Synthesis, crystal structure and magnetic properties of (acetato-κ2O,O′)bis(5,5′-dimethyl-2,2′-bipyridine-κ2N,N′)nickel(II) perchlorate monohydrate

Abstract

The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5′-dmbpy)2]ClO4·H2O (where 5,5′-dmbpy is 5,5′-dimethyl-2,2′-bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′-dmbpy–KClO4system. Within the complex cation, the NiIIatom is hexacoordinated by two chelating 5,5′-dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen-bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single-ion anisotropy,D, which arises from the reduced local symmetry of thecis-NiO2N4chromophore. The fitting of the variable-temperature magnetic data (2–300 K) givesgiso= 2.134 andD/hc= 3.13 cm−1.