Dialkoxy- and dialkyl-substituted phenylene benzothiadiazole paracyclophane-1,9-diene monomers undergo living ring-opening metathesis polymerization using ruthenium carbene initiators (G3) to give regularly alternating cis,trans-poly(p-phenylenevinylene) benzothiadiazole copolymers. These polymers can be readily isomerized in dilute solution using visible light to the all-trans polymers. The influence of the polymer microstructure and the phenylene substituents on the optical and electrochemical properties of these polymers is examined.