Dppm stabilized nickelacyclic carboxylates as building blocks of oligonuclear nickel complexes

The reaction of 1,1-bis(diphenylphosphino)methane (dppm) and [py2Ni(C2H4COO)] with trace amounts of water leads to the formation of the novel pentanuclear organonickel compound [(μ2-dppm)2{Ni(C2H4COO)}4 * Ni(OH)2] (1) bearing nickel centres in square planar as well as in octahedral coordination sphere. In presence of NiBr2, the related trinuclear complex [(μ2-dppm){Ni(C2H4COO)}2 * NiOH(H2O)(py)2]+ Br− (2) was isolated and characterized by elemental analysis, IR measurements and X-ray single crystal structural analysis. These compounds are rare examples of organonickel compounds with μ3-hydroxide ligands and to best of our knowledge the first nickelacyclic carboxylates stabilized by such simple inorganic compounds as ligands.