Accessing Ni(0) to Ni(IV) via nickel–carbon–phosphorus bond reorganization

Abstract

Two-electron oxidation of a Ni^IIPh(PCP) pincer complex initiates phosphine ligand insertion, generating an η⁶-arylphosphonium moiety coordinated to Ni^II. The reaction is fully reversible under reducing conditions. X-ray crystallography, NMR/EPR spectroscopy, electrochemistry, and DFT calculations support the proposed Ni–C–P bond reorganization mechanisms, which access oxidation states from Ni⁰ to Ni^IV.