Organopalladium-catalysed carbon-carbon bond-forming polymerization (Keck reaction) was used to synthesize a regiospecifically head-to-tail, asymmetric poly(1,4-phenylenevinylene) derivative, poly(2-n-dodecyloxy-1,4-phenylenevinylene), 3. Polymer 1 was soluble in common organic solvents, had a M-w of 980-24 000 depending on the conditions of polymerization, had an all-trans configuration to within limits of detection, and had a strong yellow fluorescence in the solid state (lambda(max) = 542 nm at 400 nm excitation). The choice of phosphine co-catalyst in the Heck coupling had a considerable effect on the degree of polymerization, with the hindered tri-o-tolylphosphine giving the best results.