Structural characterization and biological evaluation of antimony(III) and bismuth(III) complexes with imidazolidine-2-thione

Abstract

There is an emerging interest in the synthesis of antimony(III) and bismuth(III) complexes with sulfur containing ligands, this has been attributed to their wide structural diversity and their interesting application as biological agents. In the present work, four new antimony(III) and bismuth(III) complexes {[SbCl(IMT)3(μ-Cl)SbCl3(μ-Cl)]n} (1), {[SbBr2(IMT)2(μ-Br)]n} (2), {[BiBr2(IMT)2(μ-Br)]n} (3), and {mer-[BiI3(IMT)3]} (4) with imidazolidine-2-thione (IMT) have been prepared and characterized structurally, spectroscopically, and thermogravimetrically. The crystal structures of 1-4 have been determined by single-crystal X-ray diffraction. Complex 1 is the first structural example of polymeric antimony(III) chloride thioamide complex containing two different metallic centers. Complexes 2 and 3 are isostructural and the central atoms are six-coordinate in a distorted octahedral geometry with the zigzag chains formed by corner-sharing octahedra. Complex 4 is an example of neutral mononuclear bismuth(III) iodide complex with octahedral geometry. Complexes 1-4 have been evaluated for in vitro cytotoxic activity against human breast adenocarcinoma (MCF-7) cells. Complexes 1-4 appeared to show low cytotoxic activity against MCF-7 cells. The toxicity of 1-4 has been evaluated on normal human fetal lung fibroblast cells (MRC-5). The toxicity of antimony compounds 1-2 was greater than that of bismuth compounds 3-4. The influence of 1-4, on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) has been determined experimentally.