2-[(E)-2-(1H-Indol-3-yl)ethen­yl]-1-methyl­pyridinium 4-bromo­benzene­sulfonate

In the title compound, C(16)H(15)N(2) (+)·C(6)H(4)BrO(3)S(−), the cation exists in the E configuration and is essentially planar with a dihedral angle of 3.10 (5)° between the pyridinium ring and the indole ring system. The π-conjugated planes of the cation and the anion are inclined to each other at a dihedral angle of 64.32 (4)°. In the crystal structure, the cations are stacked in an anti­parallel manner along the a axis. The anions are linked into a chain along the a axis. The cations and the anions are linked into a three-dimensional network by N—H⋯O and weak C—H⋯O hydrogen bonds. The crystal structure is further stabilized by C—H⋯π inter­actions. A π–π inter­action between the five-membered heterocyclic ring of the indole system and the pyridinium ring is also observed with a centroid–centroid distance of 3.5855 (7) Å.