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Two new cobalt diphosphonates with formulae [Co4(1,4-ndpa)2(4,4'-bpy)2] ⋅ 5H2 O (1) and [Co(1,4-ndpaH)] ⋅ 1.5H2 O (2) are isolated based on naphthalene scaffold, where 1,4-ndpa4- represents deprotonation of 1,4-naphthalene diphosphonic acid and 4,4'-bpy is 4,4'-bipyridine. The cobalt atoms are four coordinated with distorted tetrahedral geometries in both 1 and 2. Compound 1 displays a three dimensional framework structure containing ladder-like chains made up of corner-sharing tetrahedra {CoNO3} and {PO3 C}. These ladder-like chains are then connected with adjacent ladder-like chains through 1,4-ndpa4- and 4,4'-bpy ligands respectively. Lattice water molecules fill the gaps in the skeleton by hydrogen bond. Compound 2 has a different type of chain structure, where the inorganic chains composed of corner-sharing {CoO4} and {PO3 C} are cross-linked by only 1,4-ndpaH3- ligands into 3D open framework structures. Magnetic studies reveal that spinorbit coupling and/ or antiferromagnetic interaction of CoII is observed in compound 1. [ABSTRACT FROM AUTHOR]

Self-assembly of phosphonic acid (5-pncH3 = (5-phosphono-1-naphthalenecarboxylic acid) and copper perchlorate hexahydrate, 1D coordination polymer, namely Cu0.5 (5-pncH2)(H2O)1. 5 (1) was hydrothermally synthesized. The crystal structure and thermal stability were characterized by single-crystal X-ray diffraction, EA, FT-IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TG-DTG). Structure analyses reveal that compound 1 crystallized in the orthorhombic system, space group Pbcm, a =0. 667 88(2) nm, b = 0. 884 14(2) nm, c = 4. 174 03(9) nm. Compound 1 has a one-dimensional chain structure, in which the adjacent CuII ions are bridged into a one-dimensional zigzag chain through the coordination water molecules. The two-dimensional layered structure is formed by the double hydrogen bond of carboxyl group on the organic phosphonic acid ligand. The thermal stability study shows that the complex exhibits a step-by-step decomposition process, and the stability of the complex skeleton structure can be maintained below 350 °C. [ABSTRACT FROM AUTHOR]