Metathesis ring opening polymerization of 5,6-dimethylenebicyclo[2.2.1]hept-2-ene

5,6-Dimethylenebicyclo[2.2.1]hept-2-ene (I) polymerizes in the presence of the two-component initiators WCl 6 /(CH 3 ) 4 Sn and MoCl 5 /(CH 3 ) 4 Sn. The product polymers were insoluble in all of many solvents investigated and are presumably cross-linked. IR and NMR data showed that the material consisted predominantly of poly(1,4-[2,3-dimethylenecyclopentylene]vinylene). A possible alternative route to this polymer via thermal dehydrochlorination of poly(1,4-[2,3-bis(chloromethyl)cyclopentylene]vinylene) was also examined