Synthesis, X-ray crystal structure and magnetic study of a dicyanamido bridged 1D chain nickel(II) complex

Reaction of Ni(NO₃)₂ · 6H₂O and sodium dicyanamide (Nadca) yields a 1D infinite chain complex {[Ni(dien)(μ_1,5-dca)(H₂O)](NO₃)}_n (1) (where dien = diethylenetriamine). The coordination environment in complex 1 around the nickel(II) ions is distorted octahedron. Three nitrogen atoms of the ligand diethylenetriamine and an oxygen atom of H₂O molecule constitute the four coordination sites of the basal plane of the octahedron. Of two axial positions of the octahedron, one position is occupied by the nitrogen atom of a μ_1,5-dca anion the remaining coordination site is occupied by a nitrogen atom of another end-to-end bridging dca from an adjacent [Ni(dien)(μ_1,5-dca)(H₂O)] moiety, yielding 1D infinite chains which propagate parallel to crystallographic a-axis. No measurable magnetic interaction was evidenced through variable temperature magnetic susceptibility measurements (4-300 K). However, the magnetic susceptibility of the compound can be explained in terms of single-ion anisotropic model with zero-field splitting for nickel(II) ions.