Cette thèse traite de l'utilisation de molécules dîtes ambiphiles, comportant à la fois un site donneur et accepteur d'électrons, en chimie organométallique, en tant que ligand.<br /><br />Dans le premier chapitre, une étude bibliographique décrit l'utilisation des acides de Lewis du groupe 13 en tant que co-catalyseur en chimie organométallique, afin de mieux comprendre quel rôle pourrait jouer celui-ci au sein d'un ligand ambiphile coordiné sur un métal de transition. Les différents modes de coordination de ces ligands sont examinés. Les rares contributions traitant de la réactivité de ce type de complexes sont également décrites.<br /><br />Le second chapitre décrit la synthèse par couplage bore-carbone d'une nouvelle famille de ligands ambiphiles, 2-picolylboranes. En fonction des substituants du bore, ces composés sont obtenus sous forme dimère ou monomère fermé par interactions datives donneur-accepteur, inter ou intramoléculaires. Le comportement en solution du 2-picolylBCy2 a été examiné attentivement. Un équilibre entre la forme dimère et monomère est mis en évidence. Des calculs théoriques valident nos conclusions. La coordination de ce ligand sur plusieurs précurseurs métalliques est étudiée. Un exemple rare de coordination pontante donneur→Ru-Cl→accepteur a été caractérisé dans le complexe [(p-cym)RuCl2(2-picolylBCy2)].<br /><br />Dans le troisième chapitre, la synthèse par hydroboration d'une famille de ligands ambiphiles, 1,2-phosphinoethylborane, est décrite. Deux complexes de ruthénium neutres contenant ces ligands, ainsi que leur dérivés cationiques sont caractérisés. Des tests catalytiques préliminaires d'hydrosilylation du benzaldéhyde avec l'un des complexes cationiques ont montré la dégradation rapide du pré-catalyseur en un complexe ruthénacycle original. Sa réactivité avec un chloroborane et un chloroalane est étudiée.

Dans le premier chapitre, une étude bibliographique présente les rôles joués par les acides de Lewis du groupe 13, principalement du bore, en chimie organométallique. Même si dans ce domaine, ils sont principalement utilisés comme co-adduit, de rares exemples montrent que placés au sein d'un complexe métallique, ils peuvent (a) réaliser l'activation intramoléculaire d'une liaison M-X, (b) servir de point d'ancrage pour approcher un substrat riche en électrons du centre réactif et (c) interagir directement avec le métal lui-même.<br /><br />Dans le second chapitre, la synthèse et l'étude de la structure adoptée par les ligands ambiphiles sont discutées. Les facteurs régissant les préférences structurales des composés mono, di et triphosphine-borane sont étudiés.<br /><br />Dans le troisième chapitre, l'étude de la coordination de composés ambiphiles monophosphine-borane PB est réalisée vis-à-vis de complexes plan carré d8 ML4. Deux modes de coordination sont mis en évidence présentant un acide de Lewis non impliqué dans la coordination P→M, puis en interaction avec un chlorure porté par le métal P→M-Cl→B.<br /><br />Dans le quatrième chapitre, l'utilisation des composés diphosphine-borane PBP permet de mettre en évidence un troisième mode de coordination faisant apparaître une interaction M→B pour des complexes de rhodium, platine et palladium. L'analyse de cette interaction montre une forte dépendance vis-à-vis de la nature du métal.<br /><br />Enfin, dans le cinquième chapitre la variation de la nature du précurseur métallique, ainsi que la modulation de l'acidité de Lewis du site accepteur conduisent à deux complexes d'or présentant une interaction originale Au-B par la coordination des composés mono-phosphine-borane PB.<br /><br />L'ensemble de ce travail a été effectué en associant études expérimentales et études théoriques réalisées par Karinne Miqueu de l'Université de Pau et des Pays de l'Adour.

This dissertation explores theologies of suffering through engagement with five theologians from across fifteen centuries of the Christian tradition: Gregory the Great, Julian of Norwich, Jeremy Taylor, C.S. Lewis and Ivone Gebara. It uses a typological method to examine the types of responses that are advocated by each theologian, and the relation of their responses to five theological touchstones: Humanity, Sin and Evil; God’s Providence; Salvation; Christ; and Eternal Life. The Introductory Chapter provides an exploration of the definitions and etymologies of suffering and grief; a description of the typological method; an examination of notable relevant literature; and an introduction to the five thinkers. Chapter One is an examination of the life and writings of the 6th century pope Gregory the Great, with particular focus on The Book of the Pastoral Rule and Moralia. Gregory understands suffering to be a discipline sent by God to the faithful. Chapter Two is an examination of the life and Revelations text of the 13th century English mystic Julian of Norwich, who focuses on the reward God desires to give those who suffer. Chapter Three is an examination of the life and writings of 17th century Anglican bishop Jeremy Taylor, with particular focus on Holy Living and Holy Dying. Taylor places an emphasis on the lifelong practice of faithfulness in preparation for death. Chapter Four is an examination of the life and writings of 20th century Anglican theologian and author C. S. Lewis, with particular attention to The Problem of Pain, The Chronicles of Narnia, A Grief Observed, and Letters to Malcom. Lewis offers the example of one who is willing to engage with the depth of his grief and to question God on his road to acceptance. Chapter Five is an examination of the life and writings of contemporary Brazilian, feminist and liberation theologian Ivone Gebara, with particular focus on her book Out of the Depths and her engagement with Latin American author Isabel Allende. Gebara questions traditional understandings of suffering, as well as when suffering is to be accepted and when suffering is unjust and should be combated. The Concluding Chapter constructs a contemporary theology of suffering drawing on the insights and wrestling with the challenges raised by the varying perspectives of the five theologians. The goal is to provide a hopeful and nuanced way of thinking theologically about suffering for contemporary Christians. The contemporary theology affirms the importance of the call, found in Gebara, to combat unjust suffering through acts of love and mercy, while also affirming that acceptance of the reality of endemic suffering, found in all five theologians, can provide one with opportunities to grow spiritually, live more faithfully and to experience the blessings in the midst of suffering that are a foretaste of heavenly bliss.

I den här uppsatsen analyseras ikonotexten, det vill säga den helhetsbild som uppstår av text och bild i samspel, i Tove Janssons Pappan och havet (1965) och den utgåva av Alice i underlandet (1966) i ny svensk översättning, som hon illustrerade under sextiotalets mitt. Uppsatsen ämnar att genom en komparativ analys, undersöka hur en framställning där Tove Jansson både skrivit och illustrerat, förhåller sig till ett verk där hon enbart varit illustratör – och vilken påverkan det har på ikonotexten. Studien visar hur Jansson på flera sätt, i sitt eget verk såväl som Carrolls berättelse, fördjupar läsförståelsen genom ikonotexten. I samspelet kan både likheter och skillnader urskiljas. Janssons illustrationer används till exempel som förmedlare av stämningar i båda böckerna. Ikonotexten i Pappan och havet betonar dock i hög grad karaktärernas inre känsloliv, medan den i Alice i underlandet förmedlar handlingens surrealism och irrationella drömflöde. Vidare förtydligas där även yttre karaktärsdrag, då Carrolls text har luckor i sin karaktärsskildring som Jansson fyller visuellt.

The purpose of this study was to evaluate Lewis (2016) simple method to determine hydraulic conductivity in soil samples. This was conducted by comparing Lewis method to a slug-test, Guelph permeameter and calculations from grain size analysis in order to find out if the method is a reliable source for measuring hydraulic conductivity. Other parameters to compare is time consumption, cost effectiveness and area of use. Four different samples were used in the testing, a sand, two tills and pyrite ash (which is a rest product from manufacturing sulfite pulp). The results indicated that measurements in the homogenic sand all methods was in a good range of each other, while in the more heterogenic till the slug-test and Lewis method was close and the calculations from grainsize analysis was much lower. Only grainsize analysis was performed on the pyrite ash and the results was similar to Lewis method. This study shows that Lewis method works well as a reliable source for K measurements and is less time consuming than all the other methods. The material required for the method can be obtained in a hardware store.

This thesis describes the activation of small molecules using frustrated Lewis pairs, in particular investigating their use to reduce CO₂ to methanol, thus producing a new route towards a renewable fuel. Chapter One summarises the requirement for a renewable fuel source, the alternative methods currently available and previous research conducted into converting CO₂ to methanol using FLPs and other reducing agents. Chapter Two describes the synthesis of a new family of electron-deficient tris(aryl)boranes, B(C₆F₅)_3-x(C₆Cl₅)_x (x = 1-3), allowing the electronic effects, resulting from the gradual replacement of C₆F₅ with C₆Cl₅ ligands, to be studied. The novel Lewis acids have been fully characterised and their Lewis acidities have been determined using NMR spectroscopy, electrochemistry and DFT studies. Chapter Three discusses the synthesis of nine novel FLPs and their use to successfully split H2. Each borohydride salt has been spectroscopically fully characterised and five of the salts have been characterised using single crystal X-ray diffraction. To determine the exact positions of the H atoms, single crystal neutron diffraction and DFT experiments were carried out on [1-H][H-TMP]. Chapter Four details attempts to use the borohydride salts, synthesised in Chapter Three, to reduce CO₂ to methanol. Each experiment was been fully investigated and their catalytic viability was determined. The X-ray crystal structure of [1-OCHO][H-TMP] is described and each formatoborate and methoxyborate salt were fully characterised. Chapter Five describes experimental procedures and characterisation data.

This thesis names the Oxford School of children’s fantasy literature as arising from the educational milieu of the University of Oxford’s English School during the mid-twentieth century. It argues that J.R.R. Tolkien and C.S. Lewis lay the foundations for the children’s fantasy genre by introducing an English curriculum at Oxford in 1931 (first examined 1933) that required extensive study in medieval literature, and by modelling the use of medieval source material in their own popular children’s fantasy works. The Oxford School’s creative use of its sources produces medieval ‘afterlives,’ lending the Middle Ages new relevance in popular culture. This research directly compares medieval literature to children’s fantasy works by Tolkien, Lewis, and four other Oxford-educated children’s fantasy authors in order to reveal the genre’s debt to actual medieval texts and to the Oxford English syllabus in particular. The four authors are Susan Cooper, Kevin Crossley-Holland, Diana Wynne Jones, and Philip Pullman. This thesis situates the tendencies of medievalised children’s fantasy in relation to Lewis and Tolkien’s personal and scholarly convictions about the patriotic, moral, and aesthetic qualities of medieval literature and folklore. Building on the theories of Michel de Certeau, this thesis demonstrates how Oxford School fantasy produces new mythologies for England and argues that, as children’s literature, these works have an implicit didactic function that echoes that of the English School curriculum. This thesis traces the attempts of some Oxford School authors to navigate or explode generic conventions by drawing upon new source material, and contends that the structures and hierarchies that underpin the genre reassert themselves even in texts that set out to refute them. It suggests that such returns to the norm can produce pleasure and invite diverse reading, growing out of the intertextual associations of each new rewriting.

In both his fiction and non-fiction, Lewis comments on myth, its characteristics and strengths, and its relation to Christian doctrine. His use of myth to examine and to illustrate Christian ideas is most important in the space trilogy, the Narnia series of children's books, and Till We Have Faces. These books are the primary sources for this thesis, and they will be examined in chronological order.

Edible potatoes originated in the Andes and were brought to Europe in the 16th century. Their introduction spurred both the European population growth and economic development. Being the world's fourth-largest food crop, potatoes continue to shape the global economy and world history. Glycoalkaloids are natural insect deterrents generated by potatoes, and are known for their toxic effects as well as potential medicinal utilities. Demissidine, the aglycone of the primary glycoalkaloids, represents one major Solanum alkaloid. Its unique indolizidine framework presents a challenging synthetic target in organic chemistry. Our synthesis of demissidine starts from readily available epiandrosterone and takes advantage of a Lewis acid-mediated fragmentation of a γ-silyloxy-β-hydroxy-α-diazoester; the D-ring of a diazo ester derivative of epiandrosterone was efficiently ruptured to provide an aldehyde tethered ynoate product. In combination with a subsequent azomethine ylide 1,3-dipolar cycloaddition and a transition metal catalyzed oxidation/reduction, the core indolizidine framework of demissidine was successfully prepared in a stereoselective manner. In addition, the syntheses of two amino acids, 5-methylenepipecolic acid and (5S)-5-methylpipecolic acid were explored; they are used for the installation of the α-oriented C25 methyl group on demissidine. The successful preparation of demissidine was supported by NMR analysis of the synthetic compound in comparison with a natural sample. As an efficient and stereoselective synthesis, our efforts toward demissidine illuminate a strategy to indolizidine frameworks that could be applied in the preparation of other polycyclic amine natural products.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.