Syntheses and crystal structures of three salts of sparfloxacin, one incorporating extended tapes of fused pentagonal water assemblies

• Published in: Acta crystallographica. Section E, Crystallographic communications Crystallographic communications, 2022-12, Vol.78 (12), p.1257-1264
• Main Authors: Shankara Prasad, Holehundi J., Devaraju, Vinaya, Basavaraju, Yeriyur B., Yathirajan, Hemmige S., Parkin, Sean
• Format: Article
• Language: English
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989022011239

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, C 19 H 23 F 2 N 4 O 3 + ·C 7 H 4 NO 4 − ·2H 2 O ( I ), sparfloxacinium 2-phenylacetate, C 19 H 23 F 2 N 4 O 3 + ·C 8 H 7 O 2 − ( II ), and sparfloxacinium 4-methylbenzoate trihydrate, C 19 H 23 F 2 N 4 O 3 + ·C 8 H 7 O 2 − ·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 edge-fused 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.