(E)-3-Dimethylamino-2-(1H-indol-3-ylcarbonyl)acrylonitrile: a chain of edge-fused rings built from a three-centre N-H...(N,O) hydrogen bond.

In the title compound, C(14)H(13)N(3)O, the intramolecular distances provide evidence for polarization of the molecular-electronic structure. A single three-centre N-H...(N,O) hydrogen bond links the molecules into chains of edge-fused R(2)(2)(16) and R(2)(4)(12) rings. Comparison with a number of related structures identifies factors of significance controlling the pattern of supramolecular aggregation.