Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-27T13:49:03Z No. of bitstreams: 1 marcelodamascenomarangon.pdf: 420801 bytes, checksum: 1541d566ceb0fcd639f11dcc6f27070a (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-27T15:20:26Z (GMT) No. of bitstreams: 1 marcelodamascenomarangon.pdf: 420801 bytes, checksum: 1541d566ceb0fcd639f11dcc6f27070a (MD5) / Made available in DSpace on 2017-09-27T15:20:26Z (GMT). No. of bitstreams: 1 marcelodamascenomarangon.pdf: 420801 bytes, checksum: 1541d566ceb0fcd639f11dcc6f27070a (MD5) Previous issue date: 2017-06-24 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo principal deste trabalho é contar a origem do número aos alunos do ensino médio, além de exibir alguns métodos de aproximação e curiosidades envolvendo este número irracional. A motivação para a escolha do tema baseou-se no histórico de dificuldades e erros encontrados tantas vezes pelos discentes em sala de aula. Serão tratados métodos de cálculo desde Arquimedes até Ramanujan, passando pelas contribuições de Viète, Wallis, Gregory, Euler e Gauss, todos numa incessante busca pelo mais importante número irracional da matemática. Mostraremos também como a geometria plana e a trigonometria contribuíram na descoberta e investigação desse número, além de sua evolução até os dias de hoje. / This study aims to unveil to the high school students the origin of number , as well as to show some approximation methods and curiosities involving this irrational number. The theme choice was based on history of difficulties and errors found several times by students in the classroom. Will be reviewed calculus methods from Archimedes to Ramanujan, passing through Viète, Wallis, Gregory, Euler, and Gauss contributions, all of them on an unceasing quest for the most important mathematics’ irrational number. We will show also show show plane geometry and trigonometry contributed on discover and investigation of this number, as well as its evolution until today.

Les Hydrocarbures Polycycliques Aromatiques (abréviés PAHs en anglais) sont des synthons importants du point de vue expérimental et théorique en raison de leurs potentielles applications dans des dispositifs optoélectroniques tels que les diodes électroluminescentes organiques, les cellules solaires ou les transistors à effet de champs. Les propriétés des PAHs peuvent être modifiées par l'insertion d'hétéroatomes dans le squelette carboné sp2. Cependant, les exemples de PAHs modifiés par un atome de P sont très rares. Nous avons démontré expérimentalement et théoriquement que l'insertion d'un atome de P en périphérie du PAH a un impact important sur la structure électronique de l'ensemble du système π-étendu, comme le montre l'étude des orbitales frontières HO (Haute Occupée) et BV (Basse Vacante). Ces deux orbitales moléculaires gardent les caractéristiques spatiales du phosphole parent. Cependant l'écart HO-BV est fortement diminué en raison de l'interaction du phosphole et du système π-conjugué bidimensionnel. En effet, la densité électronique est délocalisée sur l'ensemble de la structure carbonée. L'effet de la modification chimique de l'atome de P (dont la complexation par des métaux de transition) sur les propriétés électroniques a été étudié et il a été démontré qu'elle permet de modifier finement les propriétés optiques. L'aromaticité est également un paramètre fondamental des systèmes π-conjugués (poly)cycliques. L'aromaticité locale de chaque cycle des PAHs a été étudiée grâce au calcul du paramètre NICS(1). La modification de l'aromaticité locale de l'hétérocycle à 5 chainons (par variation de l'hétéroatome) a un fort impact sur l'aromaticité locale des cycles adjacents. Il a également été montré que la cyclo-addition sur les PAHs phosphorés a lieu sur l'hétérocycle de plus faible aromaticité et permet de préparer des PAHs inédits. / Polycyclic aromatic hydrocarbons (PAHs) are important targets of experimental and theoretical studies, because of their potential use in optical and electronic devices, such as light-emitting diodes, field-effect transistors or photovoltaics. The properties of PAH systems can be modified by embedding heteroatoms into the sp2 backbone, however for P-modified PAHs, only a few examples exist. During my PhD research, I studied the properties of P-containing extended π-systems. It has been revealed by density functional calculations that the incorporation of phosphorus at the edge position of a PAH has a significant effect on the electronic structure of the entire π-system, as can be seen through the HOMO and LUMO. On the one hand, both orbitals keep the spatial characteristics of the parent heterocycle, on the other hand, the reduced HOMO-LUMO gap compared to the parent heterocycle is a consequence of the interaction between the phosphole unit and the extended aromatic system, as the molecular orbitals are delocalized through the sp2 carbon skeleton. We investigated the effect of chemical modification (including complexation) at the phosphorus atom, and found that due to the variation of the hyperconjugative interaction it can be used to fine-tune the optical properties. Aromaticity is one of the key characteristics of π-systems. During its investigation we have established that the local aromaticities in the investigated ring system could be best described by the NICS(1) values. The modification of the local aromaticity of the five-membered ring (by the variation of the heteroatom) has a significant impact on the local aromaticities of some of the other rings as well. It has been shown that the Diels-Alder cycloaddition of the P-embedded PAHs proceeds at those rings which exhibit the lowest aromaticity.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22468号 / 工博第4729号 / 新制||工||1739(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 田中 一生, 教授 秋吉 一成, 教授 古賀 毅 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

This dissertation covers the studies of two major topics: the photochemistry of mononuclear and multinuclear gold(I) complexes and synthetic approaches to tailor photophysical properties of cyclic trinuclear d10 complexes. First a detailed photochemical examination into the photoreactivity of neutral mononuclear and multinuclear gold(I) complexes is discussed, with the aim of gold nanoparticle size and shape control for biomedical and catalysis applications. Next is a comprehensive systematic synthetic approach to tailor the photophysical properties of cyclic trinuclear d10 complexes. This synthetic approach includes an investigation of structure-luminescence relationships between cyclic trinuclear complexes, an examination into their π-acid/π-base reactivity with heavy metal cations and an exploration into the photophysical properties of new heterobimetallic cyclic trinuclear complexes. These photophysical properties inspections are used to screen materials for their employment in molecular electronic devices such as organic light-emitting diodes (OLEDs) and thin film transistors (OTFTs).

The dissertation focuses on the structure of π-regular (regular) rings.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-08-28T20:47:17Z No. of bitstreams: 2 dissertação mestrado Thiago.pdf: 5668390 bytes, checksum: 14e5eb64f1d5634b959c6abe07f3be6d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-08-28T20:47:17Z (GMT). No. of bitstreams: 2 dissertação mestrado Thiago.pdf: 5668390 bytes, checksum: 14e5eb64f1d5634b959c6abe07f3be6d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Throughout history in various situations was necessary to determine the area of a circle and those moments mathematicians were led to test their creativity and skills. There were several ways to determine the area of a circular region developed until today. Some theory was created, directly or indirectly, related to this issue as the problem of squaring the circle and the number pi. / Ao longo da história em várias situações foi necessário determinar a área de um círculo e nesses momentos matemáticos foram levados a testar sua criatividade e suas habilidades. Várias foram as formas de determinar a área de uma região circular desenvolvidas até hoje. Muita teoria foi criada, direta ou indiretamente, ligada a esse problema como o problema da quadratura do círculo e o número pi.

Single-molecular electronics and organic material electronics are expanding research fields that ultimately aim for a vast variety of different applications, ranging from organic light-emitting diodes, to novel ways to improve the performance and decrease the size of electronics components. To achieve these goals, research has to be focused both on the development of functional molecules, but also on device fabrication. The work of this thesis is focused on the development of synthetic routes towards novel molecules for potential organic electronics applications, together with an investigation of their optical and electronic properties. The first part of the thesis describes the synthesis of butadiyne-substituted and diacetylenic phosphaalkenes. Theoretical, spectroscopic and electrochemical techniques have been used to understand key steps during their synthesis, and to gain further information on the conjugative properties of their π-systems. A mechanism is proposed for the formation of the butadiyne-substituted and diacetylenic phosphaalkenes and it is shown that the phosphorus heteroatom is an intrinsic part of the π-conjugated system. The incorporation of the phosphorus heteroatom leads to decreased HOMO-LUMO gaps compared to all-carbon based reference compounds. In the second part of the thesis, acetylenic phosphaalkenes are utilized for the preparation of phosphaalkene-substituted phospholes. A first step towards the exploration of the difference in reactivity of the σ2, λ3 phosphaalkene-P and the σ3, λ3 phosphole-P is presented as the oxidation of the compounds by sulfur proceeds selectively at the σ3, λ3–P. Spectroscopic and electrochemical investigations show that the phosphaalkene is an integral part of the compounds’ π-systems, and induces a HOMO-LUMO gap decrease compared to reference compounds that lack the P=C substituent. The third part of this thesis presents an exploratory study concerning the suitability of metathesis reactions for the assembly of alkene-bridged phosphaalkenes.

The field of molecular electronics includes the study of conjugated oligomers and polymers that have significant potential for use in devices such as light emitting diodes (LEDS), field effect transistors (FETS), and photovoltaic solar cells. These materials may replace inorganic semiconductors in these devices, Achieving better device performance through lowering the band-gap and achieving higher field effect mobilities will benefit from a greater fundamental understanding of charge transfer through the aromatic subunits. π-stacking of segments of conjugated polymers has been identified as a key feature that influences the charge transfer through semiconducting organic materials. Optimizing the molecular architecture of conjugated polymers has the potential to provide materials with better charge mobility. While devices might benefit from materials that take advantage of π-stacking, access to π-stacked structures presents a synthetic challenge. 1,8-Disubstituted naphthalenes may serve as simple covalent bridging scaffolds which might hold conjugated oligomers in a π-stacked arrangement. The research described in this thesis focuses on the synthesis of well-defined phenylene ethynylene oligomers coupled to naphthalene to serve as experimental models of closely π-stacked aromatic units in conjugated polymers. The π-stacked molecules reported in this dissertation are characterized by NMR, IR, and mass spectrometry. The effects of π- stacking on the structure and behavior of conjugated oligomers are determined by X-ray crystallography, spectroscopy, and electrochemistry.

A controllable self-assembly strategy of positively charged polycyclic aromatic hydrocarbons (PCPAH) towards the formation of rectangle sheets and ribbon-like nanostructures has been achieved by choosing divalent anions with different sizes. In contrast, only rod-like nanostructures are obtained from PCPAH with univalent anions. It is revealed that the divalent anions play a key role in guiding the packing of PCPAH, which provides an unprecedented route to fabricate two-dimensional nanostructures.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20387号 / 工博第4324号 / 新制||工||1670(附属図書館) / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 松原 誠二郎, 教授 大江 浩一, 教授 中尾 佳亮 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM