Syntheses, crystal structures and thermal properties of catena-poly[cadmium(II)-di-μ-bromido-μ-pyridazine-κ(2) N (1):N (2)] and catena-poly[cadmium(II)-di-μ-iodido-μ-pyridazine-κ(2) N (1):N (2)]

The reactions of cadmium bromide and cadmium iodide with pyridazine (C(4)H(4)N(2)) in ethanol under solvothermal conditions led to the formation of crystals of [CdBr(2)(pyridazine)]( n ) (1) and [CdI(2)(pyridazine)]( n ) (2), which were characterized by single-crystal X-ray diffraction. The asymmetric units of both compounds consist of a cadmium cation located on the inter­section point of a twofold screw axis and a mirror plane (2/m), a halide anion that is located on a mirror plane and a pyridazine ligand, with all atoms occupying Wyckoff position 4e (mm2). These compounds are isotypic and consist of cadmium cations that are octa­hedrally coordinated by four halide anions and two pyridazine ligands and are linked into [100] chains by pairs of μ-1,1-bridging halide anions and bridging pyridazine ligands. In the crystals, the pyridazine ligands of neighboring chains are stacked onto each other, indicating π–π inter­actions. Larger amounts of pure samples can also be obtained by stirring at room-temperature, as proven by powder X-ray diffraction. Measurements using thermogravimetry and differential thermoanalysis (TG-DTA) reveal that upon heating all the pyridiazine ligands are removed in one step, which leads to the formation of CdBr(2) or CdI(2).