Novel Low Spin Mixed Ligand Thiohydrazide Complexes of Iron(III): Synthesis, Spectral Characterization, Molecular Modeling, and Antibacterial Activity

Abstract

Mixed ligand complexes of Fe(III) with aromatic thiohydrazides of general composition [Fe(acac)(L) 2 ] have been synthesized and characterized (acac-acetylacetonate, L = bidentate uninegative aromatic thiohydrazide ligand, for example, thiobenzhydrazide, 2-hydroxythiobenzhydrazide, furan-2-thiohydrazide, and thiophen-2-thiohydrazide). The magnetic susceptibility data and the EPR spectra of these complexes suggested the formation of rhombically distorted low spin iron center (d 5 ) in octahedral environment, which was also supported by the UV-vis spectral data of the complexes. Biological studies of these complexes also indicated that the iron-thiohydrazido complexes have superior antibacterial properties compared to the corresponding ligands.

Crystal structure of N′-(2-phenylacetyl)thiophene-2-carbohydrazide monohydrate, C13H14N2O3S

“…[5] or under microwave irradiation of N,N′-diacylhydrazines by grafting onto polymer support [6][7][8]. Hydrazides are considered to be an important class of compounds with various types of biological activity such as anti-bacterial [9], anti-in ammatory, anti-cancer [10], anti-microbial [11,12], anti-fungal [9,13] and anti-biotic [13][14][15]. First, 2-phenylacetohydrazide was prepared following the reported method [16]; the product was obtained as white crystals from ethanol in yield 86% (Lit.…”

New mixed‐ligand iron(III) complexes containing thiocarbohydrazones: Preparation, characterization, and chemical reactivity analysis through theoretical calculations

“…New bands observed in all the complexes in the range of 1565–1558 and 1277–1266 cm −1 are assigned to C=O and C–O stretchings of the acetylacetonate group (co‐ligand), respectively. [ 52–56 ]…”

“…New bands observed in all the complexes in the range of 1565-1558 and 1277-1266 cm À1 are assigned to C=O and C-O stretchings of the acetylacetonate group (co-ligand), respectively. [52][53][54][55][56] In the UV-Vis spectra of the mixed ligand Fe(III) complexes, the ligand absorption bands are dominated. The n !…”