Crystal structure of ciprofloxacin hexahydrate and its characterization

Ciprofloxacin hexahydrate has been prepared and its crystal structure has been determined by X-ray crystallography. The molecule is in the zwitterionic form in solid state, the carboxylic proton being present at terminal piperazine nitrogen atom (N(74)) which is in contrast to the previously reported structures of quinolones. Water molecules are involved in a very complicated hydrogen bonding network. Different other techniques (IR, Raman spectroscopy, thermal and elemental analysis) were used to characterize the title compound and to compare its properties with similar compounds.