Coordination of thiosemicarbazones and bis(thiosemicarbazones) to bismuth(III) as a strategy for the design of metal-based antibacterial agents.

Complexes [Bi(2Fo4Ph)Cl(2)] (1), [Bi(2Ac4Ph)Cl(2)] (2), [Bi(2Bz4Ph)Cl(2)] (3), [Bi(H(2)Gy3DH)Cl(3)] (4), [Bi(H(2)Gy4Et)(OH)(2)Cl] (5), and [Bi(H(2)Gy4Ph)Cl(3)] (6) were prepared with pyridine-2-carbaldehyde 4-phenylthiosemicarbazone (H2Fo4Ph), 1-(pyridin-2-yl)ethanone 4-phenylthiosemicarbazone (H2Ac4Ph), phenyl(pyridin-2-yl)methanone 4-phenylthiosemicarbazone (H2Bz4Ph), as well as with glyoxaldehyde bis(thiosemicarbazone) (H(2)Gy4DH) and its 4-Et (H(2)Gy4Et) and 4-Ph (H(2)Gy4Ph) derivatives. The complexes exhibited antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Pseudomonas aeruginosa. Coordination to Bi(III) proved to be an effective strategy to increase the antibacterial activity of the thiosemicarbazones and bis(thiosemicarbazones).