title: 9-(3-Fluoro-phen-oxy-carbon-yl)-10-methyl-acridinium trifluoro-methane-sulfonate monohydrate.
abstract: In the crystal structure of the title mol-ecular salt, C(21)H(15)FNO(2) (+)·CF(3)SO(3) (-)·H(2)O, the cations form inversion dimers through π-π inter-actions between the acridine ring systems. These dimers are linked via C-H⋯O and C-F⋯π inter-actions to adjacent anions, and by C-H⋯π and C-F⋯π inter-actions to neighbouring cations. The water mol-ecule links two sites of the cation by C-H⋯O inter-actions and two adjacent anions by O-H⋯O hydrogen bonds. The mean planes of the acridine and benzene ring systems are oriented at a dihedral angle of 15.1 (1)°. The carboxyl group is twisted at an angle of 84.5 (1)° relative to the acridine skeleton. The mean planes of the acridine ring systems are parallel in the crystal.
authors.affiliation: Faculty of Chemistry, University of Gdańsk, J. Sobieskiego 18, 80-952 Gdańsk,  Poland.
authors.forename: Damian
authors.initials: D
authors.lastname: Trzybiński
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ożóg
authors.forename: Karol
authors.initials: K
authors.lastname: Krzymiński
authors.forename: Jerzy
authors.initials: J
authors.lastname: Błażejowski