One-electron Ni(II)/(I) redox couple: potential role in hydrogen activation and production

The three-coordinate Ni(I) complex Ni(Cl)(P-2), where P-2 is the diphosphine (iPr)DPDBFphos, reacts with the acids HCl center dot(dioxane) and 2,6-lutidinium chloride to generate Ni(H)(Cl)(P-2) and Ni(Cl) (2)(P-2). Photolysis of the Ni(H)(X)(P-2) (for X = Cl, Br) results in formation of H-2 and the Ni(I) halide. This reaction also proceeds in reverse when heated.