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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.
111

The Preparation and Modification of Phthalocyanine Containing Materials

Korth, Bryan David January 2012 (has links)
Phthalocyanines (Pcs) are highly conjugated, 18π-electron cyclic molecules composed of four isoindoline units that exhibit unique optical, electrical and chemical properties. While originally used as dyes and pigments, the use of Pcs in modern technology has increased dramatically due to improved understanding and processing capabilities. Work in this dissertation outlines a number of methods to prepare Pc-containing materials for use in various applications. Chapter 1 provides a brief review of methods used to prepare Pc-containing polymeric materials from both symmetric and asymmetric macrocycles. Discussion will focus on methods that incorporate symmetric Pcs as the focal point, with particular attention being paid to the influence of the peripheral substitution of the Pc on macromolecular structure and properties. Further discussion will focus on the utilization of asymmetric Pcs as auxiliary functionalities, such as at the terminus or as pendant groups, of larger macromolecular materials. Chapter 2 describes the preparation of linear Pc-containing polymers through ring-opening metathesis polymerization of a Pc monomer. Through proper selection of catalyst, well-defined polymers with Pcs as pendant groups were prepared. Due to the controlled nature of ROMP, polymers of varying architectures, composition, and size were synthesized. The effect of Pc metallation, polymer composition and architecture on the site-isolation of the chromophore was investigated in both solution and condensed-phase thin films. Chapter 3 reports on efforts to prepare linear polymers with companion functionalities for post-polymerization coupling of asymmetric Pcs. Polymers with pendant furan groups were prepared for coupling with asymmetric Pcs through Diels-Alder cycloaddition. Investigation indicated that while coupling was achievable, the presence of the Pc in the resultant polymer promoted undesired crosslinking when stored at ambient conditions in light. Attempts to mitigate this problem through alternation of functionality locations were attempted by placing the furan functionality on the Pc, but degradation of the furan occurred to quickly to perform coupling sufficiently. Chapter 4 discusses the preparation of Pc-containing networks through Diels-Alder cycloaddition of furan and maleimide containing tetrasubstituted Pcs. Following preparation of the various Pcs, network formation in various states was conducted including solution, molded thick films, and patterned assemblies. Chapter 5 summarizes the results presented in Chapters 2-4 and provides an outlook for some future directions based upon the work herein. In addition, some preliminary results of some of these directions will also be presented.
112

REACTIONS OF TRIETHYL AZOMETHINETRICARBOXYLATE WITH ELECTRON-RICH OLEFINS.

Miniutti, Diana Louise. January 1983 (has links)
No description available.
113

The synthesis of trifluoroalkylated pyridine derivatives over H-form zeolites

MacDonald, Kristy January 1999 (has links)
No description available.
114

Development of a recyclable acetic ester enolate equivalent

Ray, Colin Andrew January 2001 (has links)
No description available.
115

Asymmetric synthesis using acyl-nitroso cycloadditions : applications to natural product synthesis

Pepper, Adrian Gordon January 2000 (has links)
No description available.
116

Synthetic studies towards aza-opiates

Naven, Russell T. January 1999 (has links)
No description available.
117

Studies on the biomimetic synthesis of the manzamine alkaloids

Spring, David R. January 1998 (has links)
No description available.
118

New Adventures in the Chemistry of Polycarboncyclic Ring Systems

Dong, Zhiming (Eric) 12 1900 (has links)
I. Diels-Alder reactions of 1,2,3,4,9,9-hexachloro-1,4,4a,8a-tetrahydro-1,4-metha- nonaphthalene (16) and 1,2,3,4,9,9-hexachloro-1,4,6,7-tetrahydro-1,4-methanonaphthalene (17) toward dienophiles N-methyl-1,2,4-triazoline-3,5-dione (MTAD), N-phenyl-1,2,4-triazoline-3,5-dione (PTAD) and/or N-methylmaleimide (NMM) have been examined. II. Epoxides derived from functionalized 1,4,4a,9a-tetrahydro-9,10-dioxo-1,4-methanoanthracenes (1a and 1b) undergo acid- and base-promoted intramolecular nucleophilic ring-opening to form new polycyclic alcohols. III. The title cycloalkylidenecarbene has been generated via reaction of 8-methylenepentacyclo[5.4.0.0^{2,6}.0^{3,10}. 0^{5.9}]undecan-11-one (44) with diethyl diazomethyl-phosphonate (DAMP). This species could be trapped in situ by cyclohexene, thereby affording the corresponding cycloadduct 46a and 46b.
119

Developing Methods for Growing Single-Chirality Carbon Nanotubes and Other Aromatic Systems

Fort, Eric Henry January 2010 (has links)
Thesis advisor: Lawrence T. Scott / The work described herein stems from an effort to develop a method for growing single-chirality carbon nanotubes from small hydrocarbon templates using a Diels-Alder cycloaddition/rearomatization strategy. Current technologies are incapable of producing significant amounts of homogeneous carbon nanotubes; therefore, much research has been put into the development of aromatic templates (belts and bowls), from which one type of nanotube might be grown (Chapter 1). Since no such functional template had yet been synthesized, the work in this dissertation developed reagents and methods for forming new benzene rings on aromatic test systems that would be analogous to the rim of a growing nanotube (Chapters 2 and 4). Theoretical investigations relating to nanotube dimensions (Chapter 3) were undertaken and paired with experimental work that would take into consideration the changing properties of growing tubes (Chapter 5). The test systems used for discovering new reagents for growth also became functional platforms for studies of new reactivity of polycyclic aromatic hydrocarbons (PAHs), such as bay-region oxidation (Chapter 6) and progress toward the synthesis of soluble graphene ribbons (Chapter 7). This PAH work also resulted in the observation of unique solid state properties in the crystal form (Chapter 8) and novel reactivity, generating five-membered rings by Scholl reactions of tethered PAHs (Chapter 9). Additional considerations for future nanotube templates and fullerene precursors also bore scrutiny (Chapter 10). / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
120

The use of arabinose in asymmetric Diels-Alder reaction.

January 1995 (has links)
by Ivan H.F. Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 63-67). / Acknowledgements --- p.i / Contents --- p.ii / Abstract --- p.iv / Abbreviations --- p.v / Chapter Chapter I --- Introduction / Chapter I-1. --- General background --- p.1 / Chapter I-2. --- Asymmetric Diels-Alder reaction using chiral auxiliaries --- p.2 / Chapter I-2A --- Some well-known chiral auxiliaries --- p.3 / Chapter I-2B --- Carbohydrates as chiral auxiliaries --- p.6 / Chapter I-3. --- Asymmetric Diels-Alder reaction using chiral catalysts --- p.10 / Chapter Chapter II --- Results and Discussion --- p.14 / Chapter II-1. --- "Synthesis of η6-(benzyl 2-O-acryloyl-3,4-O-isopropylidene- β-L-arabinopyranoside) tricarbonylchromium(O) (47)" --- p.15 / Chapter II-2. --- "Syntheses of 4'-methylbenzyl 2-O-acryloyl-3,4-O- isopropylidene-β-L-arabinopyranoside (57) and η6-(4'- methylbenzyl 2-O-acryloyl-3,4-O-isopropylidene-β-L- arabinopyranoside) tricarbonylchromium(O) (56)" --- p.19 / Chapter II-3. --- "Syntheses of naphthylmethyl 2-O-acryloyl-3,4-O- isopropylidene-α-L-arabinopyranosides" --- p.22 / Chapter II-4. --- Diels-Alder reaction using the dienophiles 56 and 57 as the chiral auxiliaries --- p.25 / Chapter II-5. --- "Synthesis of benzyl 3,4-O-methylene-β-L-arabinopyranoside (81)" --- p.32 / Chapter II-6. --- Using the alcohol 81 as the ligand for Lewis acid in the Diels-Alder reaction --- p.36 / Chapter Chapter III --- Conclusions --- p.38 / Chapter Chapter IV --- Experimental Section --- p.40 / Chapter IV-1. --- Experimental section for the asymmetric Diels-Alder reaction using the chiral auxiliaries --- p.41 / Chapter IV-2. --- Experimental section for the asymmetric Diels-Alder reaction using the chiral catalysts --- p.59 / References --- p.63 / List of spectra --- p.68

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