Four monomers based on 4-ethynylbenzoic acid have been synthesized, one of those featuring an activated ester. With the metathesis catalytic system WCI6/Ph4Sn, 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 with pentafluorophenyl 4-ethynylbenzoate as reactive unit was conducted. Polymer analogous reactions of the reactive polymers and copolymers with amines have been investigated and it was found that poly(pentafluorophenyl 4-ethynylbenzoate) featured a significant reactivity, such that reactions proceeded quantitatively even with aromatic amines. Moreover the UV-Vis spectra of the activated ester based polymer before and after conversion with aliphatic amines showed a change, indicating an effect on the conjugated backbone of the polymers. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 211-224, 2011