Structural study of the copper(II)–enrofloxacin metallo-antibiotic

The structure of [Cu(erx)2(H2O)2] complex was assessed using copper K-edge X-ray absorption spectroscopy (XAS) through X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) combined with EPR spectroscopy. A Jahn–Teller distorted octahedra was evidenced for Cu2+ geometry. Four equatorial oxygen atoms from two enrofloxacin ligands were found with Cu–Oeq distances of 1.93 Å (±0.02). The coordination was completed by two water molecules in axial position at an average distance of 2.11 Å.