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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.
21

Amine-Boranes: Synthesis and Applications

Henry J Hamann (10730742) 30 April 2021 (has links)
Reported herein is a brief summary of the history, properties, and applications of amine-boranes. The past methods devised for their preparation are described and the routes used to produce the compounds used in the work presented here are detailed. Building on prior synthetic approaches to amine-boranes, a new carbon dioxide mediated synthesis is presented. Proceeding through a monoacyloxyborane intermediate, the borane complexes of ammonia, primary, secondary, tertiary, and heteroaromatic amine are provided in 53-99% yields. Utilizing the amine-boranes obtained from the methods described, two divergent methods for direct amidation are introduced. The first uses amine-boranes as dual-purpose reagents, where the carboxylic acid is first activated by the borane moiety to form a triacyloxyborane-amine complex. This allows the delivery of the coordinated amine to form the amide products. A series of primary, secondary, and tertiary amides were prepared in 55-99% yields using this protocol, which displays a broad functional group tolerance. Extended from this dual-purpose methodology, a catalytic amidation is described. Utilizing ammonia-borane as a substoichiometric (10%) catalyst, a series of secondary and tertiary amide are prepared directly from carboxylic acids and amines in 59-99% yields, including amines containing typically borane reactive functionalities including alcohols, thiols, and alkenes. Amine-boranes are additionally used in two borylation methodologies. By reaction with <i>n</i>-butyl lithium, the amine-boranes are converted to the corresponding lithium aminoborohydrides, which upon reaction with a terminal alkyne provides the alkynyl borane-amine complexes in 65-98% yields. This process is compatible with both alkenes and internal alkynes, as well as a range of aprotic functionalities. A new strategy for aminoborane synthesis is also described and applied to the borylation of haloarenes. Activation of a series of amine-boranes with iodine produces the iodinated amine-borane, which undergoes dehydrohalogenation with an appropriate base to produce either monomeric or dimeric aminoboranes. Several aminoboranes were synthesized exclusively as the monomeric species, which due to their greater reactivity, were used directly in the synthesis of a series of aryl boronates in 65-99% yields.
22

Synthesis And Characterization Of Water Soluble Polymer Stabilized Transition Metal(0) Nanoclusters As Catalyst In Hydrogen Generation From The Hydrolysis Of Sodium Borohydride And Ammonia Borane

Metin, Onder 01 December 2010 (has links) (PDF)
Metal nanoclusters exhibit unique properties which differ from their bulk materials, owing to the quantum size effects. For example, the catalytic activity of transition metal nanoclusters generally increases with decreasing particle size. However, nanoclusters tend to be fairly unstable with respect to the agglomerate into bulk metal in solution and thus special precautions have to be taken to avoid their aggregation or precipitation during the preparation of such nanoclusters in solution. In order to obtain stable nanoclusters dispersed in solution, a stabilizing agent is usually added into the reaction system. The stabilization of metal nanoclusters in solution can be achieved either by electrostatically by using charged ions such as acetate ion or sterically by long chain molecules such as polymers. Polymers are one of the most widely used steric stabilizers for the preparation of stable metal nanoclusters in solution. The use of polymers as stabilizer for the synthesis of transition metal nanoclusters provides advantegous regarding solubility, conductivity, thermal stability and reusability. The metal nanoclusters stabilized by polymers generally show higher catalytic activity, stability and optical properties. In this dissertation we report the preparation and characterization of water soluble polymer stabilized transition metal(0) (metal= Ni, Co and Ru) nanoclusters and their v catalysis in hydrogen generation from the hydrolysis of sodium borohydride (NaBH4) and ammonia borane (AB) which are the best candidates as chemical hydrogen storage materials for on-board applications. The water soluble polymer stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters were prepared by using two different facile methods / (i) the reduction of metal precursors by sodium borohydride in the presence poly(N-vinyl pyrrolidone) (PVP) in methanol solution after 1h reflux, (ii) the in situ generation during the hydrolysis of ammonia borane in the presence of poly(4-styrene sulfonicacid-co-maleic acid) (PSSA-co-MA). The characterization of both type of polymer stabilized transition metal(0) nanoclusters were done by using UV-Visible electronic absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and FT-IR techniques. The catalytic activity of PVP stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters was tested in the hydrolysis of NaBH4 and AB. The catalytic acitivity of PSSA-co-MA stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters was tested only in the hydrolysis of AB in which they were in situ generated. The kinetics of hydrogen generation from both hydrolysis reactions in the presence PVP or PSSA-co-MA stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters were studied depending on the polymer to metal ratio, catalyst concentration, substrate concentration and temperature as well as the activation parameters (Arrhenius activation energy (Ea), activation enthalpy (
23

Stockage solide et génération d’hydrogène : du borohydrure de sodium NaBH4 à l’hydrazine borane N2H4BH3 : catalyse, cinétique et mécanismes / Solid-state hydrogen storage and generation : from sodium borohydride NaBH4 to hydrazine borane N2H4BH3 : catalysis, kinetic and mechanisms

Hannauer, Julien 12 December 2011 (has links)
Parmi les procédés de stockage d’hydrogène étudiés actuellement, le stockage solide de l’hydrogène dans les hydrures chimiques, associée à sa génération par une réaction de solvolyse, est une technologie prometteuse. La première partie de cette thèse s’articule donc autour de l’étude de la solvolyse de deux composés étudiés ces dernières années, le borohydrure de sodium NaBH4 et l’ammoniaborane NH3BH3. Le dégagement contrôlé d’hydrogène peut alors se faire par des réactions d’hydrolyse. La comparaison de la cinétique de la réaction d’hydrolyse du NaBH4 avec celle de la méthanolyse du NaBH4 nous a permis de décrire ces réactions avec le modèle de Langmuir-Hinshelwood. Concernant la réaction d’hydrolyse du NH3BH3, nos recherches se sont focalisées sur la préparation in situ de catalyseurs présentant de fortes activitéspar l’étude des hydrolyses spontanées et catalysées de mélanges NH3BH3-NaBH4. La seconde partie de la thèse est consacrée au développement d’un nouveau système N2H4BH3-eau pour la génération d’hydrogène. Les premiers essais, réalisés avec des métaux de transition comme catalyseur, nous ont permis de mettre en évidence que cette réaction se faisait en deux étapes catalytiques, l’hydrolyse de BH3, puis la décomposition de N2H4.Une faible sélectivité pour la décomposition complète de N2H4 étant atteinte dans ces conditions, la suite de l’étude a porté sur la préparation de catalyseurs sélectifs. La stratégie adoptée a été l’utilisation de matériaux bimétalliques Ni-Pt. La sélectivité de la réaction est alors dépendante de la teneur en Pt et une sélectivité maximum de 93 % pour la seconde étape de la réaction a été obtenue avec Ni0,89Pt0,11 / Hydrogen use as a potential alternative solution to fossil fuels is hindered by engineering problems, its storage being one of the most prominent. Various storage methods are under investigation but solid-state storage in chemical hydrides appears to be convenient with regards to their storage capacities, safety and cost. The first part of this thesis deals with the solvolysis reaction of two well known compounds, sodium borohydride NaBH4 and ammonia borane NH3BH3. The hydrogen can be easily released by hydrolysis at ambient temperature. We focused on understanding the kinetics and reaction mechanisms of NaBH4 hydrolysis. Thus, we compared this reaction with NaBH4 methanolysis, and found that the Langmuir-Hinshelwood model well captures the kinetics of the reaction. Concerning the NH3BH3 hydrolysis reaction, we concentrated our efforts on the in situ preparation of highly-active catalysts. This was achieved by studying the spontaneous and catalyzed hydrolysis of NaBH4-NH3BH3 mixtures. The second part of the thesis is dedicated to the development of the N2H4BH3-water system for hydrogen generation. Initial tests using transition metals as catalysts allowed us to determine that the reaction takes place in two steps, the hydrolysis of BH3 and the N2H4 decomposition. Since Rh as catalyst exhibits only a 29 % selectivity for the complete decomposition of N2H4, the strategy was set up to use Ni-Pt bimetallic nanoparticles. It has been found that the selectivity for the reaction is dependent on the Pt content in the Ni-Pt alloy and a selectivity of 93 % was reached in the presence of Ni0,89Pt0,11 nanoparticles
24

Wasserstoffgenerator-Systeme auf Basis chemischer Hydride zur Versorgung von PEM-Brennstoffzellen im Kleinleistungsbereich: Wasserstoffgenerator-Systeme auf Basis chemischer Hydride zur Versorgung von PEM-Brennstoffzellen im Kleinleistungsbereich

Kostka, Johannes 16 November 2012 (has links)
Drei Wasserstoffgenerator-Systeme (WGS) auf Basis chemischer Hydride wurden in dieser Arbeit als Labormuster ausgelegt, gefertigt und in ihren Betriebseigenschaften analysiert. Es wurden ein 20 W-WGS und zwei 100 W-WGS untersucht. Als chemische Hydride wurden Amminboran und Natriumborhydrid ausgewählt. Aufgrund ihrer vergleichsweise einfachen Lagerfähigkeit, ihren moderaten Freisetzungsbedingungen und ihrer volumetrisch wie gravimetrisch hohen Wasserstoffdichten erschienen sie in besonderer Weise geeignet für Wasserstoffgeneratoren im Kleinleistungsbereich. Zwar zeigen diese chemischen Hydride zurzeit hinsichtlich ihrer Kosten, ihrer Energieeffizienz bei der Herstellung und ihrer Umweltverträglichkeit keine Vorteile gegenüber verdichtetem Wasserstoff, jedoch besitzen sie mit ihrer hohen, auf das Hydrid bezogenen Energiedichte ein positives Alleinstellungsmerkmal. Bei der Entwicklung der WGS standen daher neben der Betriebszuverlässigkeit und Regelbarkeit die Optimierung der systembezogenen Energiedichte WGS im Fokus.:Versicherung Inhaltsverzeichnis Abkürzungsverzeichnis 1 Einleitung 2 Grundlagen1 2.1 Aufbau eines Wasserstoffgenerator-Systems 2.2 Anforderungen an das Wasserstoffgenerator-System 2.2.1 Anwendungsspezifische Anforderungen 2.2.2 Brennstoffzellenspezifische Anforderungen 2.3 Auswahl der Wasserstoffquelle 2.3.1 Reversible Wasserstoffquellen 2.3.2 Irreversible Wasserstoffquellen 2.4 Auslegung der Subsysteme 2.4.1 Auslegung des Vorratssystems 2.4.2 Auslegung des Reaktors 2.4.3 Auslegung des Aufbereitungssystems 3 Wasserstoffgenerator zur Amminboran-Thermolyse 3.1 Thermolyse von Amminboran in Triglyme 3.2 Systemspezifikationen 3.3 Untersuchungen der Wasserstoffquelle 3.3.1 Konzentrationsabhänigkeit der Thermolysereaktion 3.3.2 Der Mechanismus der H2-Freisetzung 3.3.3 Temperaturabhängigkeit der Thermolysereaktion 3.4 Systemkonzeption und Reaktorauslegung 3.5 Charakterisierung und Diskussion 3.5.1 Thermische Analyse 3.5.2 Betriebsverhalten 3.5.3 Energiedichte des Wasserstoffgenerator-Systems 3.6 Fazit zum Amminboran-Thermolyse basierten System 4 Wasserstoffgenerator zur Amminboran-Hydrolyse 4.1 Wasserstofferzeugung durch Amminboran-Hydrolyse 4.2 Systemspezifikationen 4.3 Untersuchungen der Wasserstoffquelle 4.3.1 Die Säure der Wasserstoffquelle 4.3.2 Reaktionskinetik der Wasserstoffquelle 4.3.3 Umsatz und Energiedichte der Wasserstoffquelle 4.4 Systemkonzept und Reaktorauslegung 4.4.1 Systemkonzept 4.4.2 Reaktorauslegung 4.4.3 Reaktorkonstruktion 4.5 Charakterisierung und Diskussion 4.5.1 Betriebsverhalten 4.5.2 Thermische Analyse 4.5.3 Energiedichte des Wasserstoffgenerator-Systems 4.5.4 Gasanalyse 4.6 Fazit zu AB-Hydrolyse basierten WGS 5 Wasserstoffgenerator zur Natriumborhydrid-Hydrolyse 5.1 Wasserstofferzeugung durch Natriumborhydrid-Hydrolyse 5.2 Systemspezifikationen 5.3 Untersuchung der Wasserstoffquelle 5.3.1 Die Säure der Wasserstoffquelle 5.3.2 Lagerfähigkeit der Wasserstoffquelle 5.3.3 Umsatz und Energiedichte der Wasserstoffquelle 5.4 Systemkonzept und Reaktorauslegung 5.5 Charakterisierung und Diskussion 5.5.1 Betriebsverhalten 5.5.2 Thermische Analyse 5.5.3 Energiedichte des Wasserstoffgenerator-Systems 5.6 Fazit zu Natriumborhydrid basierten Wasserstoffgenerator- Systemen 6 Zusammenfassung 7 Ausblick Anhang A1 Ergänzende Informationen zu den Grundlagen A2 Ergänzende Informationen zum Wasserstoffgenerator-System zur Amminboran-Thermolyse A3 Ergänzende Informationen zur Auswahl des Systemkonzeptes des Wasserstoffgenerator-Systems zur Amminboran-Hydrolyse A3.1 Bewertungskategorien und ihre Gewichtung A3.2 Einzelbewertungen der Systemkonzepte zur AB-Hydrolyse A4 Berechnungsgrundlagen der Reaktorkonstruktion zur Amminboran-Hydrolyse A5 Experimentelle Parameter und Daten zur thermischen Analyse des Reaktors zur Amminboran-Hydrolyse A.6 Ergänzende Informationen zum Wasserstoffgenerator-System zur Hydrolyse von festem Natriumborhydrid A6.1 Untersuchung der Wasserstoffquelle A6.2 Systemkonzept und Reaktorauslegung A6.3 Charakterisierung und Diskussion Abbildungsverzeichnis Tabellenverzeichnis Literaturverzeichnis Publikationen
25

Hydrierung von Bortrichlorid mit molekularem Wasserstoff in Gegenwart von Aminen als Hilfsbasen

Schellenberg, René 25 May 2011 (has links) (PDF)
In dieser Arbeit wurde die Möglichkeit untersucht, Bortrihalogenide mit Wasserstoff unter milden Bedingungen (T < 100 °C, p(H2) < 50 bar) zu hydrieren. Um eine Triebkraft für die thermodynamisch ungünstige Reaktion zu erhalten, wurden Amine als Hilfsbasen zugesetzt, welche den bei der Reaktion entstehenden Halogenwasserstoff als Ammoniumsalz binden und damit das Reaktionsgleichgewicht in Richtung der Produkte verschieben. Es wurden dafür verschiedene Amin-Boran bzw. Amin-HCl Addukte synthetisiert und mittels IR, NMR und DSC charakterisiert. Bei den anschließenden Hydrierungsversuchen wurden verschiedene Katalysatoren auf ihre Eignung getestet und weiterentwickelt. Unterstützt wurden die experimentellen Arbeiten durch Berechnungen mit Gaussian 03. IR- und NMR-Spektren vieler Addukte wurden berechnet und freie Reaktionsenthalpien der Hydrierung in Abhängigkeit des verwendeten Amins und Borhalogenids bestimmt. Mögliche Übergangszustände wurden diskutiert und ihre Aktivierungsenergien ermittelt.
26

Modulation of Nanostructures in the Solid and Solution States and under an Electron Beam

Sanyal, Udishnu January 2013 (has links) (PDF)
Among various nanomaterials, metal nanoparticles are the widely studied ones because of their pronounced distinct properties arising in the nanometer size regime, which can be tailored easily by tuning predominantly their size and shape. During the past few decades, scientists are engaged in developing new synthetic methodologies for the synthesis of metal nanoparticles which can be divided into two broad categories: i) top-down approach, utilizing physical methods and ii) bottom-up approach, employing chemical methods. As the chemical methods offer better control over particle size, numerous chemical methods have been developed to obtain metal nanoparticles with narrow size distribution. However, these two approaches have their own merits and demerits; they are not complementary to each other and also not sustainable for real time applications. Recent focus on the synthesis of metal nanoparticles is towards the development of green and sustainable synthetic methodologies. A solid state route is an exciting prospect in this direction because it eliminates usage of organic solvents thus, makes the overall process green and at the same time leads to the realization of large quantity of the materials, which is required for many applications. However, the major obstacle associated with the development of a solid state synthetic route is the lack of fundamental understanding regarding the formation mechanism of the nanoparticles in the solid state. Additionally, due to the heterogeneity present in the solid mixture, it is very difficult to ensure the proximity between the capping agent and nuclei which plays the most decisive role in the growth process. Recently, employment of amine–borane compounds as reducing agents emerged as a better prospect towards the development of sustainable synthetic routes for metal nanoparticles because they offer a variety of advantages over the traditional borohydrides. Being soluble in organic medium, amine– borane allows the reaction to be carried out in a single phase and due to its mild reducing ability a much better control over the nucleation and growth processes is realized. However, the most exciting feature of these compounds is that their reducing ability is not only limited to the solution state, they can also bring out the reduction of metal ions in the solid state. With the availability of a variety of amine–boranes of varying reducing ability, it opens up a possibility to modulate the nanostructure in both solid and solution states by a judicious choice of reducing agent. Although our current understanding regarding the growth behavior of nanoparticles has advanced remarkably, however, most often it is some classical model which is invoked to understand these processes. With the recent developments in in situ transmission electron microscopy techniques, it is now possible to unravel more complex growth trajectories of nanoparticles. These studies not only expand the scope of the present knowledge but also opens up possibilities for many future developments. Objectives • To develop an atom economy solid state synthetic methodology for the synthesis of metal nanoparticles employing amine–boranes as reducing agents. • To gain a mechanistic insight into the formation mechanisms of nanoparticles in the solid state by using amine–boranes with differing reducing ability. • Synthesis of bimetallic nanoparticles as well as supported metal nanoparticles in the solid state using ammonia borane as the reducing agent. • To develop a new in situ seeding growth methodology for the synthesis of core@shell nanoparticles composed of noble metals by employing a very weak reducing agent, trimethylamine borane and their transformation to their thermodynamically stable alloy counterparts. • Synthesis of highly monodisperse ultra-small colloidal calcium nanoparticles with different capping agents such as hexadecylamine, octadecylamine, poly(vinylpyrrolidone) and a combination of hexadecylamine/poly(vinylpyrrolidone) using the solvated metal atom dispersion (SMAD) method. To study the coalescence behavior of a pair of calcium nanoparticles under an electron beam by employing in situ TEM technique. Significant results An atom economy solid state synthetic route has been developed for the synthesis of metal nanoparticles from simple metal salts using amine–boranes as reducing agents. Amine–borane plays a dual role here: acts as a reducing agent thus brings out the reduction of metal ions and decomposes simultaneously to generate B-N based compounds which acts as a capping agent to stabilize the particles in the nanosize regime. This essentially minimizes the number of reagents used and hence simplifying and eliminating the purification procedures and thus, brings out an atom economy to the overall process. Additionally, as the reactions were carried out in the solid state, it eliminates use of organic solvents which have many adverse effects on the environment, thus makes the synthetic route, green. The particle size and the size distribution were tuned by employing amine–boranes with differing reducing abilities. Three different amine–boranes have been employed: ammonia borane (AB), dimethylamine borane (DMAB), and trimethylamine borane (TMAB) whose reducing ability varies as AB > DMAB >> TMAB. It was found that in case of AB, it is the polyborazylene or BNHx polymer whereas, in case of DMAB and TMAB, the complexing amines act as the stabilizing agents. Several controlled studies also showed that the rate of addition of metal salt to AB is the crucial step and has a profound effect on the particle size as well as the size distribution. It was also found that an optimum ratio of amine–borane to metal salt is important to realize the smallest possible size with narrowest size distribution. Whereas, use of AB and TMAB resulted in the smallest sized particles with best size distribution, usage of DMAB provided larger particles that are also polydisperse in nature. Based on several experiments along with available data, the formation mechanism of metal nanoparticles in the solid state has been proposed. Highly monodisperse Cu, Ag, Au, Pd, and Ir nanoparticles were realized using the solid state route described herein. The solid state route was extended to the synthesis of bimetallic nanoparticles as well as supported metal nanoparticles. Employment of metal nitrate as the metal precursor and ammonia borane as the reducing agent resulted in highly exothermic reaction. The heat evolved in this reaction was exploited successfully towards mixing of the constituent elements thus allowing the alloy formation to occur at much lower temperature (60 oC) compared to the traditional solid state metallurgical methods (temperature used in these cases are > 1000 oC). Synthesis of highly monodisperse 2-3 nm Cu/Au and 5-8 nm Cu/Ag nanoparticles were demonstrated herein. Alumina and silica supported Pt and Pd nanoparticles have also been prepared. Use of ammonia borane as the reducing agent in the solid state brought out the reduction of metal ions to metal nanoparticles and the simultaneous generation of BNHx polymer which encapsulates the metal (Pt and Pd) nanoparticles supported on support materials. Treatment of these materials with methanol resulted in the solvolysis of BNHx polymer and its complete removal to finally provide metal nanoparticles on the support materials. An in situ seeding growth methodology for the synthesis of bimetallic nanoparticles with core@shell architecture composed of noble metals has been developed using trimethylamine borane (TMAB) as the reducing agent. The key idea of this synthetic procedure is that, TMAB being a weak reducing agent is able to differentiate the smallest possible window of reduction potential and hence reduces the metal ions sequentially. A dramatic solvent effect was noted in the preparation of Ag nanoparticles: Ag nanoparticles were obtained at room temperature when dry THF was used as the solvent whereas, reflux condition was required to realize the same using wet THF as the solvent. However, no such behavior was noted in the preparation of Au and Pd nanoparticles wherein Au and Pd nanoparticles were obtained at room temperature and reflux conditions, respectively. This difference in reduction behavior was successfully exploited to synthesize Au@Ag, Ag@Au, and Ag@Pd nanoparticles. All these core@shell nanoparticles were further transformed to their alloy counterparts under very mild conditions reported to date. Highly monodisperse, ultrasmall, colloidal Ca nanoparticles with a size regime of 2-4 nm were synthesized using solvated metal atom dispersion (SMAD) method and digestive ripening technique. Hexadecylamine (HDA) was used as the stabilizing agent in this case. Employment of capping agent with a longer chain length, octadecylamine afforded even smaller sized particles. However, when poly(vinylpyrrolidone) (PVP), a branched chain polymer was used as the capping agent, agglomerated particles were realized together with small particles of 3-6 nm. Use of a combination of PVP and HDA resulted in spherical particles of 2-3 nm size with narrow size distribution. Growth of Ca nanoparticles via colaesence mechanism was observed under an electron beam. Employing in situ transmission electron microscopy technique, real time coalescence between a pair of Ca nanoparticles were detected and details of coalescence steps were analyzed.
27

Hydrierung von Bortrichlorid mit molekularem Wasserstoff in Gegenwart von Aminen als Hilfsbasen

Schellenberg, René 05 May 2011 (has links)
In dieser Arbeit wurde die Möglichkeit untersucht, Bortrihalogenide mit Wasserstoff unter milden Bedingungen (T < 100 °C, p(H2) < 50 bar) zu hydrieren. Um eine Triebkraft für die thermodynamisch ungünstige Reaktion zu erhalten, wurden Amine als Hilfsbasen zugesetzt, welche den bei der Reaktion entstehenden Halogenwasserstoff als Ammoniumsalz binden und damit das Reaktionsgleichgewicht in Richtung der Produkte verschieben. Es wurden dafür verschiedene Amin-Boran bzw. Amin-HCl Addukte synthetisiert und mittels IR, NMR und DSC charakterisiert. Bei den anschließenden Hydrierungsversuchen wurden verschiedene Katalysatoren auf ihre Eignung getestet und weiterentwickelt. Unterstützt wurden die experimentellen Arbeiten durch Berechnungen mit Gaussian 03. IR- und NMR-Spektren vieler Addukte wurden berechnet und freie Reaktionsenthalpien der Hydrierung in Abhängigkeit des verwendeten Amins und Borhalogenids bestimmt. Mögliche Übergangszustände wurden diskutiert und ihre Aktivierungsenergien ermittelt.:1. Einleitung und Problemstellung 2. Stand der Wissenschaft 2.1. Allgemeines 2.2. Die Amin-Boran-Addukte 2.3. Hydrierung mit Wasserstoff 2.3.1. Allgemeine Konzepte 2.3.2. Katalytische Hydrierung 2.3.3. Thermodynamische und kinetische Betrachtungen 2.4. Hydrierung mit Hydrosilanen 2.5. Quantenchemische Berechnungen 2.5.1. Grundlagen 2.5.2. Die Dichtefunktionaltheorie 2.5.3. Basissätze 2.5.4. Die Optimierungsverfahren 2.5.5. Übergangszustandsrechnungen 2.5.6. Weitere verwendete Methoden 2.6. 11B-NMR 3. Geräteteil 4. Durchgeführte Synthesen 4.1. Synthese von N-Ethyldiphenylamin 4.2. Synthese von N-Ethylbis(p-tolyl)amin 4.3. Synthese der BN-Addukte 4.4. Synthese der HCl-Addukte 4.5. Synthese von P-1 Nickel 5. Ergebnisse 5.1. Berechnungen mit Gaussian 5.1.1. Das Reaktionssystem auf Grundlage des Bortrichlorids 5.1.2. Die Hydrierung von Bortribromid und Bortriiodid mit Wasserstoff 5.1.3. Hydrierung mit Triethylsilan 5.1.4. Zusammenfassende Betrachtung der berechneten Ergebnisse 5.2. Die Addukte 5.2.1. Die "Amingrundtypen" 5.2.2. Die Addukte modifizierter Amine 5.2.3. Zusammenfassung 5.3. Hydrierung mit Triethylsilan 5.3.1. Allgemeines 5.3.2. Vergleich der Hydrierung der Bortrichlorid-Addukte von Triethylamin und N,N-Diethylanilin 5.3.3. Hydrierung bei verschiedenen Temperaturen 5.3.4. Zusammenfassung 5.4. Hydrierung mit Wasserstoff 5.4.1. Allgemeines 5.4.2. Hydrierversuche im Einkammerreaktor 5.4.3. Hydrierversuche im Zweikammerreaktor 5.4.4. Zusammenfassung 5.5. Weitere durchgeführte Experimente 5.5.1. Hydrierung von Disilanen 5.5.2. Zusatz von Chloridakzeptoren 6. Zusammenfassung und Ausblick 7. Anhang 7.1. Analytische Daten und Produktidentifizierung 7.1.1. NMR-Daten 7.1.2. IR-Daten 7.1.3. Einkristalldaten 7.2. Gaussian 03 Daten 7.2.1. Energien der Grundzustände 7.2.2. Energien der Übergangszustände 7.2.3. Berechnete IR-Spektren 7.2.4. Berechnete Reaktionsgrößen 7.2.5. Isotrope Abschirmungen 7.3. DSC-Daten 7.3.1. Boran-Amin-Addukte 7.3.2. HCl-Amin-Addukte 7.4. Die Hydrierungsansätze 8. Literaturverzeichnis 9. Formelverzeichnis

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