Preparation, structural characterization, voltammetry and Hirshfeld surface analysis of homoleptic iron(III) thiosemicarbazone complexes

Abstract

Reactions of FeSO4 precursor with thiosemicarbazones Hatc-R, where R is ethyl (Et) or phenyl (Ph), led to the formation of homoleptic iron(III) complexes of the type [Fe(atc-R)2]HSO4. The characterization of the compounds was performed by spectroscopy techniques, such as FTIR, UV–Vis, besides elemental analysis, conductometry, voltammetry and magnetic susceptibility measurement. The crystalline structure of [Fe(atc-Ph)2]HSO4·H2O was determined by single-crystal X-ray diffraction and revealed the oxidation of the Fe(II) centre to Fe(III) upon complexation of the monoanionic N,N,S-tridentate thiosemicarbazonate ligands. The magnetic susceptibility results showed the paramagnetic property of the iron(III) complexes in the extension of 1 unpaired electron. The electrochemical analyses showed a nearly reversible process of the iron complex, which is slightly influenced by the peripheral substituent groups at the N(4) position of the atc-R1− ligands. Hirshfeld surface analysis revealed that the supramolecular structure of [Fe(atc-Ph)2]HSO4·H2O is stabilized mainly by H···H, C···H/H···C and O···H/H···O interactions.