1-(Prop-2-ynyl) indoline-2,3-dione

The structure of the title compound, C11H7NO2, is isotypic to that of its homologue, 1-octylindoline-2,3-dione [Qachchachi et al. (2013). Acta Cryst. E69, o1801]. The indoline ring and the two carbonyl O atoms are approximately coplanar, the largest deviation from the mean plane being 0.021 (1) angstrom for one of the O atoms. The mean plane through the fused ring system is nearly perpendicular to the propynyl group, as indicated by the N-C-C-C torsion angle of 77.9 (1)degrees. In the crystal, molecules are linked by C-H center dot center dot center dot O hydrogen bonds and pi-pi interactions between benzene rings [intercentroid distance = 3.5630 (10)angstrom], forming a three-dimensional structure.