(E)-2-[4-(Dimethyl-amino)styr-yl]-1-methyl-quinolinium 4-methoxy-benzene-sulfonate monohydrate

In the title compound, C(20)H(21)N(2) (+)·C(7)H(7)O(4)S(-)·H(2)O, the cation is nearly planar and exists in the E configuration. The cations and anions form individual chains along the b axis and are inter-connected by weak C-H⋯O inter-actions. The 4-methoxy-benzensulfonate anions are linked to water mol-ecules through O-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure is further stabilized by a C-H⋯π inter-action involving the methoxy-phenyl ring. The sulfonate anion is also involved in a weak intra-molecular C-H⋯O inter-action which generates an S(5) ring motif.