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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.
151

Studies in synthetic organosulfur chemistry

Vines, S. Martin January 1976 (has links)
No description available.
152

Improvements on the synthesis of vinyl crown ethers

Kleissler, Charles Richard January 1982 (has links)
No description available.
153

The synthesis of alkenes from carbonyl compounds and carbanions alpha to silicon /

Mychajlowskij, Volodymyr Walter January 1977 (has links)
No description available.
154

A new approach to the synthesis of C-nucleosides.

Martel, Alain January 1972 (has links)
No description available.
155

Synthesis and stereochemistry of D-psicose and derivatives.

Herve-du-Penhoat, Philippe Charles Marie. January 1973 (has links)
No description available.
156

Exploring acyl azides chemistry in continuous flow systems

Sagandira, Cloudius Ray January 2017 (has links)
Organic azides are important in the synthesis of many target molecules of great use in fine chemical and pharmaceutical production. The use of this class of compounds is however limited due to their hazardous nature and many safety concerns, as they are highly exothermic. Micro reactors can handle exotherms extremely well, due to the inherent high surface area to volume ratio, unlike the conventional batch process. This dissertation therefore aims to investigate the safe application of micro reactors in acyl azide chemistry.With this in mind, Chapter 1 provides a comprehensive background on organic azides, reaction calorimetric studies, flow chemistry technology (micro reactors) and their theoretical advantages. This chapter also discusses the preparation of organic azides in continuous flow systems and scaling up in continuous flow systems. Chapter 2 illustrates and discusses multivariate optimisation of benzoyl azide synthesis as a model reaction, synthesis of other acyl azides using the model reaction optimised conditions and multistep synthesis of carbamates, amides and amines in continuous flow systems via the Curtius rearrangement of benzoyl azide formed in situ from benzoyl chloride and sodium azide. The chapter also discusses process hazards analysis and evaluation of benzoyl azide synthesis and decomposition using calorimetric studies. It also investigates and discusses the effects of different mixing regimes and channel sizes on scale up. Chapter 3 has comprehensive experimental details for the whole dissertation with Chapter 4 providing the concluding remarks and future work recommendations.
157

Benaderings tot die sintese van stikstofringverbindings

Crous, Renier 29 May 2014 (has links)
M.Sc. (Chemistry) / Please refer to full text to view abstract
158

Barium titanate : the relationship between the conditions of synthesis and its structural and electrical properties

Thompson, Catherine 29 May 2014 (has links)
M.Sc. (Chemistry) / Barium titanate (BaTi03) is an important material in the electronics industry as a result of its excellent dielectric properties. It has been the subject of many studies since its initial discovery, which have focussed on a wide variety of different aspects, including its synthesis, the identification of the crystal structures of its various phases, and also attempts to determine the various factors that could explain its unusual electrical properties. Since barium titanate has been studied by this wide range of disciplines, the information regarding this material is scattered over many sources. This study contains a literature survey of some of the significant work on barium titanate, in order to collect, and order, the available data into a coherent picture of the state of knowledge pertaining to the crystal structure, syntheses and electric properties of the material. From this study, it was clear that there was a distinct lack of consistent findings with respect to the identification of the tetragonal phase crystal structure. The tetragonal phase is the requisite one since it is ferroelectric, although the cubic phase also plays a significant role when the material is in the form of a very fine powder. The exact influence of the small particle size is also shown to be the object of much debate amongst the scientific community. Another area of inquiry which has attracted much attention in the past is that of the synthesis of barium titanate. The synthesis of a pure phase of barium titanate requires an intimate mixture of components which is not obtained using the standard solid-state method of synthesis, thus resulting in researchers switching to solvent-based methods of preparation. The present study also contains a summary of several of these published methods, from which four suitable methods have been selected according to certain criteria. These Criteria are that the method should be simple, use easily available materials and have been reported as having good results in terms of their dielectric properties and structural composition. It is also important that the syntheses are easy to control, to enable the extension of the work to synthesise other perovskites, poly titanates and doped barium titanate.
159

Unsaturated carbohydrate derivatives as synthons in organic synthesis

Toerien, Francois 02 April 2014 (has links)
D.Sc. (Chemistry) / Please refer to full text to view abstract
160

Synthetic route to 5-alkylresorcinols

Howarth, Barrie David January 1974 (has links)
No description available.

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