Abstract:
An ever increasing global requirement for consumables consequently increases the demand for often non-renewable resources, resulting in the need for greater efficiencies in synthetic processes. In order to achieve this goal, the field of organometallic catalysis has been ever growing to support the ideals of cleaner and greener chemistry. In this thesis studies concerning a series of new bidentate donor ligands employing both the NHC and PYA donor groups for use in transition metal catalysis is presented. The successful synthesis of the bidentate ligand N,N’-dimethyl-N’’-pyridin-4-yl nicotinamide with both a remote NHC and PYA donor groups is reported, along with the synthesis of the precursor materials 1-methyl-3-(2-oxo-2-(pyridin-2-ylamino)ethyl)-1H-imidazol-3-ium and 1-methyl-3-(2-oxo-2-(pyridin-4-ylamino)ethyl)-1H-imidazol-3-ium for the formation of other bidentate ligands incorporating the imidazolium NHC and PYA donor groups. The iridium complex IrH(L-R4)(CO)(PPh3)2 containing the new ligand L-R4 was prepared through reaction of N,N’-dimethyl-N’’-pyridin-4-yl nicotinamide with Vaskas Complex. Chapter one explains the ideology behind green chemistry and our constant drive to maintain a clean and green planet. Chapter two describes the effect of donor groups on a metal centre with focus on the NHC and PYA donor groups and their advantages over previous work in this area. Chapter three describes the development of synthetic routes to the new target ligands and chapter four explains the studies involving the metal precursor substrates and ligand coordination. Chapter five contains details of the relevant experimental data. The work described in this thesis will provide an excellent starting point for those wishing to further explore the synthesis and study of bidentate NHC and PYA donor ligands in catalysis by transition metals.