Metathesis polymerization behavior of 2‐cyanobicyclo[2.2.1]hept‐5‐ene

Abstract This paper describes the ring‐opening methathesis polymerization of homopolymers and copolymers of exo‐ and endo‐2‐cyanobicyclo[2.2.1]hept‐5‐ene (norbornenenitrile) in solution. Polymerization kinetics were followed via 1H NMR spectroscopy in real time while the final polymer microstructure was determined via 13C NMR. While pure endo monomer does not polymerize readily, it copolymerizes with exo monomer, rapidly and to high conversions. The structure of the copolymer appears to be quite similar to that of exo homopolymer. We conclude that exo monomer adds directly to either exo or endo, while endo‐endo addition is sterically hindered.