Syntheses and crystal structures of di-chlorido-bis(2,3-di-methyl-pyrazine-κ)zinc(II) and -poly[[di-chlorido-zinc(II)]-μ-2,3-di-methyl-pyrazine-κ : ].

The reactions of zinc(II)chloride with 2,3-di-methyl-pyrazine (CHN) in different ratios in aceto-nitrile lead to the formation of [ZnCl(CHN)] () and [ZnCl(CHN)] (). The asymmetric unit of consists of one Zn cation located on a twofold rotation axis, one chloride anion and one 2,3-di-methyl-pyrazine ligand that occupy general positions. In compound the asymmetric unit is built up of one zinc cation, two chloride anions and one 2,3-di-methyl-pyrazine ligand that are located in general positions in the uncommon trigonal space group 3. In compound , the Zn cations are tetra-hedrally coordinated by two chloride anions and two 2,3-di-methyl-pyrazine ligands forming discrete complexes. These complexes are arranged in columns that proceed along the -axis direction. The Zn cations in are also tetra-hedrally coordinated by two chloride anions and two 2,3-di-methyl-pyrazine ligands but linked the bridging 2,3-di-methyl-pyrazine ligands into helical infinite chains that propagate along the -axis direction. Powder X-ray diffraction measurements indicate that both compounds were obtained as pure crystalline phases.