This thesis focuses on materials whose properties are directly linked with the dimensionality of their structures. We utilise diffraction techniques to characterise three systems. The first of these is an organic crystal, 2,3,6,7,10,11-hexahydroxytriphenylene tetrahydrate that contains one-dimensional water channels. These channels are polar and net polarity is achieved at low temperatures. The structure undergoes a phase transition to a non-polar state at higher temperatures. Mapping this finding onto an Ising model is undertaken in this thesis. We also investigate the possibility of transforming the same crystals to an organic metal with oxidation. Furthermore, this work characterises two-dimensional layered structures silver(I) tricyanomethanide and nickel(II) cyanide. We show that the former possesses the unprecedented property of negative area compressibility and the latter shows ordinary compressibility behaviour. Both these structures exhibit area negative thermal expansion. Finally, we investigate copper(II) and cobalt(II) doping into the structure of nickel(II) cyanide and demonstrate that the latter leads to a 10-fold increase in area negative thermal expansion.

This thesis represents results of experiments involved in ultra-high resolution x-ray crystal structures of DNA. Detailed analysis of DNA coordinates of increased accuracy, refinement of individual anisotropic B-factors, visualization of disorder, counterions and hydration are presumably facilitated by the increased information of ultra-high resolution structures. However, recent survey of available DNA crystal structures with the data that extends beyond 1Ã... has brought a few areas of considerations; local conformational flexibility of DNA and counterions and how they have been interpreted in previous studies. While the results given here demonstrate both structural and surrounding details of DNA that may be undetected at lower resolution, some of the technical aspects of interpreting ultra-high resolution data is also addressed.

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The reaction between o-phenylenediamine and 2,3-dichloromaleic anhydride has been probed and found to give 2,3-dichloropyrrolo[1,2-a]- benzimidazol-1-one as the major product. Chlorine substitution in 2,3-dichloropyrrolo[1,2-a]benzimidazol-1-one by added benzylthiol occurs in the presence of pyridine to provide the corresponding monosulfide and disulfide derivatives. The first benzylthiol ligand undergoes reaction at the C-3 position of the five-membered pyrrolo-1-one ring, with the addition of the second benzylthiol ligand occurring at the remaining chlorine-substituted carbon. The mono- and disulfide derivatives have been isolated and characterized in solution by NMR, IR, and UV-vis spectroscopies, and the solid-state structure of 2,3-di(benzylthio)pyrrolo[1,2-a]benzimidazol-1-one has been established by X-ray crystallography.

X-ray diffraction techniques have been used to examine the structural chemistry of three compounds of Group II metals. The crystal structures of all three compounds were solved by the heavy atom method and refined, with three dimensional data, by the method of least squares.

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The myocilin olfactomedin domain (myoc-OLF) is linked to inherited forms of open angle glaucoma. Mutant myocilin accumulates within the endoplasmic reticulum of human trabecular meshwork cells leading to cell death and the build up of intraocular pressure, a common risk factor for glaucoma. In this work, a novel high affinity calcium-binding site buried within myoc-OLF was characterized. Additionally amyloidogenic peptide stretches within myoc-OLF that may be responsible for mutant myocilin aggregation were determined. Additionally the crystal structure of myoc-OLF was solved providing the first crystal structure of an olfactomedin domain protein. Insights from the structure into the relationship between disease causing mutations and myoc-OLF misfolding and the currently unknown function of myoc-OLF as explored by structural based prediction of ligand binding are also discussed.

No description available.

No description available.

No description available.