Structural diversity in the Cu(pyrazinecarboxylate)2/CdCl2 system: new one-, two- and three-dimensional mixed metal coordination polymers

Four new inorganic–organic polymeric materials have been synthesized by reacting the metal containing building block, Cu(pyzca)2, with cadmium chloride. All resulting polymers have both metals incorporated in the structure and display a variety of structural motifs, ranging from one-dimensional chains to complicated three-dimensional networks. The first compound, [Cu(Pyzca)2(H2O)CdCl2(H2O)·H2O]n (1) is a one-dimensional double chain. The next two compounds, [Cu(Pyzca)2(H2O)2Cd2Cl4(H2O)2]n (2) and [Cu(Pyzca)2(H2O)Cd2Cl4(H2O)2·3H2O]n (3), assemble in a two-dimensional brick-wall network, while the fourth, [Cu(Pyzca)2Cd2Cl4]n (4), features an intricate three-dimensional network. Synthesis, X-ray structure determinations, and the influence of water molecules coordinated to the copper centers on the coordination geometry and overall extended structure are discussed.