Synthesis, structure and cytotoxic activity of diethyltin N-[(2-oxyphenyl)methylene]phenylalaninates

Four new diethyltin N-[(2-oxyphenyl)methylene]phenylalaninates, (CH3CH2)(2)Sn[2-O-3-X-5-YC6H2CHNCH(CH2Ph)COO] (X, Y = H, H, 1; H, Br, 2; H, OCH3, 3; Br, Br, 4), have been synthesized and characterized using elemental analysis and infrared and NMR (H-1, C-13 and Sn-119) spectra. The crystal structures of 1, 2, 3, 4 have been determined. Compounds 1 and 2 have a 12-membered macrocyclic structure with a trimeric [Sn3O6C3] core. Each tin atom is six-coordinated in distorted [SnC2NO3] octahedral geometry. Compound 3 is a centrosymmetric weak dimer in which the two tin centers are linked by two asymmetric SnOSn bridges involving the phenolic oxygen of the ligand and two SnO interactions from ether oxygen of the adjacent ligand. The coordination geometry of the tin atom can be described as a distorted pentagonal bipyramid with two ethyl groups in axial positions. Compound 4 is a novel binuclear tin complex, formed by the carboxylate of a ligand asymmetrically bridging two tin atoms, which contains a five-coordinated tin and a six-coordinated tin. Bioassay results have shown that the compounds have weak in vitro activity against two human tumor cell lines, A549 and CoLo205. Copyright (c) 2016 John Wiley & Sons, Ltd.