(E)-1-Methyl-4-[2-(1-naphth-yl)vin-yl]pyridinium 4-bromo-benzene-sulfonate.

In the title compound, C(18)H(16)N(+)·C(6)H(4)BrO(3)S(-), the cation exists in the E configuration and the whole mol-ecule of the cation is disordered with a refined site-occupancy ratio of 0.733 (1):0.267 (1). The naphthalene system is not planar, the inter-planar angle between the two aromatic rings being 5.0 (5)° for the major component and 5.7 (10)° for the minor component. The cation is twisted with dihedral angles between the pyridinium ring and the two aromatic rings of the naphthalene system of 56.3 (5) and 51.4 (5)° (for the major component) and 52.2 (11) and 53.4 (11)° (for the minor component). The pyridinium ring and the benzene ring of the anion are inclined to each other at inter-planar angles of 85.0 (4) and 71.5 (9)° for the major and minor components, respectively. In the crystal packing, the cations and anions are alternately arranged with the cations stacked in an anti-parallel manner along the c axis and the anions linked together into chains along the same direction. The cations are linked to the anions into chains along [102] by weak C-H⋯O inter-actions. The crystal structure is further stabilized by C-H⋯π inter-actions and π-π contacts, with Cg⋯Cg distances of 3.502 (9) and 3.698 (6) Å. A short Br⋯O contact [3.029 (4) Å] is also present.