(E)-N′-(2,3,4-Trihydroxybenzylidene)isonicotinohydrazide dihydrate

Abstract

In the title isoniazid derivative, C13H11N3O4·2H2O, the Schiff base molecule exists in an E configuration with respect to the acyclic C=N bond. An intramolecular O—H...N hydrogen bond forms a six-membered ring, producing an S(6) ring motif. The essentially planar pyridine ring [maximum deviation = 0.0119 (8) Å] is inclined at a dihedral angle of 7.30 (4)° with respect to the benzene ring. In the crystal, intermolecular O—H...N, O—H...O, N—H...O and C—H...O hydrogen bonds link the molecules into two-dimensional arrays lying parallel to the (10overline{1}) plane. These arrays are further interconnected into a three-dimensional extended network via O—H...O and C—H...O hydrogen bonds. A weak intermolecular π–π interaction [centroid-to-centroid distance = 3.5627 (5) Å] is also observed.