Patent ID: 7365139

Claim:
A polymerisation catalyst comprising (1) a metal complex being a metal M ligated by a monodentate, bidentate, tridentate or tetradentate ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom substituted by a five-membered heterocyclic substituent joined to the nitrogen atom by a carbon atom, M being selected from Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II], Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II], Ta[III], Ta[IV], Rh[II], Rh[III], Y[II], Y[III], Sc[II], Sc[III], Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III], Hf[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV] or Nb[V], and (2) an activator compound.