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1
Gunawardena, Rohith. "Atmospheric methyl iodide." Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,91.
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Overton, Barry M. "The metabolism of n-methyl compounds." Thesis, Aston University, 1987. http://publications.aston.ac.uk/12452/.
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The metabolism of compounds containing the N-methyl group is discussed with particular consideration being made to the possible role of the product of oxidative metabolism, the N-hydroxymethyl moiety, in the generation of potentially toxic, reactive electrophiles. Particular pathways which are considered are: (i), the production of formaldehyde; (ii), the generation of iminium ions or imines; and (iii), the formation of N-formyl compounds which might act as formylating agents. 4-Chloro-N-(hydroxymethyl)benzamide and 3-(4-chlorophenyl)-1-hydroxy-methyl-1-methylurea (the product of oxidative metabolism of 3-(4-chlorophenyl)-1,1-dimethylurea) are model carbinolamides which do not readily release formaldehyde. The electrophilic properties of these model carbinolamides were investigated: neither reacted with nucleophiles such as cyanide or glutathione under physiological conditions. In contrast, N-(acetoxymethyl)-4-chlorobenzamide yielded the cyanomethylamide with potassium cyanide and S-(4-chlorobenzamidomethyl)glutathione with glutathione. 4-Chloro-N-(hydroxymethyl)benzamide and 3-(4-chlorophenyl)-1,1-dimethylurea were not biotransformed to electrophilic moieties when incubated with mouse hepatic 9000 x g supernatant and Acetyl-CoA or PAPS-generating system. N-(Acetoxymethyl)-4-chlorobenzamide was non-mutagenic to Salmonella typhimurium in the short term bacterial assay; but toxicity to the bacteria was observed. 4-Chloro-N-(hydroxymethyl)benzamide and 3-(4-chlorophenyl)-1,1-dimethylurea showed no mutagenicity or toxicity in the mutagenicity assay including an Aroclor-induced rat hepatic 9000 x g supernatant. Addition of Acetyl-CoA or a PAPS-generating system did not produce a mutagenic response. 4-Chloro-N-formlbenzamide did not act as a formylating agent towards the weak nucleophile aniline. However, 4-chloro-N-formylbenzamide, N-formylbenzamide, 3-(4-chlorophenyl)-1-formyl-1-methylurea and 3-(4-chlorophenyl)-1-formylurea are all metabolised by mouse hepatic mirosomes and post-microsomal supernatant. The results demonstrate the potential for N-hydroxymethyl compounds to generate highly reactive species if these are substrates for conjugation with sulphate (or acetate). The model compounds employed here, apparently do not show any ability to be conjugated themselves, however, other N-hydroxymethyl compounds might be readily conjugated. The formation of N-formyl compounds does not appear to be toxicologically significant, as adjudged on limited experiments performed, but rather represent a detoxification pathway.
3
Scott, Janet Lesley. "Inclusion compounds of cholic acid and methyl cholate." Thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/25589.
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Simpson, Linda. "Trivalent group 13 metal complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28885.
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The compounds tris(N-ռ-propyl-3-hydroxy-2-methyl-4-pyridinonato) aluminum(III), -gallium(III), and -indium(III) and tris(N-ռ-butyl-3-hydroxy-2-methyl-4-pyridinonato)aluminum(III), -gallium(III), and -indium(III) were synthesized. All six compounds were prepared via the metal template effect. They were characterized by IR, FAB-MS, ¹H NMR, ²⁷Al NMR, and elemental analysis. Three of the six complexes were studied by single-crystal X-ray diffraction. They formed trihydrates, unlike their N-methyl and N-ethyl analogues, which formed dodecahydrates. The ռ-butyl complex Al(C₁₀H₁₄N0₂)₃‧3H₂0 (1) and ռ-propyl complexes Al(C₉H₁₂N0₂)₃‧3H₂0 [2], and Ga(C₉H₁₂N0₂)₃‧3H₂0 {3} were basically isostructural, crystallizing in the space group P3 with the following crystal parameters for 1, [2], and {3}: α= 15.885 (1) ([15.328 (1)], {15.367 (2)}) Å, c = 7.280 (8) ([7.2321 (2)], {7.256 (2)}) Å, Z = 2. The data were refined by using 1280 ([1377], {1802}) reflections with I>3σ(I) to R and Rա values of 0.047 ([0.057], {0.055)) and 0.061 ([0.077], {0.081}), respectively. The complexes exist as the rigidly fac geometries with infinite chains of hydrogen bonds parallel to the c axis.Science, Faculty of
Chemistry, Department of
Graduate
5
El-Hamruni, Salima Maherize. "Organometallic compounds containing the (dimethylaminodimethylsilyl)bis(trimethylsilyl) methyl ligand." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326949.
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Nomura, Glenn Sterling. "Derivatives of 4-ketoperhydroazulene with bridgehead methyl groups." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/27064.
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Aston, Mark Edward. "Downstream etching of indium phosphide and indium with hydrogen atoms and methyl radicals." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28883.
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The etching of indium phosphide and indium by H atoms and methyl radicals has been studied in a discharge flow system at temperatures between 25 and 300°C. The results indicate that the hydrogen atoms react with InP to produce In metal globules and PH₃(g) at temperatures greater than 160°C. Methyl radicals were not found to react with InP. However these radicals were found to react with indium metal and the globules that are produced in the reaction of hydrogen atoms with InP. Reactions were conducted by alternately etching with H atoms and then with CH₃ radicals. Rate constants for these reactions were determined at 300°C and these values were found to be consistent with the continuous etch rates observed for a mixture of H atoms and CH₃ radicals.
The etched surfaces were studied by SEM, XPS and surface profilometry and their properties found to be consistent with the proposed mechanism for the reaction.Science, Faculty of
Chemistry, Department of
Graduate
8
Williams, Kenneth Bruce. "The effect of methyl groups on nucleophilic substitution reactions of chlorocyclotriphosphazenes." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49962.
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The reactions of methyl-substituted chlorocyclotriphosphazenes with aryl Grignard reagents and with bifunctional amines, aminoalcohols, and alkoxides were investigated.
The characterization data for the compounds formed in the reactions of monomethylpentachlorocyclotriphosphazene and the Grignard reagents were found to be informative with respect to the extent and nature of the interaction between the phosphazene ring and its exocyclic substituents.
This interaction was found to be responsible for significant effects on the reactions of the phosphazene ring with nucleophiles. The reactions of the bifunctional nucleophiles were found to be useful probes of the reactivity of the phosphazene ring. Specifically, a single methyl group is found to activate the chlorine on the same phosphorus atom, while a pair of geminally substituted methyl groups is found to deactivate the chlorine atoms on a different phosphorus atom. The results allow a new interpretation of the substitution patterns of various nucleophiles on chlorocyclotriphosphazenes.Ph. D.
incomplete_metadata
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Mizori, Farhad G. "Transmetallation from zirconium to boron : the synthesis and conjugate addition of mixed unsymmetrical tricoordinate organoboranes containing phenyl and methyl groups /." Diss., Connect to a 24 p. preview or request complete full text in PDF formate. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3138868.
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Gqogqa, Pumeza. "Hydroxylation of aromatic compounds over zeolites." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2564.
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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2009.Aromatic precursor compounds are derivatives that play an important role in biosystems and are useful in the production of fine chemicals. This work focuses on the catalytic synthesis of 2-methyl-1, 4-naphthoquinone and cresols (para- and ortho) using aqueous hydrogen peroxide as an oxidant in liquidphase oxidation of 2-methylnaphthalene and toluene over titanium-substituted zeolite TS-1 or Ti-MCM-41. Catalysts synthesised in this work were calcined at 550°C, extensively characterised using techniques such as X-ray Fluorescence for determining the catalyst chemical composition; BET for surface area, pore size and micropore volume; Powder X-ray diffraction for determining their crystallinity and phase purity and SEM was used to investigate the catalyst morphologies. The BET surface areas for Ti-MCM-41 showed a surface area of 1025 m2/g, and a 0.575 cm3/g micropore volume. However, zeolite TS-1 showed a BET surface area of 439 m2/g and a 0.174 cm3/g micropore volume. The initial experiments on 2-methylnaphthalene hydroxylation were performed using the normal batch method. After a series of batch runs, without any success as no products were generated as confirmed by GC, a second experimental tool was proposed. This technique made use of the reflux system at reaction conditions similar to that of the batch system. After performing several experimental runs and optimising the system to various reactor operating conditions and without any products formed, the thought of continuing using the reflux was put on hold. Due to this, a third procedure was brought into perspective. This process made use of PTFE lined Parr autoclave. The reactor operating conditions were changed in order to suit the specifications and requirements of the autoclave. This process yielded promising results and the formation of 2-MNQ was realised. There was a drawback when using an autoclave as only one data point was obtained, at the end of each run. Therefore, it was not possible to investigate reaction kinetics in terms of time. Addition of aqueous hydrogen peroxide (30 wt-%) solution in the feed was done in one lot at the beginning of each reaction in all oxidation reactions, to a reactor containing 2-methylnaphthalene and the catalyst in an appropriate solvent of choice (methanol, acetonitrile, 2-propanol, 1-propanol, 1-pentanol, and butanol), with sample withdrawal done over a period of 6 hours (excluding catalytic experiments done with a Parr autoclave as sampling was impossible). As expected, 2-methylnaphthalene oxidation reactions with medium pore zeolite TS-1 yielded no formation of 2-methyl-1, 4-naphthoquinone using various types of solvents, with a batch reactor, reflux system, or a Parr PTFE autoclave. This was attributed to the fact that 2-methylnaphthalene is a large compound and hinders diffusion into zeolite channels. With the use of an autoclave, Ti-MCM-41 catalysed reactions showed that the choice of a solvent and reaction temperature strongly affect 2- methylnaphthalene conversion and product selectivity. This was proven after comparing a series of different solvents (such as methanol, isopropanol, npropanol, isobutanol, n-pentanol and acetonitrile) at different temperatures. Only reactions using acetonitrile as a solvent showed 2-MNQ. Formation of 2- MNQ, indicating that acetonitrile is an appropriate choice of solvent for this system. The highest 2-methylnaphthalene conversion (92%) was achieved at 120 ˚C, with a relative product selectivity of 51.4 %. Temperature showed a major effect on 2-MN conversion as at lower reaction temperature 100˚C, the relative product selectivity (72%) seems to enhance; however, the drawback is the fact that lower 2-methylnaphthalene conversions (18%) are attained. Another important point to note is the fact that using an autoclave (with acetonitrile as a solvent), 2-methyl-1-naphthol was generated as a co-product. In conclusion, it has been shown that the hydroxylation of different aromatic compounds over zeolites conducted in this study generated interesting findings. In 2-MN hydroxylation over Ti-MCM-41 as a catalyst, only acetonitrile is an appropriate choice of solvent using an autoclave. In addition, zeolite TS-1 is not a suitable catalyst for 2-MN hydroxylation reactions. It is ideal to optimise an autoclave in order to investigate reaction kinetics and optimum selectivity. Toluene hydroxylation reactions yielded para and ortho-cresol as expected with either water or acetonitrile as a solvent. No meta-cresol was formed. The kinetic model fitted generated a good fit with water as a solvent or excess toluene, with acetonitrile as a solvent generating a reasonable fit.
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Finlay, Christine Jane. "Pectic methyl and non-methyl esters and the environmental implications of methanol emissions from plants." Thesis, Connect to e-thesis, 2007. http://theses.gla.ac.uk/176/.
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Thesis (Ph.D.) -- University of Glasgow, 2007.PhD thesis submitted to Environmental, Agricultural and Analytical Chemistry, Department of Chemistry, University of Glasgow. Includes bibliographical references. Print version also available.
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Stump, Mark Andrew. "Novel chromium compounds and their use in the polymerisation of methyl methacrylate." Thesis, University of Warwick, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298936.
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Parnham, Benjamin Lee. "Modification of bis(ditertiarybutylphosphinomethyl)benzene for improved catalyst separation and stability /." St Andrews, 2007. http://hdl.handle.net/10023/325.
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Yeadon, Alan. "A study of the polymorphism of 4-methyl-2-nitroacetanilide and related compounds." Thesis, Brunel University, 1985. http://bura.brunel.ac.uk/handle/2438/7880.
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The full crystal structures of three polymorphs of 4-methyl-2-nitroacetanilide (MNA) are described. The white form (MNA-l), is the most stable form. The least stable form is the amber farm (MNA-2). The yellow form (MNA-3) has been found to change in a topotactic manner into the white form. The relationships between the three polymorphs are discussed and possible mechanisms to account for the topotactic phase changes are presented. The polymorphs show different i.r. and Raman spectra in the solid state. These spectra, and those of deuterated analogues are interpreted and their differences explained. A study of the proton and 13-C n.m.r. spectra show that the conformation of flexible MNA molecules is markedly dependent on the nature of the solvent. The ability of other o-nitroacetanilides to exist in a white (intermolecular) and yellow (intramolecular hydrogen bonded) forms has been examined. Finally, details of the synthesis of these compounds and an account of the examination of MNA polymorphs by differential scanning calorimetry (d.s.c) are described. A description of computer programs used, including one in BASIC which will enable the contents of unit cell(s) to be viewed, is given.
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楊小雯 and Siu-man Yeung. "The synthesis and reactions of 3H-pyrroles bearing methyl and aryl groups." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31210119.
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Li, Kai Man Samuel. "Photodynamic effects of the photosensitizers Zn-BC-AM and pyropheophorbide-a methyl ester (MPPa) on nasopharyngeal carcinoma cells." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/587.
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Lorusso, Patrizia. "Metal catalysed alkylation of carbonyl compounds with formaldehyde." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7823.
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Formaldehyde is a chemical used widely in the manufacture of building materials. A remarkable example is represented by the Lucite two-step Alpha technology for the large scale production of methyl methacrylate (MMA), the essential building block of all acrylic-based products. Esters and ketones are important intermediates in the manufacture of acrylate esters therefore α-hydroxymethylenation of carbonyl compounds using formaldehyde as a one carbon alkylating agent and subsequent dehydration to the corresponding methylenated derivatives has been explored in the current work. We report a novel catalytic approach for the synthesis of methyl methacrylate (MMA) via one-pot α-methylenation of methyl propanoate (a chemical intermediate of the ALPHA process) with formaldehyde, generated in situ by Ru-catalysed dehydrogenation of methanol. Elucidation of the mechanism involved in the catalytic dehydrogenation of methanol along with the collateral alcohol decarbonylation reaction was gained through a combined experimental and DFT study. The development of an alternative process where anhydrous formaldehyde is produced in situ would provide a simplification over the current second step of the ALPHA technology where the formaldehyde is initially produced as formalin, subsequently dehydrated to afford anhydrous formaldehyde in order to ensure high selectivity to MMA. As an alternative approach, ketones, in particular 3-pentanone and 2-butanone, were targeted as potential substrates in order to overcome some of the problems related to competing reactions that occur at the ester group. Hydroxymethylenation, followed by dehydration and Baeyer-Villager oxidation, possibly catalysed by enzymes to reverse the normal selectivity, leads to the formation of acrylate esters. The catalytic reaction is enabled by a gold carbene hydroxide complex in such a way that the substrate undergoes C-H activation and the nascent metal alkyl acts as a nucleophile towards the electrophilic formaldehyde, supplied in the form of alcoform* (solution of paraformaldehyde in methanol).
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Way, Tun-Fun. "The reactions of electron-rich monomers with electrophilic compounds: Methyl tricyanoethylenecarboxylate and trimethylsilyl esters." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185196.
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The experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.The experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.
The experimental results of the current work has three parts. First, the cycloaddition and copolymerization of methyl tricyanoethylenecarboxylate 2 with electron-rich olefins, such as p-methoxystyene, trans-anethole, isobutyl vinyl ether and ethyl cis-propenyl ether are discussed. The nature of the cycloadduct is determined by the orientation of the electrophilic olefins. Copolymerization of 2 with p-methoxystyrene under free-radical initiation gave an alternating copolymer. Second, trimethylsilyl methanesulfonate and trimethylsilyl diphenylphosphate were used as initiators for cationic polymerization. In the presence or absence of hindered pyridine, trimethylsilyl diphenylphosphate and trimethylsilyl methanesulfonate did not initiate the polymerization of p-methoxystyrene, anethole, 4-isopropenylanisole, 1,3-dioxolane or trioxane. Only trimethylsilyl methanesulfonate was able to initiate the cationic polymerization of 1,3-dioxepane in the presence of a hindered base. A model study demonstrates fast desilylation of a carbocation β to a silicon by an oxygen-containing counterion. Finally, block copolydioxepane-polydimethylsiloxane has been synthesized by the "silyl sulfonate approach." In this approach, the nucleophilic macromer, lithium polydimethylsiloxanate, was reacted with chlorodimethylsilane or allylchlorodimethylsilane to produce the corresponding macromers with silylated end groups. They contained a labile substituent, an allyl or a proton, on silicon. These macromers were then converted to electrophilic macropolydimethylsiloxane arylsulfonate by reaction with an aryl or alkyl sulfonic acid. The sulfonate polydisiloxanes can initiate the cationic polymerization of 1,3-dioxepane to yield block polydimethylsiloxane-polydioxepane. This cationic polymerization did proceed in the presence of 2,6-di-t-butylpyridine, which would trap any acid impurities.
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Yoshida, Yasuko. "Global sources and distribution of atmospheric methyl chloride." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-06232006-151220/.
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Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2007.Robert Dickinson, Committee Member ; Athanasios Nenes, Committee Member ; David Tan, Committee Member ; Armistead Russell, Committee Member ; Yuhang Wang, Committee Chair.
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Isci, Asli. "Recovery Of Strawberry Aroma Compounds By Pervaporation." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605084/index.pdf.
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Pervaporation is a selective membrane technique in which a liquid feed mixture is separated by means of partial vaporization through a non-porous perm-selective membrane. This method can be used for the recovery of heat sensitive aroma compounds to avoid them from thermal damage in beverage industries.
The main objective of this study was to determine the effects of feed temperature (30, 40, 50°C), composition (different model solutions, strawberry essence), concentration (50, 100, 150 ppm) and permeate pressure (4, 8 mbar) on the recovery of aroma compounds of strawberry by pervaporation in terms of mass flux and selectivity. In addition, it was aimed to optimize the extraction conditions (extraction time, temperature, agitation speed, strawberry matrix) of Solid-phase microextraction (SPME), which is used for the analysis of strawberry aroma compounds. Optimum results for SPME were obtained at 40°
C, 700 rpm for 30 min and no matrix effect was observed. Pervaporation experiments were performed using a hydrophobic membrane, PERVAP 1070 (PDMS). As the feed temperature increased, the mass flux and selectivity increased and the total mass flux followed an Arrhenius type relation. Decreasing downstream pressure increased both total flux and selectivity, while increase in feed concentration led to higher organic fluxes but lower selectivities. In general, PERVAP 1070 showed a higher selectivity towards Methyl butyrate (MTB) than Ethyl butyrate (ETB) and MTB flux was affected negatively by the presence of ETB in the feed solution. Pervaporation experiments were also performed with a strawberry essence and strawberry model solution. The selectivities of MTB and ETB were negatively affected by the presence of other aroma compounds.
21
Hill, Stephen Bernard. "Utilisation of phosphorus containing compounds to modify the properties of poly(methyl methacrylate) based polymers." Thesis, Lancaster University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369465.
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Gescher, A. "Studies of the metabolism, anti-tumor activity and toxicity of compounds containing N-methyl moieties." Thesis, Aston University, 1986. http://publications.aston.ac.uk/21658/.
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Chai, Ming. "Thermal Decomposition of Methyl Esters in Biodiesel Fuel: Kinetics, Mechanisms and Products." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342544227.
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Steel, Colin James. "Automated radiosynthesis of 2-['1'1C]thymidine and ['1'1C]methyl halides for use in Positron Emission Tomography." Thesis, University of Hertfordshire, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323444.
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Cunliffe, Lauren Katherine. "Decomposition studies of fire retardant action of phosphorus compounds in poly (methyl methacrylate), polystyrene and their copolymers." Thesis, University of Salford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490540.
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Amawi, Rema Mouawya Klausmeyer Kevin Kenneth. "Synthesis and characterization of silver(I) salts with amino methyl pyridines containing phosphines novel complex formation upon ratio, anion, or ligand changes /." Waco, Tex. : Baylor University, 2008. http://hdl.handle.net/2104/5180.
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Tokode, Oluwatosin. "Photocatalytic destruction of volatile organic compounds from the oil and gas industry." Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/1134.
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Heterogeneous photocatalysis is an advanced oxidation technology widely applied in environmental remediation processes. It is a relatively safe and affordable technology with a low impact on the environment and has found applications in a number of fields from chemical engineering, construction and microbiology to medicine. It is not catalysis in the real sense of the word as the photons which initiate the desired photocatalytic reaction are consumed in the process. The cost of these photons is by far the limiting economic factor in its application. From a technical standpoint, the inefficient use of the aforementioned photons during the photocatalytic reaction is responsible for the limited adoption of its application in industry. This inefficiency is characterised by low quantum yields or photonic efficiencies during its application. The mechanism of the technique of controlled periodic illumination which was previously proposed as a way of enhancing the low photonic efficiency of TiO2 photocatalysis has been investigated using a novel controlled experimental approach; the results showed no advantage of periodic illumination over continuous illumination at equivalent photon flux. When the technique of controlled periodic illumination is applied in a photocatalytic reaction where attraction between substrate molecules and catalyst surface is maximum and photo-oxidation by surface-trapped holes, {TiIVOH•}+ ads is predominant, photonic efficiency is significantly improved. For immobilized reactors which usually have a lower illuminated surface area per unit volume compared to suspended catalyst and mass transfer limitations, the photonic efficiency is even lower. A novel photocatalytic impeller reactor was designed to investigate photonic efficiency in gas–solid photocatalysis of aromatic volatile organic compounds. The results indicate photonic efficiency is a function of mass transfer and catalyst deactivation rate. The development of future reactors which can optimise the use of photons and maximize photonic efficiency is important for the widespread adoption of heterogeneous photocatalysis by industry.
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Kaufmann, Christoph [Verfasser], Johannes A. [Akademischer Betreuer] Lercher, and Klaus [Akademischer Betreuer] Köhler. "Alternative routes to methyl mercaptan from C1-compounds / Christoph Kaufmann. Betreuer: Johannes A. Lercher. Gutachter: Johannes A. Lercher ; Klaus Köhler." München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/1080299459/34.
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Samanta, Susnata. "Reversible carbon dioxide gels, synthesis and characterization of energetic ionic liquids, synthesis and characterization of tetrazole monomers and polymers, encapsulation of sodium azide for controlled release." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22602.
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Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007.Committee Chair: Prof. Charles L. Liotta; Committee Member: Prof. Arthur J. Ragauskas; Committee Member: Prof. Charles A. Eckert; Committee Member: Prof. John D. Muzzy; Committee Member: Prof. Rigiberto Hernandez.
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Abd, Allah Zaenab. "Non-thermal atmospheric pressure plasma for remediation of volatile organic compounds." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/nonthermal-atmospheric-pressure-plasma-for-remediation-of-volatile-organic-compounds(2826f483-e29f-402e-93a7-5f73818c4292).html.
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Non-thermal plasma generated in a dielectric barrier packed-bed reactor has been used for the remediation of chlorinated volatile organic compounds. Chlorinated VOCs are important air pollutant gases which affect both the environment and human health. This thesis uses non-thermal plasma generated in single and multiple packed-bed plasma reactors for the decomposition of dichloromethane (CH2Cl2, DCM) and methyl chloride (CH3Cl). The overall aim of this thesis is to optimize the removal efficiency of DCM and CH3Cl in air plasma by investigating the influence of key process parameters. This thesis starts by investigating the influence of process parameters such as oxygen concentration, initial VOC concentration, energy density, and plasma residence time and background gas on the removal efficiency of both DCM and CH3Cl. Results of these investigations showed maximum removal efficiency with the addition of 2 to 4 % oxygen to nitrogen plasma. Oxygen concentrations in excess of 4 % decreased the decomposition of chlorinated VOCs as a result of ozone and NOx formation. This was improved by adding an alkene, propylene (C3H6), to the gas stream. With propylene additives, the maximum remediation of DCM was achieved in air plasma. It is thought that adding propylene resulted in the generation of more active radicals that play an important role in the decomposition process of DCM as well as a further oxidation of NO to NO2. Results in the single bed also showed that increasing the residence time increased the removal efficiency of chlorinated VOCs in plasma. This was optimized by designing a multiple packed-bed reactor consisting of three packed-bed cells in series, giving a total residence time of 4.2 seconds in the plasma region of the reactor. This reactor was used for both the removal of DCM, and a mixture of DCM and C3H6 in a nitrogen-oxygen gas mixture. A maximum removal efficiency of about 85 % for DCM was achieved in air plasma with the use of three plasma cells and the addition of C3H6 to the gas stream. Nitrogen oxides are air pollutants which are formed as by-products during the decomposition of chlorinated VOCs in plasmas containing nitrogen and oxygen. Results illustrate that the addition of a mixture of DCM and C3H6 resulted in the formation of the lowest concentration of nitric oxide, whilst the total nitrogen oxides concentrations did not increase. A summary of the findings of this work is presented in chapter eight as well as further work. To conclude, the maximum removal efficiency of dichloromethane was achieved in air plasma with the addition of 1000 ppm of propylene and the use of three packed-bed plasma cells in series. The lowest concentration of nitric oxide was formed in this situation.
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Koka, Vivian Dzigbodi. "A Study of the Effects of Titanium Dioxide Nanoparticles on the Fluorescent Intensity of Fluorescent Compounds in the Presence of Known Quenchers." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1384.
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Titanium Dioxide is a naturally occurring oxide of titanium. It has a wide range of uses in commercial products for providing whiteness and opacity. It has photocatalytic properties and can also be used to produce electricity in its nanoparticles form. This research is focused on investigating the effect of titanium dioxide nanoparticles in analysis of compounds using luminescence-based techniques. Quenching, which is one of the basic problems of fluorescent measurements, was studied in the presence of molecular oxygen and methyl iodide. The rutile phase of titanium dioxide nanoparticles was synthesized by the acid hydrolysis of titanium isobutoxide at low temperatures with nitric acid. The crystalline powder was dissolved at different concentrations and used to monitor the fluorescence intensities of carbazole, pyrene, and fluoranthene in the presence of methyl iodide and oxygen. Quenching by molecular oxygen was studied by comparing the fluorescence intensities of compounds with and without degassing the solutions. Titanium Dioxide was found to exhibit interesting effects on the fluorescent intensities of these compounds in the presence of quenchers.
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Svahn, Stefan. "Analysis of Secondary Metabolites from Aspergillus fumigatus and Penicillium nalgiovense : Antimicrobial Compounds from Filamentous Fungi Isolated from Extreme Environments." Doctoral thesis, Uppsala universitet, Avdelningen för farmakognosi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242611.
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This thesis describes the cultivation and extraction of filamentous fungi isolated from extreme environments in the search for new antibiotic compounds. Filamentous fungi are a rich source of medicines including antibiotics, and it is believed that many currently unknown fungal species and bioactive fungal metabolites remain to be discovered. Aspergillus fumigatus and Penicillium nalgiovense strains were isolated from an antibiotic-contaminated riverbed near Hyderabad, India, and soil taken from a penguin’s nest on Paulete Island, Antarctica, respectively. It was anticipated that the extreme conditions within these environments would exert unusual selective pressures on their filamentous fungi, possibly causing the secretion of new bioactive compounds. The cultivation, extraction and analysis of metabolites from the A. fumigatus strain resulted in the isolation of the antimicrobial substance gliotoxin. Subsequent investigations revealed that this strain’s secretion of gliotoxin was increased by as much as 65 % when it was cultivated in the presence of pathogen-associated molecular patterns. These results indicate the existence of a fungal receptor/signaling system for detecting nearby bacteria. The scope for using gliotoxin and the related metabolite bis(methyl)gliotoxin as biomarker metabolites for diagnosing the lethal pulmonary condition invasive aspergillosis was also investigated. Bronchoalveolar lavage fluid from 42 patients with and without possible invasive aspergillosis was extracted and analyzed. The results obtained suggest that gliotoxin and bis(methyl)gliotoxin are not suitable markers for diagnosing invasive aspergillosis. Studies on the P. nalgiovense strain from Antarctica resulted in the isolation of the antifungal agent amphotericin B. The secretion of this compound increased when P. nalgiovense was cultured on a potato-dextrose agar enriched with coconut flakes rather than liquid RPMI 1640 medium. This was the first time amphotericin B was isolated from any organism other than the bacterium Streptomyces nodosus. The results presented in this thesis will be useful in the continuing search for novel bioactive compounds, the diagnosis of fungal infections, and as a source of insight into the interactions between microorganisms. Moreover, they show that even extensively studied fungal genera such as Aspergillus and Penicillium are not completely understood and may produce unexpected or previously unknown bioactive metabolites under appropriate conditions.
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Chia, Poh Wai. "The C-F bond as a conformational probe in agonist receptor interactions." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/2615.
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Chapter 1 gives an introduction on the physical and electronic properties of fluorine and the C-F bond. The application of fluorine in organic chemistry, which is mainly attributed to the electronic properties of fluorine is described. The role of fluorine in neuropsychiatric drug development and for influencing the conformational study of bioactive amines is also illustrated. Chapter 2 of the thesis describes the synthesis of the two fluorinated stereoisomers (2R, 3S) and (2S, 3S) 3-fluoro N-methyl–D-aspartate (NMDA). These were prepared as analogues to study the binding conformation of NMDA on the glutameric NMDA receptor. The (2S, 3S)-3-fluoro NMDA D-72 was successfully prepared from diethyl D-tartrate. The (2S,3R)- stereoisomer was prepared by separation of diastereoisomers generated by reaction of a meso- epoxide with an enantiomerically pure amine, followed by fluorination. Both the (2S,3R)- and (2R,3S)- enantiomers were prepared separately, however assignment of the absolute configuration to each enantiomer could not be unambiguously proven. The fluorinated 3F-NMDA stereoisomers were assessed by dose response analysis and TEVC analysis in the rat glutamate receptor. The biological results show that the (2S, 3S)-3F NMDA D-72 is a good agonist, whereas (2R, 3S)- and (2S, 3R)-3-fluoro NMDA are inactive stereoisomers. The result of this study indicates that (2S, 3S)-3F NMDA D-72 is the only relevant agonist that can access a conformation for binding to NMDA receptor. Chapter 3 describes the preparation of fluorinated analogues of the calcium receptor agonist Cinacalcet. The (2R,1’R)-123 and (2S,1’R)-124 fluoro Cinacalcet diastereoisomers were prepared from 3’-(trifluoromethyl)cinnamic acid and 3’’-SF₅-137 Cinacalcet was synthesized from pentafluorosulfanyl benzyl alcohol. The biological assessment in the calcium receptor (CaR) revealed that both (2R,1’R)-123 and (2S,1’R)-124 fluoro Cinacalcet is slightly lower in potency compared to the non-fluorinated Cinacalcet 117. This suggests that the Cinacalcet 117 adopts an extended conformation when bound to the receptor. The 3’’-SF₅-137 Cinacalcet possesses equipotent activity with Cinacalcet 117.
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Ranaivonjatovo, Henri Jacques. "Derives du phosphore et de l'arsenic dicoordonnes doublements lies : diphosphenes, diarsenes et phospha-arsenes." Toulouse 3, 1986. http://www.theses.fr/1986TOU30069.
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Synthese de diphosphenes, diarsenes et phospha-arsenes par la voie organolithiee (action de lithiens encombres sur les dichlorophosphines). L'action du dbu sur les trichlorogermyl phosphines rp(h)gecl::(3) s'est revelee une voie d'acces generale aux disphosphenes. Reactivite, structures
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DUARTE, CELINA L. "Aplicacao do processo avancado de oxidacao por feixe de eletrons na degradacao de compostos organicos presentes em efluentes industriais." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10757.
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Made available in DSpace on 2014-10-09T12:43:41Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:09:56Z (GMT). No. of bitstreams: 1 06654.pdf: 9860874 bytes, checksum: a9212efd0462f2603abb2f237d62a703 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Chang, Liang. "Sustainable Transformations of Methyl Coumalate : efficient Preparations of Unsaturated Carboxylic Acids, 2HPyrans, Trifluoromethyl Benzenes and Fluorescents Molecules." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS109.
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Dans ce travail, nous décrivons le développement de nouvelles transformations utilisant le coumalate de méthyle, composé renouvelable biosourcé. Un couplage double séquentiel d'alkyl-alkyle ou d'alkyl-hydrure one-pot conduit à des acides insaturés d’intérêt. Nous décrivons une synthèse efficace de 2H-pyranes tétrasubstitués dans des conditions douces, puis nous décrivons une réaction efficace et sans solvant avec des dicétones trifluorométhylées, pour conduire à des benzènes trifluorométhylés. Enfin, nous avons rapporté une nouvelle stratégie générale de réaction de désaromatisation de composés hétérocycliques de type pyrido [1, 2-a] bicycliquesIn this work, we have described the development of new transformations using bio-based renewable methyl coumalate as feedstock. An iron and copper catalyzed one-pot sequential double alkyl-alkyl or alkyl-hydride 1,6-addition with methyl coumalate was described. We then described an efficient synthesis of tetrasubstituted 2H-pyrans under mild condition. Later we reported a solvent-free reaction of methyl coumalate with trifluoromethyl-β-diketones, in a tBuOK-catalyzed domino sequence. A novel reaction, for efficient C-C bond formation between the bio-based methyl coumalate and a variety of imines and aldehydes via MBH pathway was reported. Finally, we reported a novel, general dearomatization strategy with an unprecedented pyrido[1, 2-a] fused heterocyclic scope
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Parnham, Benjamin L. "Modification of bis(ditertiarybutylphosphinomethyl)benzene for improved catalyst separation and stability." Thesis, University of St Andrews, 2007. http://hdl.handle.net/10023/325.
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Palladium complexes of bis(di-tert-butylphosphinomethyl)benzene (DTBPMB) show remarkably high activity as alkene methoxycarbonylation catalysts, in addition to numerous other catalytic conversions, and are currently being commercialised by Lucite in ethene methoxycarbonylation to methyl propanoate. Any large-scale exploitation of this catalyst system for heavier products, however, is likely to be hindered by catalyst-product separation problems common to homogeneous catalysts; hence modification of this catalyst system to allow facile product separation was investigated. Tethering of DTBPMB residues onto polystyrene via Suzuki-type coupling of suitable precursors onto bromopolystyrene and boronic acid functionalised polystyrene resins was investigated and the phosphine was successfully immobilised. Phosphination of the resins was not complete however and as such there is concern that other phosphine residues may be present which do not exhibit a bidentate binding motif. The synthesis of a potassium sulfonate derivative of DTBPMB (KBPMBS) was successful and immobilisation of this onto ion exchange resins was also investigated. Some preliminary results from studies into 1-octene methoxycarbonylation using palladium complexes of these resins were obtained. Supporting of this diphosphine onto silica via a sol-gel co-condensation methodology was also investigated; the synthesis of a suitably functionalised precursor containing a sulfonamide linkage was successful via protection of the diphosphine using borane. Although formation of the silica support was successful, attempts to deprotect the phosphine-borane resulted in cleavage of the ligand from the support. An alternative route to this supported ligand was attempted and others discussed. Synthesis of a suitable sol-gel precursor via alkene hydrosilation was also attempted and is discussed. Supporting of the sulfonated phosphine, KBPMBS onto silica functionalised with imidazolium tethered residues was also investigated, although complete leaching of the phosphine from the support by methanol washing was observed. Immobilisation of the synthesised KBPMBS ligand in an ionic liquid (IL) phase was investigated. Complex formation and catalytic activity were demonstrated and a positive effect on conversion was observed upon addition of carbon dioxide to the system; possibly due to the increased CO solubility within the IL phase. Efficient product separation from the IL-immobilised catalyst system was demonstrated, both by organic extraction and using supercritical carbon dioxide flow. However, poor catalyst stability under these conditions appears to present a barrier to recycling this system, with loss of conversion observed on catalyst recycling. Other attempts to immobilise the DTBPMB ligand are discussed and reduction of the sulfide derivative of DTBPMB was demonstrated using hexachlorodisilane, which could be used as a general synthetic strategy for protecting highly electron rich phosphines. It is possible that increasing the bulk of the DTBPMB ligand may increase catalyst stability and result in catalyst systems with higher turnover numbers. Therefore syntheses of bulky ligands based on the DTBPMB backbone were investigated. 1,2,4,5-tetrakis(di(tert-butyl)phosphinomethyl)benzene was successfully synthesised although palladium complexes of this showed no activity in catalytic methoxycarbonylation. Attempts to synthesise a related biphenyl-based tetraphosphine is also discussed, although isolation of this in a pure form was not achieved. Routes toward tetraphenyl and dimethyl-diphenyl functionalised derivatives of DTBPMB have also been explored, although only a monophosphine was isolated due to difficulties in obtaining an intermediate di(chloromethyl) precursor in both synthetic pathways, although this now appears to have been overcome.
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Huang, Weisheng. "Catalytic asymmetric cyclopropanation and oxidation of tri-, di- and monofluoromethyl styrenes Rhodium catalysed enantioselective synthesis of mono-(halo)-methyl-cyclopropanes Catalytic enantioselective synthesis of highly functionalized difluoromethylated cyclopropanes General catalytic enantioselective access to monohalomethyl and trifluoromethyl cyclopropanes Catalytic asymmetric synthesis of α,α-difluoromethylated and α-fluoromethylated tertiary alcohols." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMIR25.
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Ce manuscrit décrit la synthèse énantiosélective de cyclopropanes trifluorométhylés, difluorométhylés et mono-halométhylés hautement fonctionnalisés. Cette synthèse repose sur la cyclopropanation d’alcènes. De plus, la synthèse d’alcools tertiaires difluorométhylés à partir des oléfines fluorées correspondantes suivant un processus de dihydroxylation asymétrique est décrite. Ce manuscrit se découpe en 3 chapitres. Le premier chapitre décrit la première synthèse catalytique asymétrique de cyclopropanes difluorométhylés en utilisant le Rh₂((S)-BTPCP)₄ comme catalyseur pour la réaction de cyclopropanation d’oléfines α,α-difluoromethylées avec des composés diazoïques di-accepteurs. Un large éventail de cyclopropanes a été obtenu avec de très bon rendements et d’excellentes diastéréosélectivités et énantiosélectivités (>20:1 et jusqu’à 99% ee). Le second chapitre illustre la synthèse de cyclopropanes trifluorométhylés suivant une stratégie similaire. Ces derniers ont été obtenus avec des très bons rendements et d’excellentes diastéréosélectivités et énantiosélectivités (>20:1 et jusqu’à 99% ee). Ces travaux ont également permis une extension aux dérivés mono-halométhylés. Dans un troisième chapitre, l’époxydation asymétrique de styrenes α,α-difluoromethylés a été étudiée. Malheureusement, tous les essais métallo- ou organocatalysés se sont avérés infructueux. Par la suite la réaction de dihydroxylation asymétrique de ces styrenes α,α-difluorométhylés a été développée pour conduire aux alcools tertiaires difluorométhylés énantioenrichis. L’utilisation d’AD-mix-α et AD-mix-β comme catalyseurs a permis d’obtenir les produits désirés avec de très bons rendements et d’excellentes énantiosélectivités. De plus, cette réaction a été étendue aux styrenes α,α-difluorométhylés, α-monofluorométhylés, β-difluoromethylé et β-trifluorométhyléThis thesis presents the enantioselective synthesis of functionalized trifluoromethyl, difluoromethyl and monohalomethyl cyclopropanes based on the cyclopropanation reaction of alkenes bearing various fluorinated groups. In addition, the synthesis of enantioenriched fluorinated tertiary alcohols resulting from the dihydroxylation of fluorinated olefins is discussed. This thesis is divided into three chapters. In the first chapter, we reported the first example of catalytic asymmetric synthesis of difluoromethyl cyclopropanes, which is achieved by using Rh₂((S)-BTPCP)₄ as a catalyst to perform the cyclopropanation reaction of α,α-difluoromethyl olefins with donor-acceptor diazo compounds and di-acceptor diazo compounds. This methodology allows the access to a broad range of cyclopropanes in high yields with excellent diastereo- and enantioselectivities (up to >20:1 and up to 99% ee). In the second chapter, a practical and efficient asymmetric synthesis of trifluoromethyl cyclopropane derivatives was described and a series of functionalized cyclopropanes were obtained in excellent diastereoselectivities with excellent enantioselectivities (up to >20:1 and 99% ee). These investigations also extended to the synthesis of highly enantioselective monohalomethyl cyclopropanes. In the third chapter, the initial propose aimed at exploring the asymmetric epoxidation of α,α-difluoromethyl styrenes. The reaction was performed in the presence of a metal-catalyst or an organic catalyst, unfortunately, none of the result was positive. Therefore, we turned our attention to the asymmetric synthesis of α,α difluoromethylated tertiary alcohols. To this propose, the use of commercially available reagents AD-mix-α and AD-mix-β as the best catalysts, allowed the reaction with α,α-difluoromethyl styrenes to construct the corresponding α,α-difluoromethylated tertiary alcohols in good to high yields with excellent enantioselectivities (up to 99% ee). In addition, this transformation could be applied to a broad range of substrates, including variety of α,α-difluoromethyl styrenes, α-monofluoromethyl styrenes, β-difluoromethyl styrene and β-trifluoromethyl styrene
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Sharma, Rajan. "Synthesis & biological evaluation of neuroprotective molecules with polycyclic scaffolds." University of the Western Cape, 2017. http://hdl.handle.net/11394/6228.
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Doctor Pharmaceuticae - DpharmAmong neurological disorders, many of the most devastating disorders are neurodegenerative. Modern research associates excitotoxicity to a variety of neuropathological conditions, suggesting that the neurodegenerative diseases with distinct etiologies may have excitotoxicity as a common pathway. Excitotoxicity occurs through over-stimulation of receptors for excitatory neurotransmitters like the N-methyl-D-aspartate (NMDA) receptors. Due to the relevance of NMDA receptors and excitotoxic processes, the antagonism or modulation of NMDA receptors is used as a therapeutic tool against neurodegenerative diseases. NMDA receptor activity can be modulated by S-nitrosylation and this modulation of NMDA receptor activity can be utilised in the development of neuroprotective drugs.
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Sakri, El-Bahri. "Etude cinétique de la polymérisation photochimique du méthacrylate de méthyle en présence d'agents complexant organochloroaluminiques." Paris 6, 1986. http://www.theses.fr/1986PA066140.
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Clark, S. "A new method for the analysis of metal and metalloidal compounds." Thesis, De Montfort University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383105.
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Figadère, Bruno. "Les composes organomanganeux mixtes : addition 1-2 selective sur des aldehydes ou des cetones portant un groupe fonctionnel, enolisation regioselective de cetones : application en synthese." Paris 6, 1987. http://www.theses.fr/1987PA066371.
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Les reactifs organomanganeux rmnx(x=cl, br, i; r=n-, sec- t-alkyl, alcenyl, aryl, alcynyl) s'additionnent aux aldehydes et cetones fonctionnels pour donner selectivement les alcools correspondant avec d'excellents rendements. Les reactifs rmnz(z=nphme) enolisent les cetones avec une excellente regioselectivite. Les enolates manganeux ainsi prepares sont tres aisement acyles, silyles, alkyles, hydroxyalkyles, avec des rendements de 60% a 90%, a la temperature ambiante
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Man, Ka-yan Kitty, and 文嘉欣. "Synthesis of transition metal containing polymers and fabrication of photonic devices by self assembly method." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31245821.
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Vankova, Viera. "Metalorganic vapour phase epitaxial growth and characterisation of Sb-based semiconductors." Thesis, Nelson Mandela Metropolitan University, 2005. http://hdl.handle.net/10948/d1019678.
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This study focuses on the growth and characterization of epitaxial InAs and InAs1-xSbx. Layers are grown on InAs, GaAs and GaSb substrates by metalorganic vapour phase epitaxy, using trimethylindium, trimethylantimony and arsine as precursors. The growth parameters (V/III ratio, Sb vapour phase compositions) are varied in the temperature range from 500 ºC to 700 ºC, in order to study the influence of these parameters on the structural, optical and electrical properties of the materials. The layers were assessed by X-ray diffraction, electron and optical microscopy, photoluminescence and Hall measurements. Furthermore, the influence of hydrogenation and annealing on the electrical and optical properties of GaSb was investigated. It is shown that the growth temperature and the V/III ratio play a vital role in the resulting surface morphology of homoepitaxial and heteroepitaxial InAs layers. Growth at low temperatures is found to promote three-dimensional growth in both cases, with improvements in the surface morphologies observed for higher growth temperatures. All the investigated epilayers are n-type. It is shown that the electrical properties of heteroepitaxial InAs epilayers are complicated by a competition between bulk conduction and conduction due to a surface accumulation and an interface layer. The low temperature photoluminescence spectra of homoepitaxial InAs are dominated by two transitions. These are identified as band-to-band/excitonic and donor-acceptor recombination. The incorporation efficiency of antimony (Sb) into InAs1-xSbx is dependent on the growth temperature and the V/III ratio. Under the growth conditions used in this study, the incorporation efficiency of Sb is controlled by the thermal stability of the two constituent binaries (i.e. InAs and InSb). Changes in the low temperature photoluminescence spectra are detected with increasing x. From temperature and laser power dependent measurements, the highest energy line is attributed to band-to-band/excitonic recombination, while the peak appearing approximately 15 meV below this line is assigned to donor-acceptor recombination. The origin of an additional “moving” peak observed for higher Sb mole fraction x is tentatively attributed to quasi-donor-acceptor-recombination, arising from increased impurity/defect concentrations and a higher compensation ratio in the material. However, the unusual behaviour of this peak may also be ascribed to the presence of some degree of ordering in InAsSb. The exposure of a semiconductor to a hydrogen plasma usually leads to the passivation of shallow and deep centres, thereby removing their electrical and optical activity. In this study, the passivation and thermal stability of the native acceptor in p-type GaSb is also investigated. It is shown that this acceptor can be passivated, where after improvements in the electrical and optical properties of GaSb are observed. Upon annealing the passivated samples above 300 °C, the acceptor is reactivated.
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Ojala, S. (Satu). "Catalytic oxidation of volatile organic compounds and malodorous organic compounds." Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514278704.
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Abstract
This thesis describes efforts made on the development of an existing catalytic incinerator. The development work, called process characterization, consists of four general parts. These are the development of measurement methodology, the studying of construction materials, the selection of suitable catalysts and the testing of the effects of process operation conditions. The two application areas for catalytic incineration considered in this thesis are solvent emission abatement (VOC, volatile organic compounds) and chip bin emission abatement (SVOC, sulphur-containing volatile organic compounds).
As a baseline, the process characterization is started with the development of measurement methodology. In general, the methodology will decrease costs and simplify the carrying out of the actual measurements and thereby make the measurement time more effective. In the methodology it is proposed that continuous total concentration measurement should be used in connection with qualitative sampling to obtain reliable measurement data.
The selection of suitable construction materials for the application is very important. As shown in this thesis, the end conversions in solvent emission abatement may even be improved through the selection of the proper construction materials. In chip bin emission abatement, the problem arises from corrosive oxidation products that set limits on the construction materials used as well as on oxidation conditions.
Catalyst selection is based on the following catalytic properties: activity, selectivity and durability. These catalytic properties are studied either at the laboratory or on an industrial scale. The catalytic materials tested are Pt, Pd, Pt-Pd, Cu-Mn oxides, MnO2-MgO, CuxMg(1-x)Cr2O4 and CuxCr2O4. The most important selection criteria in solvent emission abatement are proposed to be activity and selectivity. In the case of chip bin-SVOC-abatement, these are selectivity and durability. Based on these criteria, catalysts containing Cu-Mn oxides and Pt were demonstrated to be the best catalysts in VOC oxidation, and catalyst containing MnO2-MgO was shown to be best catalyst in SVOC oxidation.
A study on the effect of process operation parameters (temperature, concentration and gas hourly space velocity (GHSV)) and moisture was carried out with the aid of factorial design. In VOC (n-butyl acetate) oxidation, the most influential process parameter was GHSV, which decreased the end conversion when it was increased. In SVOC (DMDS) oxidation, the effect of temperature was most significant. The end conversions increased as the temperature increased. Moisture slightly decreased the formation of by-products in n-butyl acetate oxidation. In DMDS oxidation, moisture slightly increased the end conversions at a lower temperature level (300°C).
At the end of the thesis, these process parameters are also discussed from the standpoint of the catalysts' activity, selectivity and durability. Finally, proposals for process improvements are suggested.
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EL, JAZOULI MUSTAPHA. "Formation de liaisons carbone-carbone par l'intermediaire des imidothioesters : applications synthethiques." Caen, 1985. http://www.theses.fr/1985CAEN2016.
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Apres une etude de la metallation, suivie d'alkylation, de quelques imidothioesters satures, des reactions d'aldolisation dont la selectivite est examinee, sont realisees a partir d'un n-phenyl imidothioester. Les imidothioesters alpha -insatures dont la reactivite vis-a-vis de magnesiens et de lithiens est etudiee sont de bons accepteurs de michael. Par l'intermediaire des alkylthio-enaminates et d'une cetenimine issue de leur decomposition thermique, de nouvelles voies d'acces a des cetones dissymetriques, sont decrites a partir de n-phenyl imidothioesters satures et alpha -insatures. Synthese de cetones terpeniques et d'une pheromone
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Sherman, D. J. "Studies on some platinum metal compounds." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382671.
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Taylor, Paul H. "Metal free-oxygenation of carbonyl compounds." Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54244/.
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The findings to date have contributed to the development of a novel and useful class of synthetic protocol and have resulted in a greatly enhanced understanding of the fundamental workings of the &agr;-oxygenation.
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Mobbs, B. E. "Arene transition metal complexes in synthesis." Thesis, University of Oxford, 1985. http://ora.ox.ac.uk/objects/uuid:4c7030d4-297e-4af8-a622-d5b4963fc0a3.
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This thesis deals with the applications of organopalladium and organochromium chemistry to the functionalisation of the benzopyran ring system, at a variety of oxidation levels. Section I demonstrates the functionalisation of 3-, 6-, and 8-bromochromones via palladium (0) insertion into the C-Br bond. The resultant arylpalladium species are shown to undergo addition to the least substituted end of a variety of olefins including methyl acrylate, acrylonitrile and styrene. Subsequent palladium-hydride elimination leads to overall palladium catalysed vinylation of the chromone and the synthesis of a number of novel compounds. Vinylation occurs regiospecifically at the site of chromone bromination and is shown to allow clean substituent introduction into each of the three sites. The palladium catalysed reaction of 3,6-dibromo-chromone with methyl acrylate leads to vinylation at both the C3 and C6 positions. Carbonylation of the 6-bromochromone in ethanol or butanol leads to the 6-ethyl or 6-butyl esters respectively. The palladium catalysed vinylation of the 6-bromochromone with ethyl vinyl ether leads to a mixture of products from addition of the chromone to either end of the olefin. With p-bromophenol or p-bromo-N,N-dimethylaniline the reaction gives exclusively the acetylated product arising from addition to the more substituted end of the olefin. This change in orientation is rationalised by considering the polarisation of the olefin and the arylpalladium species. Section II demonstrates the functionalisation of chroman and 4-chromanol via coordination to the Cr(CO)3 moiety. (η6-Chroman)Cr(CO)3 is synthesised and is shown to undergo regiospecific ring deprotonation at C8 under kinetic conditions or regiospecific benzylic deprotonation at C4 under thermodynamic conditions. The resultant anions are quenched with alkyl halides, aldehydes, Eschenmoser's salt and methyl disulphide resulting in selective functionalisation of either site. No mixed products are observed. The uncomplexed arene is shown to be totally unreactive under identical conditions. (η6-4-Chromanol)Cr(CO)3 is synthesised and is shown to undergo regiospecific C8 ring deprotonation by comparison with authentic samples of the C5 and C8 methylated alcohols. Protection of the hydroxyl group as its methyl, t-butyldimethylsilyl or methoxymethyl ethers is found not to alter the regiochemistry of deprotonation. The 4-chromanol t-butyldimethylsilyl and tri-i-propylsilyl ethers are synthesised and coordinated to the metal unit. Cleavage of the silyl ethers is shown to proceed with loss of stereochemistry, indicating C-0 bond cleavage.
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Blincko, Stuart. "Novel luminescent compounds for immunoassay." Thesis, City University London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255249.
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