Green synthesis, spectroscopic characterization, and biological studies of some fluoroimine-based oxovanadium(V) complexes

Abstract Background In the realm of inorganic synthesis, the adoption of green chemistry principles has led to the utilization of "Microwave-assisted synthesis" as an energy-efficient methodology. Microwave irradiation, offering clean, cost-effective, and safe heating, outperforms traditional methods, resulting in more efficient reactions and higher yields. A new series of oxovanadium(V) complexes with four monobasic bidentate ligands L 1 (2-(2-fluorophenyl)methylene]hydrazinecarbothioamide, L 2 (2-{1-(2-fluorophenyl)ethyledene}]-hydrazinecarbothioamide), L 3 ([2-(2-fluorophenyl)methylene]-hydrazinecarboxamide)) and L 4 ([2-{1-(2-fluorophenyl)ethyledene}]-hydrazinecarboxamide) were synthesized by the condensation of ligands with VOCl 3 in 1:1 and 1:2 molar ratio in dry methanol using the microwave-assisted irradiation and traditional heating methods. The Schiff base ligands and their corresponding vanadium complexes were characterized by elemental analysis method, melting point and molecular weight determinations, IR, UV–Vis, 1 H-NMR, 13 CNMR, and X-ray powder diffraction. Result Based on these spectral elucidation penta and hexa-coordinated environments around the vanadium metal can be proposed for 1:1 and 1:2 complexes having square pyramidal and octahedral geometries, respectively. To evaluate biological studies, the ligands, and their respective complexes were screened for in vitro antibacterial, antifungal, DNA cleavage, and antioxidant activities. The results indicate that the vanadium (V) complexes are better antimicrobial and DNA-cleaving agents as compared to the parent Schiff base. The Schiff base complexes exhibit moderate to good scavenging activity and hence they are good antioxidant agents. Conclusion As a result, microwave-aided synthesis seems to be extremely helpful in energy savings and reaction sustainability. The chelating agents coordinated to the vanadium atom via oxygen/sulfur and azomethine nitrogen to create Penta and Hexa-coordinated environments around the vanadium(V) metal atom for the (1:1) and (1:2) vanadium (V) complexes having square pyramidal and octahedral geometry, respectively, based on analytical and spectroscopic evidence. The oxovanadium derivatives are more effective than the parent ligands in terms of DNA cleavage and antioxidant activity. Graphical Abstract