Copper Carboxylate-phosphonates: Syntheses,Crystal Structures and Magnetic Properties

Two novel copper carboxyly-phosphonates, namely, Cu_(2.5)(5-pnc)(SO_4)_(0.5)(OH)(H_2O)_(0.5)(1) and Cu_(0.5)(5-pncH_2)(H_2O)_(1.5)(2)(5-pncH_3 = 5-phosphono-1-naphthalenecarboxylic acid), have been synthesized and characterized by X-ray diffraction, infrared spectroscopy, elemental analysis, and thermogravimetric analysis. In compound 1, each {PO_3C} tetrahedron is corner-shared with two {Cu(1)O_4}, two {Cu(2)O_5} and one {Cu(3)O_5},thus forming a one-dimensional inorganic chain along the c axis containing 8-membered rings of Cu_3O_4S] and 19-membered cages of Cu_5O_(10)P_4]. The inorganic chains are further connected by a 5-pnc~(3-) ligand to generate a three-dimensional framework. Compound 2 exhibits a one-dimensional structure, in which the inorganic chains of Cu-O-Cu]_n are connected by the organic ligands through hydrogen bonding interactions, forming an infinite two-dimensional layer. Magnetic measurements of 1 indicate that dominant antiferromagnetic interactions are mediated between the Cu~(2+) centers.