by Ming Lok Yeung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 54-56). / ACKNOWLEDGMENT --- p.i / ABBREVIATION --- p.ii / ABSTRACT --- p.iii / CONTENTS --- p.iv / Chapter I. --- INTRODUCTION --- p.1 / Chapter II. --- RESULTS AND DISCUSSION --- p.8 / Chapter II-1 --- [3+2] CYCLOADDITION OF FISCHER CARBENE COMPLEXES WITH NITRONES --- p.8 / Chapter II-2 --- KINETIC STUDIES OF THE [3+2] CYCLO ADDITION --- p.18 / Chapter III. --- CONCLUSION --- p.35 / Chapter IV. --- EXPERIMENTAL --- p.36 / Chapter V. --- APPENDIX --- p.49 / Chapter V. --- REFERENCES --- p.54 / Chapter VI. --- LIST OF SPECTRA --- p.57 / Chapter VII. --- SPECTRA --- p.58

This thesis explores the design, synthesis and characterisation of iridium(III) complexes for optoelectronic applications; in particular, cationic [Ir(CˆN)₂(NˆN)]⁺-type emitters (where CˆN is an anionic bidentate cyclometalating ligand such as 2-phenylpyridinato, ppy, and NˆN is a neutral bidentate ligand such as 2,2'-bipyridine, bpy) for use in light-emitting electrochemical cells (LEECs). Design strategies aim to achieve high photoluminescence quantum yields (Φ[sub](PL)) for these complexes. Chapter 1 provides an overview of the fundamental photophysics of luminescent transition metal complexes, before reviewing state of the art iridium complexes employed in LEEC devices. Chapter 2 employs a combination of the electron-deficient 2,4-difluorophenylpyridine (dFppy) CˆN ligand and various functionalised biimidazole (biim) NˆN ligands. Within the family of different biim ligands the emission energy does not vary significantly, but the excited state kinetics di.er depending on the rigidity of the biim ligand. Combining the lead biim ligand with a sterically bulkier CˆN ligand gives an iridium complex that emits deep blue light with 90% Φ[sub](PL) in MeCN. Chapter 3 describes an approach to replacing the electrochemically unstable aryl carbon-fluorine bonds in dFppy, while maintaining the deep blue emission colour observed for the complexes in Chapter 2. Chapter 4 expands on the concept of rigid biim ligands to bibenzimidazoles (bibenz). Combining conjugated bibenz NˆN ligands with more conjugated CˆN ligands allows for the emission colour of these complexes to be tuned to the orange/red. The Φ[sub](PL) necessarily falls due to the energy gap law, but is nevertheless higher than values measured for reference complexes. Chapter 5 explores the use of an arylazoimidazole ligand with donor-acceptor intraligand charge transfer characteristics in order to red-shift the emission further. The resultant complex is poorly emissive, but shows a panchromic absorption profile and high molar absorptivity, which is unusual for iridium(III) complexes. The absorption profile can be tuned as a function of the protonation state of the imidazole.

Recent research has indicated that dissolved organic matter (DOM) may plan an important role in the ability of natural waters to complex metals. This research was conducted because the quantitative nature of this role is uncertain. Gas-liquid chromatography was used to study the hydrolyzable amino acids at twelve sampling sites on the Williamson River at monthly intervals for two years. The relative abundances showed little spacial or temporal variation. The two-year averages for total amino acids ranged from about 0.5 (mu)M to about 8 (mu)M. A separation technique was used to show that (GREATERTHEQ) 96% of the dissolved amino acids were associated with aquatic humus. Since it was found that amino acids contributed less than 1% to humic carbon and since a published report found that carbohydrates contributed less than 2% to humic carbon, this research provided the necessary data to conclude that DOM in the Williamson River is essentially aquatic humus. Humus complexation capacity is often operationally defined as amount of metal bound per unit weight of humus. This research has shown that the titrimetric methods commonly used to obtain this parameter underestimate its magnitude. However, it was shown that these methods can be combined with acidic functional group analyses to determine upper and lower limit for this parameter. For Williamson River humus, the range was 7.2 - 15.4 (mu)mols copper per mg humic carbon. Titrations of humus into a copper-oxalate metal-ion buffer enabled the determination of the copper-humus binding "constant" at humas : copper ratios found in the Williamson River, (LESSTHEQ) 4300. The binding "constant" was a variable and a function of pH. At a humus: copper ratio of 4300, the values of the function at pH 5.0, 5.5, 6.0, and 6.5 were: 3.0 x 10('6), 8.9 x 10('6), 3.0 x 10('7), and 1.7 x 10('8). Current models of metal-humus complexation, were shown to be inappropriate via rigorous mathematical examination and via application to computer-simulated titrations. A model, in which it is assumed that the concentrations of binding sites in humus are normally distributed with respect to the log of the metal binding constant for each site, is proposed. Application of this model to simulated titrations and to experimental data proved it to be superior to other current models.

Abstract not available

Includes bibliographies / 128 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1987

Thesis (Ph. D.)--Institute of Paper Chemistry, 1964. / Bibliography: leaves 90-93.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Platinum complexes (cisplatin, carboplatin and oxaliplatin) are effective anticancer agents. However the major drawbacks of platinum chemotherapy are toxic side effects and resistance. The affinity of platinum complexes to sulfur donor ligands of side chains of methionine and cysteine amino acids was assumed to be responsible for toxicity and resistance. Recently, it was found that the reaction of platinum complex with proteins containing sulfur donor ligands could actually favor its anticancer activity. Copper transporter 1 (Ctr 1), a protein involved in the transport of copper into the cell, also helps in the influx of cisplatin by binding to N-terminal domain of Ctr 1 which is rich in methionine and histidine residues. A better understanding of how the size and shape of amine ligand, and leaving groups affect the reaction of platinum (II) complexes with methionine could give new ways to optimize its anticancer activity. This preliminary research focuses to answer this by HPLC-UV-VIS analysis of bulky platinum complexes including [Pt(dien)Cl]Cl, Pt(Me4en)(NO3)2 and Pt(en)(NO3)2 with two methionine containing small peptides that serve as models for protein interactions.

The thesis outlines the development of novel cationic zinc complexes for application in lactide polymerization catalysis. These complexes were characterized spectroscopically and crystallographically, and where appropriate their efficacy as catalysts for the polymerization of lactide was evaluated. The strongly donating, neutral chelating ligands employed in this study were prepared by installation of either one or two phosphinimine donors on a dibenzofuran backbone. An efficient synthetic methodology was then developed for the synthesis of cationic complexes of the formula [LZnE+][BAr4-], wherein E = C2H5, CH3, Ph, C6F5, OAc, OC6F5, or methyl-(D,L)-lactate, and AR = Ph, C6F5, or m-(CF3)2-C6H3. Only the cationic zinc-lactate species were found to be highly active polymerization catalysts. Tuning of the steric and electronic properties of the ligand resulted in the discovery of zinc-lactate systems that promote rapid and well-controlled polymerization of lactide under mild conditions, marking the first well-defined cationic metal catalysts to do so. / xxiv, 254 leaves : ill. ; 29 cm + 1 CD-ROM

Bibliography: leaves 204-208 / 208 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1985