The research which is contained in this thesis is in the area of the development of 1H spectral editing techniques for use in vitro and in vivo. The in vivo 1H NMR spectrum potentially contains a wealth of biological data. Information on the metabolic and physiological status of the "sample" can potentially be obtained non-invasively. However, due to the inhomogeneous environment encountered in vivo, most 1H NMR signals are indistinguishable, with only a few metabolites being observed. A number of techniques have previously been developed to try to edit the in vivo 1H spectrum, but with limited success. In this thesis new 1H editing sequences are developed by using a number of simple spectral editing techniques. Several spectral editing sequences have been developed around individual metabolites such as ethanolamine and taurine. In these cases the initial design of the editing sequence was the double-quantum filter. In each sequence, the selectivity of the experiment was increased by the introduction of chemical shift selective pulses. Two more general editing sequences which can edit for a number of metabolites have also been developed. The first sequence is called SELECTER and can be used to edit for the metabolites aspartate, myo-inositol and GABA. This editing sequence is based around the principle of magnetisation transfer. In the case of aspartate and myo-inositol, SELECTER gives greater edited signal intensity, than for other spectral editing techniques. The other more general spectral editing sequence edits for singlet resonances, namely N-acetyl-aspartate, choline and creatine in the in vivo 1H NMR spectrum. Although these metabolites are clearly visible, underlying metabolite resonances distort their measurement. Previous attempts to remove these unwanted resonances introduced errors such as transverse relaxation attenuation. The sequence developed removes underlying metabolite resonances from around singlets in a shorter time where transverse relaxation losses are much lower, thus minimising any errors.

We have designed a new class of MII-catalysts, namely molybdenum and tungsten (II) complexes of the type PhCH2(Et)3N+[M(CO)4C1Br2]- and M(CO)5(OTf)2 (M = Mo or W), which induce intramolecular cyclization of olefinic aldehydes to afford products with a cis-configuration at the newly formed chiral centres in some cases. These catalysts can be tuned to drive the reaction either toward the end or Prins-type product (32 or 89). The latter reaction occurs via an anti addition of the carbonyl carbon and OH across the C=C bond, as evidenced by isotopic labeling. A chair-like transition state with an axial carbonyl oxygen is proposed to rationalise the stereoselectivities observed.

A review is presented of the development and application of liquid-liquid biphase systems in homogeneous catalysis and the concept and application of fluorous biphase systems (FBS) in catalysis. Novel monodentate phosphorus(III) ligands of general formula PhxP(OC6H4-4-C6F,3)3.x and PhCHF-* (x = 0, 1 or 2), and the phosphite ligands P(OC6H4-4-C8Fl7)3, P(OC6H4-4-C10F2i)3, P(OC6H4-3-C6F13)3 and P(OC6H4-2-C6Fi3)3 have been synthesised and fully characterised by 'H, 19F and 3,P{1H} NMR spectroscopy, mass spectrometry and elemental analysis. The monodentate phosphinite, phosphonite and phosphite ligands (L) have been reacted with a variety of transition metal complexes to form complexes of the type cis- and trans- MC 2L2 (M = Pt, Pd), cw- PtCl2(PEt3)L , M(n5-C5Me5)Cl2L (M = Ir, Rh) and RI1CIL3 . The complexes have been isolated and characterised using analytical techniques including H, 19F and 31P{!H} NMR spectroscopy, mass spectrometry, IR spectroscopy, X-ray crystallography and elemental analysis. The steric and electronic influences of the perfluoroalkyl substituents on the chemical and physical properties of the metal complexes have been assessed by comparison of their spectroscopic and structural data with that for their related protio complexes. Preliminary catalytic studies involving P(OC6H4-4-C6Fi3)3 as a modifying ligand in the rhodium-catalysed hydroformylation of 1-hexene and 1-nonene under FBS conditions have been undertaken. The influence of the perfluoroalkyl substituents on the rate of reaction, product selectivity and catalyst/product separation has been examined. The synthesis of bidentate phosphonite and phosphite ligands containing perfluoroalkyl substituents has been investigated. The derivatised bidentate phosphonite ligands (C6F13-4-C6H40)2PCH2CH2P(OC6H4-4-C6F, 3)2 and {5,5' - (C6F13)2-2,2,-02C,2H6}PCH2CH2P{2,2,-02C,2H6-5,5,-(C6F13)2} (L-L) have been reacted with transition metal complexes to form coordination complexes of the type PtCl2(L-L) and Rh(u-C1)(L-L)]2.

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A detailed study into the crystal habit modification of the NaClO3 / Na2S2O6 (host / impurity) system is presented. Ordinary morphology of NaClO3 present faces of {001}, {110} and {111} types. The presence of impurity Na2S2O6 has led to rapid development of new faces of {111} type on the NaClO3 crystals grown from solution. Above 70ppm doping concentration, the morphology of NaClO3 crystal is dominated by {111} faces. Crystal twinning occurred under 800ppm doping concentration and above. X-ray topography was used to investigate the growth history and defect configuration of the pure and doped crystals. Lattice distortions at various lattice planes within the pure and doped crystals were determined using X-ray multiple-wave diffraction (XRMD). The local structure of S2O6 2- in NaClO3 crystal was determined using X-ray absorption fine structure (XAFS). Molecular modelling was applied to investigate the molecular similarity between the impurity and the host. Strong impurity incorporation in the {111} sectors was revealed by X-ray topography. The growth history of doped crystal was reconstructed and interpreted with respect to the inhibiting effect of S2O6 2-. Disturbance in lattice planes of doped crystals was investigated, which was attributed to the incorporation of S2O6 2- on { 111} faces. It also revealed different types of local strain on the { 111 } faces along two different directions. The three-dimensional orientation and the actual structure of S2O6 2- impurity on the {111} faces of NaClO3 crystal were obtained. A structural model for the impurity incorporation was established, showing good consistency with the experimental results. In addition, the segregation coefficient of the impurity was determined by elemental mapping, indicating strong impurity incorporation on the {111} faces rather than others. The incorporated S2O6 2- was concluded to be capable of disrupting the proper packing structure of the {111} faces, obstructing the generation and propagation of growth steps, and decreasing of driving force for crystal growth.

What is the shape of a droplet? Its interfacial tension dictates that it is very close to a perfect sphere. Herein, the interfacial tension is reduced to ultralow values (0.1 - 100 uN/m) by careful formulation of surfactant additives, such as for mixtures that form microemulsions. The droplet need not be spherical but can accommodate external forces of a similar magnitude. The control and precision of forces afforded simply by light - in the form of highly focused Nd:YAG laser beams - are exploited in this work to deform hydrocarbon oil-in-water emulsion droplets of 1-10 um diameter. To this end, a novel, integrated platform for microfluidic generation, optical deformation and 3D fluorescent imaging of droplets is presented. Previous attempts to characterise optically-controlled microdroplet shapes have been limited to 2D projections. Here, that ambiguity is resolved using 3D confocal laser scanning- and structured illumination microscopy. 2D and 3D arrays of up to four Gaussian point traps are generated by holograms and acousto-optics. A variety of regular, prolate, oblate and asymmetric shapes are produced and correlated with parameters such as optocapillary number, trap separation and capillary length. Exotic shapes exhibiting zero or negative mean and Gaussian curvatures are presented alongside their brightfield counterparts. The complex phase behaviour of emulsion droplets and their parent phases is observed to couple strongly to thermal absorption of the beams. The rich interfacial chemistry, its relation to the forces determining droplet shape and the surprising ability to create nanofluidic networks between droplets are investigated.

A new system-theoretic approach for studying the stability and control of chemical reaction networks (CRNs) is proposed, and analyzed. This has direct application to biological applications where biochemical networks suffer from high uncertainty in the kinetic parameters and exact structure of the rate functions. The proposed approach tackles this issue by presenting "structural" results, i.e. results that extract important qualitative information from the structure alone regardless of the specific form of the kinetics which can be arbitrary monotone kinetics, including Mass-Action. The proposed method is based on introducing a class of Lyapunov functions that we call Piecewise Linear in Rates (PWLR) Lyapunov functions. Several algorithms are proposed for the construction of these functions. Subject to mild technical conditions, the existence of these functions can be used to ensure powerful dynamical and algebraic conditions such as Lyapunov stability, asymptotic stability, global asymptotic stability, persistence, uniqueness of equilibria and exponential contraction. This shows that this class of networks is well-behaved and excludes complicated behaviour such as multi-stability, limit cycles and chaos. The class of PWLR functions is then shown to be a subset of larger class of Robust Lyapunov functions (RLFs), which can be interpreted by shifting the analysis to reaction coordinates. In the new coordinates, the problem transforms into finding a common Lyapunov function for a linear parameter varying system. Consequently, dual forms of the PWLR Lyapunov functions are presented, and the interpretation in terms of the variational dynamics and contraction analysis are given. An other class of Piecewise Quadratic in Rates Lyapunov function is also introduced. Relationship with consensus dynamics are also pointed out. Control laws for the stabilization of the proposed class of networks are provided, and the concept of control Lyapunov function is briefly discussed. Finally, the proposed framework is shown to be widely applicable to biochemical networks.

The moving contact line problem is one of the main unsolved fundamental problems in fluid mechanics, with relevant physical phenomena spanning multiple scales, from the molecular to the macroscopic scale. In this thesis, at the macroscale, it is shown that classical asymptotic analysis is applicable at the moving contact line. This allows for a direct matching procedure between the inner (nanoscale) region and the outer (macroscale) region, therefore simplifying the analysis presented to date in the literature. At the mesoscale, a unified derivation for single and binary fluid diffuse interface models is presented, consolidating two models present in the literature. Results from an asymptotic analysis of the sharp interface limit of the binary fluid diffuse interface model are compared with numerical computations of the inner region in the vicinity of a moving contact line. Finally, the nanoscale structure of the density profile in the vicinity of the con- tact line is studied using density functional theory (DFT). At equilibrium, an effective disjoining pressure is extracted and results are compared with coarse-grained Hamiltonian theory. A derivation of Navier-Stokes like dynamic DFT equations is presented. Results for the moving contact line are compared with predictions from molecular kinetic theory. Computations for both DFT and diffuse interface approaches are performed using pseudospectral methods mapped to unbounded domains. The numerical scheme is presented, and the inclusion of hard-sphere effects via a fundamental measure theory is discussed.

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No description available.