The title compound, C(21)H(42)N(6), was prepared by the reaction of 2,4,6-trichloro-1,3,5-triazine with dipropyl-amine. The structure of the mol-ecule is tripodal.

The Co(III) atom in the title compound, [Co(C(12)H(6)N(2)O(4))(C(12)H(7)N(2)O(4))], is six-coordinated in a distorted octa-hedral geometry by four N atoms and two O atoms of the chelating 2,2'-bipyridine-6,6'-dicarboxyl-ate and 6'-carb-oxy-2,2'-bipyridine-6-carboxyl-ate ligands. Intermolecular O-H⋯O hydrogen bonds and face-to-face π-stacking inter-actions [centroid-centroid distance = 3.6352 (1...

The Rh(III) ion in the title compound, [Rh(C(12)H(6)N(2)O(4))(C(12)H(7)N(2)O(4))], is coordinated by four N atoms and two O atoms from two chelating ligands L and HL (H(2)L = 2,2'-bipyridine-6,6'-dicarb-oxy-lic acid) to form a distorted octa-hedral geometry. Face-to-face π-stacking inter-actions are observed between inversion-related pyridine rings, with a centroid-to-centroid distance of 3.581...

In the title compound, [Ni(C(12)H(7)N(2)O(4))(2)]·4H(2)O, the Ni atom is located at the centre of a distorted octa-hedron, formed by four N atoms and two O atoms from the same two tridentating chelated 6-carb-oxy-2,2'-bipyridine-6'-carboxyl-ate (L) ligands. Face-to-face π-stacking inter-actions between inversion-related pyridine rings with centroid-centroid distances of 3.548 (3) and 3.662 (3) ...