Organotin(IV) complexes derived from 1,4-naphthalenedicarboxylic acid: synthesis, structure, in vitro cytostatic activity.

• Diorganotin complexes show 2D network containing tetraorganodistannoxane units. • Organotin(IV) carboxylates with n -butyl and phenyl show higher antitumor activity. • Complexes 2 - 3 show lower cytotoxicity than organotin precursors in HBL-100 cells. • Complex 3 can lead to depolarization of mitochondrial membrane potential. • Complex 3 could induce cellular reactive oxygen species accumulation. Seven organotin(IV) complexes, [(R 3 Sn) 2 L] n (R = Me 1 , R = n -Bu 2), [(Ph 3 Sn) 2 L] (3), [(R 2 Sn) 2 L(μ 3 -O)] n (R = Me 4 , R = n -Bu 5), [R 2 SnL(1,10-phen)] n (R = Me 6), [(R 2 SnCl) 2 L(1,10-phen) 2 ] (R = n -Bu 7) derived from 1,4-naphthalenedicarboxylic acid (H 2 L) have been synthesized and characterized by elemental analysis, FT-IR, PXRD, NMR and X-ray crystallography. The single crystal diffraction reveals that complexes 1 and 2 represent 2D network structures, which both contain tetranuclear 26-membered macrocycles. Complexes 3 and 7 display dinuclear tin monomers, which can form 1D infinite chain by C-H ··· O and C-H ··· π interactions. Meanwhile, complexes 4 and 5 display 2D network containing tetraorganodistannoxane unit, while complex 6 adopts a 1D infinite chain structure, which further constructs 2D supramolecular architecture through C-H ··· O intermolecular interactions. What's more, in vitro cytostatic activity of the complexes 1 - 3 against cervical carcinoma cell lines (HeLa), hepatocellular carcinoma cell lines (HepG-2) and human normal breast cell lines (HBL-100) have been investigated, and the results show that organotin derivatives with n -butyl and phenyl group (2 and 3) exhibit significantly higher anticancer activity than complex 1 with methyl group. Meanwhile, organotin(IV) complexes (1 - 3) display lower cytotoxicity than corresponding organotin(IV) precursors [trimethyltin chloride, bis(tri- n -butyltin) oxide and triphenyltin chloride] in HBL-100 cells. Furthermore, cytostatic assessments of complex 3 against HepG-2 cells reveal that the effect of cytostatic and apoptotic may through ROS-mediated pathway. Image, graphical abstract [ABSTRACT FROM AUTHOR]