Abstract
In the title compound, the asymmetric unit comprises an N,N,N-trimethyl-1-(4-vinyl-phen-yl)methanaminium cation and a 4-vinyl-benzene-sulfonate anion, C12H18N+·C8H7O3S-. The salt has a polymerizable vinyl group attached to both the cation and the anion. The methanaminium and vinyl substituents on the benzene ring of the cation subtend angles of 86.6 (3) and 10.5 (9)° to the ring plane, while the anion is planar excluding the sulfonate O atoms. The vinyl substituent on the benzene ring of the cation is disordered over two sites with a refined occupancy ratio of 0.542 (11):0.458 (11). In the crystal, C-H⋯O hydrogen bonds dominate the packing and combine with a C-H⋯π(ring) contact to stack the cations and anions along the a-axis direction. Hirshfeld surface analysis of the salt and of the individual cation and anion components is also reported.