catena-Poly[[[diaqua-terbium(III)]-µ-6-carboxy-nicotinato-µ-pyridine-2,5-di-carboxyl-ato] dihydrate].

The title compound, {[Tb(C(7)H(3)NO(4))(C(7)H(4)NO(4))(H(2)O)(2)]·2H(2)O}(n), is isotypic with the analogous Tm(III) compound [Li, Zhang, Wang & Bai (2009). Acta Cryst. E65, m411]. The Tb(III) atom is octa-coordinated by two water mol-ecules and by four carboxyl-ate O atoms and two pyridyl N atoms from two pyridine-2,5-dicarboxyl-ate (2,5-pydc) and two 6-carboxy-nicotinate (2,5-Hpydc) ligands. The 2,5-pydc and 2,5-Hpydc ligands bridge Tb(III) atoms, generating helical coordination polymers along [001]. An extensive network of O-H⋯O hydrogen bonds is formed between the coordination polymers and the uncoordinated water mol-ecules. The refined Flack parameter of 0.54 (2) suggests inversion twinning.

catena-Poly[[(2,2'-bipyridine-κN,N')nickel(II)]-µ-oxalato-κO,O:O,O].

The title compound, [Ni(C(2)O(4))(C(10)H(8)N(2))](n), is isostructural with its Mn(II), Fe(II), Cu(II) and Zn(II) analogues. Each Ni(II) atom is chelated by two oxalate ligands and one 2,2'-bipyridine, forming a slightly distorted octa-hedral geometry. Oxlate acts as a bridge to link neighbouring pairs of Ni(II) cations, forming a one-dimensional wave-like chain. The crystal showed partial inversion twinning.

Tetra-kis(µ-2,4-difluoro-benzoato)bis-[(2,4-difluoro-benzoato)(1,10-phenanthroline)gadolinium(III)].

In the title compound, [Gd(2)(C(7)H(3)F(2)O(2))(6)(C(12)H(8)N(2))(2)], the asymmetric unit comprises one Gd(3+) cation chelated by two 2,4-difluoro-benzoate and one 1,10-phenanthroline ligands. Two cations are linked into a centrosymmetric dimer via three bridging carboxyl-ate groups of 2,4-difluoro-benzoate ligands. Each Gd(3+) ion is nine-coordinated by seven O atoms and two N atoms.

Bis{µ-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}bis-[(thio-cyanato)manganese(III)].

The reported structure is a monoclinic polymorph of the title compound, [Mn(2)(C(16)H(14)N(2)O(2))(2)(NCS)(2)], which has been characterized previously in an ortho-rhom-bic form. Each Mn(III) atom is chelated by a tetra-dentate 2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolate ligand and by the N atom of a thio-cyanate anion, in a square-pyramidal arrangement. The complexes form centrosymmetric dimers, with an Mn-O contact of 2.557 (3) Štrans to each thio-cyanate anion, completing a distorted octa-hedral coordination geometry.

Tris[2-(propyl-imino-meth-yl)phenolato-κN,O]cobalt(III).

The title compound, [Co(C(10)H(12)NO)(3)], was synthesized from cobalt(III) fluoride and 2-(propyl-imino-meth-yl)phenol in refluxing methanol. The Co(III) ion is hexa-coordinated by three N and three O atoms from three bidentate Schiff base ligands in an octa-hedral geometry.

µ-Oxido-bis-{chlorido[tris-(2-pyridylmeth-yl)amine]chromium(III)} bis(hexafluoridophosphate).

The title compound, [Cr(2)Cl(2)O(C(18)H(18)N(4))(2)](PF(6))(2), is isostructural with the V(III) analogue. Each Cr(III) atom is chelated by the tetra-dentate tris-(2-pyridylmeth-yl)amine ligand via four N atoms, and further coordinated by one Cl atom and one bridging O atom, giving a slightly distorted octa-hedral coordination geometry. The dinuclear complex is centrosymmetric, with the bridging O atom lying on a centre of inversion.

Diazido-bis(2,2'-biimidazole)cobalt(II).

In the title compound, [Co(N(3))(2)(C(6)H(6)N(4))(2)], the Co(II) atom lies on a centre of inversion and is bonded to two azide ions and two bidentate 2,2'-biimidizole ligands, giving a slightly distorted octa-hedral CoN(6) coordination geometry. In the crystal structure, inter-molecular N-H⋯N hydrogen bonds exist between the 2,2'-biimidizole ligands and the azide ions, linking the complexes into sheets.