Synthesis, structural characterization and cytotoxicity of the antimony(III) chloride complex with N,N-dicyclohexyldithiooxamide

Abstract

The reaction of antimony(III) chloride with the bidentate substituted dithiooxamide ligand, N,N-dicyclohexyldithiooxamide (HDTOA), in 1:1 molar ratio, leads to the formation of the polymeric complex {[SbCl3(HDTOA)1.5]}n (1). The complex was characterized by FT-IR spectroscopy, 1H,13C NMR spectroscopy and TG–DTA analysis. Crystal and molecular structure of 1 was determined by X-ray diffraction analysis. Complex 1 ([C21H36Cl3N3S3Sb]) crystallizes in trigonal space group, with a=13.8829(2)Å, b=13.8829(2)Å, c=27.3440(5)Å, α=90.00°, β=90.00°, γ=120.00° and Z=12. The complex is polymeric consisting by [SbCl3(HDTOA)1.5] building blocks. The octahedral geometric demand of the metal center is covered by three mutually cis chlorides and three sulfur atoms from three different HDTOA ligands. Each HDTOA ligand bridged two metal centers of two units through their sulfur donor atoms, acting as bidentate bridging ligand forming a 3D network. Complex 1 was also, evaluated for its in vitro cytotoxic activity against leiomyosarcoma (LMS) and human breast adenocarcinoma (MCF-7) cell lines. The ID50 values were higher than the corresponding of cisplatin against these cell lines. Partial Least Squares (PLS) regression analysis was carried out to correlate the variation of the ID50 values (Y-variables) with the variations of energetic parameters (X-variables), calculated from molecular docking calculation.