A P−P Bond as a Redox Reservoir and an Active Reaction Site

The carbonylation of a nickel(II) anilido species 2 led to the formation of a dinickel(0)–CO complex (P 2 P‐PP 2 ){Ni(CO)} 2 3 with a P−P bond along with isocyanate generation. In this reaction, the central phosphide moiety of an anionic PPP ligand (PPP − = − P[2‐P i Pr 2 C 6 H 4 ] 2 ) acts as a single‐electron donor to form a P radical. Alternatively, 3 can be synthesized from the reduction of (PPP)NiCl ( 1 ) in the presence of CO; thus, the reaction proceeds by radical coupling of a . P−Ni 0 −CO species. The reverse reaction occurred to generate 1 when 3 was treated with AgCl. Since the P−P bond is light‐sensitive, its homolysis is possible and was explored by EPR spectroscopy and DFT analysis. Finally, various bond‐activation reactions of 3 occurred under visible‐light conditions, thus indicating that a P−P bond can act as an active reaction site.