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 Ni^II atom is located on an inversion centre and is in a six-coordinated octa­hedral geometry, formed by four pyridine N atoms from four N²,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 Ni^II atoms 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 Ni^II atoms. Investigation of the thermal stability shows that the network is stable up to 573 K.

catena-Poly[[[diaqua­[3-(pyridin-4-yl)benzoato-[kappa]²O,O']terbium(III)]-bis­[[mu]-3-(pyridin-4-yl)benzoato-[kappa]²O:O']] monohydrate]

In the title compound, {[Tb(C₁₂H₈NO₂)₃(H₂O)₂]·H₂O}_n, the Tb^III cation is in an eight-coordinate environment, ligated by six carboxyl­ate O atoms from five 3-(pyridin-4-yl)benzoate (L) ligands and by two O atoms from water mol­ecules. The cations are bridged by the carboxyl­ate O atoms of the L ligands to form a two-stranded polymeric chain which is assembled into a three-dimensional supra­molecular network through regular inter­chain O-H...N hydrogen bonding. On excitation at 320 nm, the title compound displays a series of emissions, which were assigned to the characteristic electronic transitions of Tb^III.