1-[(4-{[(2-Oxo-1,2-dihydro-naphthalen-1-yl-idene)meth-yl]amino}-anilino)methyl-idene]naphthalen-2(1H)-one dihydrate

Abstract

The title compound, C(28)H(20)N(2)O(2)·2H(2)O, comprises a Schiff base mol-ecule with an imposed inversion centre in the middle of p-phenyl-enediamine unit and water mol-ecules of crystallization. In the structure, the Schiff base mol-ecule is present as the keto-amino tautomer with a strong intra-molecular N-H⋯O hydrogen bond. The Schiff base mol-ecules and water mol-ecules of crystallization create infinite [010] columns through O-H⋯O hydrogen bonds. Inter-molecular attractions within columns are through additional π-π inter-actions [centroid-centroid distance = 3.352 (1) Å] between parallel Schiff base mol-ecules. 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.

Fig. 1.

A general overview of (I) showing numbering scheme with anisotropic thermal ellipsoids pictured at 30% probability level. Thin lines display intra N–H···O, and the two intermolecular hydrogen bonds O–H···O and C–H···O. Hydrogen atoms are drawn as spheres of arbitrary radius.

Fig. 2.

The display of three intermolecular contacts of water molecule with nearby Schiff base molecules. Two Schiff base molecules connected by π–π interactions are additionally bridged with a water molecule through two strong hydrogen bonds O1W–H1A···O1i [(i): x, y + 1, z] and O1W–H1B···O1, respectively. The third intermolecular contact of water molecule is via C13–H13···OW1ii 3.247 (5) Å [(ii): x, - y + 3/2, z] interaction.

Fig. 3.

Water molecules of crystallisation occupy the cylindrical voids formed by assembling Schiff base molecules into the [010] columns.

Fig. 4.

The display of herringbone packing arrangement of Schiff base molecules viewed down c-axes. Water molecules and all hydrogen atoms were omitted for clarity.