Abstract
A pyrazine-2-carboxylate (pzCO2) complex of copper(II) has been synthesized, studied structurally and magnetically, and compared with structurally similar compounds. The structure of [CuCl(pzCO2)] (1) is reported and compared with the known structures of [Cu(pzCO2)2] (2) and [Cu(pzCO2)2(H2O)2] (3). Single-crystal X-ray diffraction measurements show that 1 crystallizes in the monoclinic space group Pc, with two crystallographically independent five-coordinate Cu(II) ions in a geometry close to square-pyramidal. It has a bilayer structure in the packing. Magnetic susceptibility data of 1 show that it exhibits weak ferromagnetic interactions (2 J = 2.26(7) K). In contrast, magnetic susceptibility data of 2 and 3 show weak antiferromagnetic interactions.