Thesis (M. Phil.)--University of Hong Kong, 1979.

published_or_final_version / Chemistry / Master / Master of Philosophy

Phenylgermane, benzylgermane and p-tolylgermane were obtained by reduction of the corresponding organotrichlorgermanes prepared by organomercuration reactions of germanium tetrachloride. Phenylgermane was also prepared by the reaction of germyl bromide with phenyllithium, and p-digermylbenzene, with p-bromogermylbenzene, by reaction of germyl bromide with the exchange products from the reaction of n-butyllithium and p-dibromobenzene. The effectiveness of the reagent sodium germyl (and potassium germyl) was investigated in reactions with methylene chloride and bromide for the preparation of digermylmethane, which was also made by reduction of bis(trichlorogermyl)methane prepared from cesium trichlorogermanate(II). The usefulness of the halogenation of germane by carbon tetrachloride and tetrabromide, and methyl and hydrogen bromide, for the preparation of germyl chloride and bromide was investigated. Vibrational assignments were made to characteristic bands in the infrared spectra of the new aromatic germanium hydrides and some chloro derivatives. Ion fragmentation patterns were examined. The proton nuclear magnetic resonance spectra of the organogermanium hydrides and chloro derivatives were interpreted on the basis of the existence of germanium-aromatic ring (p → d) π bonding, but this effect was not very important for the interpretation of the ultraviolet spectra. Calculation of the energy levels of toluene, phenylsilane and phenylgermane by the Extended Hückel method and comparison with ultraviolet spectral data indicated that (p → d) π bonding was important only in phenylsilane. / French abstract, if available fr

Thesis (Ph.D.)--McGill University. / Typewritten MS.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Wei Chunmei. / "September 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 137-140). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

*Please refer to dissertation for diagrams. / In Chapter 2, the development of organocatalysis is briefly summarized. Also the development of asymmetric Morita-Baylis-Hillman (MBH) reaction and asymmetric Diels-Alder (DA) reaction and their strategies are presented. Some representative examples are delineated with in-depth discussion. / In Chapter 3, the idea of the design of organocatalysts from tetraphenylenes is illustrated. The syntheses of enantiopure (S,S)- and ( R,R)-1,8,9,16-tetrahydroxytetraphenylene (1) and racemic 1,4,5,8,9,16-hexahydroxytetraphenylene (2) are described. The functionalization of compounds 1 and 2 and the attempt to synthesize amino acid from compound 1 are discussed. The syntheses of racemic and chiral amine derivatives from compound 1 and their applications on the catalysis of MBH reaction and asymmetric DA reaction are presented and discussed. / In Chapter 4, the application of marcocyclic compounds on enantiomeric recognition is briefly reviewed. The strategies and syntheses of the two enantiomeric tetrameric form of 1,8,9,16-tetraalkoxytetraphenylene, which is a potential chiral recognition reagent, are discussed. / In Chapter 5, the background information of the chemistry of liquid crystals is briefly reviewed, and the syntheses of different alkoxy-derivatives from compound 1 are presented. Among these derivatives, three of them were found to have liquid crystal properties. The details on the characterization of their liquid crystal properties are discussed. / In Chapter 6, a short summary and conclusion of the results in the previous chapters are given. / In Chapter 7, experimental details are summarized.* / Tetraphenylenes are structurally exceptional molecules featuring a rigid conformation. As such, substituents of these compounds would demonstrate highly directional disposition. As a result, these molecules, in their optically pure forms, are potential candidates as organocatalysts in asymmetric synthesis. In this thesis, some essential background information and previous works about the development of the tetraphenylenes are first presented in Chapter 1. / The second part is about the potential applications of tetraalkoxytetraphenylene derivatives. / The thesis is divided into two parts. The first part is about the applications of amino-substituted tetraphenylene derivatives as organocatalysts. / pt. 1. Amino-substituted tetraphenylene derivatives as organocatalysts -- pt. 2. Potential applications of tetraalkoxytetraphenylenes. / Hau, Chun Kit. / Adviser: H. N. C. Wong. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 260-282). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

No description available.

The goal of this project is to synthesize and purify a library of novel 4-alkyl-3,5-diamino-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazoles. These molecules are similar to other fiproles, which have been shown by Sammelson et al. to have pesticidal activities at the GABA receptor.' Fiproles are analogues of Fipronil, a very important pesticide. Replacing the cyano group normally located at the 3-position of the pyrazole ring with an amino group will change the binding potency of the phenylpyrazoles. Changes in binding produced by the changes introduced in molecular structure can create more information about the GABA receptor.Synthesis of our target compounds starts with production of monosubstituted malononitriles. Conventionally a two-step process, our research developed a new, efficient one-step process using borohydride as the only reagent. We utilized this method in the synthesis of desired monosubstituted malononitriles. These were converted to unsymmetrical disubstituted malononitriles, and to our target fiprole compounds, through a 4-alkyl-3,5-diaminopyrazole intermediate. / Department of Chemistry