4-(4-Methyl-phenyl-sulfon-yl)piperazin-1-ium tri-fluoro-acetate.

In the title salt, C11H17N2O2S(+)·CF3COO(-), the cation is protonated at the secondary piperazine N atom. The dihedral angle between the benzene ring and the piperazine mean plane is 85.54 (10)°. In the crystal, cations and anions are connected by two types of strong N-H⋯O hydrogen bonds into chains extending along [101]. The chains are further assembled into (10-1) layers via stacking inter-actions between benzene rings of the cations [centroid-centroid distance = 3.7319 (13) Å] and a C-H⋯O inter-action involving a piperazine C-H group and a sulfonyl O atom. Another C-H⋯O inter-action between the piperazine ring and the sulfonyl group connects the ions into a three-dimensional network.