Tin(IV) Schiff base complexes: Synthesis, thermodynamic and anti bacterial investigation, experimental and theoretical studies

Abstract

A series of five coordinated diorganotin(IV) unsymmetrical Schiff base complexes have been synthesized. The structure determination and characterization of these complexes were made on the basis of UV-Vis, IR, (¹H and ¹¹⁹Sn) NMR spectroscopy as well as elemental analysis. The binding site of the ligand was identified by IR spectroscopic measurement. Computational analyses at the level of DFT were performed to study its electronic and molecular structures. The molecular geometry, infrared vibrational frequencies, HOMO-LUMO energy gap, dipole moment, Mulliken charges, HF energies were calculated. The theoretical results were consistent with the experimental data reported. The Schiff base ligands and synthesized tin(IV) complexes were screened for their in vitro growth inhibiting activity against different strains of bacteria. Results indicated that the complexes exhibited good antibacterial activities than the ligands. Also the thermodynamic formation constants of the Schiff bases as donors with Me₂SnCl₂ as an acceptor were measured using UV-Vis spectrophotometric titration for 1:1 complex formation at constant ionic strength (I = 0.1 M NaClO₄) and at 25 ºC.

KEY WORDS: Tin(IV) complexes, Thermodynamic parameter, Biological activity, Computational analyses

Bull. Chem. Soc. Ethiop. 2019, 33(1), 77-90

DOI: https://dx.doi.org/10.4314/bcse.v33i1.8