Synthesis, thermal analyses, characterization and biological evaluation of new enrofloxacin vanadium(V) solvates(L) (L = An, DMF, Py, Et3N and o-Tol)

• Synthesis and isolation of some new vanadium(V)complexes with enrofloxacin as antibacterial agent.
• Characterization of the isolated solid complexes by spectroscopic techniques.
• The lowest energy model structure and the effect of L on the distribution of charge density over all atoms in the complexes and nature of HOMO and LUMO have been proposed by using the density functional theory (DFT) method.
• Studying the biological activity of enrofloxacin complexes.

Five metal complexes of antibacterial agent enrofloxacin with vanadium(V) in the presence of aniline, pyridine, orthotolidine and triethylamine as nitrogen donor molecules and dimethylformamide as oxygen donor molecule have been prepared and characterized with physicochemical and diverse spectroscopic techniques (IR, UV–Vis. and 1H NMR spectroscopes) as well as thermal analysis. The deprotonated enrofloxacin complexes of V(V) were isolated as solids with the general formulas; [VO(Enr)2DMF]Cl·5H2O, [VO(Enr)2An]Cl·2H2O, [VO(Enr)2o-Tol]Cl·H2O, [VO(Enr)2Py]Cl·4H2O and [VO(Enr)2Et3N]Cl·6H2O. The prepared complexes are formed with a metal to ligand ratios as 1:2:1 for all complexes. The lowest energy model structure of each complex has been proposed by using the density functional theory (DFT) at the B3LYP/CEP-31G level of theory. The energy barrier for the pyridine complex greater than others complexes while, Et3N complex has lower value. The ligand and their metal complexes were also evaluated for their antibacterial activity against three Gram (+ve) and three Gram (−ve) microorganisms.

Five vanadium(V) complexes with enrofloxacin drugs were synthesized and characterized using IR, UV–Vis, 1H NMR and thermal analyses techniques. Antibacterial behavior was investigated and the structures were confirmed by using DFT at the B3LYP/CEP-31G level of theory.Figure optionsDownload as PowerPoint slide