Preparation, characterization, and computational study on transition metal complexes derived from thiophene Schiff base and evaluation of their cytotoxicity against hepatic cell line, antioxidant activities, and ligand's anticorrosive properties

Abstract

Novel thiophene Schiff base ligand (L) was synthesized through the condensation of 2‐thiophene‐methylamine and 3‐formyl‐4‐methoxyphenylboronic acid. Transition metal complexes with the formulae [M(L)(H2O)2Cl]Cl2.xH2O (M = Er(III), x = 4 and La(III), x = 5) and [M(L)(H2O)Cl2]Cl.xH2O (M = Yb(III), x = 4 and Ru(III), x = 0) were synthesized. Different spectral and physicochemical methods were used to confirm and identify the stoichiometry, structure, and bonding style of transition metal chelates. The creation of 1:1 molar ratio (M:L) complexes was supported by elemental data. According to IR spectra, the thiophene Schiff base ligand (L) acted as a tridentate ligand that is neutrally coordinated by S‐thiophene, N‐azomethine, and o‐methoxy groups. All chelates formed in octahedral structures according to the findings data. Thermogravimetric analysis (TG and DTG) was employed to examine the heat decomposition of these compounds. DFT/B3LYP method, a molecular modeling methodology, is used to support the expected shape of the produced ligand. Chemical hardness and softness, HOMO and LUMO energy levels, electrophilic index, bond lengths, angles, dipole moment, electronegativity, and other factors were calculated. Against HepG‐2 cell line, the in vitro anticancer activity of all chelates and free ligands was evaluated. These synthesized compounds showed good effectiveness. Additionally, DPPH scavenging was used to assess antioxidant activity, with extremely positive results. Molecular docking with the hepatic protein receptor 3ELJ was used to confirm the anticancer results. Finally, the effectiveness of the current thiophene ligand's ability to block Al‐Si alloys in 1 M HCl solution was examined utilizing electrochemical methods. The high inhibition efficiency was obtained revealing the effectiveness of using this thiophene Schiff base ligand on an industrial scale.