Vinylic polymerization of bicyclo[2.2.1]hept-2-ene by Co(II)-catalysis

The vinylic polymerization of bicyclo[2.2.1]hept-2-ene (norbornene) with Co(II) compounds, such as Co(II)stearate, substituted bis(1,3-diketo)cobalt(II), Co(dppe)Cl-2, and the metallocene [eta(5)(C5Me5)Co-eta(2)-Cl](2), in chlorobenzene activated with methylaluminoxane (MAO) is reported. MAO* synthesized by the hydrolysis of trimethylaluminium in chlorobenzene instead of toluene increases the catalytical activity strongly, and a turn over of 2.7 tons of poly(2,3-bicyclo[2.2.1]hept-2-ene) per mol cobalt per hour was achieved. The polymers obtained are amorphous (WAXS). They show weight-average molecular weights up to (M) over bar(w) = 1.5 . 10(6) and are soluble in chlorobenzene, 1,2-dichlorobenzene, cyclohexane, and decahydronaphthalene.