Description:
<jats:title>Abstract</jats:title>
<jats:p>An extended x-ray absorption fine structure (EXAFS) for L<jats:sub>III</jats:sub> Eu crystal edge at 6977 eV energy was studied on an original complex based on europium. The ligand was coordinated entirely with respect to europium atom for [Eu(dafone)<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub>.(H<jats:sub>2</jats:sub>O)<jats:sub>2</jats:sub>](Cl)(H<jats:sub>2</jats:sub>O), where dafone is 4,5-diazafluoren-9-one. The EXAFS spectra showed close-neighbor correlations between europium and nitrogen atoms as well as to the adjoining carbon backbones on macrocyclic cages, which resulted in the bond lengths, the Debye-Waller factor, and coordination numbers. The Eu (III) complex <jats:italic>in vitro</jats:italic> antibacterial efficacy on a set of Gram-negative bacteria and Gram-positive bacteria showed that the complex displays marked antibacterial behavior. The minimum complex inhibitory concentrations showed that the Eu complex displays significantly higher antibacterial impact on conventional <jats:italic>Staphylococcus aureus</jats:italic> and <jats:italic>Escherichia coli</jats:italic> bacterial strains compared to those of silver sulfadiazine and europium nitrate. The Eu (III) bacterial inhibitions are closely linked to relevant DNA binding affinities.</jats:p>