catena-Poly[[[diaqua­zinc]-bis­{[mu]-N²,N⁶-bis­[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide}] dinitrate]

In the title compound, {[Zn(C₁₉H₁₇N₅O₂)₂(H₂O)₂](NO₃)₂}_n, the Zn^II cation is located at an inversion centre within a slightly distorted octa­hedron, ligated by four N atoms from four N²,N⁶-bis­[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxam­ide (L) ligands occupying a plane about the Zn^II atom with the two water O atoms perpendicular to that. In the complex mol­ecule, the bidentate bridging L ligands display helical R and S conformers, and link the Zn^II cations into a one-dimensional centrosymmetric double-chain structure con­taining 32-membered rings. The nitrate anions reside in these rings and are involved in multiple N-H...O hydrogen-bond inter­actions. On excitation at 390 nm, the title compound displays a strong blue emission centred at 449 nm. Investigation of the thermal stability shows that the network structure is stable up to 420 K.

Poly[bis­[μ₂-3-(pyridin-4-yl)benzoato-κ³N:O,O′]lead(II)]

In the title compound, the Pb atom sits on a crystallographic C₂ axis and is six-coordinate, ligated by two chelating carboxyl­ate groups from two 3-(pyridin-4-yl)benzoate ligands and by two N atoms from another two benzoate ligands. Each ligand is conformationally chiral and bridges two Pb^II centres, extending the structure into a corrugated two-dimensional (4,4) net.

The purine-carboxylate-containing coordination polymer poly[[[mu]₄-1-(2-carboxyl­ato­ethyl)-6-oxo-6,9-di­hydro-1H-purin-9-ido]zinc(II)]

A three-dimensional metallohelicate is constructed from one-dimensional metal-organic helices of purine-containing 3-(6-oxo-6,9-di­hydro-1H-purin-1-yl)propionate ligands and zinc(II) ions.