Square-planar mesitylenido(triphenylphosphane)nickel(II) complexes containing bidendate N,O-ligands: Changes in catalytic efficiency upon small alterations in the ligand backbone

Square planar arenido(triphenylphosphane)nickel(II) complexes containing a heterocyclic bidentate N,O-chelate ligand are catalysts for the copolymerisation of ethene and carbon monoxide. To examine the influence of the N,O-ligand on the catalytic activity new nickel(II) complexes with altered heterocyclic ring size in the corresponding N,O-ligands were synthesised and fully characterised. The crystal structures of all protonated N,O-ligands and the corresponding nickel complexes were determined. The catalytic activity of the new complexes in the copolymerisation reaction of ethene and carbon monoxide as well as in the polymerisation reaction of ethene were studied.