Synthesis and structure of a Ni(II)-Cu(II)-Ni(II) trinuclear complex with a new macrocyclic complex ligand

A trinuclear complex, [Cu(NiL)(2)(NCS)(2)], was prepared by the reaction of a new macrocyclic oxamido complex ligand NiL, Cu(ClO)(2)center dot 6H(2)O and KNCS. L denotes the doubly deprotonated form of dimethyl 5,6,7,8,15,16-hexahydro-15-methyl-6,7-dioxodibenzo[1,4,8,11] tetraazacyclotetradecine-13,18-dicarboxylate. Excess Cu(ClO)(2)center dot 6H(2)O is necessary for the formation of the title compound. The structure of the title complex was further characterized by X-ray single-crystal analysis. Cu(II) and each Ni(II) is bridged by the oxamido group from the corresponding macrocyclic ligand. The coordination geometry around each Ni( II) ion is slightly distorted square planar with N-4 donor set, and the Cu( II) ion has a distorted octahedral coordination geometry of O4N2 donor set. pi center dot center dot center dot pi interactions and C-H center dot center dot center dot O hydrogen bonds link the molecules to form two-dimensional supramolecular layers.