Reactivity Studies of Alkoxy-Substituted [2.2]Paracyclophane-1,9-dienes and Specific Coordination of the Monomer Repeating Unit during ROMP

The polymerization of alkoxy-substituted [2.2]paracyclophane-1,9-dienes via ring-opening metathesis polymerization (ROMP) to obtain soluble poly(p-phenylenevinylene)s is a versatile method due to its living nature which enables the possibility of block copolymerization and end group modification. However, detailed studies on the reactivity behavior and the polymerization process of alkoxy-substituted [2.2]paracyclophane-1,9-dienes have not been reported so far. Herein we present a detailed study on the varying tendencies of the four isomers of dimethoxy-(2-ethylhexyloxy)-[2.2]paracyclophane-1,9-diene to undergo ROMP. Therefore, we carried out polymerization combining all individual isomers with five different metathesis catalysts and collected initiation and propagation kinetics for various combinations. Furthermore, we revealed a specific coordination of the monomer repeating unit to the catalyst during the polymerization process and succeeded to polymerize not only the pseudogeminal isomers but also one of the pseudo-ortho isomers.