Crystal structures of (1,4,7,10-tetraazacyclododecane-κ4N)bis(tricyanomethanido-κN)nickel and (1,4,7,10-tetraazacyclododecane-κ4N)(tricyanomethanido-κN)copper tricyanomethanide

Abstract

The structures of two mononuclear transition-metal complexes with tricyanomethanide (tcm−) and 1,4,7,10-tetraazacyclododecane (cyclen) ligands, [Ni(C4N3)2(C8H20N4)], (I), and [Cu(C4N3)(C8H20N4)](C4N3), (II), are reported. In the neutral complex (I), the nickel cation is coordinated by one cyclen ligand and two monodentate N-bound tcm−anions in a distorted octahedral geometry. The tcm−ligands are mutuallycis. The CuIIatom in (II) displays a distorted tetragonal–pyramidal geometry, with the four N-donor atoms of the cyclen ligand in the equatorial plane, and one tcm−anion bound through a single N atom in an axial site, forming a monocation. The second tcm−molecule acts as a counter-ion not directly coordinating to the copper cation. In both (I) and (II), extensive series of N—H...N and C—H...N hydrogen bonds generate three-dimensional network structures.