Addition of tetraethylthiuram disulfide to antimony(III) iodide; synthesis, characterization and biological activity

Abstract

Three new antimony(III) iodide complexes with the N,N-diethylcarbamodithioic acid of formulae {[(SbI(Et2DTC)2)(I2)]n} (1), {[(Sb(Et2DTC)2)4 (SbI6) (I3)]n} (2) and {[SbI(Et2DTC)2]2} (3), (Et2DTCH: N,N-diethylcarbamodithioic acid, C5H11NS2) were synthesized from the reaction of antimony(III) iodide with tetraethylthiuram disulfide in 1:1 stoichiometry. The complexes 1–3 were characterized by melting point, elemental analysis, FT-IR spectroscopy, Raman spectroscopy, 1H, 13C NMR spectroscopy and Thermal Gravimetry–Differential Thermal Analysis (TG–DTA). Moreover, crystal structures of complexes 1–3 were determinated with single crystal X-ray diffraction analysis. Complexes 1–3 derived from ligand reduction with concomitant degradation of the tetraethylthiuram disulfide to dithiocarbamates. Complexes 1 and 2 are polymer but complex 3 is dimmer. Complex 1 consists of two residues, [SbI(Et2DTC)2] and [I2], while 2 consists of three residues, four cationic [Sb(Et2dtc)2]+, one [SbI6]3− and one [I3]− counter anion.Complexes 1–3 were evaluated for their in vitro cytotoxic activity against human breast adenocarcinoma (MCF-7) and human cervix adenocarcinoma (HeLa) cells. Structure Activity Relationship (SAR) studies reveal that the high activity of the complexes is positively correlated with the low H-all atoms intermolecular contacts.