Novel europium(III), terbium(III), and gadolinium(III) Schiff base complexes: Synthesis, structural, photoluminescence, antimicrobial, antioxidant, and molecular docking studies

• Published in: Polyhedron 2025-01, Vol.265, p.117275, Article 117275
• Main Authors: Sogukomerogullari, Hatice Gamze, Başaran, Eyüp, Kepekçi, Remziye Aysun, Türkmenoğlu, Burçin, Sarıoğlu, Ahmet Oral, Köse, Muhammet
• Format: Article
• Language: English
• Subjects: Antimicrobial activity; Antioxidant activity; Lanthanide complex; Molecular docking; Photoluminescence; Schiff base
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2024.117275

Schiff base lanthanide complexes were synthesized. Broth microdilution and agar disk diffusion tests were used to evaluate the antibacterial activity of the compounds against various types of bacteria and fungi. In silico methods were used to determine binding modes and identify different targets for antibacterial and antioxidant assay results. [Display omitted] Three lanthanide (III) complexes, L-Eu, L-Tb, and L-Gd, were synthesized using a Schiff base ligand (H2L) composed of (2,2′-(thiophene-2,5-diylbis(methaneylyl-idene))bis(azaneylyl-idene))diphenol. Complexes with the generic formula LnL(Cl)(H2O)·xH2O, where L is the ligand, was studied using elemental analysis, spectrum analysis (IR, mass- UV–Vis), and molar conductivity. Next, the photoluminescence characteristics of the lanthanide complexes were investigated. An assessment was conducted to ascertain the antioxidant activity of the synthetic compounds compared with that of the stable free radical DPPH. The antibacterial activity of the Schiff base metal complexes was assessed against a strain of yeast as well as against a number of Gram-positive and Gram-negative bacteria. Computational studies were also performed to elucidate the mechanisms of the antimicrobial and antioxidant effects. In molecular docking, 1LL9, 6J2O, 3JPU, 2MBR, and 1HD2 crystal structures were determined as targets and the docking score values of H2L, L-Tb, L-Gd, and L-Eu compounds for these targets were calculated.