This thesis describes the development and application of a rapid and sensitive electrospray ionization-mass spectrometry (ESI-MS) method to study the weak hydrophobic interactions seen in many Ub-Ub-binding domain (UBD) complexes. A range of UBDs has been screened against mono-Ub, di-Ub (Ub2) and tetra-Ub (Ub4). Affinities in the 2-200 J.lM range were found to be in excellent agreement with data obtained from other biophysical techniques. Insights into the UBD's preference for poly-Ub chain linkage and length are also provided by this methodology. Detection of a ternary complex involving Ub interacting simultaneously with two different UBDs demonstrated the co-existence of multisite interactions. A simple, clean and effective method for reducing charge states observed in ESI-MS without the use of any solution additives or instrumental modifications is also reported; with the charge reduction method ultimately promoting the investigation ofthe Ub-UBD interactions. Moreover, the development and application of a top-down proteomics approach to characterize the topology of an unanchored Ub dimer purified from rat skeletal muscle is also described in this thesis. This study has identified the topology of the Ub2 to be Lys48-linked. In addition, ESI-MS of endogenous Ub2 species has revealed the presence of cyclic Lys48-linked Ub2 and demonstrates for the first time that cyclisation of poly-Ub can also occur in vivo. Further to these studies, the inhibitory activity of small peptides against the complex formed by Ub with the ZnF domain of isopeptidase T (IsoT) is also investigated. Finally, the unusual effects of cation adduction upon the gas-phase conformation of three-helix bundle UBDs are revealed by ESI-IMS-MS and reported in this thesis.

This thesis details the synthesis of molecular species designed for a variety of nanotechnological applications. The first chapter gives a brief introduction to nanotechnology and explains the concepts of supramolecular chemistry and self-assembly which are the basis on which this project is built. Special attention is given to non-covalent bonding interactions such as hydrogen-bonding and π- π interactions which drive the formation of complex architectures. The discussion is followed by many examples from the literature describing work that has been accomplished in various fields of supramolecular chemistry. The second chapter describes the synthesis, characterization and surface deposition studies of 1,4-diphenyl-1,3-butadiyne-3,3’-5,5’-tetracarboxylic acid (DPBDTC). Recent work on surface deposition studies of terphenyl-tetracarboxylic acid (TPTC) has shown the formation of a 2D network that resembles an aperiodic tiling structure that shows orientational order but no translational symmetry. DPBDTC was designed in order to improve the aperiodic characteristics of the network formed. An experimental exploration of the phase space of interacting random tilings was also possible using the network obtained from DPBDTC deposited from nonanoic acid along with networks obtained with different molecules and under different conditions. The third chapter focuses on the synthesis, characterization and surface deposition studies of a series of porphyrin molecules functionalised with isophthalic acid and ferrocene groups at the meso-positions. The isophthalic acid groups are incorporated to encourage intermolecular interactions while the ferrocene groups are designed as potential carriers of binary information in the form of the redox states of the iron center. The above molecules were designed in order to study their potential use in molecular memory systems. The series of molecules consisted of porphyrins having the acetylene spacer in various positions. The diethyl-ester protected derivatives of the carboxylic acids and their zinc and magnesium metal complexes were studied using spectroelectrochemistry in order to reveal the qualitative redox properties of these systems. The fourth chapter discusses the design, synthesis and characterization of a series of metallated homoleptic and heteroleptic dypyrrinato complexes, using the dipyrrin 5-ethynyl-ferrocenyl dipyrrin. These molecules were synthesized with the prospect of validating the role of such complexes as a part of a dye or an electrolyte in dye-sensitized solar cells. Electrochemical and spectroelectrochemical studies in solution were also performed.

This thesis describes the investigation of phase behaviour of binary and ternary mixtures at high pressure. The particular applications chosen to be explored in this phase behaviour investigation were supercritical fluid electrodeposition (SCFED) and carbon capture and storage (CCS). Chapter 1 introduces the phase behaviour of mixtures. Chapter 2 describes the equipment and analytical techniques used throughout this thesis including the high-pressure variable-volume view cell, electrical conductivity cell, high pressure FTIR cell, and high-pressure optical fiber phase analyser. Chapter 3 details the solubility and conductivity investigation of several supporting electrolytes in difluoromethane (CH2F2), which provided an electrochemical bath with sufficient conductivity for electrodeposition in supercritical fluids. The most effective supporting electrolyte amongst the eight ionic compounds tested was [N(nC4H9)4][Al(OC(CF3)3)4] which was found to give a moderate solubility and the highest conductivity (222 Scm2mol-1) in CH2F2. [N(nC4H9)4][Al(OC(CF3)3)4] was followed by [N(nC4H9)4][FAP] and [N(nCH3)4][FAP], , making all of them to be satisfactory potential supporting electrolytes for SCFED. Chapter 4 describes the investigation of water solubility in CO2/N2 mixtures relevant to the CCS process. The scope of the investigation covers a wide pressure range and two levels of N2 (xN2= 0.05 and xN2= 0.10). This experimental study was conducted by using the FTIR technique as described in further detail in Chapter 2. It was found that the presence of N2 in CO2 lowered the solubility of H2O in supercritical CO2 with N2 compared to pure CO2. The solubility of water also decreases significantly when the concentration of N2 is increased from 5% to 10%. Chapter 5 further explores the role of phase behaviour in the application of CCS with the investigation of the phase envelope of the ternary mixtures of CO2 and permanent gases (Ar, N2, and H2). Three ternary mixtures were measured (90% CO2 + 5% N2 + 5% Ar, 98% CO2 + 1% N2 + 1% Ar, and 95% CO2 + 3% H2 + 2% Ar) by using the fiber optic reflectometer, as described in further detail in Chapter 2. The experimental data presented in this part also have been used to validate the equation of state for the CCS applications. It was found that the phase envelope of CO2 shifted to a higher pressure and the two-phase region become broader with the presence of permanent gases. Overall, both GERG-2004 and gSAFT provide a good agreement between the predicted and experimental data for all the ternary mixtures investigated, with the exception of the bubble-point line for the 3%H2 + 2%Ar + 95% CO2 mixture. Finally, Chapter 6 summarises the research that was conducted in this thesis. It also evaluates the progress made towards achieving the aims initially set-up in Chapter 1.

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The focus of this thesis is the design of low-dimensional coordination polymers (CPs) using semi-rigid N-donor ligands based on heterocyclic molecules, especially benzotriazole, and the investigation of their potential magnetic and catalytic properties. Chapter 1 serves as a general introduction to the chemistry discussed in the thesis. The first part emphasizes on the synthetic aspects and applications of CPs. The second part presents the unique chemical characteristics of benzotriazole and includes a thorough literature review on its use as a ligand in coordination chemistry, culminating to the development of a ligand system for the design of the targeted materials. Chapter 2 introduces the main family of benzotriazole-based ligands (L1-L3) employed in this thesis, focusing on their coordination chemistry with cobalt salts. The synthesis and characterisation of a series of novel 0D, 1D and 2D compounds with a large structural variety is reported. Synthetic aspects and magnetic properties of selected compounds are discussed. Chapters 3, 4 and 5 report a series of copper coordination compounds employing L1-L3 as well as analogous N-donor ligands (L4-L8). A system of 1D CPs is established and investigated for its catalytic properties in a range of organic transformations that includes the synthesis of 1,4-dihydropyridines through a previously unreported route, the A3 coupling and the ‘click' azide-alkyne cycloaddition reaction. Investigations into optimising the catalytic behaviour and mechanistic aspects of this system are presented. In Chapter 6 the coordination capabilities of L1-L3 are combined with the rich chemistry of silver salts to generate a structurally diverse family of 0D, 1D and 2D compounds. Investigations of their potential catalytic properties in the A3 coupling and alkyne hydration reactions are additionally presented. Chapter 7 provides an overall conclusion to the work presented in the thesis, including its contributions to the reported literature as well as potential future directions. Finally, experimental and synthetic details as well as crystallographic data are presented in Chapter 8 and Chapter 9 respectively.

The application of organic materials in electronic devices depends, in part, on the ability to control the electrical properties by structural modification. This thesis explores the possibility of modifyng the properties in the cofacially stacked polymeric phthalocyanine, fluoroaluminium phthalocyanine (AIPcF) by copolymerisation with the structurally related fluorogallium phthalocyanine (GaPcF). Copolymers of AIPcF and GaPcF of composition 2:1,1:1 and 1:2 were prepared for the first time. The purification, chracterisation, and evaluation of the 1:1 copolymer were carried out. It was found that the material could be purified by entrainer sublimation without major change in the composition. The polymeric nature of the material was established through spectroscopic methods, thermogravimetric analysis and X-ray powder diffraction. Evaluation of evaporated copolymer films by XPS, depth profiling by argon ion bombardment, and electron bombardment largely confirmed the expected composition but indicated that a limited amount of fractionation or selective decomposition had occurred. A detailed study of the properties of compactions and films by a.c. and d.c. show that the copolymer is intermediate between the monomers in its properties, and different from the mixture of the monomers. The a.c. measurements suggest that the films of both pure materials and copolymer have a higher imperfection concentration than the compaction. Two preliminary studies are also reported. Iodine doping of the copolymer leads to high conductivity which is limited by disorder. The photoconduction response of the copolymer is higher than that of either component, suggesting copolymerisation as a means of enhancing this property. The successful synthesis of this copolymer offers a route to the copolymerisation of electrically dissimilar materials as a means of enhancing the conductivity in linear chains.

The interactions of biological molecules are traditionally investigated using ensemble techniques. These provide information on the molecular behaviour based on averaged data resulting from collective ensemble properties. While this has enabled the resolution of structure and function of many proteins and other biomolecules, an understanding of how and why the molecules go about structural changes and modulate inter- and intra-molecular interactions is difficult to gain using these approaches. More recently, single molecule techniques have evolved. These allow us to follow the behaviour of the individual molecules over time and/or under changing conditions. From such data, subtle molecular changes can be resolved without the need to synchronise the system. Further, variations within a biological system can be detected which would be lost using the ensemble techniques, due to the concomitant averaging procedures. This is exploited to help understand the molecular procedures involved. In this thesis, the application and comparison of two of the main single molecule techniques, optical tweezers and AFM, are described. With these, a range of systems was investigated; namely drug-DNA, protein-DNA, and cell adhesive interactions. The presented results provide new and complementary information on the different biological systems, demonstrating the diversity of single molecule applications. The combination of different experimental approaches was further exploited to gain a more complete picture of the observed processes.

The gas-phase, thermal hydrogenations of propene and cyclopropane over various titania-supported metal catalysts have been investigated. Catalysts were prepared either by a photodeposition or a thermal reduction method. Absolute initial hydrogenation rates were calculated from total gas pressure vs time measurements. The activities of all catalysts were found to be very dependent upon catalyst state, as modified by reductive or oxidative pretreatments. These results are discussed in terms of reversible strong metal-support interactions, initiated via hydrogen spillover. For 0.5 %mass Pt on Ti02, the order of reaction with respect. to hydrocarbon was 0.5. An adsorption mechanism involving the alkylidene species is proposed as one possible explanation of this result. A negative order of reaction with respect to hydrogen was recorded. A Langmuir-Hinshelwood mechanism, involving competitive adsorption of hydrocarbon and hydrogen at supported metal sites, is proposed. Differences in behaviour between catalysts prepared by photodeposition and the thermally-prepared catalyst were observed during the hydrogenation studies. These include different apparent activation energies, maximum reaction rates at differing propene: hydrogen ratios and irreversible degradation of all photodeposited catalysts during cyclopropane hydrogenation. These differences are taken as being strongly indicative of differences in supported metal morphologies, arising as a consequence of the preparative routes employed. Temperature programmed desorption and scanning electron microscopy studies were undertaken in an attempt to establish and characterise these potential morphological differences. Although the results of these studies were, at best, inconclusive, the possible nature of such supported metal morphological differences is discussed on the basis of available evidence generated within this and other, similar, studies. The liquid-phase photocatalytic dehydrogenation of propan-2-ol, using the same catalysts, was also briefly investigated. Variations in measured activation energies suggest that photodeposited catalysts in the 'as prepared' state are contaminated with variable levels of impurity residues, particularly chloride ions.

The work, which is reported in this thesis, is concerned with the photochromic processes, or light induced changes of colour displayed by the hexaaryl bi-imidazolyl system. The thesis includes a study of the solid state photochromic decay reaction, in which the colour change is brougnt about by the dimerisation of triphenyl imidazolyl radicals. Equipment, used in conjunction with a U.V./visible spectrophotometer, was assembled to allow the process to be followed at various temperatures and from the data accrued a kinetic scheme, based upon a diffusion controlled reaction involving a radical-dinier complex species, has been suggested. Investigations were also carried out into. the photochromic processes of the bi-imidazolyl system in benzene solution. Based on earlier observations, the work included the study of the effect of variation of the parent dimer concentration upon the generation and decay kinetics of the triphenyl imidazolyl radicals and the related radicals fluorinated on the 2 phenyl ring. Kinetic schemes, most of which have necessarily involved a postulation of radical-dimer complexes of some sort, have been formulated for each radical system at each dimer concentration used. Rate constants for the reactions have been given. The electron spin resonance spectra for the three fluorinated derivatives of the triphenyl imidazolyl radical have been reported. Assignment of the splitting constants was attempted by use of simple Hückel molecular orbital calculations but this proved largely unsuccessful. Accurate theoretical reproduction of the experimental spectra was thus not achieved. It was decided, that Hückel was in too many ways unsatisfactory for the system, and work on an alternative, more complete molecular orbital approach (that of Pople, Pariser and Parr) was initiated. A computer program was obtained to permit such calculations to be made, and although not all problems had been overcome by the end of the time allowed for this thesis much headway had been made, and guide lines for further work have been suggested.