Poly[[hexa­aqua­(μ₃-2,2′-bipyridine-4,4′,6,6′-tetra­carboxyl­ato-κ⁶O⁴:N,O⁶,O^6′,N′:O^4′)dinickel(II)] dihydrate]

In the title complex, {[Ni₂(C₁₄H₄N₂O₈)(H₂O)₆]·2H₂O}_n, the two Ni^II atoms are located in different special positions (one on a twofold rotation axis and the second on a centre of symmetry) and have different distorted octa­hedral environments (one by two N atoms from a bipyridine unit, two O atoms from two water mol­ecules and two O atoms from two carboxyl­ate groups, and the second by four O atoms from four water mol­ecules and two O atoms from two carboxyl­ate groups). Thus, the environments of the Ni^II atoms may be denoted as NiN₂O₄ and NiO₆. In the crystal, there exists an extensive network of classical O—H...O hydrogen bonds.

Bis{2,4-dibromo-6-[(E)-(4-fluoro­benz­yl)imino­meth­yl]phenolato-κ²N,O}cobalt(II)

The complete mol­ecule of the title complex, [Co(C₁₄H₉Br₂FNO)₂], is generated by crystallographic twofold symmetry, with the Co^II atom lying on the rotation axis. The coordination of the metal atom by the two N,O-bidentate ligands results in a squashed CoN₂O₂ tetra­hedron. The six-membered chelate ring is an envelope, with the metal atom as the flap. The dihedral angle between the planes of the aromatic rings within each ligand is 84.1 (6)°.

Bis{2,4-dibromo-6-[(E)-(4-fluoro­benz­yl)imino­meth­yl]phenolato-κ²N,O}zinc

In the title Schiff base complex, [Zn(C₁₄H₉Br₂FNO)₂], the Zn^II atom is located on a twofold rotation axis and is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a compressed tetrahedral geometry. The bond lengths and bond angles are within normal ranges. The dihedral angle between the least-squares planes of the aromatic rings within each ligand is 82.76 (17)°.