Syntheses, supramolecular networks and Hirshfeld surface and thermal analyses of two new cadmium chloride coordination polymers with an N,O-chelating ligand

摘要

Two new coordination polymers, namely poly[[(3-aminopyrazin-4-ium-2-carboxylate- kappa N-2(1), O) di-mu-chlorido-cadmium(II)] monohydrate], {[CdCl2(C5H5N3O2)]center dot-H2O}(n), (1), and poly[2-amino-3-carboxypyrazin-1-ium [(3-aminopyrazine-2-carboxylato-kappa N-2(1), O)di-mu-chlorido-cadmium(II)] monohydrate], {(C5H6N3O2)[Cd(C5H4N3O2)-Cl-2]center dot H2O}(n), (2), have been synthesized from the reaction of cadmium(II) chloride and 3-aminopyrazine-2-carboxylic acid (Hapca) under mild conditions in acidic media. The two coordination polymers have been characterized by single-crystal X-ray diffraction and show chloride-bridged zigzag chains with octahedrally coordinated metal ions, where Hapca acts as a bidentate ligand via the pi-conjugated N atom and a carboxylate O atom. The chains are further interconnected via noncovalent interactions into threedimensional supramolecular networks. The dominant H center dot center dot center dot O and H center dot center dot center dot Cl interactions for both compounds were quantified using Hirshfeld surface analysis. The thermal stability and topological analysis of the two-dimensional networks of (1) and (2) are also discussed.