Diorganotin Complexes with N(4)-Phenylthiosemicarbazones: Synthesis, Spectroscopic Characterization, and Antibacterial Activity

Abstract

The organotin(IV) complexes, SnPh2La (1), SnMe2La (2), SnBu2La (3), SnPh2Lb (4), SnMe2Lb (5), SnPh2Lc (6), SnMe2Lc (7), and SnBu2Lc (8) were obtained by reaction of SnR 2Cl2 (R = Ph, Me, and Bu) with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H2La), 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide (H2Lb), and 1-(2-hydroxy-3-methoxybenzylidene)-4-phenylthiosemicarbazide (H2Lc). The synthesized complexes have been investigated by elemental analysis, IR, 1H NMR, and 119Sn NMR spectroscopy. The data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination number of tin is 5. The in vitro antibacterial activities of the ligands and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and compared with the standard antibacterial drugs. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures and tables]