Hydrogen bonding in C-substituted nitroanilines: pi-stacked sheets of R-4(4)(20) and R-4(4)(28) rings in 2-cyano-4-nitroaniline

In the title compound, C7H5N3O2, which crystallizes with Z' = 2 in space group P2(1)/c, the two independent molecules both exhibit positional disorder, with refined site-occupancy factors of 0.947 (2) and 0.053 (2) for the major and minor components, respectively. The major components have polarized molecular electronic structures. The two major components are linked into sheets of alternating R-4(4)(20) and R-4(4)(28) rings by two N - H...O hydrogen bonds [H...O = 2.18 and 2.21 Angstrom, N...O = 3.022 (2) and 3.043 (2) Angstrom and N - H...O both 159degrees] and two N - H...N hydrogen bonds [H...N = 2.14 and 2.17 Angstrom, N...N = 2.990 (2) and 3.001 (2) Angstrom, and N - H...N = 162 and 158degrees]. The sheets are linked into a three-dimensional framework by a single aromatic pi-pi stacking interaction.