Syntheses, crystal structure and thermal behavior of poly[di-μ-bromido-μ-2,3-di-methyl-pyrazine-κ2 N 1:N 4-cadmium(II)].

The title compound, [CdBr2(C6H8N2)] n , was prepared by the reaction of cadmium bromide with 2,3-di-methyl-pyrazine in aceto-nitrile. Powder X-ray diffraction (PXRD) indicated that a pure phase had been obtained. The asymmetric unit consists of one Cd cation located on a center of inversion, one 2,3-di-methyl-pyrazine ligand situated on a twofold rotation axis and one bromide anion in a general position. In the extended structure, the cadmium cation is octa-hedrally coordinated by four bridging bromide anions and two bridging 2,3-di-methyl-pyrazine coligands. The cations are linked via common bromide-ion edges into [010] chains that are further connected into (100) layers by the bridging 2,3-di-methyl-pyrazine coligands. Measurements using thermogravimetry and differential thermoanalysis reveal that the compound decomposes in two separate steps in which a more 2,3-di-methyl-pyrazine-deficient compound is formed, which according to PXRD measurements is crystalline.