1,1′-(Ethane-1,2-di­yl)bis­(indoline-2,3-dione)

The mol­ecule of the title compound, C(18)H(12)N(2)O(4), is situated on a crystallographic centre of symmetry. The mol­ecule has a zigzag structure, with two parallel symmetry-related indoline-2,3-dione fragments linked by an ethyl­ene group at each N atom. In the crystal, the mol­ecules stack in columns along the b axis. There are two such columns in the structure. The mol­ecules within each column are parallel; however, the mol­ecules in the two columns differ in the respective orientation of the indoline-2,3-dione fragments. In one column, they are approximately parallel to (112), while in the other they are approximately parallel to ([Image: see text]12). The inter­planar angle between the indoline-2,3-dione fragments in the two columns is 80.83 (3)°. The mol­ecules within each column are related by mutual displacement of their centres of symmetry, that is (0, ±1/2, ±1/2). The packing between the mol­ecules is provided by weak inter­actions only, viz. C—H⋯O hydrogen bonds and π–π [centroid–centroid distance = 3.8745 (8) Å] and C=O⋯π inter­actions.