Crystal structures of (1,4,7,10-tetra-aza-cyclo-dodecane-κ(4) N)bis-(tri-cyano-methanido-κN)nickel and (1,4,7,10-tetra-aza-cyclo-dodecane-κ(4) N)(tri-cyano-methanido-κN)copper tri-cyano-methanide

Abstract

The structures of two mononuclear transition-metal complexes with tri-cyano-methanide (tcm(-)) and 1,4,7,10-tetra-aza-cyclo-dodecane (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 octa-hedral geometry. The tcm(-) ligands are mutually cis. The Cu(II) atom in (II) displays a distorted tetra-gonal-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.

Keywords: 1,4,7,10-tetra­aza­cyclo­dodeca­ne; copper complex; crystal structures; nickel complex; tri­cyano­methanide.