Polymerization method of norbornene and norbornene derivatives and polymerized composition thereof

A process for the photochemically induced polymerization of a monomer or at least two different monomers in the presence of a metal compound as catalyst, the monomer(s) being selected from norbornene and norbornene derivatives, which is characterized in comprising: the photochemically ring opening displacement polymerization reaction being carried out in the presence of 0.001 to 20 mole fraction (based on the amount of monomer(s)) of at least a heat-stable ruthenium or osmium compound of the formula (II), in which ruthenium or osmium; L1 is a photolabile ligand selected from the group consisting of nitrogen; monocyclic, polycyclic and fused arenes having 6 to 24 C-atoms which are unsubstituted or substituted by substituents, from the group consisting of OH, C1-C4-alkyl, C1-C4-alkoxy, C6-C12-aryl or halogen; C1-C22- aliphatic, cycloaliphatic, aryl or aroaliphaticnitrile, which is substituted by C1-C4-alkoxy or halogen.