Catalyst Deactivation by β‐Hydride Elimination: Olefin and Alkyne Insertion into Arenido–Nickel(II) Bonds

Abstract

AbstractSquare planar arenido‐(triphenylphosphane)nickel(II) complexes (3) containing a N,O‐chelate ligand are catalysts for the carbon monoxide/ethene copolymerisation reaction. Pathways for catalyst deactivation have been elucidated by investigating the reactions of such complexes with aliphatic unsaturated compounds like olefins and alkynes. We have shown that the double or triple bond, respectively, inserts into the nickel–carbon bond followed by β‐hydride elimination resulting in aryl‐substituted olefins and allenes, which have been identified by means of GC/MS. The remaining nickel forms a bis(N,O‐chelate ligand)nickel complex, the crystal structure of which has been determined. The nickel atom is coordinated in a square‐planar manner by two ligands. Additional coordination of two neighbouring complexes via their nitrile groups completes the coordination of the nickel to a distorted octahedron and forms a two‐dimensional metal‐organic framework (MOF).