A new polymeric copper(II) complex containing pyrazine-2-carboxyamide (pzca): Synthesis and crystal structure of {[Cu(pzca)(CH3CN)3](ClO4)2 · H2O}n

The copper(II) polymeric complex {[Cu(pzca)(CH3CN)3](ClO4)2 · H2O}n (1) (pzca stands for 2-pyrazine carboxamide) has been synthesized and characterized by X-ray crystal structure determination. The copper(II) ion has an elongated octahedrally geometry due to the coordination of three donor atoms from two different pzca ligands and one acetonitrile molecule in the equatorial plane and two acetonitrile molecules in axial positions. The pzca ligand acts as a tridentate with a pyrazine bridge between two Cu(II) ions leading to a Cu⋯Cu separation of 6.7852 Å. Adjacent chains are linked through hydrogen-bonding interactions to generate a two-dimensional layer structure.