A stereoselective approach has been developed for the flexible synthesis of substituted 2-pyrrolidones and 2-piperidones. By employing the key Overman rearrangement, efficient transfer of stereochemistry was achieved, and an acylation and ring closing metathesis strategy afforded a library of target N-heterocycles. In addition, the optimisation of a synthesis of 4-oxopipecolic acid derivatives from L-aspartic acid was investigated. A novel, milder and higher yielding 6-endo-trig cyclisation procedure was developed. This allowed for the generation of a library of 2,6-cis-substituted 4-oxopipecolic derivatives. Stereoselective carbonyl reduction extended the synthesis further to include 4-hydroxypipecolic acid derivatives.

Development of cascade RCM reactions, where two different approaches are proposed. The first route involves a ruthenium-catalysed enyne RCM reaction, followed by a metallotropic [1,3]-shift and a final alkene RCM. The second route incorporates an enyne RCM reaction followed by direct alkene metathesis. These methodologies provide access to common bicyclic and tricyclic polyether skeletons such as those present in tamulamide, prymnesin, gambierol and maitotoxin, respectively. The second project is concerned with the synthesis of the C-G ring fragment of gambieric acid and the development of novel methodology for the formation of the seven membered E ring.

We present a synthetic route to the homoallylic alcohols, using the well-established asymmetric organocatalysed allylation of aldehydes. These alcohols were transformed in one step into the substituted tetrahydrofurans in the presence of achiral Lewis acids, forming three chiral centres for the price of two. A synthetic route towards chiral substituted tetrahydropyrans and unsaturated 1,5 diol-building blocks has also been developed.

Previous research in the Bucher group led to the generation of a novel phenalenyl derived radical, naphtho[2,1,8-mna]xanthenyl (NX). Through the photolysis of 9-phenyl-1H-phenalen-1-one (9-phenyl-PN), a transient 5aH-naphtho[2,1,8-mna]xanthene with a very weak C(sp3)-H bond was formed and could undergo hydrogen abstraction in the presence of an electron acceptor such as tetracyanoethylene (TCNE) or benzoquinone (BQ). As a result, NX was formed which exhibited a long persistence based on electronic stabilisation (Scheme A). This thesis deals with the practical preparation of potential precursors of NX type radicals involving new naphtho[2,1,8-mna]xanthenium (NX+) salts synthesised from 9-aryl-1H-phenalen-1-ones (9-aryl-PNs). 9-aryl-PNs will be prepared by a Michael-type Grignard addition which was introduced by C.F. Koelsch and J.A. Anthes. The key-step to the organic salts is the demethylation of the methoxy group at the o-position of the pendant 9-C aryl substituent of 9-aryl-PNs. Subsequently a reactive hemi-ketal will be formed which undergoes hydrolysis resulting in NX+.

The first part of this thesis is concerned with work towards the total synthesis of ß-lactam antibiotics, and a second part deals with two topics arising from the author's contribution to research on cobaloximes being conducted in these laboratories. The introduction to ß-lactam antibiotics describes characteristics related to their biological action and synthesis. Published synthetic methods are discussed as routes to analogues of penicillins and cephalosporins, particularly those in which sulphur is replaced by oxygen. Synthesis of such an oxa-penam by photocyclisation of an a-diazoamide is described in chapter 2. Attempts to synthesise more stable oxa-penams are the subjects of chapters 3 and 4. Formation of the C5-C6 bond of an oxapenam by radical-induced cyclisation of N-acyloxazolidines was not achieved photochemically, or chemically with azo-bis-isobutyronitrile or nickel peroxide. The former two sets of conditions initiated oxidation of the oxazolidine ring, and azo-bis- sobutyronitrile also effected a characteristic cleavage of peptide derivatives. Nickel peroxide caused trimerisation of some amides and an ester of cyanoacetic acid to derivatives of 1,2,3-tricyanocyclopropane. Reaction of acyl chlorides and triethylamine with 2-oxazolines did not give ß-lactams. 1:1 Adducts of acyl chlorides and oxazolines were identified as reaction intermediates, and the products analysed in the particular case of phthalimidoacetyl chloride. Chapter 5 describes the reactions of vicinal diols with hydrogen bromide in acetic acid. Certain such diols are converted rapidly and stereospecifically to vicinal acetoxybromides via an intermediate 2-methyl-l,3-dioxolan-2-ylium ion formed by 'frontside' participation. Applicability and limitations of this reaction as applied to a range of acyclic and cyclic diols is discussed. In the final chapter, the product of a degradation of alkylcobaloximes by acetic anhydride in pyridine is proved to be a derivative of imidazo[1,2-a]pyridine by chemical methods and single crystal X-ray analysis. Limited studies on the reaction mechanism and its relation to coenzyme B12 action are discussed.

The biochemistry of certain oligomycin resistant mutants of the yeast Saccharomyces cerevisiae D22 has been studied. During the course of this investigation various techniques have been used and as a result of one of the methods used ideas have been proposed on the mode of oligomycin and aurovertin inhibition of mitochondrial energy linked functions. The interaction of DCCD with yeast SMP membranes has also been studied and a mechanism for the inhibition of yeast SMP ATPase activity is proposed. This mechanism closely resembles the inhibition of red blood cell ATPase activity by carbodi-imides but it is different from the postulated mechanism of DCCD inhibition of beef heart mitochondrial ATPase activity. Both yeast SMP membranes and a soluble oligomycin sensitive ATPase from these SMP have been used for a comparative study of the parental and oligomycin resistant strains. No gross changes were evident in the whole SMP membrane structure, but there were differences seen in the local lipid environment around the ATPase complex. These differences appeared to be related to differences in the oligomycin sensitivity of the ATPase complex. The importance of lipids within the ATPase complex is further illustrated by a new solvent extraction technique which removes oligomycin sensitivity from the SMP ATPase activity.

The coordination chemistry, in particular the position of the penta-coordinate state, of the halides of the early transition metals (titanium, vanadium and chromium) has been studied from two viewpoints. 1) The reactivity and stability of the metals in the penta-coordinate state has been investigated. A solution decomposition to a dimeric state, containing the metals in octahedral environment, was found to be active in the MC13 2NMe3 adducts. The nature of this decomposition and the reactivity of the product has been investigated. 2) The complex formation of the metals with bulky multi-dentate ligands, inductive to penta-coordination, was studied. '!he octahedral nature of the metal was found to be sufficiently powerful to control the donor roles of the ligands involved. The zirconium/trimethylamine system has been investigated, in the (+4) and (+3) oxidation states. Here, in contrast to the first series metals, the ability of the metal to readily assume a coordination number greater than six is seen to playa major role in reaction. Possible structures for the adducts obtained are discussed in terms of eight coordinate polymeric species.

We explore two distinct domains in the field of soft matter. The first three experimental chapters concern the synthesis, characterisation and application of Janus particles fabricated by heterogeneous polymerisation techniques. Initially in Chapter 2 we describe an optimised one pot seeded emulsion polymerisation strategy to render submicron amphiphilic Janus particles exhibiting surface active behaviour which can be tuned by the variation of hydrophilic to hydrophobic lobe volume ratios. These particles have been shown to inhibit ice recrystallisation in aqueous systems. In Chapter 3 we explore the synthesis of hard-soft Janus particles comprising of respective high and low glass transition temperature lobes. Although the rate of polymerisation is unaffected by available seed particle surface area, particles with multiple soft lobes and secondary nucleation occur below a seed surface area threshold. We additionally demonstrate the ability to fabricate sub-micron hard-soft Janus particles. Chapter 4 utilises the particles made in the previous chapter as building blocks to fabricate ‘colloidal molecules’ and colloidosomes. In the former case, cluster morphology of particles is shown to be governed by surface area minimisation of the central soft domain. The final two experimental chapters explore two different strategies to emulsify water into chocolate whilst retaining the desirable physical characteristics of the confectionery. In Chapter 5 we utilise colloidal silica and a cationic polyelectrolyte to generate highly stable quiescent Pickering emulsions, allowing up to 50% of the fat content in chocolate to be replaced with water and fruit juice. Chapter 6 improves upon this work by allowing the replacement of up to 80% of the fat content in chocolate by the dispersion of aqueous hydrogels within the chocolate fat matrix. In both chapters we characterise the physical properties of the formulations and demonstrate their suitability for use in chocolate confectionery.

The advantages of polycrystalline boron doped diamond (pBDD) are many when compared to other electrode materials in the field of electrochemistry. The superior properties of pBDD has generated substantial interest over the last 10 years, accelerating diamond to the cutting edge of electroanalytical studies, which benefit from lower levels of detection when utilising pBDD. The impressive chemical properties of pBDD allow it to be used in hostile environments where extreme temperature, pressure and pH may exist, affording researchers a means to create devices and sensors that could not be made with other materials. In addition pBDD also possesses extreme physical properties, notably its exceptionally high thermal conductivity which allows rapid transfer of heat energy. Currently, pBDD is widely used as an electrode material by many institutions, the production and employment of this material varies considerably. It is therefore of great importance to understand this material on a fundamental level, utilising experimental procedures that yield reproducible results. The aims of this thesis are as follows: to suitably characterise a series of pBDD electrodes and elucidate which attributes afford the best performance, to enhance the electrochemical response of pBDD with temperature effects by exploiting its high thermal conductivity. A series of electrochemical, spectroscopic and electrical experiments are performed to assess different pBDD samples, which contain varying amounts of boron and non-diamond carbon impurities. The effect of electrode heating is explored. This is performed with a laser light source that allows rapid heating and cooling of the pBDD electrode, leaving the bulk solution temperature relatively unchanged. Enhancements are seen at elevated temperatures for several redox couples, showing the feasibility of using laser electrode heating with pBDD. In the final chapter, elevated temperatures through electrode heating of an all diamond structure are used to enhance the deposition and subsequent stripping of lead in solution.

Metal phthalocyanines (MPcs) prepared as single crystals, polycrystalline powders and thin films have been analysed using a combination of surface science techniques, diffraction based structural characterisation and magnetic characterisation. Vanadium oxide phthalocyanine (VOPc) prepared as thin films on the (111) surface of gold, silver and copper is analysed by (STM) low energy electron diffraction (LEED) and ultraviolet photoemission spectroscopy (UPS). Similar surface and electronic structure is observed on gold and silver, but profoundly different assembly and electronic properties were observed on copper. The effect of increasing the substrate temperature during growth on the structure and morphology of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc) is investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). An evaporated copper iodide (CuI) structural template layer is also used to alter the arrangement of FePc molecules in thin films. The single crystal structure of fluorinated copper phthalocyanine (F16CuPc) is re-determined using synchrotron X-ray diffraction. Thin films of F16CuPc grown on graphene oxide supports are analysed using X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). This allows assignment of both crystal structure and texture in polycrystalline thin films of a variety of thicknesses. F16CuPc is also analysed using superconducting quantum interference (SQUID) magnetometry in both powder and thin film morphologies. 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA) structural template layers are used to alter the orientation of crystallites and the effect of this on the magnetic properties are analysed.