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Oxidation and hydrolysis in the system titanium (III)-oxygen-hydrogen has been studied by a variety of techniques in this work. Solids produced by base precipitation were poorly defined. Although they had an analytical formula corresponding to titanium trihydroxide, the absence of a sharp hydroxide stretching frequency in infra-red spectra showed that they were not simple hydroxides. Such solids, when dry, oxidized immediately upon contact with air to give poorly crystallised products. Heating caused crystallisation when alkali metal hydroxide had originally caused precipitation, the product contained both alkali metal hexatitanate and titanium dioxide of anatase structure; if aqueous ammonia had been the precipitating agent the solid consisted of the anatase structure alone. Aging of solids precipitated by alkali metal hydroxide yielded solely hexatitanates. In a similar manner, mixed alkali metal hexatitanates, of any composition, were prepared by aging and oxidizing the solid precipitated by controlled mixtures of aqueous alkali metal hydroxides. When zinc ions were also initially present, they too participated in the crystallisation process, yielding various zinc titanates. Precipitation by solid sodium hydrogen carbonate yielded poorly defined titanium trihydroxide rather than a carbonate. Hydrolysis products oxidized too quickly to be collected. Oxidized products had either the rutile or anatase structure; when a complexing anion was present the rutile structure was favoured, while the anatase structure was obtained when the anion was only weakly complexing. The thermal decomposition and oxidation of titanium (III) oxalate hydrate was also studied. An intermediate, titanyl oxalate, was observed, while the final, fully oxidised, product had the anatase structure at lower temperatures. Titanium (III) chloride hexahydrate and titanium (III) sulphate pentahydrate were also investigated. No stable intermediates were isolated; fully oxidized products had the anatase structure. A discussion of the various factors which influence the formation of the observed structures concluded this work.

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The subject of this thesis is the synthesis and characterisation of novel self-assembling 2-hydroxycarboxylic acids and triphenylenes, as well as the sol-gel synthesis of silica nanomaterials. Moreover, the studies of covalent or noncovalent interactions between the templates and silanes are also included. Chapter 1 contains a general introduction of two different strategies that can be used for the generation of nanomaterials, and different types of silica nanomaterials. Chapter 2 describes the use of organic bases as additives to stabilise the shortlived, 5- and 6- coordinate silicon species formed in the mixture of simple 2- hydroxyacid, glycolic aci~ (GA) and tetramethoxysilane (TMOS). The effects of various conditions including the ratios of reactants, the amount of water added, etc on the formation of silicon complexes are systematically investigated. Chapter 3 contains the synthesis and characterization of achira1 and chiral 2- hydroxycarboxylic acids with different substituents. Solubility and gelation studies are also included. Moreover, contained in this chapter is the investigatiqn of covalent interactions between 2-hydroxycarboxylic acids and TMOS by the combination of different characterization techniques. In addition, the generation of silica materials on the basis of gelation studies and covalent interactions is also discussed. Chapter 4 describes the synthesis and characterization of novel triphenylene compounds which may self-assemble into well-defined nanostructures. Followed by the investigation of the self-assembly of triphenylenes in different solvents and the use of triphenylenes as templates for the sol-gel synthesis of silica materials. Chapter 5 summarizes the whole project and proposes the future work.

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Metal fluorides (MgF3-, AIF4 - and BeF3-) have been used to mimic the transition state and ground state of phosphate transfer enzymes. The aim of this thesis is to study how phosphate transfer enzymes are able to achieve rate enhancements of 1021 over the uncatalysed reaction, using the full complement of metal fluoride analogues. NMR and X-ray crystallography have been used synchronically to extend the current knowledge of phosphate transfer in β-phosphoglucomutase (βPGM) and phosphoserine phosphatase (PSP). The charge balance theory proposes that the active site of phosphate transfer enzymes is set-up to neutralise the negative charge on the substrate and has been proposed in the literature using phosphoglycerate kinase. Chapter 3 of this thesis shows that the charge balance hypothesis holds true for ~PGM and highlights the importance of local charge in the active site. Chapters 4 and 5 establish the use of BeF3- as a ground state analogue in ~PGM. Complexes in the absence and presence of substrate, have been fully characterised by 19F NMR, IH and 15N chemical shift analysis including backbone assignment and X-ray crystallography. Key residues involved in cap and core domain closure have been recognised through this analysis. A minor conformer of the βPGM:MgF3-:G6P TSA complex was observed in the 19F NMR spectrum. Chapter 6 establishes the nature of this complex as arising from a change in geometry from trigonal bipyramidal to octahedral geometry around the central magnesium ion in the metal fluoride moiety. The full complement of metal fluoride complexes of PSP have been formed and characterised by 19F NMR in chapter 7. The 19F chemical shift and sum isotope shift for each fluoride has been recorded in each complex and has been compared to the available X-ray crystal structures to establish that the NMR and crystallography data report on the same structures.

In the first part of this thesis, the preparation of the known, compounds trans-(Et(_3)P)(_2)Pt(X)mC(_6)H(_4)F, and trans-(Et(_3)P)(_2)Pt(X)pC(_6)H(_4)F where X = C1, SnC1(_3) and of the new compounds trans-(Et(_3)P)(_2)Pt( GeC1(_3))mC(_6)H(_4)F and trans-(Et(_3)P)(_2)Pt(GeC1(_3))pC(_6)H(_4)F is described. Attempts to prepare further such compounds where X = SiMe(_3), GeBr(_3) were unsuccessful. The mass, infra-red, proton, magnetic resonance, fluorine magnetic resonance and X-ray photoelectron spectra of these compounds were recorded and the (^19)F n.m.r. and X-ray photoelectron spectra were used to investigate the trans-effect of the group IVb ligands, in these platinum-group IVb element complexes. In the first chapter the trans-effect theory is discussed. The second chapter is concerned with the experimental details and spectral data. The results obtained are discussed in the light of other evidence for the high trans-effect in platinum(ll)-group IVb compounds in Chapter 2. In Part II, the preparation of some methyleneamino derivatives containing groups R(_2)C:N- attached to silicon, germanium and phosphorus (R = t-butyl, p-tolyl, phenyl) is described. The new compounds prepared are [R(_2)C:N](_4) Ge, (R = phenyl, p-tolyl), [Bu(_2)(^t)C:N](_x) GeX(_4-x) (x = 1,2,3; X = Br, C1), and Me(_x)Si[N:C(p-tolyl)(_2)](_4-x) (x = 1,2) (Chapter 1) and P[N:CR(_2)](_3) (R = p-tolyl, phenyl), X(_2)P[N:CR(_2)] (X = C1, Ph; R = t-butyl, phenyl, p-tolyl) and OPC1(_x) (N:CR(_2))(_3-x') (R = t-butyl, p-tolyl, phenyl; x = 0,1,2) (Chapter 2). The mass, infrared and (^1)H nuclear magnetic resonance spectra were recorded and, for the phosphorus compounds the (^31)P n.m.r. spectra were recorded. These compounds were prepared with the object of finding model systems for the study of dative N=M π-bonding nitrogen and silicon, germanium and phosphorus. The shape (linear or bent) of the M-N-C skeletons (M = silicon,germanium and phosphorus) in these moisture sensitive methyleneamino compounds could not be unambiguously determined from the n.m.r. andinfrared spectral data obtained. The mass spectral data and molecular weight determination indicated the compounds to be in a monomeric state of association (^31)P n.m.r. data are discussed with reference to analogous isocyanate, isothiocyanate and amino derivatives of phosphorus, (Chapter 2).Attempts to prepare Bu(^t)(_2) C:NMe are described in Appendix 1 and experimental techniques, instrumentation and analytical methods are described in Appendices 2,3 and 4.