P-Phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene and m-phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene homopolymers (3 and 4) have been prepd. by the ring-opening metathesis polymn. (ROMP) of strained cyclophanedienes, initiated by the second generation Grubbs catalyst. The as-formed polymers have a backbone of alternating cis- and trans-vinylene linkages due to the opening of only one vinylene of the cyclophanediene. Irradn. with UV light results in an isomerization to an all-trans-vinylene microstructure for all polymers. The polymer chain ends remain active after complete consumption of the cyclophanediene, and block copolymers can be prepd. by addn. of further cyclophanediene. The optical and electronic properties of the homopolymers and block copolymers are reported. [on SciFinder (R)] ; CAN 152:75531 35-7 Chemistry of Synthetic High Polymers Organic Materials Innovation, Centre School of Chemistry,The University of Manchester,Manchester,UK. Journal 1201800-67-0P Role: PEP (Physical, engineering or chemical process), PRP (Properties), RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), PROC (Process), RACT (Reactant or reagent) (homopolymers and block copolymers of p-phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene and m-phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene by ring-opening metathesis polymn.); 1201800-69-2P; 1201800-70-5P Role: PEP (Physical, engineering or chemical process), PRP (Properties), SPN (Synthetic preparation), PREP (Preparation), PROC (Process) (homopolymers and block copolymers of p-phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene and m-phenylenevinylene-2,5-diethylhexyloxy-p-phenylenevinylene by ring-opening metathesis polymn.)