2,3,4,6,7,8,9,10-Octa-hydro-pyrimido[1,2-a]azepin-1-ium 2-cyano-1-(2,6-dimethylanilino)-2-(phenyl-sulfonyl)ethenethiol-ate.

In the title compound, C(9)H(17)N(2) (+)·C(17)H(15)N(2)O(2)S(2) (-), the Csp(2)-N bonds in the tetra-hydro-pyrimidine ring of the cation are delocalized. The negative charge is localized on the S atom of the thione group. Cations and anions are linked by N-H⋯S inter-molecular hydrogen bonds.