A tetragonal molecular cage and polymeric macrocyclic complex based on a clip-like bis-pyridyl-bis-amide ligand

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

In the title compound, {[Zn(C(19)H(17)N(5)O(2))(2)(H(2)O)(2)](NO(3))(2)}(n), the Zn(II) cation is located at an inversion centre within a slightly distorted octahedron, ligated by four N atoms from four N(2),N(6)-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-N2,N6-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide}dichloridonickel(II)]N,N-dimethylformamide tetrasolvate]

In the title compound, {[NiCl2(C19H17N5O2)2]·4C3H7NO}n, the NiIIatom is located on an inversion centre and is in a six-coordinated octahedral geometry, formed by four pyridine N atoms from fourN2,N6-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide (BPDA) ligands occupying the equatorial plane and two chloride anions at the axial sites. The bidentate bridging BPDA ligands link the NiIIatoms into a two-dimensional corrugated grid-like flexible layer with a (4,4)-connected topology, which consists of left- and right-handed helical chains sharing the common NiIIatoms. Investigation of the thermal stability shows that the network is stable up to 573 K.