Crystallographic investigations have been carried out on 11H-benzo[b]indeno[3,2-e] pyran and its 2-bromo-substituted derivative, and the crystal structure of both compounds has been determined. The intensity data for both compounds was collected on a 4-circle single-crystal diffractometer. A small section of this work has been devoted to the practical details relating to the mode of operation of this instrument. 2-bromo-11H-benzo[b]indeno[3,2-e] pyran crystallises in the monoclinic system: a = 7.508, b = 5.959, c = 26.172 A, mu = 92.55°, ? = 4, space group P21/c. The structure was solved by Fourier methods and refined by full-matrix least squares to R = 0.072. 11H-benzo[b]indeno[3,2-e] pyran crystallises in the orthorhombic system; a = 22.425, b = 5.816, c = 16.398 A, ? = 8, space group Pca21. This structure, solved by direct methods and refined by full-matrix least squares to R = 0.122, is characterised by having two molecules per asymmetric unit related by a pseudo-centre of symmetry. Both molecules show a non-planar configuration and lack of aromatic character within their central regions. Molecular orbital calculations by Huckel and CNDO methods have been carried out on both molecules and a comparison of the calculated and experimental bond lengths has been made. The results of these calculations have also been used in an attempt to explain the characteristic mode of packing of the two molecules.

The principal basis for the following work is to demonstrate the importance of controllable crystallisation and consequential applications for both silica-based significant inorganic materials and carbonaceous materials. Microemulsions have been employed as a vector to explore the possibility of thermodynamically controlling the crystallisation process, utilising the 3D confinement of crystallisable material within nano-scale droplets. This opens a route to circumvent Ostwald’s Rule of Stages, for a multitude of potential applications. We show here that both quartz and nanographite can be synthesised at room temperature and pressure using this methodology. Previous attempts at silica synthesis from within the microemulsion have only presented the amorphous phase, leaving many questions unanswered, whilst failing to reveal the underlying cause. Further, traditional methods of quartz synthesis employs hydrothermal conditions, or temperatures >1100 0C. Microemulsions were adopted to behave as confined mini reactors for the synthesis of α-quartz at room temperature and pressure from a precursor from sodium metasilicate nonahydrate (SMS) which can be used as a precursor of silica, circumnavigating the traditional hydrothermal methodologies. At higher supersaturations, both the metastable amorphous phase and the high temperature polymorph, cristobalite were also observed. Upon the acidification of the microemulsions, the size and morphology of the quartz nanoparticles was found to be dependent upon the pH and the ratio of surfactant:silica units. Conventional wisdom stipulates that graphite can only be produced using high temperatures, with natural graphite arising via progressive metamorphisms of carbonaceous material subjected to temperatures above ~600 K and pressures >2 kbar. Previous attempts to use carbohydrate precursors have resulted in the formation of luminescent carbon dots or required templation, followed by calcination. In these prior investigations, high temperatures or extremely severe reactants are used to drive the precipitation of graphitic forms. Analogous experiments were successful in employing the 3D nano-confinement microemulsions as confined mini reactors for the synthesis of nanographite at room temperature and pressure from a sucrose precursor, through a simple process of acidifying sucrose microemulsions. Crucially, the reaction was conducted in nanometre-sized microemulsion droplets to exert control over the reaction and sheet stacking process, ensuring that only sufficiently pristine graphene nanosheets could stack, thereby producing nanographite in a simple one-step synthesis under ambient conditions. The primary nanographitic particles of size ~3-30 nm stacked to form larger µm-sized nanographitic aggregates. The amount of nanographite produced from the microemulsions is limited as sucrose concentration must be kept very low to slow the reaction kinetics to ensure the mainly graphitic, rather than amorphous, product.

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The crystal growth of ibuprofen as a function of crystallisation environment is presented. Measurement of solubility as a function of solvent (ethanol 95%, ethyl acetate, acetonitrile and toluene) and temperature using UV/Vis spectroscopy and gravimetric analysis reveals less than ideal behaviour, consistent with strong solute-solute interactions, particularly in the case of acetonitrile. Examination of the nucleation kinetics reveals a comparatively small metastable zone width (MSZW) (ΔT = 10.0 - 13.9oC) with interfacial tensions in the range 2.56 – 5.52.10-3 (J/m2). The growth rates for the {001} and {011} faces of spontaneously nucleated single crystals are precisely measured in-situ using optical microscopy revealing that their growth rates increase with increasing supersaturation to different extents, depending on the solvent type with concomitant impact on the crystal habit. For similar supersaturations, the growth rate of {011} is lowest in ethanol and highest in acetonitrile, whilst that of {001} is lowest in toluene and highest in ethanol. The aspect ratios, as a function of supersaturation, are generally higher at the 15 mL than the 0.5 mL crystalliser scale size. The data is consistent with a 2-D Birth and Spread growth model for both surfaces and scale sizes. This is in good agreement with the calculated surface entropy α factor. The measured growth rate dispersion for these faces is much less for these spontaneously nucleated crystals in stagnant, supersaturated solutions when compared to the literature data obtained for a stirred batch crystalliser. Additional higher index re-entrant faces are found at high levels of supersaturation consistent with their alignment either parallel to the {012} or {112} face. The growth rate in the non-agitated jacketed vessel is found to be slightly higher than that for the agitated reactors with both being in quite in a good agreement with literature data suggesting that these results on single crystals will have utility in representative the growth rates of a population of crystals in an agitated crystallizer. Observations are is rationalised using molecular and crystallographic modelling revealing e.g. that polar protic solvents inhibit the growth rate of faces containing available hydrogen bonding binding sites, such as carboxylic acid groups. Molecular conformational searching reveals the molecular structure in the solid-state to be close to that of molecules minimum intra-molecular energy. Conformer population analysis as a function of solvent reveals no significant solvent effect on the low energy conformer distribution indicative a low likelihood of polymorphic behaviour for this compound in good agreement with literature.

Colloidal crystals have been the focus of intense scientific interest owing to the wide range of proposed applications, including photonic crystal devices, sensor arrays and templates for three-dimensionally ordered macro-porous materials (3-DOM). The broad spectrum of interest stems from the exciting structural properties these materials possess, i.e. porosity, interconnectivity and periodicity. The fabrication of colloidal crystals stripes with features at the pitch of 25 - 450 μm is of interest for a number of reasons: First, to permit the integration of colloidal crystal structures into devices; second, to increase understanding of the mechanisms governing colloidal self-assembly; and third, to allow the creation of arrays of heterostructures combining colloidal crystals of two or more sphere sizes. However, it remains a significant challenge to direct the self-assembly of three-dimensionally periodic colloidal crystals reproducibly over large areas, as the patterning techniques are often time consuming and not suitable to scale-up. In this thesis the successful formation of highly-ordered colloidal crystal stripes over large areas is presented using the combination of two easily integrated techniques, micro-contact printing (μ-CP) and evaporative vertical deposition (EVD). The large area over which directed deposition has been achieved and the combination of μ-CP and EVD are novel. The technique has also been demonstrated on functional substrates. This versatility and scalability represents a significant step towards the formation of low-cost devices based on these materials. Characterisation by reflectance spectroscopy, white light interferometry, and optical and scanning electron microscopy establishes the high spatial selectivity of the technique and the three-dimensional periodicity of the striped colloidal crystal arrays formed.

The Xiphos is a new diffractometer that has been been designed and built to determine the solid-state structures of materials at ultra low temperatures. As one of very few single-crystal X-ray diffractometers capable of collecting diffraction data from crystals cooled to 2 K, the Xiphos has an enormous potential for improving our understanding of the relationship between the solid-state structure and the physical properties of many materials which show interesting and valuable behaviour at ultra low temperatures. However, there are some challenges to collecting good quality data due to the beryllium vacuum shrouds surrounding the crystal which are necessary components of the cryostat used for reaching these low temperatures. A new program called Masquerade is described that helps to overcome these challenges by generating ‘masks’ describing the position of the beryllium scattering from the vacuum shrouds. These masks can be used during data integration to prohibit measuring the diffracted intensities of X-ray reflections which are contaminated by beryllium scattering. A new protocol for data collection is also presented to recover the reflection intensities that are missing as a result of the masks. Results are presented showing a marked improvement in the accuracy of the reflection intensities which can be obtained from diffraction patterns collected with the Xiphos when the data have been contaminated by beryllium scattering from the vacuum shrouds. Several additional computer programs have been developed which enhance the data collection process by monitoring the sample temperature and offering the ability to monitor the status of the Xiphos and the progress of a diffraction experiment remotely. The development and use of these programs is described herein. To show the Xiphos and Masquerade in action, structural studies at a range of temperatures between 2 K and 160 K are presented on charge-transfer complexes which exhibit superconductivity below 7 K, in addition to studies at ultra low temperatures of spin-crossover complexes, organic radicals and single molecular magnets. The relationship between the solid-state structure and interesting physical properties can be better understood by determining the structure at the same temperatures at which the properties are exhibited; a process that can now be undertaken routinely in a university laboratory with the Xiphos.

The Grätzel photovoltaic cell is described in the introductory chapter and the main experimental method used in this study, X-ray crystallography, in the second chapter. The work described in chapter 3 and 4 was inspired by the Grätzel cell namely, the synthesis and characterisation of iodide and poly-iodides in chapter 3 and transition metal complexes synthesised using 2,2’-dipyridyl ketone in chapter 4.Chapter five looks in detail at a series of tri-angular lanthanide complexes, a chance discovery made while synthesising the 2,2’-dipyridyl ketone complexes described in chapter 4. These tri-angular clusters have interesting magnetic properties that are also described.

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