Bismuth(III) bromide-thioamide complexes: synthesis, characterization and cytotoxic properties

Abstract

AbstractNew bismuth(III) bromine compounds of the heterocyclic thioamides were prepared and structurally characterized. The reaction of heterocyclic thioamides with bismuth(III) bromide resulted in the formation of the {[BiBr2(μ2-Br)(MMI)2]2·CH3COCH3·H2O} (1), {[BiBr2(MBZIM)4]·Br·2H2O} (2), {[BiBr2(μ2-Br)(tHPMT)2]2·CH3CN} (3), {[BiBr2(μ2-Br)(PYT)2]2·CH3CN} (4) and {[BiBr2(μ2-Br)(MBZT)2]22CH3OH} (5) complexes (MMI: 2-mercapto-1-methylimidazole, MBZIM: 2-mercaptobenzimidazole, tHPMT: 2-mercapto-3,4,5,6-tetrahydro-pyrimidine, PYT: 2-mercaptopyridine and MBZT: 2-mercaptobenzothiazole). The complexes1–5were characterized by melting point (m.p.), elemental analysis (e.a.), molar conductivity, Fourier-transform infrared (FT-IR), Fourier-transform Raman (FT-Raman), nuclear magnetic resonance (1H and13CNMR) spectroscopy, UV-Vis spectroscopy and thermogravimetric-differential thermal analysis (TG-DTA). The molecular structures of1–5were determined by single-crystal X-ray diffraction. Complex2is a first ionic monomuclear octahedral bismuth(III) bromide, while the complexes1,3–5are the first examples of dinuclear bismuth(III) bromide derivatives. Complexes1–5were evaluated in terms of theirin vitrocytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The toxicity on normal human fetal lung fibroblast cells (MRC-5) was also evaluated. Moreover, the complexes1–5and free heterocyclic thioamide ligands were studied upon the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX).