N,N-Bis(2-hydroxy-benzyl-idene)-2,2'-bipyridyl-3,3'-dicarbohydrazide.

In the title compound, C(26)H(20)N(6)O(4), the two aroylhydrazone side groups exist as diastereomeres, both in the keto form in the crystal structure. The aroylhydrazone units support the mol-ecular conformation through an intra-molecular N-H⋯O hydrogen bond. Two mol-ecules are connected into a centrosymmetric dimer by inter-molecular N-H⋯N hydrogen bonds. These dimers are connected into chains along the a axis by inter-molecular O-H⋯O hydrogen bonds. The combination of these hydrogen bonds results in layers in the bc plane. The layers are further linked by weak C-H⋯π contacts to form a three-dimensional network structure.