2,2′-{1,1′-[Pentane-1,5-diylbis(oxynitrilo)]diethylidyne}diphenol

In the title compound, C21H26N2O4, there is half a molecule in the asymmetric unit with a crystallographic twofold rotation axis passing through the central C atom of the –CH=N—O—(CH2)5—O—N=CH– bridge. The dihedral angle formed by the two benzene rings is 80.85 (2)°. Strong intramolecular O—H...N and C—H...O hydrogen bonds help to establish the molecular conformation. There are also weak intermolecular π–π stacking interactions between neighbouring benzene rings [centroid–centroid separation = 3.502 (3) Å].