Vinylic polymerization of norbornene by Pd(II)-catalysis in the presence of ethylene

Pd(II) catalysts with nitrilo ligands and BF4− counter ions give the best results in vinylic polymerization of norbornene. Absolute molecular weight determination of polynorbornene (PN) by means of light scattering and the three-dimensional shape of PN were also investigated. By correlation of molecular weights Mw with intrinsic viscosity (Staudinger-index) [η], yield a close to 0.5 exponent for the Mark-Houwink equation with solvents chlorobenzene and cyclohexane at 25°C expected for polymer molecules with confined conformation. The vinylic polymerization of norbornene with [(CH3CN)4Pd][BF4]2 (I) in nitromethane in the presence of ethylene results in PN with narrow molecular weight distrib…