Synthesis, IR spectrum, thermal behaviour and crystal structure of a novel one-dimensional cyano-bridged zinc(II)/nickel(II) complex

Abstract

The cyano-bridged heteronuclear coordination polymer of zinc(II)/nickel(II) has been prepared by N-(2-hydroxyethyl)-ethylendiamine (hydet-en), alternatively named 2-(2-aminoethylamino)-ethanol and characterised by IR and thermal analysis. In the bimetallic complex, the decomposition of hydet-en ligands is seen to be endothermic whereas that of the cyano ligands is found to be exothermic. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The crystal structure of the zinc(II)-nickel(II) complex consists of a one-dimensional polymeric chain -Zn(hydet-en)(2)-NC-Ni(CN)(2)-CN-Zn(hydet-en)(2)- in which the zinc(II) and nickel(II) atoms are linked to each other by the cyano groups. The shift and splitting of the cyano stretching vibration is also evidence for the formation of cyano bridges. The nickel atom has a square-planar arrangement with four cyanide-carbon atoms where two cyano groups are in terminal position and two further ones in a bridging position. The Zinc atom has a distorted octahedral arrangement with two cyano and two hydet-en ligands. Both cyano and hydet-en ligands act as N-donor ligands and ethanol groups of the hydet-en ligand are not involved in the coordination. The NH, NH2 and OH groups of the hydet-en ligand are involved in intra- or intermolecular hydrogen bonding.