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.

Copper(II) complex with a fluoroquinolone antibiotic (enrofloxacin) has been synthesized. It has been characterized by EPR and X-ray absorption (EXAFS and XANES) spectroscopies.Figure optionsDownload as PowerPoint slideHighlights
► Copper enrofloxacin complex was synthesized and fully characterized.
► EPR combined with XAS studies underlines a tetragonal distorted octahedral geometry.
► Enrofloxacin is bound to Cu2+ through carboxylate and pyridone moieties.