No description available.

by Chung Sai Cheong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 94-99). / DESCRIPTIVE NOTE / ABSTRACT --- p.iii / ACKNOWLEDGEMENTS --- p.v / Chapter CHAPTER ONE: --- INTRODUCTION --- p.1 / Chapter CHAPTER TWO: --- EXPERIMENTAL --- p.6 / Chapter 2.1 --- Synthesis --- p.6 / Chapter 2.2 --- NMR Measurement --- p.6 / Chapter 2.2.1 --- Solid State 59Co NMR --- p.6 / Chapter 2.2.2 --- Solution NMR --- p.7 / Chapter 2.2.2.1 --- 59Co NMR Measurements --- p.7 / Chapter 2.2.2.2 --- 13C NMR Measurements --- p.8 / Chapter 2.3 --- UV-Vis Spectral Measurements --- p.9 / Chapter 2.4 --- Computer Simulation --- p.10 / Chapter CHAPTER THREE: --- QUANTITATIVE CORRELATION OF SHIELDING ANISOTROPY AND NQCC - APPLICATION TO SOLVATION STUDIES OF OCTAHEDRAL COBALT (III)COMPLEXES / Chapter 3.1 --- Introduction --- p.11 / Chapter 3.2 --- Theory --- p.15 / Chapter 3.3 --- Results and Discussion --- p.20 / Chapter 3.3.1 --- The 59Co NMR Powder Spectrum of Diamagnetic Cobalt Complexes --- p.20 / Chapter 3.3.2 --- The Correlation of NQCC with Chemical Shift Anisotropy in the Solid State --- p.34 / Chapter 3.3.3 --- Application of Equation 3.16in Solution Studies --- p.39 / Chapter 3.3.3.1 --- The Chemical Shift --- p.39 / Chapter 3.3.3.2 --- The Effective Correlation Time --- p.48 / Chapter 3.3.3.3 --- The Nuclear Quadrupole Coupling Constant --- p.49 / Chapter 3.4 --- Summary --- p.51 / Chapter CHAPTER FOUR: --- 59Co AND 13C RELAXATION OF Co(acac)3 IN HYDROGEN BONDING (KALOMETHANE) SOLVENTS / Chapter 4.1 --- Introduction --- p.53 / Chapter 4.2 --- Results and Discussion --- p.57 / Chapter 4.2.1 --- The Static NMR Powder Spectrum Co(acac)3 --- p.57 / Chapter 4.2.2 --- Chemical shift --- p.60 / Chapter 4.2.3 --- Relaxation --- p.67 / Chapter 4.2.3.1 --- The 13C Relaxation --- p.67 / Chapter 4.2.3.2 --- The 59Co Relaxation --- p.71 / The Spin Rotation Interaction --- p.71 / The Temperature Behaviour of Relaxa- tion Rate --- p.72 / The Nuclear Quadru- pole Coupling Constant --- p.76 / The Correlation Time --- p.82 / Chapter 4.3 --- Summary --- p.90 / Chapter CHAPTER FIVE: --- CONCLUSION --- p.91 / REFERENCES --- p.94

Graduation date: 1997

No description available.

A series of SNS ligands have been successfully synthesised and characterised by IR, NMR and MS. The ligands are divided into two groups and represented by the general formulae: 2,6- bis(RSCH2)pyridine [R= methyl, ethyl, butyl, cyclohexyl, phenyl] and bis(RSCH2CH2)amine [R= ethyl, butyl, decyl]. Cobalt complexes of the respective ligands with the general formulae Co[2,6-bis(RSCH2)pyridine]Cl2 and Co[bis(RSCH2CH2)amine]Cl2 were synthesised and characterised by IR, elemental analysis and X-ray crystallography (for selected complexes). Thus, to investigate the electronic and steric effects of the ligand structure on the chemistry and reactivity of the complexes, the substituents bonded to the two sulfur donor atoms were sequentially varied and two different nitrogen sources were chosen. Crystal structures of Co[2,6- bis(CH2SCH2)pyridine]Cl2 (Ia), Co[2,6-bis(CH2CH2SCH2) pyridine]Cl2 (IIa) and Co[2,6- bis(CH2CH2CH2CH2SCH2)pyridine]Cl2 (IIIa) were obtained. It was found that complex Ia exists as a molecular dimer linked through two chloride bridges resulting in an octahedral geometry around each metal centre, while complexes IIa and IIIa are monomers exhibiting a trigonal bypyrimidal geometry. The complexes were tested as catalysts for the activation of paraffinic C−H bonds towards the formation of oxygenated products: octanol, octanone, octanal and octanoic acid from the substrate n-octane. Gas chromatography was utilised to quantify the products formed and also to calculate the conversion and selectivity of each catalyst system. The catalytic testing revealed that the ketone products were the most dominant with selectivities of ca. 90%. The catalyst that was the most active was Co[bis(CH2CH2SCH2CH2)amine]Cl2 (Ib) with a total n-octane conversion of 23%. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 111-115).

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: George C. Hadjipanayis, Dept. of Physics & Astronomy. Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 2000. / On t.p. "2̳", "x̳", "1̳-̳x̳" are subscripts. Vita. Includes bibliographical references.

The tricobalt cluster PhCCo3(CO)9 (1) reacts with the bidentate phosphine ligand 2,3-bis(diphenylphosphino)maleic anhydride (bma) in the presence of added Me3NO to give the diphosphine-substituted cluster PhCCo3(CO)7(bma) (2). Cluster 2 is unstable in solution, readily losing CO to afford Co3(CO)6[(μ2-η2/η1-C(Ph)C=C(PPh2)C(O)OC(O)](μ2-PPh2) (3) as the sole observed product. VT-31P NMR measurements on cluster 2 indicate that the bma ligand functions as both a chelating and a bridging ligand. At -97 °C, 31P NMR analysis of 2 reveals a Keq of 5.7 in favor of the bridging isomer. The bridged bma cluster 2 is the only observed species above -50°C. The solid-state structure of 2 does not correspond to the major bridging isomer observed in solution but rather the minor chelating isomer. The conversion of 2 to 3 followed first-order kinetics, with the reaction rates being independent of the nature of the reaction solvent and strongly suppressed by added CO, supporting a dissociative loss of CO as the rate-determining step. The activation parameters for CO loss were determined to be ΔH≠ = 29.9 ± 2.2 kcal/mol and ΔS≠ = 21.6 ± 6 eu.

Ho, Yuk Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references. / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Composite Materials --- p.1 / Chapter 1.2 --- General Properties of Composite Materials --- p.2 / Chapter 1.3 --- Fabrication of Composite Materials --- p.3 / Chapter 1.3.1 --- Liquid State Sintering --- p.4 / Chapter 1.3.2 --- Casting --- p.6 / Chapter 1.3.3 --- Other Fabrication Techniques --- p.7 / Chapter 1.4 --- Phase Transformation --- p.8 / Chapter 1.5 --- Nucleation and Growth --- p.10 / Chapter 1.5.1 --- Homogeneous nucleation --- p.10 / Chapter 1.5.2 --- Heterogeneous nucleation --- p.10 / Chapter 1.5.3 --- Growth --- p.11 / Chapter 1.6 --- Phase Separation by Spinodal Decomposition --- p.11 / Chapter 1.6.1 --- The Initiation of Spinodal Decomposition --- p.12 / Chapter 1.6.2 --- Dynamics of Spinodal Decomposition --- p.12 / Chapter 1.6.3 --- Difference between Coherent Spinodal and Nucleation and Growth --- p.17 / Chapter 1.7 --- Methods in Obtaining Large Under-cooling --- p.19 / References --- p.20 / Figures --- p.23 / Chapter Chapter 2 --- Experiment --- p.29 / Chapter 2.1 --- Introduction --- p.29 / Chapter 2.2 --- Preparation of Fused Silica Tubes --- p.29 / Chapter 2.3 --- Sample Preparation --- p.30 / Chapter 2.3.1 --- Alloying --- p.30 / Chapter 2.3.2 --- Fluxing --- p.30 / Chapter 2.3.3 --- Under-cooling --- p.31 / Chapter 2.4 --- Microstructure Analysis --- p.32 / Chapter 2.4.1 --- Sample Surface Analysis --- p.32 / Chapter 2.4.2 --- Scanning Electron Microscopy (SEM) --- p.32 / Chapter 2.5 --- Transmission Electron Microscopy (TEM) --- p.32 / Chapter 2.5.1 --- Specimen Requirement --- p.33 / Chapter 2.5.2 --- "Cutting, Grinding, Polishing and Pouching" --- p.33 / Chapter 2.5.3 --- Dimpling --- p.34 / Chapter 2.5.4 --- Ion Milling --- p.34 / Chapter 2.5.5 --- Microstructure Characterization by TEM --- p.35 / Chapter 2.6 --- Mechanical Properties --- p.37 / Chapter 2.6.1 --- Hardness Testing --- p.37 / Chapter 2.6.2 --- Compression Testing --- p.37 / Chapter 2.7 --- Characterizations of Untreated Samples --- p.38 / References --- p.39 / Figures --- p.40 / Chapter Chapter 3 --- Formation and Properties of Co-Si-B Metal Matrix Composites --- p.44 / Abstract --- p.44 / Introduction --- p.45 / Experimental --- p.46 / Results --- p.47 / Chapter A. --- Microstructures --- p.48 / Eutectic Co75Si15B10 --- p.48 / Network Co75Si15B10 --- p.48 / Chapter B. --- Mechanical Behavior --- p.50 / Eutectic Co75Si15B10 --- p.50 / Network CO75Si15B10 --- p.51 / Discussions --- p.53 / Conclusion --- p.53 / Acknowledgement --- p.54 / References --- p.55 / Figures --- p.56 / Chapter Chapter 4 --- On the Network Morphology of Co75Si15B10 Alloys --- p.68 / Abstract --- p.68 / Introduction --- p.69 / Experimental --- p.69 / Results --- p.69 / Discussions --- p.74 / Acknowledgement --- p.77 / References --- p.78 / Figures --- p.79 / Chapter Chapter 5 --- Conclusion --- p.100