The importance of ligand-induced backdonation in the stabilization of square planar d10 nickel π-complexes

A series of Ni π-complexes are explored using a combination of spectroscopic and computational methods to reveal an intriguing contribution to backbonding: metal-mediated ligand-to-ligand backdonation. Such ligand-induced backdonation is the dominant contribution for weakly π-acidic ligands such alkenes and allows for strong bonding even though the metal centre retains a formal d¹⁰ electronic configuration.