N'-[(E)-(3-Fluoro-pyridin-2-yl)methyl-idene]pyridine-3-carbohydrazide dihydrate.

The organic molecule in the title dihydrate, C12H9FN4O·2H2O, exists in the E conformation with respect to the azo-methane C=N double bond. The mol-ecule is approximately planar, with a maximum deviation of 0.117†(1)†à for the carbonyl O atom from the mean plane of the mol-ecule. Both pyridine rings are essentially coplanar with the central C(=O)N2C unit [dihedral angles = 1.99†(7) and 5.71†(8)°], exhibiting a significant difference in dihedral angles from its benzohydrazide analogue. The crystal packing features N-H⋯O, O-H⋯N and O-H⋯O hydrogen-bond inter-actions, which lead to the formation of a chain along the c-axis direction through one of the water mol-ecules present, and these chains are stacked one over the other by means of π-π inter-actions [with centroid-centroid distances of 3.7099†(10) and 3.6322†(10)†à ] between the aromatic rings in neighbouring anti-parallel mol-ecules, building a three-dimensional supra-molecular network.