abstract Four monomers based on 4-ethynylbenzoic acid have been synthesized, one of those featuring an activated ester. With the metathesis catalytic system WCl 6/Ph 4 Sn, these acetylenic monomers could successfully be polymerized yielding conjugated polymers with molecular weights of around 10,000 to 15,000 g/mol and molecular weight distributions M w/M n≤ 2.1. Also the copolymerization of phenylacetylene or methyl 4-ethynylbenzoate ...