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))(I-2)](n)} (1), {[(Sb(Et2DTC)(2))(4) (SbI6) (I-3)](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, H-1, C-13 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 [I-2], while 2 consists of three residues, four cationic [Sb(Et(2)dtc)(2)](+), one [SbI6](3-) and one [I-3](-) 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. (C) 2016 Elsevier B.V. All rights reserved.