Investigation (IR, UV-visible, fluorescence, X-ray diffraction and thermogravimetric) studies of Mn(II), Fe(III) and Cr(III) complexes of thiosemicarbazone derived from 4- pyridyl thiosemicarbazide and monosodium 5-sulfonatosalicylaldehyde and evaluation of their biological applications

Abstract

Trivalent chromium, iron and divalent manganese complexes of thiosemicarbazone ligand (NaH3PyTSC) were synthesized. The complexes were considered by analytical and spectral methods. IR spectra proposed that the ligand behaves as a binegative tridentate ONS in [Mn(H2PyTSC)(H2O)]2 and [Fe(H2PyTSC)(H2O)2Cl]2 via the deprotonated SH, (C=N)az and SO3 group and as a tri-negative tetradentate O2NS in [Cr(HPyTSC)(H2O)2]2.H2O complex through deprotonated of thiol (SH) group, SO3 group,OH group,and the nitrogen of (C=N)az. Based on UV-visible spectra and magnetic data, the tetrahedral geometry is suggested for [Mn(H2PyTSC)(H2O)]2 complex and octahedral geometry for both [Cr(HPyTSC)(H2O)2]2.H2O and [Fe(H2PyTSC)(H2O)2Cl]2 complexes. The photochemical activities of the complexes under study were discussed. The proposed coordination geometries were further confirmed by means of geometry optimization using DFT calculations. The thermogravimetric analysis of the Mn(II) and Cr(III) complexes were achieved, also, the kinetic and thermodynamic parameters were calculated by utilizing of the Coats–Redfern and Horowitz–Metzger equations. The cyclic voltammetry studies of Mn(II) in absence and presence of the ligand was performed. Molecular docking of both Cr(III) and Mn(II) complexes against cell lines HePG-2, MCF-7 and HCT-116 targets, displayed good docking scores. Biological studies for the prepared compounds were investigated for their antioxidant, anticancer, DNA, and antimicrobial potencies.