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

In the title compound, C14H13N3O, the intramolecular distances provide evidence for polarization of the molecular-electronic structure. A single three-centre N-H center dot center dot center dot(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.