(E)-N′-(5-Chloro-2-hydroxy­benzyl­idene)-4-(8-quinol­yloxy)butanohydrazide monohydrate

The crystal of the title Schiff base compound, C(20)H(18)ClN(3)O(3)·H(2)O, was twinned by a twofold rotation about (100). The asymmetric unit contains two crystallographically independent mol­ecules with similar conformations, and two water mol­ecules. The C=N—N angles of 115.7 (6) and 116.2 (6)° are significantly smaller than the ideal value of 120° expected for sp (2)-hybridized N atoms and the dihedral angles between the benzene ring and quinoline ring system in the two mol­ecules are 52.5 (7) and 53.9 (7)°. The mol­ecules aggregate via C—Cl⋯π and π–π inter­actions [centroid–centroid distances = 3.696 (5)–3.892 (5) Å] and weak C—H⋯O inter­actions as parallel sheets, which are further linked by water mol­ecules through N—H⋯O and O—H⋯O hydrogen bonds into a supra­molecular two-dimensional network.