synthesis, spectroscopic properties and biological activity of new mono organotin(iv) complexes with 5-bromo-2-hydroxybenzaldehyde-4,4-dimethylthiosemicarbazone

The organotin(IV) complexes [RSn(L)] (where R = Me (2), R = n-Bu (3), R = Ph (4); H2L (1) = 5-bromo-2-hydroxybenzaldehyde-4,4-dimethylthiosemicarbazone) have been synthesized by the reaction of organotin(IV) chloride(s) with H2L (1). All the compounds have been characterized by CHN analyses, UV–vis, FT-IR, 1H, 13C and 119Sn NMR spectral studies. The molecular structure of H2L (1) has been confirmed by X-ray crystallography. The infrared spectrum gives confirmation for the compound (H2L) in the thione form, which is supported with the observed bond lengths from the crystal structure. Spectral studies revealed that the dinegative tridentate ligand is bonded to the tin(IV) atom via phenolic-O, azomethine-N and thiolate-S atoms. 119Sn NMR data in DMSO-d6 suggested penta-coordinated Sn(IV) atom in solutions for all complexes (2–4). The compound, H2L (1) crystallizes into a monoclinic lattice with the space group P21/c, Z = 4, V = 1,191.75(8)Å3. The compounds were also tested for their antiproliferative activity against human colon cancer cell line (HCT 116) and displayed strong cytotoxic activities.