A series of lanthanide complexes with 2‐fluoro‐N'‐(furan‐2‐ylmethylene) benzohydrazide ligand: Synthesis, characterization, luminescent properties and biological evaluation

Abstract

Lanthanide (III) complexes were synthesized with Schiff base ligand 2‐fluoro‐N′‐(furan‐2‐ylmethylene) benzohydrazide (L). These complexes were characterized using elemental analysis, molar conductivity measurements, spectral analysis, luminescence and thermogravimetric analysis. The Schiff base ligand is a tridentate chelate and coordinates to the central lanthanide ion with 1:2 metal‐to‐ligand ratio. The conductivity data show a 1:1 electrolytic nature with general formula [LnL2(NO3)2]NO3. Eu and Tb complexes exhibit the characteristic luminescence emissions of the central metal ions attributed to efficient energy transfer from the ligand to the metal centre. Most of the complexes exhibit antibacterial activity against a number of pathogenic bacteria. Furthermore, the antioxidant activity of the ligand and its Ln (III) complexes was determined using a radical scavenging method, which indicates that the Ln (III) complexes exhibit more effective antioxidant activity than the ligand.