N (2),N (2′)-Bis(2-hydroxy­benzyl­idene)-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 mol­ecular conformation through an intra­molecular N—H⋯O hydrogen bond. Two mol­ecules are connected into a centrosymmetric dimer by inter­molecular N—H⋯N hydrogen bonds. These dimers are connected into chains along the a axis by inter­molecular 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.