Three organic salts of sparfloxacin, a difluorinated third-generation fluoroquinolone antibiotic, have been synthesized and their crystal structures determined. The salts, sparfloxacinium 4-nitrobenzoate dihydrate, C19H23F2N4O3+center dot C7H4NO4-center dot 2H(2)O (I), sparfloxacinium 2-phenylacetate,C19H23F2N4O3+center dot C8H7O2- (II), and sparfloxacinium 4-methylbenzoate trihydrate, C19H23F2N4O3-center dot C8H7O2-center dot 3H(2)O (III), exhibit similar inter-species packing interactions. The overall crystal structures each, however, have their own distinct characteristics, which are described here along with a Hirshfeld surface analysis of the various atom-atom contacts involving the sparfloxacinium cations. In the crystal structure of III, an extended supramolecular tape of edgefused hydrogen-bonded water pentagons was found. These pentagonal water and tape motifs are compared to related constructs in a broad selection of structure types, ranging from macromolecules to small molecules, clathrates, and exotic 'ice' formations on clean metal surfaces.
