A polymorph of diaquabis(pyrazine-2-carboxylato-κ2N1,O)copper(II)

Abstract

The title compound, [Cu(C5H3N2O2)2(H2O)2], is a new polymorph of the previously reported compound [Klein et al. (1982). Inorg. Chem. 21, 1891–1897]. The CuII atom, lying on an inversion center, is coordinated by two N atoms and two O atoms from two pyrazine-2-carboxylate ligands and by two water molecules in a distorted octahedral geometry with the water molecules occupying the axial sites. Intermolecular O—H...O, O—H...N and C—H...O hydrogen bonds connect the complex molecules into a two-dimensional layer parallel to (10overline{1}), whereas the previously reported polymorph exhibits a three-dimensional hydrogen-bonded network.