5,5′-Bis(diethylamino)-2,2′-[butane-1,4-diyldioxybis(nitrilomethylidyne)]-diphenol

The title complex, C26H38N4O4, was synthesized by the reaction of 4-diethylamino-2-hydroxybenzaldehyde with 1,4-bis( aminooxy) butane in ethanol. It crystallizes as discrete centrosymmetric molecules adopting an extended conformation where the two salicylaldoxime groups are separated from each other. Intramolecular O-H center dot center dot center dot N hydrogen bonding is observed between the hydroxy groups and oxime N atoms. Intermolecular pi-pi stacking interactions [3.979 (2) angstrom] between aromatic rings are apparent in the crystal structure. Each ethyl group is disordered over two positions; in one the site occupancy factors are 0.55 and 0.45, in the other 0.53 and 0.47.