2-(4-Fluoro-2-nitro-phen-yl)-4-hy-droxy-9-phenyl-sulfonyl-9H-carbazole-3-carbaldehyde.

In the title compound, C25H15FN2O6S, the carbazole ring system is essentially planar, with a maximum deviation of 0.1534 (16) Å for the C atom connected to the 4-fluoro-2-nitro-phenyl ring. It is almost orthogonal to the phenyl-sulfonyl and nitro-phenyl rings, making dihedral angles of 88.45 (8) and 79.26 (7)°, respectively. The mol-ecular structure is stabilized by O-H⋯O and C-H⋯O hydrogen bonds, which generate three S(6) ring motifs. In the crystal, mol-ecules are linked by two C-H⋯O hydrogen bonds, which generate C(6) and C(9) chains running in the [100] and [010] directions, respectively, so forming a two-dimensional network lying parallel to (001). There are also supra-molecular R 4 (3)(28) graph-set ring motifs enclosed within these networks.