Crystal structure of ciprofloxacin hydrochloride 1.34-hydrate.

Ciprofloxacin belongs to a family of quinolone antibacterial agents. The crystal structure of ciprofloxacin hydrochloride 1,34-hydrate was determined. Most of the bond lengths and angles of the ciprofloxacin cation are very similar to those of ciprofloxacin hexahydrate, which appears in the zwitterionic form. The exceptions are the carbon-oxygen bond distances in the carboxylic group, since in the title compound this group is not deprotonated. Various inter- and intramolecular hydrogen bonds were found in the molecule and are described.