| abstract |
The invention concerns a catalytic composition and a process for the dimerisation, codimerisation or oligomerisation of olefins, said composition comprising a mixture of at least one bivalent nickel complex which contains two tertiary phosphine molecules, at least one nickel complex which contains neither water nor phosphine, and at least one alkylaluminium halide. The mixture is particularly for use in ionic type non aqueous liquid compositions, such as those formed by quaternary ammonium halides and/or quaternary phosphonium halides with aluminium halides and/or alkylaluminium halides. |