Bis{4-[(E)-2-(1H-indol-3-yl)ethen­yl]-1-methyl­pyridinium} 4-chloro­benzene­sulfonate nitrate

In the title mixed salt, 2C16H15N2 (+)·C6H4ClO3S(-)·NO3 (-), one of the cations shows whole mol-ecule disorder over two sets of sites in a 0.711 (7):0.289 (7) ratio. The 4-chorobenzenesulfon-ate anion is also disordered over two orientations in a 0.503 (6):0.497 (6) ratio. The cations are close to planar, the dihedral angles between the pyridinium and indole rings being 1.48 (3)° in the ordered cation, and 5.62 (3) and 2.45 (3)°, respectively, for the major and minor components of the disordered cation. In the crystal, the cations are stacked in an anti-parallel manner approximately along the a-axis direction and linked with the anions via N-H⋯O hydrogen bonds and C-H⋯O inter-actions, generating a three-dimensional network. Weak C-H⋯π and π-π inter-actions [with centroid-centroid distances of 3.561 (2)-3.969 (7) Å] are also observed.