1-[(4-{[(2-Oxo-1,2-dihydro­naphthalen-1-yl­idene)meth­yl]amino}­anilino)methyl­idene]naphthalen-2(1H)-one dihydrate

The title compound, C(28)H(20)N(2)O(2)·2H(2)O, comprises a Schiff base mol­ecule with an imposed inversion centre in the middle of p-phenyl­enediamine unit and water mol­ecules of crystallization. In the structure, the Schiff base mol­ecule is present as the keto–amino tautomer with a strong intra­molecular N—H⋯O hydrogen bond. The Schiff base mol­ecules and water mol­ecules of crystallization create infinite [010] columns through O—H⋯O hydrogen bonds. Inter­molecular attractions within columns are through additional π–π inter­actions [centroid–centroid distance = 3.352 (1) Å] between parallel Schiff base mol­ecules. The columns are joined into infinite (011) layers through weak C—H⋯O hydrogen bonds. The layers pack in an assembly by van der Waals attractions, only being effective between bordering non-polar naphthalene ring systems.