Synthetic approaches to multidentate thioether and pyridyl ligands

This thesis consists of three chapters. In the first chapter, a series of bis(pyridyl)siloxane ligands with various organosilicon spacer groups was synthesized that vary by the length and flexibility of the spacer units. These compounds were obtained by the silylation reaction of commercially available dichlorosilanes with pyridylcarbinol derivatives. The reaction procedure is straightforward and gives the products in high yields and high purity. Next, N-acyl-methionine was converted into pyridylamide derivatives by reaction with the corresponding pyridylamines in the presence of a coupling agent (EEDQ). These multidentate pyridyl ligands were obtained in good yields. All compounds were characterized by NMR spectroscopy and elemental analysis.;In the second chapter, silyl-substituted thioether ligands were prepared that differed in the identity and number of ligating groups attached to silicon and the nature of the alkyl groups on silicon. The ligand syntheses involved deprotonation of a thioether with n-butyllithium followed by reaction with the appropriate chlorosilane. Yields were 45--75% after purification. The newly synthesized ligands were reacted with silver triflate to form silver(I) dithioether complexes. The ligands and metal complexes were characterized by proton and carbon NMR spectroscopy and elemental analysis. The structures of the metal complexes were determined by X-ray crystallography.;In the third chapter, 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT) was used as a substrate for ionic thiol-ene reactions. By simply choosing different thiol starting materials, a wide variety of functionalization was introduced into the products. The reactions were typically complete within twenty minutes, and the products were obtained in high yields and excellent purity. Tripodal star-shaped oligomers were also prepared in high yield from TAT by alternating thiol-ene and acrylate esterification reactions. The combination of thioether groups and hydrogen bonding moieties suggest these products can be used as metal chelating ligands. All products were characterized by 1D and 2D NMR spectroscopy and elemental analysis.