Seven metal-organic coordination polymers, namely [Cd(sfdb), and [Cd(sfdb)(bpy)] n (7) [H 2 sfdb = 4,4Ј-sulfonyldibenzoic acid, phen = 1,10-phenanthroline, quin = 2,2Ј-biquinoline, bpy = 2,2Ј-bipyridine] have been synthesized according to the principles of crystal engineering and structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction analyses. Compounds 1-3 form 1D zigzag chains. Two phen ligands chelate to one cadmium atom in 1, which is rare in similar polymers, while two 2,2Ј-bpy ligands coordinate one cadmium atom in 2. The zigzag chains in 3 propagate in two different directions (rotated by 75°) that are assembled by supramolecular forces

Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.003 Å; R factor = 0.029; wR factor = 0.075; data-to-parameter ratio = 14.9. metal-organic compounds m2190 # 2007 International Union of Crystallography

Two novel metalϪorganic coordination polymers, [Cd(bqdc)(phen) 2 ] n (1), [Cd(bqdc)(phen)] n (2), (H 2 bqdc ϭ 2,2Ј-biquinoline-4,4Ј-dicarboxylic acid, phen ϭ 1,10-phenanthroline) were obtained with different metal/ligand ratios through hydrothermal method. Their structures were determined by single-crystal X-ray diffraction. In two complexes, central Cd 2ϩ ions and (bqdc) 2Ϫ ligands display completely different coordination modes. 1 is a 1-D zigzag chain, two phen ligands chelate to one cadmium atom, 2053 which is rare in similar polymers. 2 is a 3-D framework, exhibits an unusual eight-coordinate structure (CdN 2 O 6 ) and the coordination polyhedron can be described as distorted monocapped pentagonal bipyramid. 1 and 2 are stable in air, and show blue photoluminescence at room temperature.

In the title compound, [Ni(C6H19N4)2][Fe(CN)6], the Ni2+ and Fe2+ cations are both octahedrally coordinated. The complex cations and anions, both of which are centrosymmetric, are linked by a network of N—H...N hydrogen bonds to form a three‐dimensional network.

By using a precursor complex [Fe3O(PhCO2)6(H2O)3]NO3 as starting material and 2,2′‐bpy (= 2,2′‐bipyridine) as rigid chelating ligand, the new dinuclear iron‐oxido complex [Fe2O(PhCO2)2(2,2′‐bpy)2(N3)2]·H2O (1) was synthesized and structurally characterized. The reaction of [Fe3O(PhCO2)6(H2O)3]NO3 with 2,2′‐bpy and sodium azide in 1:3:3 ratio gave the dinuclear complex 1, whereas a 1:6:3 ratio reaction system only gave the complex [Fe(2,2′‐bpy)3]3+, which indicated that 2,2′‐bipyridine plays a crucial function in the nuclear forming procedure. Meanwhile, the N3– ligands take up the chelating domain of oxygen and reduce the nucleation. Different π–π interactions exist in 1, which extend its structure to a three dimensional supramolecular framework.