Synthesis, Structure, and Anticancer Activity of Two Organotin Heterocyclic Carboxylates Complexes

Two organotin heterocyclic carboxylate complexes di(o-bromobenzyl)tin bis(2-pyridinecarboxylate) (1) and tri(2-methyl-2-phenyl propyl)tin 3-indole butyrate (2) have been synthesized by a solvothermal method using methanol as solvent. The complexes were characterized by elemental analysis, IR spectroscopy, NMR (H-1, C-13, and Sn-119), X-ray diffraction, and thermogravimetric analysis. The crystal structures of the complexes were determined by X-ray single-crystal diffraction. The results show that the complexes have a single tin core structure, and the tin atoms are six-coordinate distorted octahedron configuration and four-coordinate distorted tetrahedron configuration respectively. The stabilities, orbital energies, and composition characteristics of some frontier molecular orbitals of 1 and 2 have been carefully investigated with quantum chemistry calculation. In addition, the in vitro antitumor activities suggest that 1 and 2 had higher activities than cisplatinum against human hepatoma cells (HUH7), human lung cancer cells (A549), human epidermal cancer cells (A431), human colon cancer cells (HCT-116), and breast cancer cells (MDA-MB-231). CCDC: 2133058, 1; 2133057, 2.