Synthesis, crystal structure, antibacterial, antiproliferative and QSAR studies of new bismuth(III) complexes of pyrrolidineditiocarbamate of dithia-bismolane and bismane, oxodithia- and trithia-bismocane

Abstract

Four new bismuth(III) complexes; (CH2S)2Bi[S2CN(CH2)4] (2), CH2(CH2S)2Bi[S2CN(CH2)4] (3), S(CH2CH2S)2Bi[S2CN(CH2)4] (4), O(CH2CH2S)2Bi[S2CN(CH2)4] (5) were prepared from the reaction of the sodium salt of pyrrolidine-dithiocarbamate (1) with four chloro-dithia-bismuth(III) compounds containing five-, six- and eight-membered heterocycles. The complexes were characterized by elemental analyses, infrared, and 1H and 13C NMR spectroscopy. In addition, the single crystal X-ray structures of 2–4 were obtained, showing an asymmetric bidentate coordination mode of the dithiocarbamate ligand moiety. The metal center in 2 and 3 is tetracoordinated, while in 4 a pentacoordinate metal center is observed, the latter is achieved through the 1,5-transannular Bi⋯S interaction, which is common in these types of metallocane rings. Antibacterial assays showed that 2–5 were active in ATCC and clinical isolated strains. Antiploliferation assays were carried out showing high antiproliferative effect against breast cancer cell lines, in vitro. A QSAR model employing quantum global and local chemical descriptors was constructed to gain further insight into their antibacterial activity.