Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 203-217).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 55-57).

Thesis (Ph. D.)--University of Florida, 1984. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 298-307).

Thesis (Ph. D.)--University of Akron, Dept. of Chemistry, 2005. / "May, 2005." Title from electronic dissertation title page (viewed 09/24/2005). Includes bibliographical references.

Thesis (Ph.D.) - University of St Andrews, November 2009.

Thesis (Ph.D.) - University of St Andrews, May 2008. / Restricted until 29th May 2010.

Proefschrift Rijksuniversiteit Groningen. / Auteursnaam op omslag: Rob Hoen. Met lit.opg. - Met samenvatting in het Nederlands, Duits en Spaans.

The work described in this thesis concerns the synthesis of actinide complexes and their reactivity towards small unsaturated molecules. Complexes bearing tetraphenoxide, borohydride and boroxide ligands have been evaluated. Additionally, work towards the synthesis of heterobimetallic uranium transition metal complexes and their applications in catalysis is discussed. Chapter one reviews important organoactinide complexes reported in the literature which effect chemical transformations on small unsaturated substrates. Actinide complexes supported by aryloxide or borohydride ligands are reviewed, along with actinide complexes in which metal p-arene interactions are present. Chapter two reports the synthesis and characterisation of a set of tetraphenol ligands, in addition to a number of attempted synthetic routes to tetraphenol ligands with alternate substitution. The chemistry of those tetradentate aryloxide ligands is introduced with bimetallic uranium(IV) and thorium(IV) complexes using different An(IV) and U(III) precursors. Chapter three reports the synthesis and characterisation of monometallic uranium and thorium complexes using a tetraphenol ligand. The varying chemistry between the two similar An(IV) ions, where the uranium complexes exist as a mixture of oligomers and the thorium complexes remain as well defined mononuclear complexes, is discussed within. A range of base adducts of mononuclear actinide complexes are reported, including a thorium trimethylsilylazide complex, a rare example of a metal organoazide. Chapter four describes the synthesis of homoleptic boroxide and heteroleptic borohydride complexes of uranium(III). The reactivities of these complexes with small unsaturated molecules are assessed, including the reaction of a low coordinate uranium(III) boroxide complex towards CO2 to provide a dinuclear uranium carbonate bridged complex. Chapter five introduces work towards heterobimetallic uranium transition metal complexes carried out in the Arnold group. The application of these complexes towards ring opening polymerisation chemistry is discussed in addition to investigations into the incorporation of transition metals into uranium(IV) complexes. Chapter Six presents the detailed experimental methods used to carry out this research.

In an industrial application a GFAAS method for monitoring the Rh concentration in process streams is being used. Matrix effects are known to exist with the application of this technique; in fact, it was observed that different solvents lead to different results. Therefore, standard additions have to be employed for quantitative determinations, resulting in high costs and long analysis times. In an attempt to understand these interfering effects, fractional factorial designs were proposed to determine whether any GFAAS parameter was responsible for, or related to, the matrix effects. Seven GFAAS parameters were investigated: final temperature, ramp time and hold time of the transitions step (from the dry step); final temperature, ramp time and hold time of the ashing/pyrolysis step; ramp time of the atomisation step. The results showed that the matrix effects were not related to any specific parameter. A complete factorial design was implemented to demonstrate the fundamental role of the atomisation temperature. SEM analysis showed that the surface of the graphite tubes might be affected in different ways by different solvents. A Principal Component Analysis demonstrated that the matrix effects may be related to the viscosity and melting point of the solvents and may be independent of their molar mass. To identify the origins of these effects, an investigation on the link between the tube surface-sample matrix interactions and the physical properties of the matrices is recommended. Since GFAAS parameters cannot compensate for the matrix effects, standard additions remain the preferred mode of operation as it accounts for the effects in-situ. / Chemistry / M.Sc. (Chemistry)

A series of mononuclear complexes of general formula [M(η5-C5Me5)Cl3-n(pzH)n](n-1)+ (n = 1,2) has been prepared as a result of an investigation of the reactivity of pyrazole with rhodium and iridium cyclopentadienyl and pentamethyl-cyclopentadienyl precursors. These complexes are discussed in terms of the dynamic processes that are exhibited in the 1H NMR experiment and in terms of their use as precursors to dimeric species. Dinuclear complexes of formula [M(η5-C5R5)Cl(μ-pz)]2 containing pyrazolyl bridges have been prepared from the mononuclear compounds and from the chloro-bridged dimers of formula [M(η5-C5R5)Cl2]2 by treatment with triethylamine, but not from the dipyrazole iridium cation [Ir(η5-C5Me5)Cl(pzH)2]+ 26 which has been found to be unreactive to this type of symmetrical dimer formation: the low reactivity is attributed to a relative non-lability of the pyrazole groups. The dimeric complexes have been shown to undergo a core conformational change upon chemical reduction or halide abstraction. The chair conformation of the pyrazolyl bridged complex [Rh(η5-C5ME5)Cl(μ-pz)]2 38 has been proven crystallographically. Chloride abstraction from 38 yields the binuclear product [(Rh(η5-C5ME5)(μ-pz))2(μ-Cl)]BF4 46 which is bridged by two pyrazolyl and one chloride ligand and has been structurally characterized by X-ray diffraction to contain a boat conformation for the pyrazolyl framework. Reduction of either 38 or the C5H5 analogue 40 results in the metal-metal bonded dinuclear complexes [Rh(η5-C5ME5)(μ-pz)]2 48 and 49. The C5H5 complex 49 has been crystallographically determined to possess the boat conformation. The reactivity of the metal-metal bonded products has been investigated: one and two fragment addition is discussed and a number of oxidative addition products have been structurally characterized. The mononuclear dipyrazole iridium cation 26 which contains non-labile pyrazole groups is utilized to prepare mixed-metal and mixed-oxidation state dimers with the formula [Ir(η5-C5Me5)Cl(μ-pz)MLn]. The synthesis and potential for further investigation of these complexes is discussed. / Graduate