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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The Preparation, Multinuclear Magnetic Resonance and Solid-State Investigation of Some Classically Bonded Anions of the Heavy Main-Group Elements Derived from Zintl Phases

Devereux, Lesley Ann 09 1900 (has links)
<p> The synthesis and X-ray crystallographic determination of solid derivatives of homo- and heteropolyatomic anions derived from Zintl phases has generally yielded the least soluble of the ions present in solution. Many other species present in these solutions have remained unidentified until recently when considerable effort directed towards the investigation of the solution chemistries of Zintl anions has been put forth.</p> <p> The present work is mainly concerned with the characterization of new Zintl anions in solution using multinuclear magnetic resonance spectroscopy as the primary investigative tool. These studies include (1) the tetrahedral SnCh4^4- (Ch = selenium and/or tellurium), (2) the dimer of SnSe3^2-, Sn2Se6^4-, (3) several interesting but, as-of-yet, unidentified species present in solutions derived from ternary Na/Sn/Te alloys and present in the reaction of Sn(II) Cl2 with Te2^2-, and (4) a set of possible multi-thallium-tellurium species. Relevant chemical shifts and nuclear spin-spin coupling constants are reported and trends discussed.</p> <p>119Sn Mössbauer investigations of all tin-containing species is also presented as is a brief discussion of the X-ray crystallographically determined polytelluride, Te4^2-.</p> / Thesis / Master of Science (MSc)
12

Ligand Design and Exploration of Electronic Properties Based on Dinuclear Platinum Complexes / 白金二核錯体を基盤とした配位子設計と電子物性の探索

Moriyama, Hayato 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第24446号 / 理博第4945号 / 新制||理||1706(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 北川 宏, 教授 有賀 哲也, 教授 吉村 一良 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
13

Liganden mit N/S-Donorsets in der Münzmetallchemie: Modellkomplexe für Methanobactin und multinukleare, lumineszierende Pyrazolat-Komplexe / Ligands with N/S-Donorsets in coinage metal chemistry: model complexes for methanobactin and multinuclear, luminescent pyrazolate complexes

Jahnke, Ann Christin 25 June 2012 (has links)
No description available.
14

Síntese e caracterização de complexos organometálicos de Cu(I), Cu(II) e Ni(II) com ferroceno-triazenos e triazenido de Hg(II) com interação Metal-Areno-Pi / Synthesis and characterization of Cu(I), Cu(II) AND Ni(II) organometallic complexes with ferrcene-triazenes and Hg(II) triazenido with Metal-Arene-Pi interaction

Paraginski, Vanessa Teixeira Kunz 29 January 2016 (has links)
This Thesis aimed the synthesis of new metal complexes with triazenido ligands and triazenes chains directly linked to ferrocene fragment by a new synthesis methodology. The complex bis-[1,3-bis(2-biphenyl)triazenido-κN1]mercury(II) was synthesized, melting point 222–224 °C and yield 82 %, characterized by IR, UV-Vis, 1H e 13C RMN, elemental analysis, mass spectrometry by ESI(+)TOF, single crystal x-ray diffraction. The triazenes 1,1’-bis[1-phenyl-3(H)triazene]ferrocene (Compound 1) and 1,1’-bis(benzo-1,2,3-triazol-1-phenyltriazene)ferrocene (Compound 6) were synthesized by ferrocene metalation with BuLi and substitution by correspondent azide, with yields higher than 70 %, melting points 151 and 160 °C, respectively, were characterized by UV-Vis (Compound 1), 1H and 13C NMR, elemental analysis, IE-MS (Compound 1) ESI(+)TOF (Compound 6), single crystal x-ray diffraction (Compoound 1), powder x-ray diffraction, scanning electron microscopy (SEM) and thermogravimetric analysis. Starting from Compound 1 the following heterobimetallic complexes were sinthesized: {[Fe(C5H4NNNH5C6)]2Ni2} (Compound 2), {[Fe(C5H4NNN(H)H5C6)]2Cl2Cu2} (Compound 3 with protonated triazene), {[Fe(C5H4NNNH5C6)]2[Cu(PPh3)2]2} (Compound 4), {[Fe(C5H4NNN(H)H5C6)]2Cu4} (Compound 5). Compounds 6 and 7 didn’t yields suitable single crystals for X-ray diffraction, but based on the MS-ESI(+)TOF and 1H NMR analysis the respective structures based on 1,1’-bis[1-phenyl-3(H)triazene]ferrocene could be predicted. The new triazenes synthesis by methodology under study showed good yields and can be done in two steps. The compounds purification is simple by only extraction with organic solvent and water precipitation followed by filtration enabling the development of further new triazenes including other metallocenes and other azides. / O objetivo desta tese foi a síntese de novos complexos metálicos envolvendo ligantes triazenidos e triazenos diretamente ligados ao ferroceno. Foi sintetizado o complexo bis-[1,3-bis(2-bifenil)triazenido-κN1]mercúrio(II) com ponto de fusão 222–224 °C e rendimento de 82 %, caracterizado por infravermelho, UV-Vis, 1H e 13C RMN, análise elementar, espectroscopia de massas por ESI(+)TOF, difração de raios X em monocristal. Os triazenos 1,1’-bis[1-fenil-3(H)triazeno]ferroceno (Composto 1) e 1,1’-bis(benzo-1,2,3-triazol-1-feniltriazeno)ferroceno (Composto 6) foram sintetizados por metalação via BuLi, seguida da substituição pela azida correspondente com rendimentos superiores a 70 %, com pontos de fusão de 151 e 160 °C, respectivamente, foram caracterizados por UV-Vis (Composto 1), 1H e 13C RMN, análise elementar, espectroscopia de massas por IE (Composto 1) ESI(+)TOF (Composto 6), difração de raios X em monocristal (Composto 1), difração de raio X de pó, microscopia eletrônica de varredura e análise termogravimétrica. A partir do Composto 1 foram sintetizados os complexos multinucleares: {[Fe(C5H4NNNH5C6)]2Ni2} (Composto 2), {[Fe(C5H4NNN(H)H5C6)]2Cl2Cu2} (Composto 3 com triazeno protonado), {[Fe(C5H4NNNH5C6)]2[Cu(PPh3)2]2} (Composto 4), {[Fe(C5H4NNN(H)H5C6)]2Cu4} (Composto 5). O Composto 6 e o Composto 7 não resultaram em cristais adequados para medida, com as análises por EM-ESI(+)TOF e 1H RMN pode-se fazer uma predição da estrutura baseada nas estruturas com o 1,1’-bis[1-fenil-3(H)triazeno]ferroceno. A síntese de novos triazenos pela metodologia estudada possui bom rendimento e é realizada em apenas duas etapas, a purificação dos triazenos é simples, envolvendo apenas a extração com solvente orgânico e a precipitação em água seguida de filtração possibilitando o desenvolvimento de novos triazenos com outros metalocenos e outras azidas.
15

INVESTIGATIONS TOWARDS THE PREPARATION OF PHOTORESPONSIVE POLYMERS BASED ON PHOTOCLEAVABLE TELLURIUM-CONTAINING CROSS-LINKS

Gendy, Chris 10 1900 (has links)
<p>The goal of this research project is to synthesize, characterize, and examine the properties of a material that undergoes a decrease in refractive index upon exposure to light. It is anticipated that such photoresponses could elicit previously unknown nonlinear phenomena including self-trapped black beams. An appropriate material for these investigations would be a polymer cross-linked by photocleavable groups causing a Δ<em>n</em> < 0. Organo-ditellurides, molecules that contain a Te-Te bond, would be appropriate for the crosslinks as their σ*<sub>Te-Te</sub> ← n<sub>Te</sub> transition usually absorbs light between 400 and 500 nm, and can lead to photodissociation of the chalcogen-chalcogen bond.</p> <p>Initial attempts to directly functionalize a polymer (polystyrene) resulted in intractable solids. A more promising approach relies on the preparation of cross-linking agents followed by co-polymerization. Despite literature claims, to date, there is no structurally authenticated photoresponsive molecule that simultaneously contains vinyl (CH=CH) and telluride (-Te-) functional groups. The work in this thesis has yielded what would be the first example, in addition to a crystal structure obtained by X-ray diffraction, the compound has been characterized by multinuclear NMR (<sup>1</sup>H, <sup>13</sup>C, <sup>125</sup>Te) and vibrational spectroscopy with the support of DFT calculations.</p> / Master of Science (MSc)
16

Compostos de coordenação envolvendo aroil(n,n-dialquil-calcogenoureias) monopodais e bipodais

Schwade, Vânia Denise 24 January 2014 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presentes the study realized with monopodal and bipodal aroyl(N,N-dialkylchalcogenoureas) involving different metallic ions to obtain mononuclear, dinuclear and trinuclear compounds. The compounds were characterized by X-ray diffraction, 1H NMR, I.R., ESI+ MS and elemental analysis. In the first part, the chemistry of aroyl(N,N-dialkylchalcogenoureas) with {ReVO}3+ was investigated, where mononuclear and dinuclear compounds were obtained. In the second part, the chemistry of isophthaloylbis(N,N-diethylchalcogenoureas) was investigated against different metallic ions. Dinuclear complexes of AuI, CuII, HgII and InIII, and polymeric compounds with PbII and SnII were obtained. Compounds were also obtained with CuI and TeII. The structural analysis of the AuI, CuII, PbII and InIII compounds with isophthaloylbis(N,N-diethylthiourea), H2L1, have shown that the ligand can exhibit different orientations of the arms‟ to make bis(bidentate) chelate coordination, by the oxygen and sulphur atoms, or bis(monodentate), by the sulphur atoms. These orientations occur due the metal characteristics, as geometry or the influency of the lone pair of electrons. The third part was focused in exploring the synthesis of trinuclear compounds using combinations of metals with dipicolinoylbis(N,N-diethylchalcogenoureas). With the derivatized ligand, 4-chlorodipicolinoylbis(N,N-diethylthiourea), H2L4, trinuclear [MIIBaIIMII] and [MIIGdIIIMII] (where MII = Mn, Co) compounds were obtained; and with the dipicolinoylbis(N,N-diethylselenourea), H2L5, the compounds [MnIIBaIIMnII] and [MIISmIIIMII] (MII = Mn, Co) were obtained. The composition of these compounds for the charge compensation follows that observed for the known compounds with the dipicolinoylbis(N,N-diethylthiourea) ligand, H2L2, in the way that, depending on the combination of metals used, two or three bis(chalcogenourea) anions are involved, where also acetate and/or chloride anions can be involved. The derivatization (additional Cl atom in the pyridine ring of the ligand molecule) led to the connection of the trinuclear molecules due to Ba∙∙∙Cl interactions, verified by the structural analysis of one compound. With the H2L2 and H2L4 ligands the incorporation of PbII in the trinuclear systems was explored, and [PbIIBaIIPbII] compounds were obtained. In these compounds the PbII metallic centers are located in the border positions by the chelate S,O coordination of three bis(thioureato) anions. On the other hand, [MIIPbIIMII] compounds were obtained for MII = Mn and Ni with H2L2, in which PbII is located in the central cavity formed by the S,O chelate coordination to the MnII and NiII metallic centers. However, from the combination PbII/NiII, a tetranuclear compound was also obtained, leading to a discussion of radius ratio between the metals as an aspect to be considered to obtain trinuclear systems, seeking the alignment of the metallic centers in the complexes. / Este trabalho apresenta um estudo realizado com aroil(N,N-dialquil-calcogenoureias) monopodais e bipodais envolvendo diferentes íons metálicos, na obtenção de compostos mononucleares, dinucleares e trinucleares. Os compostos foram caracterizados por difração de raios X, 1H RMN, I.V., IES+ EM e análise elementar. Na primeira parte, foi investigada a química de aroil(N,N-dialquilcalcogenoureias) envolvendo núcleos de {ReVO}3+, onde foram obtidos compostos mononucleares e dinucleares. Na segunda parte, foi investigada a química de isoftaloilbis(N,N-dietilcalcogenoureias) frente a diferentes íons metálicos. Foram obtidos complexos dinucleares de AuI, CuII, HgII e InIII, e poliméricos com PbII e SnII. Também foram obtidos compostos envolvendo CuI e TeII. A análise estrutural dos compostos de AuI, CuII, PbII e InIII com isoftaloilbis(N,N-dietiltioureia), H2L1, mostrou que o ligante pode apresentar diferentes orientações dos braços‟ para coordenação quelato bis(bidentada), pelos átomos de oxigênio e enxofre, ou bis(monodentada), pelo átomo de enxofre. Estas orientações ocorrem devido às características dos metais, como geometria ou influência do par isolado de elétrons. Na terceira parte explorou-se a síntese de compostos trinucleares utilizando-se combinações de metais, com dipicolinoilbis(N,N-dietilcalcogenoureias). Com o ligante derivatizado, 4-clorodipicolinoilbis(N,N-dietiltioureia), H2L4, foram obtidos compostos trinucleares [MIIBaIIMII] e [MIIGdIIIMII] (onde MII = Mn, Co); já com o ligante dipicolinoilbis(N,N-dietilselenoureia), H2L5, foram obtidos os compostos [MnIIBaIIMnII] e [MIISmIIIMII] (MII = Mn, Co). A composição destes compostos para o balanceamento de cargas segue à observada para os compostos conhecidos com o ligante dipicolinoilbis(N,N-dietiltioureia), H2L2, de forma que, dependendo da combinação de metais utilizada, são envolvidos dois ou três ânions bis(calcogenoureatos), podendo ainda estar envolvidos ânions acetato e/ou cloreto. A derivatização (átomo de Cl adicional no anel piridínico da molécula do ligante) levou à conexão de moléculas trinucleares a partir de interações Ba∙∙∙Cl, verificada pela análise estrutural de um dos compostos. Com os ligantes H2L2 e H2L4 foi explorada a incorporação de PbII em sistemas trinucleares, sendo obtidos compostos [PbIIBaIIPbII]. Nestes, os centros metálicos de PbII localizam-se nas posições das extremidades, pela coordenação quelato S,O de três ânions bis(tioureatos). Por outro lado, compostos [MIIPbIIMII] foram obtidos para MII = Mn e Ni com H2L2, nos quais PbII localiza-se na cavidade central formada pela coordenação quelato S,O aos centros metálicos de MnII e NiII. Porém, da combinação PbII/NiII, um composto tetranuclear também foi obtido, o que levou à uma discussão de razão de raios entre os metais como aspecto a ser considerado para a obtenção de sistemas trinucleares, buscando o alinhamento dos centros metálicos nos complexos.

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