Crystal structure and X-ray photoelectron spectroscopy of ciprofloxacinium tetrachloroaurate monohydrate

The complex (CfqH(2)AuCl(4) center dot H2O ((CfqH(2))(+) is the ciprofloxacinium cation) was isolated and analyzed by spectral luminescence, X-ray photoelectron spectroscopy, and X-ray diffraction analysis. The central Au(III) atom has no direct interatomic contacts with the 1-cyclopropyl-6-fluoro-4-oxo-(1-piperazinyl)-1,4-dihydro-3-quinolinecarboxylic acid (CfqH) molecule. The structure is formed by the [AuCl4](-) anions having a square structure, (CfqH(2))(+) cations, and water molecules combined by hydrogen bonds. The protonation of CfqH occurs at the terminal nitrogen atom of the piperazinyl group. Core-level X-ray photo-electron spectra of carbon, oxygen, nitrogen, and fluorine were measured. Cleavage of the Su-Cl bond was shown to be the primary step of the photoinduced decomposition of the compound.