The asymmetric unit of the title salt, C16H19N2S+·ClO4−, consists of two crystallographically independent cations and anions. In the salt, protonation occurs at the nitrile N atom attached to the S atom of the corresponding λ6-sulfanenitrile. The structures of the two independent cations are almost the same and the configuration around the S atom is a slightly distorted tetrahedral geometry, with two S—N bonds and two S—C bonds. The S—N(pyrrolidine) and S=N bond lengths are 1.6216 (18) and 1.503 (2) Å, respectively, for one cation, and 1.6236 (19) and 1.502 (2) Å, respectively, for the other. The dihedral angles between the two phenyl rings in the cations are 76.61 (9) and 76.42 (9)°. There are N—H...O hydrogen bonds, which link the cation and the anion. The cation–anion pairs are further linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional network.
