(E)-2-{(2-Hydroxy­naphthalen-1-yl)methyl­ene}hydrazinecarboxamide

In the title mol­ecule, C(12)H(11)N(3)O(2), the dihedral angle between the mean planes of the naphthalene and carboxamide groups is 28.9 (8)°. The hydrazine N atoms are twisted slightly out of the plane of the carboxamide group [C—C—N—N torsion angle = −175.06 (13)°]. The crystal packing is influenced by N—H⋯O hydrogen bonding which includes a bifurcated hydrogen bond between the amide N atom and nearby carboxyl and hydroxyl O atoms. A second bifurcated hydrogen bond occurs between the hydroxyl O atom and nearby amide (inter­molecular) and hydrazine (intra­molecular) N atoms. As a result, mol­ecules are linked into a co-operative hydrogen-bonded network of infinite one-dimensional O—H⋯O—H⋯O—H chains along the (101) plane of the unit cell in a zigzag pattern, the dihedral angle between the mean planes of the naphthalene groups of adjacent mol­ecules in the chain being 86.9 (2)°. A MOPAC PM3 calculation provides support to these observations.