1,1′-Dibutyl-3,3′-biindolinylidene-2,2′-dione.

The title molecule, C24H26N2O2, has its central C=C double bond placed on an inversion centre, and both indolin-2-one units are coplanar. The three terminal C atoms of the two butyl groups are disordered over two positions; the site occupancy factors are ca. 0.54 and 0.46. The central C=C bond exhibits an E configuration and is conjugated with the indole heterocycles. This aromatic character is related to the planarity of the isoindigo core and is reminiscent of that observed in stilbene. [ABSTRACT FROM AUTHOR]