Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies

The present thesis describes the development of heterogeneous catalytic methodologies using metal−organic frameworks (MOFs) as porous matrices for supporting transition metal catalysts. A wide spectrum of chemical reactions is covered. Following the introductory section (Chapter 1), the results are...

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Main Author: Pascanu, Vlad
Format: Doctoral Thesis
Language:English
Published: Stockholms universitet, Institutionen för organisk kemi 2016
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132711
http://nbn-resolving.de/urn:isbn:978-91-7649-485-1
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spelling ndltd-UPSALLA1-oai-DiVA.org-su-1327112016-09-15T05:01:52ZCatalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic StudiesengPascanu, VladStockholms universitet, Institutionen för organisk kemiStockholm : Department of Organic Chemistry, Stockholm University2016The present thesis describes the development of heterogeneous catalytic methodologies using metal−organic frameworks (MOFs) as porous matrices for supporting transition metal catalysts. A wide spectrum of chemical reactions is covered. Following the introductory section (Chapter 1), the results are divided between one descriptive part (Chapter 2) and four experimental parts (Chapters 3–6). Chapter 2 provides a detailed account of MOFs and their role in heterogeneous catalysis. Specific synthesis methods and characterization techniques that may be unfamiliar to organic chemists are illustrated based on examples from this work. Pd-catalyzed heterogeneous C−C coupling and C−H functionalization reactions are studied in Chapter 3, with focus on their practical utility. A vast functional group tolerance is reported, allowing access to substrates of relevance for the pharmaceutical industry. Issues concerning the recyclability of MOF-supported catalysts, leaching and operation under continuous flow are discussed in detail. The following chapter explores puzzling questions regarding the nature of the catalytically active species and the pathways of deactivation for Pd@MOF catalysts. These questions are addressed through detailed mechanistic investigations which include in situ XRD and XAS data acquisition. For this purpose a custom reaction cell is also described in Chapter 4. The scope of Pd@MOF-catalyzed reactions is expanded in Chapter 5. A strategy for boosting the thermal and chemical robustness of MOF crystals is presented. Pd@MOF catalysts are coated with a protecting SiO2 layer, which improves their mechanical properties without impeding diffusion. The resulting nanocomposite is better suited to withstand the harsh conditions of aerobic oxidation reactions. In this chapter, the influence of the nanoparticles’ geometry over the catalyst’s selectivity is also investigated. While Chapters 3–5 dealt with Pd-catalyzed processes, Chapter 6 introduces hybrid materials based on first-row transition metals. Their reactivity is explored towards light-driven water splitting. The heterogenization process leads to stabilized active sites, facilitating the spectroscopic probing of intermediates in the catalytic cycle. <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Submitted. Paper 8: Submitted.</p><p> </p>Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132711urn:isbn:978-91-7649-485-1application/pdfinfo:eu-repo/semantics/openAccess
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
description The present thesis describes the development of heterogeneous catalytic methodologies using metal−organic frameworks (MOFs) as porous matrices for supporting transition metal catalysts. A wide spectrum of chemical reactions is covered. Following the introductory section (Chapter 1), the results are divided between one descriptive part (Chapter 2) and four experimental parts (Chapters 3–6). Chapter 2 provides a detailed account of MOFs and their role in heterogeneous catalysis. Specific synthesis methods and characterization techniques that may be unfamiliar to organic chemists are illustrated based on examples from this work. Pd-catalyzed heterogeneous C−C coupling and C−H functionalization reactions are studied in Chapter 3, with focus on their practical utility. A vast functional group tolerance is reported, allowing access to substrates of relevance for the pharmaceutical industry. Issues concerning the recyclability of MOF-supported catalysts, leaching and operation under continuous flow are discussed in detail. The following chapter explores puzzling questions regarding the nature of the catalytically active species and the pathways of deactivation for Pd@MOF catalysts. These questions are addressed through detailed mechanistic investigations which include in situ XRD and XAS data acquisition. For this purpose a custom reaction cell is also described in Chapter 4. The scope of Pd@MOF-catalyzed reactions is expanded in Chapter 5. A strategy for boosting the thermal and chemical robustness of MOF crystals is presented. Pd@MOF catalysts are coated with a protecting SiO2 layer, which improves their mechanical properties without impeding diffusion. The resulting nanocomposite is better suited to withstand the harsh conditions of aerobic oxidation reactions. In this chapter, the influence of the nanoparticles’ geometry over the catalyst’s selectivity is also investigated. While Chapters 3–5 dealt with Pd-catalyzed processes, Chapter 6 introduces hybrid materials based on first-row transition metals. Their reactivity is explored towards light-driven water splitting. The heterogenization process leads to stabilized active sites, facilitating the spectroscopic probing of intermediates in the catalytic cycle. === <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Submitted. Paper 8: Submitted.</p><p> </p>
author Pascanu, Vlad
spellingShingle Pascanu, Vlad
Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
author_facet Pascanu, Vlad
author_sort Pascanu, Vlad
title Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
title_short Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
title_full Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
title_fullStr Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
title_full_unstemmed Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies
title_sort catalytic processes mediated by metal−organic frameworks : reactivity and mechanistic studies
publisher Stockholms universitet, Institutionen för organisk kemi
publishDate 2016
url http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132711
http://nbn-resolving.de/urn:isbn:978-91-7649-485-1
work_keys_str_mv AT pascanuvlad catalyticprocessesmediatedbymetalorganicframeworksreactivityandmechanisticstudies
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