The objective of this thesis is to explore quinoline and pyridine functionalized multidentate ligand systems that are capable of accommodating two metal species and to study the reactivity of the resulting bimetallic complexes, in the aim of investigating potential synergistic effects between the metal centres. A series of functionalized 1,2,4,5-tetrakis(quinolin-8-yl)benzene ligands were synthesized. The dinuclear platinum complexes of these ligands could activate C-Cl bonds of chlorinated solvents and dearomatize the central benzene ring of the ligand concurrently. A series of extended ligands where the central benzene ring was replaced by trans-stilbene, diphenylacetylene and pyrene groups were synthesized in order to explore more ligand-based reactivity. Two dinuclear diphenylplatinum complexes were synthesized. A series of mono- and bis-quinolinyl functionalized thiophene ligands have also been synthesized. Dinuclear platinum complexes of the bisquinolinyl thiophenes were isolated, which represented the first group 10 metal complexes of η2-thiophene, a long sought-after intermediate relevant to the hydrodesulfurization (HDS) process. Oxidation of these diplatinum complexes by MeOTf led to the isolation of mononuclear chiral five-coordinate platinum(IV) complexes, and a ligand twisting mechanism of these complexes was proposed on the basis of dynamic NMR studies and DFT calculations to elucidate the interconversion of two enantiomers. The reactions of monoquinolinyl functionalized thiophenes and [Pt(CH3)2(SMe2)]2/[PtH(dippe)]2 led to selective C-H/C-S bonds activation of the thiophene moieties respectively. A luminescent U-shaped bis-dipyridylamine functionalized anthracene ligand was designed and synthesized. This compound was fabricated into OLED devices and shown to be a promising emissive material. As a ligand, it adopted different coordination modes, acting as either binucleating double bidentate ligand, or mononucleating tetradentate ligand. Three dirhodium, dizinc and monozinc complexes were synthesized. Pyridine and phosphine functionalized 4,5-diazafluorene ligands were synthesized and the former ligand served as a mononucleating ligand via the two nitrogen donor atoms of the diazafluorenyl moiety while the latter ligand could act as a binucleating ligand via the phosphorus donor atom, two nitrogen donor atoms and the carbon donor atom. Several Ru, Rh, Pt, Cu and Au complexes were synthesized, and two Pt-Pt, Pt-Cu bimetallic complexes were isolated and characterized based on the phosphine functionalized ligand.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 167-187). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 167-187). Also available on the Internet.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--University of Hong Kong, 1986.

published_or_final_version / Chemistry / Master / Master of Philosophy

No description available.

Homogeneous organometallic species serve as useful catalysts for a vast number of chemical transformations. Ancillary ligands which bind to the metal center are employed to modulate the reactivity of the metal, and have been key to the discovery and improvement of most types of transition metal-mediated reactions. This thesis describes the design and application of P,N-ligands in platinum group-catalyzed reactions, specifically the Ru- and Ir-catalyzed ketone transfer hydrogenation (TH) and the Pd-catalyzed cross-coupling of aryl (pseudo)halides and N-H containing substrates. A zwitterionic Ru-species featuring a donor substituted P,N-indenide ligand was found to be an excellent catalyst for ketone TH, providing turnover frequencies (TOFs) as high as 300 000 h-1, while related cationic Ru-complexes ligated by P,N-indene ligands were found to be rather poor catalysts. Ir-complexes supported by either indene or indenide P,N-ligands were also found to be active TH catalysts (TOFs ~30 000 h-1), however phenylene P,N ligands, specifically (o-tBu2P-C6H4)NMe2, displayed optimal catalytic performance, allowing for rapid ketone reduction (TOFs of >100 000 h-1), at low catalyst loadings (as low as 0.004 mol% Ir). Enantioselective TH was achieved by employing the suitably substituted, commercially available P,N-ligand, Cy-Mandyphos in combination with [Ir(COD)Cl]2 and NaPF6. The use of P,N-ligands in Pd-catalyzed C-N cross coupling, specifically (o-R2P-C6H4)NMe2 (R = tBu or 1-Ad), allowed for the development of a highly versatile catalyst system for this reaction. In combination with [Pd(allyl)Cl]2 or [Pd(cinnamyl)Cl]2, the above described ligands enabled the cross-coupling of aryl and heteroaryl chlorides and bromides to a diverse range of amine and related substrates such as primary alkyl- and arylamines, cyclic and acyclic secondary amines, N-H imines, hydrazones, lithium amide, and ammonia. Reactions could be performed at low catalyst loadings (0.5-0.02 mol% Pd) with excellent functional group tolerance and chemoselectivity. The ligand N-[2-di(1-adamantylphosphino)phenyl]morpholine in combination with [Pd(cinnamyl)Cl]2 was found to provide excellent reactivity for the cross-coupling of ammonia to aryl chlorides with catalyst loadings of 0.3-5 mol% Pd. Sterically unbiased substrates containing electron-donating groups were tolerated with minimal competing diarylation. Aryl tosylates could be coupled with ammonia at room temperature and chemoselective ammonia arylation in the presence of other amine functionality was well tolerated. Pd-catalyzed cross-coupling of hydrazine with aryl chlorides and tosylates was achieved employing N-[2-di(1-adamantylphosphino)phenyl]-morpholine as the ligand. Good yields of the desired, mono-functionalized aryl hydrazine product was observed for a range of substrates at 5 mol% Pd. Selective hydrazine coupling was observed in the presence of other NH-functionality and NH-indazoles could be prepared by the tandem cross-coupling/condensation of hydrazine with 2-chlorobenzaldehydes.

No description available.

No description available.