| This dissertation describes the usage of nitrogen and oxygenated ligand sets such as acetylacetone (acac), 6-phenyl-4,4'-bis(tert-butyl)-2,2'-bipyridine(NNC) on Iridium metal and diamine-bisphenolate (NNOO) on Rhodium for the activation of the C-H bonds of arenes and functionalization such as hydroarylation of olefins.;The first chapter is an introduction to CH activation and its importance towards CH bond functionalization. The use of acidic solvents for CH activation are also addressed and the catalyst inhibition by water or methanol. Approaches for the next generation of CH functionalization of catalysts are also addressed.;Chapter two addresses synthesis and characterization of air and thermally stables biamine-bisphenolate (NNOO)Rh(III)Cl(S) (X= Cl, Ph; S = H2O, CH3OH) type complexes with the objective of designing new CH activation catalyst precursors having predisposed cis coordination states for CH activation. NMR and X-ray diffraction studies revealed that the NNOO ligands coordinate to Rh as non-planar tetradentate ligands, with O,O donors either in a cis or trans position, depending on fairly subtle differences. DFT studies suggest that the preference for cis/trans-O,O is controlled by the bulk of the phenolate substituents, and the rigidity of the N-C-C-N bridge. Finally, transmetalation of the Rh Cl bond with Ph2Hg led to a Rh-Phenyl complex with conserved geometry.;Our group has been exploring the chemistry of electron rich, tridentate pincer, NNC ligated, Ir(III) homogeneous complexes in order to identify systems that could be sufficiently thermally, protic and oxidant stable to allow coupling of the CH activation and M-R Functionalization reactions to generate functionalized products in new catalytic systems. We had earlier demonstrated that Ir(NNC)(C 2H5)(TFA)(L) complexes where NNC is 6-phenyl-4,4'-(di-tert-butyl)-2,2'-bipyridine and L is NCCH3 or ethylene(C2H4) undergo stochiometric C-H activation of hydrocarbons at 110 0C. In chapter 3 we examine the mechanism for the catalytic H/D exchange between benzene and toluene with this system where R = Ph.;Chapter 4 summarizes the usage of air and water stable O-donor ligated, late metal complexes, (acac-O,O)2Ir(R)(L), based on the simplest beta-diketonate, acetylacetonate for the anti-Markovnikov, hydroarylation of unactivated olefins, which has been shown to operate by arene C-H activation followed by olefin insertion. |
