Nuclear magnetic resonance evidence for a new microstructure in ethene-cyclopentene copolymers

We have analyzed the microstructure of a series of copolymers of ethene and cyclopentene prepared with a novel ferrocene-substituted catalyst using one- and two-dimensional 13 C- and 1 H-NMR methods. Up to 64% of the cyclopentene is incorporated as 1,3-cyclopentylene units, which has not been observed previously in copolymers. The subspectra were derived based on a triad model. The polymers appeared to be atactic with mainly cis-incorporated cyclopentylene units. No ring opening could be detected.