Direct Observation of β‑Chloride Elimination from an Isolable β‑Chloroalkyl Complex of Square-Planar Nickel

Reported here are the isolation, structural characterization, and decomposition kinetics of the four-coordinate pentachloroethyl nickel complex, NiCl­(CCl2CCl3)­(CNArMes2)2 (ArMes2 = 2,6-(2,4,6-Me3C6H2)2C6H3). This complex is a unique example of a kinetically persistent β-chloroalkyl in a system relevant to coordination–insertion polymerization of polar olefins. Kinetic analysis of NiCl­(CCl2CCl3)­(CNArMes2)2 decomposition indicates that β-chloride (β-Cl) elimination proceeds by a unimolecular mechanism that does not require initial dissociation of a CNArMes2 ligand. The results suggest that a direct β-Cl elimination pathway is available to four-coordinate, Group 10 metal vinyl chloride polymerization systems.