A three-component cocrystal: benzoyl(hydroxy­imino)­acetonitrile-18-crown-6-water (2/1/4)

In the title compound, 2C₉H₆N₂O₂·C₁₂H₂₄O₆·4H₂O, the 18-crown-6 (1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane) mol­ecule resides across a centre of inversion. The adduct exists as a mol­ecular hydrogen-bonded complex featuring integration of two kinds of synthons, viz. [(18-crown-6)(H₂O)₄] [O...O = 2.8645 (18)-2.9014 (18) Å] and an oxime/aqua ensemble, PhC(O)C(CN)NOH...OH₂ [O...O = 2.5930 (18) Å]. The reliability of the oxime/aqua motif, sustained by the highly acidic cyano­oxime, is an essential factor in the construction of multicomponent cocrystals and the accommodation of oxime species in macrocyclic hosts. The supra­molecular structure is generated by the alternation of hydro­philic [(18-crown-6)(H₂O)₄] layers and bilayers of benzoyl(hydroxy­imino)­aceto­nitrile mol­ecules, resulting in stacking inter­actions between the phenyl and cyano groups of 3.666 (2) Å.