Synthesis, characterization and crystal structure of a novel tri-nuclear ni(II) cluster bearing tetra-μ-phenoxo and Di-μ-acetato bridges

A novel trinuclear nickel (II) cluster {[NiL(EtOH)](2)(OAc)(2)Ni}. 2EtOH has been synthsized and characterized by elemental analyses, TG-DTA, IR and H-1-NMR etc. The X-ray crystallography of the cluster indicates that the ligand moieties of the cluster provide the N2O2 donors set to Ni2, while one oxygen atom of the mu-acetato and one oxygen atom of the ethanol molecule coordinate to Ni2, consequently forming a slightly distorted octahedral geometry. The double mu-acetato bridges adopt the more familiar mu O-C-O form which connect the Ni2-Ni1 and Ni1-Ni2#, respectively, so quadruple mu-phenoxo oxygens from 2 ligand moieties and double oxygen atoms from mu-acetato constitute another octahedral geometry. It is worthy noting that the distance from the Ni1 to Ni2 (3.089 angstrom) is significantly longer than other coordination bond, shows a weaker interaction. In addition, the HOMO and LUMO levels of the cluster were deduced.