2-[(E)-2-(4-Ethoxyphenyl)ethenyl]-1-methylquinolinium 4-fluorobenzene-sulfonate

In the structure of the title salt, C20H20NO+center dot C6H4FO3S-, the 4(ethoxyphenyl) ethenyl unit is disordered over two positions with a refined site-occupancy ratio of 0.610 (6):0.390 (6). The cation is nearly planar, the dihedral angle between the quinolinium and benzene rings being 6.7 (4) and 1.7 (7)degrees for the major and minor components, respectively. The ethoxy group is essentially coplanar with the benzene ring [C-OC-C-methy = 177.1 (8) and 177.8 (12)degrees for the major and minor components, respectively]. In the crystal, cations and anions are linked into chains along the b-axis direction by C-H center dot center dot center dot O-sulfonyl weak interactions. These chains are further connected into sheets parallel to (001) by C-H center dot center dot center dot O-sulfonyl weak interactions. The chains are also stacked along the a axis through pi-pi interactions involving the quinolinium and benzene rings [centroid-centroid distances = 3.636 (5) for the major component and 3.800 (9)angstrom for the minor component]. C-H center dot center dot center dot pi interactions are also present.