In the title compound, C(16)H(16)BrN, the tricyclic carbazole system is essentially planar (r.m.s. deviation of all non-H atoms = 0.010 Å). The dihedral angle between the two outer carbazole rings is 1.1 (3)°. There are no directional inter-molecular contacts in the crystal packing.

In the title mol-ecule, C(18)H(12)N(2)O(4)S, the carbazole skeleton is nearly planar [maximum deviation = 0.037 (1) Å] and is oriented at a dihedral angle of 73.73 (5)° with respect to the benzene ring. An intra-molecular C-H⋯O hydrogen bond links a nitro O atom to the carbazole skeleton. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. ...

In the title mol-ecule, C18H12BrN, the 4-bromo-phenyl ring is inclined to the mean plane of the carbazole moiety (r.m.s. devation = 0.027 Å) by 49.87 (5)°. In the crystal, molecules stack along [001] and are linked by C-H⋯π interactions forming a corrugated two-dimensional network lying parallel to (100).

The whole mol-ecule of the title compound, C26H16N2S4, is generated by twofold rotational symmetry. The carbazole skeleton is nearly planar [maximum deviation = 0.054 (5) Å]. In the crystal, aromatic π-π stacking is observed between parallel carbazole ring systems of adjacent mol-ecules, the shortest centroid-centroid distances between pyrrole and benzene rings being 3.948 (3) and 3.751 (3) Å.