Synthesis, structural analysis, and systematic exploration of the antitumor activities of triphenyltin(IV) 2-hydroxy-5-(phenyldiazenyl)benzoates through the modulation of trifluoromethyl variants

By reacting 5-[(E)-2-(2-trifluoromethylphenyl)-1-diazenyl]-2-hydroxybenzoic acid (H′HL³), 5-[(E)-2-(3-trifluoromethylphenyl)-1-diazenyl]-2-hydroxybenzoic acid (H′HL⁴), and 5-[(E)-2-(4-trifluoromethylphenyl)-1-diazenyl]-2-hydroxybenzoic acid (H′HL⁵), with the triphenyltin source Ph₃SnOH, three triphenyltin(IV) 2-hydroxy-5-(phenyldiazenyl)benzoates [Ph₃Sn(HL³)] (3), [Ph₃Sn(HL⁴)] (4) and [Ph₃Sn(HL⁵)] (5) were obtained. The resulting tin complexes were characterized using standard spectroscopic techniques and single-crystal X-ray diffraction (SC-XRD). Triphenyltin complexes 3–5 exhibit a monomeric distorted tetrahedral configuration, with the fluoro substituted 2-hydroxy-5-(phenyldiazenyl)benzoates coordinating in a monodentate fashion. Additionally, the crystal structure of H′HL⁵ is reported. Alongside these, two triphenyltin compounds [Ph₃Sn(HL¹)] (1) and [Ph₃Sn(HL²)] (2), are included to evaluate and compare their anti-proliferative properties. Here, HL¹ and HL² represent 5-[(E)-2-(phenyl)-1-diazenyl]-2-hydroxybenzoate and 5-[(E)-2-(4-fluorophenyl)-1-diazenyl]-2-hydroxybenzoate, respectively. The in vitro antiproliferative activity of the triphenyltin(IV) compounds 1–5 was evaluated against MCF-7 (human breast cancer), HeLa (human cervical cancer), and HEK-293 (normal human embryonic kidney) cells and a mechanism of action is proposed on the basis of various biological assays.