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Homoleptic Co(II), Ni(II), Cu(II), Zn(II) and Hg(II) complexes of bis-(phenyl)-diisoindol-aza-metheneGresser, Roland, Hoyer, Alexander, Hummert, Markus, Hartmann, Horst, Leo, Karl, Riede, Moritz January 2011 (has links)
The synthesis of five homoleptic transition metal complexes of bis-(phenyl)-diisoindol-aza-methene is described together with the optical, electrochemical and thermal properties of these compounds. Additionally, crystal structures for the Co and the Zn complex are reported. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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A family of 2D and 3D coordination polymers involving a trigonal tritopic linkerHauptvogel, Ines Maria, Bon, Volodymyr, Grünker, Ronny, Baburin, Igor A., Senkovska, Irena, Müller, Uwe, Kaskel, Stefan January 2012 (has links)
Five new coordination polymers, namely, [Zn2(H2O)2(BBC)](NO3)(DEF)6 (DUT-40), [Zn3(H2O)3(BBC)2] (DUT-41), [(C2H5)2NH2][Zn2(BBC)(TDC)](DEF)6(H2O)7 (DUT-42), [Zn10(BBC)5(BPDC)2(H2O)10](NO3)(DEF)28(H2O)8 (DUT-43), and [Co2(BBC)(NO3)(DEF)2(H2O)](DEF)6(H2O) (DUT-44), where BBC – 4,4′,4′′-(benzene-1,3,5-triyl-tris(benzene-4,1-diyl))tribenzoate, TDC – 2,5-thiophenedicarboxylate, BPDC – 4,4′-biphenyldicarboxylate, DEF – N,N-diethylformamide, were obtained under solvothermal conditions and structurally characterized. It has been shown that compounds DUT-40, DUT-41 and DUT-44 exhibit 2D layered structures with large hexagonal channels. Utilization of additional angular dicarboxylic TDC linker led to the formation of the DUT-42 compound with the structure consisting of three interpenetrated 3D networks. Using the linear co-linker dicarboxylic BPDC, DUT-43 was obtained which forms a complicated 3D architecture arising from the polycatenation of triple-layered 2D building units and 2D single layer units. The pore accessibility of the synthesized compounds in the liquid phase was proved by the adsorption of dye molecules. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Nouveaux polymères de coordination à base de titane et de dérivés phénoliques / New coordination polymers based on titanium and phenolic derivativesAssi, Hala 21 October 2016 (has links)
Les solides hybrides poreux ou les « MOFs » sont l'une des classes les plus récentes de polymères de coordination poreux cristallins. En raison de la variété de leur structure et leur composition, Ils sont actuellement considérés comme des candidats prometteurs dans divers domaines (le stockage de gaz, la séparation des fluides, la catalyse, la biomédecine…). Cependant, la littérature sur l'activité photocatalytique de ces solides n’a commencé à s’exploser que très récemment, bien que l’utilisation de ces matériaux comme photocatalyseurs hétérogènes soit avantageux en comparaison avec les semi-conducteurs classiques. Compte tenu des propriétés photocatalytiques bien établies de TiO2, il semble logique de se concentrer sur le titane(IV) pour la conception de nouveaux MOFs pour de telles applications. Néanmoins, en raison de la difficulté de contrôler la réactivité de cet ion métallique en solution (en particulier hors des conditions très acides), très peu de MOFs à base de titane ont été décrits, parmi les MOFs nombreux connus dans la littérature. Ainsi, l'obtention de solides cristallins à base de titane dans l'eau et en milieu basique reste un défi majeur dans ce domaine. Dans nos travaux, certaines stratégies ont été suivies afin de bénéficier des avantages de l’utilisation des cations Ti4+ et parallèlement confronter leurs limitations en se focalisant sur l'exploration de la chimie de ces cations (alcoxydes de titane, complexes et oxo-clusters) avec divers ligands polytopiques, en particulier les dérivés hydroxycarboxylates et polycatécholates pour la conception de nouveaux solides hybrides poreux stables à base de titane. Ces ligands présentent des avantages importants par rapport aux carboxylates purs, tels que la diversité structurale potentiellement plus élevée, les liaisons Ti-O plus fortes conduisant à une stabilité chimique améliorée en milieu basique, et une large absorption dans le visible assurée par un transfert de charge ligand-métal. D'autre part, l'utilisation des complexes moléculaires ou des oxo-clusters de titane sera une opportunité prometteuse dans le but de contrôler l'hydrolyse spontanée et la réactivité élevée des ions Ti4+. En privilégiant la synthèse solvo- et hydrothermale à l'aide du « système haut-débit », ces stratégies ont conduit à l’obtention de nouveaux solides cristallins (composés moléculaires et polymériques 1D /2D /3D). La synthèse, la caractérisation structurale au travers de la combinaison de différentes techniques (diffraction des rayons X, analyse thermogravimétrique, spectroscopie IR, RMN du solide, mesure de sorption...), l'étude de certaines propriétés et l’étude préliminaire de l’activité photocatalytique (production de dihydrogène de l’eau) de ces nouveaux solides seront ainsi discutées dans ce manuscrit. / Crystalline Metal-Organic Frameworks MOFs are one of the most recent classes of crystalline porous coordination polymers. Due to the variety of their structure and composition, they are currently considered as promising candidates in various domains (gas storage, fluid separation, catalysis, biomedicine…). However, the literature on the photocatalytic activity of these solids has exploded only very recently, although the many advantages of using these materials as heterogeneous photocatalysts in comparison with classical semiconductors. Considering the well-established photocatalytic properties of TiO2, it seems logical to focus on titanium in order to design new MOFs for such applications. Nevertheless, because of the difficulty in controlling the reactivity of these ions in solution (especially out of the very acidic conditions), very few crystalline titanium-based MOFs have been described, among the numerous MOFs known in the literature. Thus, obtaining titanium-based MOFs in water and basic medium remains a big challenge. In our work, some strategies has been followed in order to benefice from the advantages of the titanium ions and at the same time confront their limitations by focusing on the exploration of the chemistry of Ti4+ ions (titanium alkoxides, complexes and oxo-clusters) with various polytopic ligands, especially hydroxycarboxylate and polycatecholate derivatives in order to design new stable titanium-based MOFs. Such ligands provide important advantages in comparison with pure carboxylates, such as a potentially higher structural diversity, stronger Ti-O bonds leading to an enhanced chemical stability in basic medium, and a strong absorption in the visible range ensured by ligand to metal charge transfer. On the other hand, the use of titanium molecular complexes or oxo-clusters will be a promising opportunity in order to control the spontaneous hydrolysis and the high activity of Ti4+ ions. By privileging the solvo- and hydrothermal synthesis using the «high-throughput system», these strategies lead to obtain new crystalline solids (molecular and 1D/2D/3D polymeric compounds). The synthesis, the structural characterization by a combination of different technics (X-ray diffraction, TGA analysis, IR spectroscopy, Solid State NMR, sorption measurement…), the study of some properties and the preliminary photocatalytic experiments (water splitting reaction) of these new solids will be discussed in this manuscript.
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レイヤー積層型多孔性配位錯体が示す吸着誘起構造転移現象の機構解明沼口, 遼平 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18307号 / 工博第3899号 / 新制||工||1598(附属図書館) / 31165 / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 宮原 稔, 教授 田門 肇, 教授 山本 量一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
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Overtone Spectroscopy of Hydrogen in MOF-5Nelson, Jocienne N. 18 June 2014 (has links)
No description available.
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Infrared and Thermal-Desorption Spectroscopy of H<sub>2</sub> and D<sub>2</sub> in Metal Organic FrameworksShinbrough, Kai 26 July 2017 (has links)
No description available.
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Semi-hidrogenación de alquinos con nuevos catalizadores de paladioBallesteros Soberanas, Jordi 03 July 2023 (has links)
[ES] En esta Tesis se ha estudiado en profundidad la reacción de semi-hidrogenación de alquinos catalizada por materiales de paladio. Más especificamente, esta Tesis empieza estudiando un sistema simple para la semi-hidrogenación de alquinos: clústeres de paladio en disolución formados a partir de la reducción in situ de sales de paladio, en el Capítulo 3. Este concepto, se usará posteriormente para sintetizar un catalizador soportado y soluble en el Capítulo 4. Estos clústeres catalizan de forma muy eficiente la semi-hidrogenación de alquinos internos. Entre otros alquinos internos estudiados en el Capítulo 4, los 1,4-alquinodioles se investigaron en más profundidad en el Capítulo 5, donde se muestra su habilidad para desactivar la ruptura del hidrógeno molecular sobre catalizadores de paladio. Además, se estudiará su desimetrización diastereoisomérica durante la reacción semi-hidrogenación. La semi-hidrogenación de alquinos terminales, a pesar de ser típicamente más sencilla, no procede de forma eficiente en los sistemas catalíticos de los capítulos anteriores. Es por ello que en el Capítulo 6 se pone énfasis en estos alquinos terminales y, mediante la interacción entre fosfinas y catalizadores de paladio sobre carbono, se consigue una hidrogenación selectiva de estos sustratos sobre catalizadores clásicamente no selectivos. Finalmente, el último Capítulo 7 se dedica a la semi-hidrogenación del acetileno, el alquino con mayor presencia industrial a nivel global con diferencia. Los elevados requerimientos de rendimiento y el alto volumen de producción del proceso de semi-hidrogenación de acetileno se satisfacen en este caso mediante el uso de un MOF con dímeros de Pd-Au. / [CA] En aquesta Tesi s'ha estudiat en profunditat la reacció de semi-hidrogenació d'alquins catalitzada per materials de pal·ladi. Més especificament, aquesta Tesi comença estudiant un dels sistemes més simples per a la semi-hidrogenació d'alquins: clústers de pal·ladi en dissolució formats a partir de la reducció "in situ" de sals de pal·ladi en el Capítol 3. Aquest concepte s'empra posteriorment per a sintetitzar un catalitzador suportat i soluble en el Capítol 4. Aquests clústers catalitzen de forma molt eficient la semi-hidrogenació dels alquins interns. Entre d'altres alquins interns estudiats en el Capítol 4, els 1,4-alquindiols s'investiguen en més profunditat en el Capítol 5, on es mostra la seva habilitat per a desactivar la ruptura de l'hidrogen molecular sobre catalitzadors de pal·ladi, així com la desimetrizació diastereoisomérica que sofreixen durant la reacció de semi-hidrogenació. Malgrat ser típicament més senzilla, la semi-hidrogenació d'alquins terminals no procedeix de manera eficient en els sistemes catalítics dels capítols anteriors. És per això que en el Capítol 6 es posa èmfasi en aquests alquins terminals i, mitjançant la interacció entre fosfines i catalitzadors de pal·ladi sobre carboni, s'aconsegueix una hidrogenació selectiva d'aquests substrats sobre catalitzadors clàssicament no selectius. Finalment, l'últim Capítol 7 es dedica a la semi-hidrogenació de l'acetilè, un dels alquins terminals amb major presència industrial a nivell global. Els elevats requisits de rendiment i l'elevat volum de producció d'aquest procés de semi-hidrogenació d'acetilè se satisfan, en aquest cas, mitjançant l'ús d'un MOF amb dímers de Pd-Au. / [EN] In this Thesis, the semi-hydrogenation reaction of alkynes catalyzed by palladium materials has been studied in depth. More specifically, this Thesis starts by studying a very simple system for the semi-hydrogenation of alkynes: palladium clusters in solution formed from the in situ reduction of palladium salts, in Chapter 3. This concept will be subsequently used to synthesize a supported and soluble catalyst in Chapter 4. These clusters catalyze very efficiently the semi-hydrogenation of internal alkynes. Among other internal alkynes studied in Chapter 4, 1,4-alkynodiols are further investigated in Chapter 5, where their ability to deactivate molecular hydrogen cleavage over palladium catalysts is shown, as well as the diastereoisomeric desymmetrization that they undergo during the semi-hydrogenation reaction. Despite being typically simpler, the semi-hydrogenation of terminal alkynes does not proceed efficiently in the catalytic systems of the previous chapters. Hence, in Chapter 6, emphasis is placed on these terminal alkynes and, by means of the interaction between phosphines and palladium-on-carbon catalysts, a selective hydrogenation of these substrates over classically non-selective catalysts is achieved. Finally, the last Chapter 7 is devoted to the semi-hydrogenation of acetylene, the alkyne with the largest global industrial presence by far. The high yield and production volume requirements of the acetylene semi-hydrogenation process are met in this case by using a MOF with Pd-Au dimers. / Ballesteros Soberanas, J. (2023). Semi-hidrogenación de alquinos con nuevos catalizadores de paladio [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/194631
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Spatiotemporal Design of the Metal–Organic Framework DUT-8(M)Miura, Hiroki, Bon, Volodymyr, Senkovska, Irena, Ehrling, Sebastian, Bönisch, Nadine, Mäder, Gerrit, Grünzner, Stefan, Khadiev, Azat, Novikov, Dmitri, Maity, Kartik, Richter, Andreas, Kaskel, Stefan 22 May 2024 (has links)
Switchable metal–organic frameworks (MOFs) change their structure in time and selectively open their pores adsorbing guest molecules, leading to highly selective separation, pressure amplification, sensing, and actuation applications. The 3D engineering of MOFs has reached a high level of maturity, but spatiotemporal evolution opens a new perspective toward engineering materials in the 4th dimension (time) by t-axis design, in essence exploiting the deliberate tuning of activation barriers. This work demonstrates the first example in which an explicit temporal engineering of a switchable MOF (DUT-8, [M1M2(2,6-ndc)2dabco]n, 2,6-ndc = 2,6-naphthalene dicarboxylate, dabco = 1,4diazabicyclo[2.2.2]octane, M1 = Ni, M2 = Co) is presented. The temporal response is deliberately tuned by variations in cobalt content. A spectrum of advanced analytical methods is presented for analyzing the switching kinetics stimulated by vapor adsorption using in situ time-resolved techniques ranging from ensemble adsorption and advanced synchrotron X-ray diffraction experiments to individual crystal analysis. A novel analysis technique based on microscopic observation of individual crystals in a microfluidic channel reveals the lowest limit for adsorption switching reported so far. Differences in the spatiotemporal response of crystal ensembles originate from an induction time that varies statistically and widens characteristically with increasing cobalt content reflecting increasing activation barriers.
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Nouveaux catalyseurs hétérogènes chiraux pour le dédoublement cinétique hydrolytique des époxydesTERMINAUX / New Chiral Heterogeneous catalysts for the Hydrolytic Kinetic Resolution of Terminal EpoxidesHong, Xiang 11 October 2012 (has links)
L’objectif de ce travail étaient le développement de catalyseurs hétérogènes efficaces pour promouvoir des réactions asymétriques, en utilisant la polymérisation oxydante ou la formation de polymères de coordination. De nouveaux complexes de salen Co(III) chiraux modifiés par des groupements aromatiques sur les position 5, 5’ ont été préparés et testés dans le dédoublement cinétique hydrolytique (HKR) des époxydes terminaux en conditions homogènes. Ces complexes ont été ensuite engagés dans les polymérisations oxydantes électrochimiques ou chimiques, et une stratégie de copolymérisation a fourni des polymères chiraux très efficaces et stables pour catalyser l’HKR dans des conditions hétérogènes. Nous avons alors cherché à préparer un catalyseur capable de catalyser deux réactions en cascade, en copolymérisant deux complexes de salen portant des métaux différents. Pendant ces études, les complexes de salen Mn ont révélé leur participation active à la réaction d’HKR des époxydes terminaux catalysée par les complexes de salen Co(III), en augmentant l’excès énantiomérique du produit de façon significative. Les études mécanistiques ont été ensuite réalisées pour tenter de comprendre le rôle des complexes de Mn dans cette réaction. De plus, des complexes de salen fonctionnalisés par le groupement pyridine ou le groupement de type acide isophtalique ont été synthétisés. Ces complexes ont été utilisés pour préparer de nouveaux réseaux de polymères de coordination poreux chiraux (collaboration avec l’équipe LCI de l’ICMMO et l’Institut Lavoisier à Versailles), qui sont ensuite testés comme catalyseurs hétérogènes dans la réaction de Henry asymétrique et la réaction d’HKR. / The aim of this work was to prepare new chiral heterogeneous catalysts for asymmetric catalysis by oxidative polymerization of chiral organometallic complexes or by formation of chiral metal organic frameworks. New chiral salen Co(III) complexes modified by oxidizable aromatic groups at position 5,5’ have been prepared and tested as homogeneous catalysts in the Hydrolytic Kinetic Resolution (HKR) of terminal epoxides. These complexes have also been engaged into the oxidative electrochemical and chemical polymerization, and a copolymerization strategy has afforded very efficient and stable heterogeneous catalysts for the HKR. The idea of copolymerization has then been extended to the copolymerization of two salen complexes with different metals, which is expected to promote successively two different asymmetric transformations. During preliminary investigations, the salen Mn complexes have been found to be able to enhance the catalytic performance of salen Co(III) complexes in the HKR by increasing significantly the enantiomeric excess of the products. Mechanistic studies have thus been realized to understand the role of salen Mn complexes in this reaction. Besides, some chiral salen complexes functionalized by pyridine or isophtalic acid groups have been synthesized for the preparation of new chiral metal organic frameworks (collaboration with LCI of ICMMO and Institut Lavoisier of Versailles), which have also been tested in the asymmetric Henry reaction and the HKR as heterogeneous catalysts.
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Growth and Studies of Phase Transitions in Multifunctional Perovskite MaterialsYadav, Ruchika January 2015 (has links) (PDF)
Crystal growth and characterization of few multifunctional materials with perovskite (ABX3) structure are discussed in this thesis. Efforts were made to modify the magnetic and electric behaviour of these materials by selective tuning of A, B and X components. Structural, magnetic and dielectric characterization are detailed in various chapters for doped (A and B site) rare-earth manganites and organometallic compounds with different (Chloride or formate) anions.
The relevant aspects of crystal structure and its relationship with ordered ground states are discussed in the introductory chapter. A detailed review of prominent theories pertaining to magnetic and ferroelectric ordering in the literature is provided. Growth of various inorganic compounds by solid-state reaction and floating zone method as well as use of solvothermal techniques for growing organometallic compounds are discussed. Material preparation, optimization of crystal growth processes and results of characterization are addressed in various chapters.
The effect of Yttrium doping on structural, magnetic and dielectric properties of rare-earth manganites (RMnO3 where R = Nd, Pr) has been investigated. Neutron diffraction studies (Pr compounds) confirm A-type antiferromagnetic structure and fall in transition temperature as the Yttrium doping level increases. Diffraction experiments in conjunction with dc magnetization and ac susceptibility studies reveal magnetic frustration in excess Yttrium dopedcompounds. When mutliglass properties of 50% B-site doped Nd2NiMnO6 were investigated, evidence of re-entrant cluster glass phase was seen probably due to presence of anti-site disorder. The relaxor-like dielectric behaviour arises from crossover of relaxation time in grain and grain boundary regions. Multiferroic behaviour of the organometallic compound (C2H5NH3)2CuCl4 as well as the ferroelectric transition were investigated in detail. The role of Hydrogen bond ordering in driving structural transitions is elucidated by low temperature dielectric and Raman studies in (C2H5NH3)2CdCl4. It was found possible to tune the magnetic and ferroelectric properties in metal formate compounds (general formula AB(HCOO)3) by selectively choosing organic cations [(CH3)2NH2+; C(NH3)3+] and transition metal ion [B = Mn, Co and Cu]. The nature of magnetic ordering and transition temperature could be altered by the transition metal ion. The effect of reorientation of organic cations which leads to ferroelectric nature is discussed using dielectric and pyroelectric data. Significant results are summarized in the chapter outlining general conclusions. Future prospects of work based on these observations are also provided. The conclusions are corroborated by detailed analysis of experimental data.
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