4,4'-[Ethylenebis(nitrilomethylidyne)]dibenzonitrile.

The mol-ecule of the title Schiff base compound, C(18)H(14)N(4), lies across a crystallographic inversion centre and adopts an E configuration with respect to the azomethine (C=N) bonds. The imino groups are coplanar with the aromatic rings with a maximum deviation of 0.1574 (12) Å for the N atom. Within the mol-ecule, the planar units are parallel, but extend in opposite directions from the dimethyl-ene bridge. In the crystal structure, pairs of inter-molecular C-H⋯N hydrogen bonds link neighbouring mol-ecules into centrosymmetric dimers with R(2) (2)(10) ring motifs. An inter-esting feature of the crystal structure is the short inter-molecular C⋯C inter-action with a distance of 3.3821 (13) Å, which is shorter than the sum of the van der Waals radius of a carbon atom.