Synthesis and crystal structure of catena-poly[cobalt(II)-di-μ-chlorido-μ-pyridazine-κ2 N 1:N 2]

Abstract

The reaction of cobalt dichloride hexahydrate with pyridazine leads to the formation of crystals of the title compound, [CoCl2(C4H4N2)] n . This compound is isotypic to a number of compounds with other divalent metal ions. Its asymmetric unit consists of a Co2+ atom (site symmetry 2/m), a chloride ion (site symmetry m) and a pyridazine molecule (all atoms with site symmetry m). The Co2+ cations are coordinated by four chloride anions and two pyridazine ligands, generating trans-CoN4Cl2 octahedra, and are linked into [010] chains by pairs of μ-1,1-bridging chloride anions and bridging pyridazine ligands. In the crystal structure, the pyridazine ligands of neighboring chains are stacked onto each other, indicating π–π interactions. Powder X-ray diffraction proves that a pure crystalline phase was obtained. Differential thermonalysis coupled to thermogravimetry (DTA–TG) reveal that decomposition is observed at about 710 K. Magnetic measurements indicate low-temperature metamagnetic behavior as already observed in a related compound.