This thesis addresses the nature of global (many body) fluctuations in highly correlated systems. We begin with the question of temperature dependence in finite two dimensional XY (2dXY) model magnets. Such systems have a fully critical low temperature phase. It is shown analytically, backed up by extensive Monte Carlo simulations, that the non-Gaussian distribution of order parameter fluctuations is not strictly universal but has an explicit temperature dependence - contrary to previous findings. The temperature dependence is used to explain why past studies derived the same distribution for fluctuations of the full order parameter and an approximate linearized form. The appearance of spin vortices in the related Harmonic model is discussed and an argument is presented for why these defects must always appear as bound pairs. The linearized order parameter of the 2dXY model leads to a family of dimensionally dependent models defined in reciprocal space. An argument is presented for the interpretation of these systems as being critical and a direct space Hamiltonian is derived for the one dimensional case. This model has order parameter fluctuations distributed according to the Fisher-Tippett-Gumbel distribution from extreme value statistics (EVS). The link between criticality and EVS is investigated, as are the origins of the non-Gaussianity. The ability to distinguish between critical distributions is discussed. It is seen that for one, two and three dimensions the critical models presented lead to functionally similar fluctuation distributions. A previously reported link between EVS and l/f noise is investigated. Our one dimensional critical model is mapped onto the action used to generate l/f signals and we propose an alternative interpretation of the link in the context of a 1/q dispersion of spatial normal modes. The experimental observability of the FTG distribution in l/f signals is considered with emphasis on imperfections in the noise. A physically relevant method of generating l/f noise from the superposition of random telegraph signals is also examined.

No description available.

Pancratistatin and narciclasine are natural products isolated from Pancratium litorale1 and Narcissus poeticus2 respectively. Pancratistatin and Narciclasine have been shown to possess potent antitumour activity3 however they have never been widely exploited due to their limited availability from natural sources.4 Pancratistatin and narciclasine both contain a dihydroisoquinolinone framework. The work described in this thesis explores synthetic routes relating to this dihydroisoquinolinone framework, as well as comparable tetrahydroisoquinolines. An initial proposed synthetic route involved the synthesis of the dihydroisoquinolinone framework via the corresponding indanone. Indanones have also been shown to possess potential antitumour activity.5 A range of lactam and indanone analogues were synthesised and a selection were tested for biological activity against cancer cell lines. The most biologically active lactam analogue synthesised was lactam 170. Lactam 170 was synthesised via two steps from commercially available starting materials in an overall 51 % yield and was tested in the HT29 colon cancer cell line to give an IC50 value of 9 μM. Indanone 177 is an analogue of natural product indanocine and was synthesised via two steps in an overall 49 % yield. Analogue 177 was tested in the 60 cell line screen by the National Cancer Institute (NCI) to give a mean GI50 value of 1.29 μM and is currently under consideration for further testing. This thesis describes the synthesis and biological testing of the aforementioned compounds as well as an array of analogues.

This thesis describes a new approach towards a formal synthesis of the marine natural product diazonamide A. Firstly, the biological anti-cancer activity of diazonamide A is explained. The investigations towards the synthesis of the C-10 quaternary centre by numerous laboratories are then reported, as well as the successful total and formal syntheses. Secondly, our strategy is presented. One of the difficulties of the synthesis is the generation of the quaternary centre at C-10. This project aims to construct this stereocentre based on a novel strategy, involving the synthesis of a 3,3- disubstituted chiral oxindole using an oxidative rearrangement of indoles. Approaches to the synthesis of the required precursor, namely a 2,3- disubstituted indole, are described herein. Our first route involves functionalisation of the indole at C-3 with the introduction of an oxazole ring before coupling of a tyrosine fragment at C-2. In the second route, the indole is functionalised at C-2 first with the introduction of the tyrosine fragment and the oxazole ring is attached at the C-3 position afterwards. Macrocyclisation of the 2,3-disubstituted indole is then detailed. Next, the oxidative rearrangement was investigated on both a macrocyclised precursor and an acyclic precursor. Thorough analysis of the results obtained from various systems led to a successful oxidative rearrangement, and therefore successful installation of the C-10 quaternary centre. Further optimisation is needed to complete the formal synthesis of diazonamide A. Finally, the experimental procedures are reported.

The novel thiolated cyclotriveratrylene based molecule cyclotrithiophenolene, 2.8 was synthesised from cyclotriphenolene in three steps. Compound 2.8 undergoes dimerisation via disulfide bond formation to the anti-disulfide linked S-cryptophane 0.0.0 2.10, preferentially over the syn-disulfide linked S-cryptophane 0.0.0 2.9. The host properties of compound 2.10 have been investigated in the presence of a number of gaseous guests including methane and nitrogen. The methoxy analogue of compound 2.8, namely cyclotrithioguaiacylene 2.3, does not undergo selective dimerisation to the desired disulfide linked cryptophane. The proposed explanation for this is due to steric clashes between the methoxy groups. Novel 10 and 20 coordination polymers or discrete coordination complexes have been prepared with previously reported cyclotriguaiacylene-type ligands tris-[4-(3- pyridyl)benzoyl]cyclotriguaiacylene L3.1, tris-[4-(4-pyridyl)benzoyl]cyclotriguaiacylene L3.2, tris-[3-(3-pyridyl)benzoyl]cyclotriguaiacylene L3.3, tris-[4-(3,5- pyrimidyl)benzoyl]cyclotriguaiacylene L3.4, and novel tris-[3-(3-pyridyl-4- benzyl)benzoyl]cyclotriguaiacylene L3.5. Complexes include: the discrete anti-metallo- cryptophane [M3(L3.1 MN03)s] where M = Zn 3.1, M = Cd 3.2; the discrete coordination complex [Nis(L3.3MOAc)g(OHMOH2h].(OAc).2(NMP).2(H20) 3.7 (where NMP = N- methylpyrrolidone); the 10 networks [Cd2(L3.2)(N03h(H20MOMAh].(N03).4(OMA) 3.3 (where OMA = dimethylacetamide) [Zn(L3.2MCF3COO)(H20)].(CF3COO).7(NMP) 3.5 and [Co(L3.3)(N03h].4(NMP) 3.6; the 20 network [Cd2(L3.2MN03MNMP)].9(NMP).4(H20) 3.4, which has a rare (42.62)(4.62h topology; and the 20 networks [CU1.5(L3.4)(OMA)(H20h].3(CF3COO) 3.8 and [Ag(L3.5)].(BF4) 3.9 which have 63 topology. Coordination polymers 3.4 and 3.9 display 20-20 four-fold interpenetration. Organometallic coordination polymers and a discrete capsule were prepared with Ag(l) salts and tris-allyl-cyclotriguaiacylene L4.1 or hexa-allyl-cyclotriguaiacyclene L4.2, predominately through the formation of 1J2-vinyl interactions. The 3D networks [Agg(L4.1 h(H20h]·(L4.1 ).9(SbFs) 4.5 and [Ag2(L4.1 )z].2(SbFs) 4.6 display unusual topologies, or the discrete [Ag2L4.1z] capsule 4.7, were formed dependent upon stoichiometries of Ag(SbFs) and reaction conditions. Isostructural 10 networks [Ag2(L4.1 )(H20)z].2(X).2(MeN02) were formed when X = (BF 4-) 4.1 or (CI04-) 4.2. Formation of the 3D network [Ag2(L4.1 )(CF3S03)z] 4.3 or 20 network [Ag2(L4.1 )(CF3S03h] 4.3 was dependent upon Ag(CF3S03) stoichiometries. L4.2 formed the 10 network [Ag2(L4.2).(H20)].2(BF 4) 4.8 and 3D network [Ag4(L4.2)4(H20)4].4(SbFs).4(MeN02) 4.9.

Abstract This thesis is concerned with microbially derived cis-3,5-cyclohexadiene-1,2- dihydroxy-1-carboxylic acid and its iron tricarbonyl derivatives as precursors for the efficient and practical synthesis of useful products. The opening chapter consists of a review of the biocatalytic cis-dihydroxylation process including its mechanism and applications in synthesis. In a Chapter 2 the utility of cyclohexadiene iron tricarbonyl complexes to date is outlined, with particular focus on their preparation and reactivity. Synthetic routes towards the synthesis of the natural products gabaculine and carbazole alkaloids are described, followed by the preparation of tarniflu and general methods of decomplexation. Chapter 3 presents the synthesis of novel iron tricarbonyl complexes and studies on their reactivity are disclosed. (Figure A.) Chapter 4 describes the formation of a new rearrangement product of the acetonide protected iron tricarbonyl complexes. In order to validate this process, independent studies with labelled compounds have been employed. Following Myers' procedure for microbial oxidation of p-deutero-benzoic acid, quantities of a novel deutero-diol product were successfully prepared and used to elucidate the mechanism of the rearrangement process. (Figure B) In Chapter 5 the formation of the f]5 cyclohexadienyl complexes is discussed followed by the outcome of the nucleophilic addition products. Chapter 7 provides detailed specific and general procedures for the synthesis of the compounds described within this thesis, along with their characterisation data. The appendices provide analytical support to this thesis and list of publications. Each chapter includes a separate discussion of the results and Chapter 6 provides an overall summary and suggestions for possible future work.

No description available.

Le procédé de captage du CO2 en post-combustion par lavage aux amines est actuellement le plus mature pour réduire les émissions de dioxyde de carbone industrielles. Cependant, s'il existe de nombreux démonstrateurs, son coût en termes d'investissement et de fonctionnement est encore trop important pour être mis en oeuvre à une large échelle. La cinétique de réaction amine-dioxyde de carbone est un des principaux facteurs influençant ces coûts. Les objectifs de ces travaux portent sur l'étude et la compréhension de la cinétique de réaction amine-CO2 et de la mise en place d'un modèle structure-propriété prédictif. Cette démarche est adaptée au grand nombre d'amines envisageables pour le procédé. Dans un premier temps nous avons étudié cinq types d'amines (primaires, secondaires acycliques, secondaires cycliques, tertiaires et multi-amines) représentatifs des molécules candidates. Parmi ces molécules deux comportements peuvent être distingués : d'une part les amines qui forment des carbamates et d'autre part celles qui n'en forment pas. Des mesures réalisées sur des solutions diluées d'amine, à différentes concentrations et à 25°C, obtenues par la technique d'écoulement bloqué ont permis de caractériser la cinétique intrinsèque de chacune des 87 amines par deux constantes cinétiques. Pour chaque type d'amine les principaux facteurs structuraux, électroniques et géométriques influant sur la cinétique de réaction ont été identifiés. Un modèle statistique utilisant des descripteurs moléculaires pour décrire les différents paramètres de chaque amine a permis d'établir une relation structure - propriété pour différentes constantes cinétiques. Un nouveau descripteur de l'encombrement stérique de l'azote a également été calculé pour décrire les résultats et prédire la réactivité des amines / The post-combustion process by amine scrubbing is currently the most mature to reduce carbon dioxide emissions from industry. However, if there are numerous demonstrators, the investment and operating cost of this process are still too important to develop it in a large scale. The kinetics of reaction between the amine and the carbon dioxide is one of the major factor which influence the costs. The objectives of this work are to study and understand the kinetics of the amine-CO2 reaction and to set up of a predictive structure-property model. This approach is adapted to the large number of possible amines which can be candidates for the process. In a first time we study five kinds of amines (primary, acyclic secondary, cyclic secondary, tertiary and multi-amines) representatives of candidate molecules. Among those molecules, two behaviours can be distinguished: one the one hand amines which form carbamates and on the other hand those which do not form carbamates. Measurements have been realised at 25 °C in diluted solutions by stopped-flow technique to characterize the intrinsic kinetics of each of the 87 studied amines using two kinetic constants. For each kind of amine, the main structural factors, electronic and geometric, which impact the kinetics of reaction have been identified. Then, from a statistical model using molecular descriptors to describe the different parameters of each amine, a structure-property relationship has been set up with the different kinetic constants. A descriptor of the steric hindrance has been developed

La pyrolyse de sept molécules modèles de composés toxiques (le diéthyl éther, le bromoéthane, le chloroacétate de méthyle, le nitrométhane, le nitrate d’isopropyle, la diéthylamine, le chlorobenzène) a été étudiée lors de la thèse dans deux types de réacteur à l’échelle du laboratoire : un réacteur parfaitement agité (RPA) en silice et le réacteur tubulaire (RT) en alumine. Ce dernier pilote a été développé durant ce travail pour réaliser des études à des températures supérieures à 1200 K. Les profils axiaux de température dans le réacteur tubulaire ont été mesurés pour en tenir compte lors des simulations. Parallèlement à l’utilisation de la Chromatographie en phase Gazeuse, une nouvelle technique analytique pour notre laboratoire a été utilisée : la spectroscopie Infra-rouge à Transformée de Fourier (IRTF) pour laquelle une méthode d’analyse a été développée. Au cours de ces différentes études, des modèles cinétiques détaillés ont été développés à l’exception de la diethylamine. Globalement, ces modèles cinétiques reproduisent bien dans chaque étude la décomposition du réactif en fonction de la température et la formation des produits majoritaires déterminés expérimentalement. Etant donné le manque de données cinétiques dans la littérature pour la pyrolyse ou l’oxydation de composés bromés, chlorés et azotés, de nombreux paramètres cinétiques ont été estimés dans la plupart des modèles cinétiques développés / The pyrolysis of seven surrogates of toxic compounds (diethyl ether, bromoethane, methyl chloroacetate, nitromethane, isopropyl nitrate, diethylamine and chlorobenzene) was studied during the thesis in two different types of reactors at the laboratory scale: a silica jet-stirred reactor (JSR) and an alumina tubular reactor (TR) to carry out studies at temperatures above 1200 K. Axial temperature profiles were measured and were used to take into account the temperature gradient in the TR. In addition to gas chromatography, a new analytical technique for our laboratory was used: The Fourier Transform InfraRed Spectroscopy (FTIR), for which an analysis method has been developed. As part of the study, detailed kinetics models were developed except for the diethylamine. Overall, these kinetics models well predict the reactivity temperature dependence and the formation of the major products determined experimentally. Since there is a lack of kinetic data in the literature for the pyrolysis and oxidation of brominated, chlorinated and nitrogen compounds, many kinetic parameters were estimated in most of the kinetic models developed

Ce manuscrit constitue la synthèse d'efforts visant à évaluer l'impact des composés oxygénés contenus dans des mélanges représentatifs de Biodiesel, sur leur tendance à la production de suie d'une part, et sur les propriétés physico-chimiques et la réactivité des suies d'autre part. Pour ce faire, une production stationnaire de particules de suie par un brûleur académique générant des flammes non-prémélangées a été mise en point. Dans un premier temps, nous avons montré que la teneur ainsi que la structure des additifs oxygénés à base d'ester méthylique affectent la formation de suie dans la flamme. Ainsi, les résultats ont démontré que l'efficacité d'un carburant à réduire la tendance à la production de suie en terme d'indice YSI est de plus en plus importante lorsque le contenu et/ou la longueur de la chaîne aliphatique carbonée de l'ester méthylique augmentent dans le carburant de référence. Dans un second temps, les suies " modèles " récupérées dans la région post-flamme ont été caractérisées puis comparées entre elles ainsi qu'avec une suie Biodiesel " réelle ". Les analyses ont montré que les suies issues des " surrogates " Biodiesel contenant la teneur en ester la plus élevée et la chaîne aliphatique carbonée la plus longue présentaient la distribution de taille la plus étroite, le diamètre des agrégats le plus petit, les teneurs en oxygène et en fraction organique soluble les plus faibles et étaient moins réactives. Enfin, nous avons observé que les suies " modèles " issue du brûleur académique de SANTORO et la suie " réelle " possèdent des propriétés physico-chimiques très proches et une réactivité similaire. / The aim of this work was to evaluate the effect of oxygenated compounds concentration and structure on sooting tendencies of surrogate Diesel and Biodiesel, and to investigate the properties and the oxidative reactivity of soot obtained by their combustion using an atmospheric axi-symmetric co-flow non-premixed flame burner. Results evidenced that ester functions contained in Biodiesel surrogates reduce soot production. This decrease was more pronounced when the concentration of the oxygenated additive investigated was higher. However, it has been determined that YSI decreases when the aliphatic carbon chain of the ester additive is longer. On the other hand, physico-chemical characterizations of the generated model soot revealed that oxygen and soluble organic fraction (SOF) content decreases when the amount of methyl ester based additives increases in the reference fuel. Moreover, the behavior towards oxidation indicated that the Biodiesel-derived soot was less reactive than the Diesel-derived one. Finally, it was noticed from the results obtained from laser granulometry and TPOs that the particle size distribution and the reactivity of model soot collected from the burner are in the same range of size and of maximum oxidation temperature as soot derived from a Diesel engine functioning under specific conditions and with different type of fuel blending.