Synthesis, characterization, and cytotoxic activity of tricyclohexyltin(IV) carboxylates derived from cyclic dicarboxylic anhydrides

Abstract

Some tricyclohexyltin(IV) carboxylates, HOOC–R–COOSn(c-C6H11)3 (1) and (c-C6H11)3SnOOC–R–COOSn(c-C6H11)3 (2) [R = 1,2-C6H4 (a), 1,2-C6F4 (b), (Z)-CH=CH (c), CH2CH2 (d)], have been synthesized from reaction of tricyclohexyltin hydroxide with cyclic dicarboxylic anhydrides under microwave irradiation in 1 : 1 and 2 : 1 M ratio, respectively, and characterized by elemental analysis, IR and NMR (1H, 13C, and 119Sn) spectra. Crystal structures of 1a–1c and 2d are determined by X-ray single crystal diffraction. The carboxylate in each compound is monodentate to tin. Compounds 1a and 1c possess a trans-C3SnO2 trigonal bipyramidal geometry with axial positions occupied by carboxylate and carbonyl oxygen of carboxylate of an adjacent molecule forming a one-dimensional chain. Compound 1b is tetrahedral and forms R 2 2(8) hydrogen-bonded dimers by pairs of intermolecular O–HO hydrogen bonds between two carboxylic acid groups. Compound 2d is dinuclear with tin possessing distorted tetrahedral geometry; a trimer supramolecular structure is formed by weak intermolecular SnO interactions. The compounds have potent in vitro cytotoxic activity against two human tumor cell lines, A549 and HeLa.