Four triorganotin(IV) esters based on 3,5-bifluorobenzenetelluronic acid: Syntheses, structures, in vitro cytostatic activity and BSA-binding assessment.

• Four new triorganotin(IV) esters based on 3,5-bifluorobenzenetelluronic acid. • Complexes 1 – 2 display dimeric structure, while 3 – 4 display monomeric structure. • In vitro cytostatic activity and BSA-binding properties of complexes 1 – 4 were tested. Four novel 3,5-bifluorobenzenetelluronic triorganotin(IV) esters, namely (3,5-F 2 C 6 H 3 TeOH) 2 (μ-O) 2 (OSnR 3) 4 (R = Me: 1 , R = Ph: 2) and (3,5-F 2 C 6 H 3 TeOH)(OSnR 3) 4 (R = Me: 3 , R = Ph: 4) have been synthesized and characterized by the reaction of deprotonated 3,5-bifluorobenzenetelluronic acid ligand and corresponding R 3 SnCl (R = Me, Ph). All the complexes have been characterized by means of elemental analysis, FT-IR, NMR (1H, 13C, 119Sn) spectroscopy, and X-ray crystallography. Structural analyses of these complexes reveal that complexes 1 and 2 exhibit centrosymmetric dimeric structure with an almost planar four-membered Te 2 (μ 2 -O) 2 core in the center, while 3 and 4 form monomeric structure with a single Te center. The Te atoms adopt octahedral geometry in all the complexes. Complexes 1 – 4 could form 2D or 3D supramolecular structures through intermolecular C-H···F or C-H···O interactions. Preliminary in vitro cytostatic studies show that complexes 1 – 4 exhibit effective cytostatic activity against human cervix adenocarcinoma cell lines (HeLa) and human hepatocellular carcinoma cell lines (HepG-2). For further assessing apoptosis properties of complex 2 , the levels of apoptosis were examined. The BSA-binding properties were investigated by means of fluorescence titration. The results indicate that complexes 1 – 4 could quench the intrinsic fluorescence of BSA. [ABSTRACT FROM AUTHOR]