2-Phenyl-acetic acid-3-{(E)-2-[(E)-pyridin-3-yl-methyl-idene]hydrazin-1-ylidenemeth-yl}pyridine (2/1).

The asymmetric unit of the title 1:2 adduct, C(12)H(10)N(4)·2C(8)H(8)O(2), comprises a single mol-ecule of 2-phenyl-acetic acid and half a mol-ecule of 3-pyridine-aldazine; the latter is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are connected into a three-component aggregate via O-H⋯N hydrogen bonds. As the carboxyl group lies above the plane through the benzene ring to which it is attached [C-C-C-C = 62.24 (17)°] and the 4-pyridine-aldazine mol-ecule is almost planar (r.m.s. deviation of the 16 non-H atoms = 0.027 Å), the overall shape of the aggregate is that of a flattened extended chair. Layers of these aggregates are connected by C-H⋯O and C-H⋯π inter-actions and stack parallel to (220).