Synthesis, crystal structure and fluorescence of a 1-D polymeric zinc(II) complex with pyrazine-2-carboxylate as a bridging ligand

A one-dimensional chain complex {[Zn(pyz)(SCN)(H2O)(2)] . H2O}(infinity) (pyz=pyrazine-2-carboxylic anion) has been synthesized and its crystal structure determined by X-ray crystallography. The complex crystallizes in an orthorhombic system and the space group is P2(1)2(1)2(1) with a=6.873(3), b=9.847(4), c=16.466(7)Angstrom. The Zn(II) ion is located in a distorted octahedral environment with two oxygen atoms O(3) and O(4) from terminal ligands of two water molecules, another oxygen atom O(1) from the carboxylate group of pyz, and three nitrogen atoms, N(1), and N(2A) from two different pyz and N(3) from a terminal thiocyanate anion, in which a chelated five-membered ring is formed by coordination of O(1) and N(1) to the Zn(1) atom. Therefore, an infinite zigzag chain consisting of Zn(II) ions and pyz anions is constructed and the chains are linked together with hydrogen bonding from coordinated and uncoordinated water molecules. The fluorescence spectra for the bridging ligand Na(pyz) and the complex were measured at room temperature in aqueous solution and in the solid state.