Tris(1,10-phenanthroline-[kappa]²N,N')iron(II) bis­(2,4,5-tricarb­oxy­benzoate) monohydrate and tris­(2,2'-bipyridine-[kappa]²N,N')iron(II) 2,5-dicarb­oxy­benzene-1,4-dicarboxyl­ate-benzene-1,2,4,5-tetra­carb­oxy­lic acid-water (1/1/2)

The title compounds, tris­(1,10-phenanthroline-[kappa]²N,N')iron(II) bis­(2,4,5-tricarb­oxy­benzoate) monohydrate, [Fe(C₁₂H₈N₂)₃](C₁₀H₅O₈)₂·H₂O, (I), and tris­(2,2'-bipyridine-[kappa]²N,N')iron(II) 2,5-dicarb­oxy­benzene-1,4-dicarboxyl­ate-benzene-1,2,4,5-tetra­carb­oxy­lic acid-water (1/1/2), [Fe(C₁₀H₈N₂)₃](C₁₀H₄O₈)·C₁₀H₆O₈·2H₂O, (II), were obtained during an attempt to synthesize a mixed-ligand complex of Fe^II with an N-con­taining ligand and benzene-1,2,4,5-tetra­carb­oxy­lic acid via a solvothermal reaction. In both mononuclear complexes, each Fe^II metal ion is six-coordinated in a distorted octa­hedral manner by six N atoms from three chelating 1,10-phenanthroline or 2,2'-bipyridine ligands. In compound (I), the Fe^II atom lies on a twofold axis in the space group C2/c, whereas (II) crystallizes in the space group P2₁/n. In both compounds, the uncoordinated carboxyl­ate anions and water mol­ecules are linked by typical O-H...O hydrogen bonds, generating extensive three-dimensional hydrogen-bond networks which surround the cations.

A novel one-dimensional Co^II coordination polymer: catena-poly[[hexa­aqua­cobalt(II)] [[diaqua­bis­(sulfato-[kappa]O)cobalt(II)]-[mu]-4,4'-bipyridine-[kappa]²N:N'] [[triaqua­(sulfato-[kappa]O)cobalt(II)]-[mu]-4,4'-bipyridine-[kappa]²N:N']]

The title compound, {[Co(H₂O)₆][Co(SO₄)(C₁₀H₈N₂)(H₂O)₃][Co(SO₄)₂(C₁₀H₈N₂)(H₂O)₂]}_n, contains three crystallographically unique Co^II centres, all of which are in six-coordinated environments. One Co^II centre is coordinated by two bridging 4,4'-bipyridine (4,4'-bipy) ligands, one sulfate ion and three aqua ligands. The second Co^II centre is surrounded by two N atoms of two 4,4'-bipy ligands and four O atoms, i.e. two O atoms from two monodentate sulfate ions and two from water mol­ecules. The third Co^II centre forms part of a hexaaquacobalt(II) ion. In the crystal structure, there are two different one-dimensional chains, one being anionic and the other neutral, and adjacent chains are arranged in a cross-like fashion around the mid-point of the 4,4'-bipy ligands. The structure features O-H...O hydrogen-bonding inter­actions between sulfate anions and water mol­ecules, resulting in a three-dimensional supra­molecular network.