Both types of norbornene polymerisation with homogeneous catalysts have been studied. Palladium leads to vinyl-type polymerisation whereas rhodium and ruthenium lead to ring opening. In the case of palladium-catalysed polymerisation we have been able to trap the reactive intermediate PdCl2(C7H10)4 and have studied its behaviour during polymerisation. With ruthenium we have studied the effect of two ligands: cyclopentadiene which leads to a complete blocking of the reaction and triphenylphosphine the effect of which varies according to the ratio [Formula: see text]. Use of the three alcohols, ethanol, n-butanol, and tert-butanol, as solvent shows a variation in reaction rate on charge using RuCl3•3H2O but no change for [Formula: see text]. This indicates that the role of the alcohol is not limited to that of solvent but it must participate in the reaction especially during the formation of the reactive intermediate. [Journal translation]

The kinetic parameters for the polymerisation reaction of norbornene with RuCl3•3H2O, and RuCl2(PΦ3)3 using homogeneous catalysis have been determined (first-order with respect to two initiators, zero-order with respect to the monomer with RuCl3•3H2O, and variable order with RuCl2(PΦ3)3: Ea 6.2 kcal/mol for RuCl2(PΦ3)3 and 22.8 for RuCl3•3H2O) and leads us to propose different reaction mechanisms for the polymerisation starting from the two initiators, at least for the initiation step. With RuCl2(PΦ3)3 the slow step of the reaction is the metathesis whereas with RuCl3•3H2O the slow step is a ligand exchange at the initiator involving solvent (alcohol) by a dissociative or associative mechanism. This slow step is confirmed by a study of varying alcohol concentration and initiator aging. [Journal translation]