Synthesis and characterization of novel organonickel and organocobalt complexes via carbon–chlorine bond activation

Abstract The ortho -metalated nickel(II) complexes 3 , 4 , 7 and 8 were obtained by the reaction of ortho -halogeno aromatic bis-Schiff bases 1 , 2 , 5 and 6 with the stoichiometric amount of Ni(PMe 3 ) 4 . The combination of 5 and 6 with two equivalents of Ni(PMe 3 ) 4 resulted in oxidative addition of the double C–Cl bonds to afford ortho -bis-chelated nickel(II) complexes 9 and 10 . The reaction of 6 with Co(PMe 3 ) 4 gave rise to di-nuclear ortho -metalated cobalt(II) complex 12 through C–Cl bond activation while the reaction of 5 with Co(PMe 3 ) 4 delivered bis-chelated cobalt(I) complex 11 through both C–Cl and C–H bond activation. The structures of complexes 3 , 4 , 8 , 9 , 11 and 12 were determined by X-ray single crystal diffraction. The catalytic activity of bis-chelated cobalt(I) complex 11 as catalyst for C,C-coupling reaction was explored.