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1
Delcroix, Valerie A. "Aromatic compound degradation by cresol-utilizing Rhodococcus strains." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263367.
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Ferguson, John Alasdair Kerr Jamie. "Some sigmatropic rearrangements of polyfluoroaromatic and heteroaromatic compounds." Thesis, Durham University, 1986. http://etheses.dur.ac.uk/6870/.
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This Thesis describes some [3,3] and [2,3] -sigmatropic rearrangements that can occur in a variety of polyfluoroaromatic and -heteroaromatic compounds. The presence of fluorine on the aromatic moiety precludes the normal rearomatization process. The work is conveniently divided into two parts. Part A concerns the preparation and thermal (Claisen) rearrangement of derivatives of allyl 5-fluoropyrimidin-4-yl ether. These rearrange upon thermolysis to give isomers in which the terminus for the migration of the allyl group is N-3, provided that there is no preceding reaction which localises a double- bond between C-4 and C-5 - in which case C-5 is the migration terminus. Hydrolysis of some of the N-allyl derivatives results in the formation of some new derivatives of 5-fluorouracil. Part B describes the reactions that occur when polyfluor - inated monocyclic, polycyclic and heterocyclic ring systems are treated with dimethylsulphoxide activated by dicyclohexycarbodi-imide or by trifluoroacetic anhydride. Fluorinated phenolic type compounds give products which are the result of a [2,3] sigmatropic rearrangement of the derived sulphoniumylide. Fluorinated anilines and thiophenols behave differently. Dearomatization occurs under very mild conditions. A number of reactions of the fluorinated cyclohexa-2,4-dienone products are described. The preparation and attempted rearrangement of 2,3,4,5,6- pentafluorobenzylmethylsulphoxide is also discussed.
3
Sherburn, Michael S. "Radicals and reactive rings." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277935.
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Cheong, C. L. "Substitution of polyhalogenoaromatic compounds by sterically hindered nucleophiles." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376844.
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Taylor, J. M. "A study of the reaction of N-chloroamines with electron-rich aromatic compounds." Thesis, University of York, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379028.
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Rehfuss, Marc Y. "Characterization and phylogenetic analysis of a phenol and halogenated aromatic compound degrading microbial consortium /." Search for this dissertation online, 2004. http://wwwlib.umi.com/cr/ksu/main.
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Takuya, Matsumoto. "Development of Novel Conjugated Compounds Based on Characteristics of Gallium Element." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199329.
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Culka, Martin [Verfasser], and G. Matthias [Akademischer Betreuer] Ullmann. "Computational Modeling of Enzyme Reactions Involved in Aromatic Compound Metabolism / Martin Culka ; Betreuer: G. Matthias Ullmann." Bayreuth : Universität Bayreuth, 2017. http://d-nb.info/1147479453/34.
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Frazer, Andrew Richard. "Development of stable isotope probing for the isolation of biocatalytic genes from aromatic compound-degrading bacteria." Thesis, Queen's University Belfast, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.579722.
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This thesis described the development of DNA Stable Isotope Probing (SIP) with the goal of identifying microorganisms and genes involved in the metabolism of aromatic compounds. The research had three main components. Results have been presented in chapters 3, 4 and 5. • Chapter 3 focused on investigating the effect of growth on 2H labelled compounds, developing a method for the isolation of 2H labelled DNA and understanding the limitations of this approach using a range of pure cultures. • Chapter 4 describes experiments used to validate the 2H DNA SIP method using environmental samples and compare SIP results aiming to identify 16s rRNA and dioxygenase sequences using 2H and I3C labelled benzoic acid. • Chapter 5 utilised the methods developed in chapters 3 and 4 to investigate the organisms and genes involved in the degradation of naphthalene vs. methylnaphthalenes in a mixed enrichment culture inoculated with P AB contaminated soil from a former Belfast gas works site. The aim of these experiments was to demonstrate that 2H DNA SIP could be used to gain new information on methylated P AB microbiology and be used specifically for the isolation of biocatalytic genes. • Chapter 1 Presents an introduction to this research • Chapter 2 describes the materials and methods used during the course of this research. • Chapter 6 summarises the work as a whole, suggests future work and discusses the implications of this research in the wider scientific community. • Chapter 7 References
10
Thomas, Philippe. "Impacts of Exposure to Polycyclic Aromatic Compounds (PACs) and Their Alkylated Congeners in North American River Otter (Lontra canadensis)." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40896.
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Polycyclic aromatic compounds (PACs) are a group of chemicals encompassing thousands of different aromatic, alkyl aromatic and heterocyclic hydrocarbons (i.e.- containing N, S, or O- atoms); 16 of which have been designated as priority pollutants due to their toxicity and prevalence. Several studies have highlighted increases in the concentrations of C1-C4 alkylated PACs and heterocyclic aromatic hydrocarbons such as dibenzothiophenes in the atmosphere, water, soil and sediments, plants, wildlife and fish in the Athabasca Oil Sands Region (AOSR). Although there has been considerable research attention related to the toxic, carcinogenic and mutagenic properties of PACs, there is an increasing awareness that these chemicals may also have profound endocrine disrupting properties in wildlife. North American river otter (Lontra canadensis) are good indicators of ecosystem health due to their ecology and sensitivity to environmental pollutants. In this thesis, we first demonstrated the utility of adopting paleotoxicological frameworks in defining environmental baseline levels of PACs and likely biological effects from exposure to these complex environmental mixtures. These methods allowed us to reconstruct historical PAC deposition patterns to impacted areas while simultaneously determining likely biological effects such as endocrine disruption. Next, we showed how PACs exhibited trophic dilution in a Boreal food chain dominated by river otters. Snails, prey and predator fish, as well as river otters were collected from four main study areas in the AOSR in northeastern Alberta, Canada. Bioaccumulation factors such as biota-sediment accumulation factors (BSAF) and trophic magnification factors (TMF) were used to evaluate the partitioning behavior of PACs in the environment and subsequent risks to biota. Our results revealed localized enrichment of certain PACs and subsequent metabolism in higher order vertebrates. Finally, we successfully combined ecotoxicological and physiological analyses paired with population genetic estimates to investigate endocrine disruption and population-level responses to exposure to PACs. River otters are known for their habitual use of latrine sites. Latrine sites represent a unique opportunity for biomonitoring programs to study river otters using indirect sampling methods. In this thesis, PACs were characterized and evaluated in sediment, lower and higher trophic biota with demonstrated impacts on endocrine processes and river otter population health. Effects-based assessments such as the ones presented in this thesis are more powerful for environmental monitoring programs than stressor-based assessment methods (such as describing presence/absence or levels of contaminants) as they provide greater biological context to monitoring data. In turn, these are helpful in selecting triggers for environmental effects monitoring or adaptive management programs.
11
Smartt, Helen Anne. "Effects of the Desorption and Dissolution of Polycyclic Aromatic Hydrocarbons on Phytoremediation at a Creosote-Contaminated Site." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/45332.
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Creosote, containing many high molecular weight hydrophobic polycyclic aromatic
hydrocarbons (PAH's), is present in the subsurface environment at the Oneida Tie-Yard
in Oneida, Tennessee. Phytoremediation using hybrid poplar trees was chosen as the
remedial technology on-site. Since monitoring began, the contaminant plume has been
shrinking consistently and evidence has shown that remediation is taking place.
However, remediation may be rate-limited by the desorption and dissolution kinetics of
the PAH's on-site.
The objectives of this research are to: (1) estimate the desorption and dissolution rates
of 10 PAH's found in the subsurface and (2) estimate the amount of each PAH and total
mass of contaminant that is irreversibly sorbed to the soil. Three laboratory desorption
and dissolution experiments were performed using contaminated soil samples from the
Oneida Tie-Yard site. The first experiment was a batch desorption equilibrium
experiment, the second was a batch desorption kinetics experiment, and the third was a
soil column dissolution kinetics experiment. The target compounds in this study were:
naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene,
fluoranthene, pyrene, chrysene, and benzo(b)fluoranthene.
The resulting data for the desorption equilibrium experiment revealed that rates of
equilibrium were truly not instantaneous in the systems studied. However, because
approximately 76% of PAH's desorbed by the first sampling event (3 days), an
equilibrium isotherm was considered appropriate. Results showed that there is a sorbed
reversible concentration that readily desorbs to the aqueous phase for each PAH.
Additionally, it was determined that the percent removal of sorbed PAH's decreases with
increasing molecular weight. Desorption curves based on experimental data were found
to exhibit linear behavior over large variations in aqueous concentration, but showed
exponential behavior as concentrations approached zero. Freundlich sorption equilibrium
isotherms for the 10 monitored PAH's on-site were generally found to have N coefficient
values over 1, especially over large variations in solution phase concentration, indicating
a non-uniform sorbent.
Dissolution of resistant PAH's under field-like conditions was determined to occur
over long periods of time. Dissolution rates calculated from experimental data were
shown to generally decrease with increasing molecular weight. Overall, desorption and
dissolution kinetics of PAH's were shown to be rate-limiting factors to remediation at the
Oneida Tie-Yard.Master of Science
12
Hashimoto, Sigma. "Syntheses of Polycyclic Aromatic Compounds with Heteroatom Junctions via Tandem Hetero-Friedel－Crafts Reactions." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174950.
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Kim, Moon Koo. "Stable carbon isotope ratio of polycyclic aromatic hydrocarbons (PAHs) in the environment: validation of isolation and stable carbon isotope analysis methods." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/1099.
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Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, toxic contaminants that are released to the environment from various petrogenic and pyrogenic sources. In an effort to more clearly identify and trace sources of PAHs in the environment, purification and compound specific isotope analysis methods were developed to accurately measure the stable carbon isotope ratio of individual PAHs. Development of the method included improving accuracy and precision of the isotopic measurement by producing highly pure extracts using various chromatographic techniques. The method was refined by improving compound separations using purification techniques and high resolution chromatographic columns. The purification method consists of alumina/silica gel column chromatography, gel permeation chromatography and thin layer chromatography. The mean recovery of PAHs after the purification procedure was approximately 80 %. Sample purities after purification were verified by GC/FID and full scan mass spectrometry. To better resolve peaks and provide more accurate stable carbon isotope measurements, various gas chromatographic conditions were evaluated. The precision of the method ranged between 0.08 and 0.43 . The analytical protocols were evaluated to confirm compositional and stable isotopic integrity during purification and stable isotopic analysis. To confirm the utility of the purification and isotope analysis methods, various environmental samples from marine, land and lacustrine environments were analyzed. The isolates were analyzed for the composition and the stable carbon isotope ratios of PAHs. The stable carbon isotope ratio was measured by GC/IRMS and the results, along with quantitative compound compositions, were used to characterize and identify the contaminant sources. The sources of the PAHs in the study areas were differentiated by PAH molecular ratios and confirmed by stable carbon isotope ratios. This study confirms that compound specific isotope analysis of pollutants by GC/IRMS can be used to identify PAH sources in environmental samples. The study also confirms that the purification and stable carbon isotope analysis methods that were developed can be used to accurately measure the stable carbon isotope ratios of PAHs in environmental samples for the purpose of source identification. GC/IRMS measurement of stable isotopic compositions can be an effective fingerprinting method when used in conjunction with traditional molecular composition methods.
14
Morimasa, Yohei. "Organocatalytic Diboration and Silaboration Based on Pyridine-Mediated Activation of Boron-Containing σ-Bond." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/265204.
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京都大学新制・課程博士
博士(工学)
甲第23432号
工博第4887号
新制||工||1764(附属図書館)
京都大学大学院工学研究科合成・生物化学専攻
(主査)教授 杉野目 道紀, 教授 村上 正浩, 教授 大江 浩一
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DFAM
15
Jiang, Mei. "Mobile Laboratory Measurement of Black Carbon, Particulate Polycyclic Aromatic Hydrocarbons and Other Exhaust Emissions in Mexico City." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/41133.
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Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are two atmospheric pollutants produced by motor vehicles using carbonaceous fuels. As a part of the Mexico City Project, measurements of BC, PPAHs and many other gas- and particle-phase emissions were measured in Mexico City using a mobile laboratory during the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003). The main goal of this research is to estimate emissions of BC and particulate PAHs (PPAHs) for Mexico Cityâ s vehicle fleet. The emissions of gas-phase pollutants such as carbon monoxide (CO), total nitrogen oxides (NOy) and volatile organic compounds (VOC) are also estimated. The mobile lab has previously been used to chase vehicles and measure their emissions, but analysis has traditionally focused on determining emission factors of individual vehicles associated with specific chasing events. The laboratory continuously samples ambient air from an inlet at the front of the van, and it is always â seeingâ exhaust plumes from the vehicles around it while driving through traffic. We have developed an algorithm that automatically identifies the exhaust plume measurement points, which are then used as the basis for calculation of emission factors. In the nearly 90 hours of on-road sampling during the field campaign, we have identified ~30,000 exhaust measurement points. The large sample size enables us to estimate fleet-average emission factors and thus the emission inventory. Motor vehicles are estimated to emit annually 1,960 tons of BC, 56.2 tons of PPAHs, 1,320,000 tons of CO, 125,000 tons of NOy and 2440 tons of VOCs. The spatial and temporal patterns of BC and PPAHs in different locations with in MCMA are also studied.Master of Science
16
Er-Rhaimini, Abderrahman. "Hétérocycles azotes N-benziles : synthèse de dérivés N-benziles de l'adénine : étude de la photoélimination de substituants benzyliques." Angers, 1986. http://www.theses.fr/1986ANGE0002.
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Synthèse des cinq N-(dimethoxy-3,5 benzyl) adénines. Photolyse de ces compose en solution aqueuse. Tentative de synthèse de l'(imidazo (1,2-a) pyridinyl-6methyl)-1 adénine. Ce travail montre que des substituants benzyliques photoéliminables peuvent être utilisés comme groupes protecteurs dans des synthèses mettant en jeu l'adénine et ses dérivés.
17
Sperfeld, Martin [Verfasser], Gabriele [Gutachter] Diekert, Erika [Gutachter] Kothe, and Matthias [Gutachter] Boll. "Microbial communities at a gasworks site : a marker gene- and cultivation-based approach to explore anaerobic aromatic compound degradation / Martin Sperfeld ; Gutachter: Gabriele Diekert, Erika Kothe, Matthias Boll." Jena : Friedrich-Schiller-Universität Jena, 2019. http://d-nb.info/1177386933/34.
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Haddad, Aziza. "Dégradation d'hydrocarbures aromatiques par une souche d'Arthrobacter sp. : régulation des voies de biodégradation." Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL072N.
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Au cours de ce travail, une bactérie gram-positif identifiée comme étant Arthrobacter sp. MI-97 a été isolée à partir d'un sol pollué par de nombreux hydrocarbures aromatiques. Nous avons étudié par la suite son potentiel dégradatif, l'effet de la nature, de la concentration en substrats et de mélanges de xénobiotiques et identifiés les voies cataboliques. La régulation de l'expression des voies ortho et méta a été abordée en présence de différents substrats et dans différentes conditions de culture (batch et continu). L’assimilation du benzoate inhibe/réprime l'acetyl-CoA synthetase. Dans certains cas, les deux voies cataboliques sont induites pour éviter l'accumulation d'un substrat suicide. L’analyse génétique montre que les gènes responsables de la dégradation de ces composés aromatiques sont tous chromosomiques. Le gène codant pour la métadioxygenase a été cloné et séquencé. Il est classé dans la famille des métadioxygenases responsables de la dégradation des composés mono-aromatiques. Une tentative de purification de cette protéine a été entreprise à partir de la souche recombinante et sauvage et une caractérisation biochimique a été réalisée.
19
Lamour, Philippe. "Synthèse de pipéridines substituées à activité biologique potentielle." Rouen, 1993. http://www.theses.fr/1993ROUES005.
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Le concept d'intermédiaires de haute énergie dans la biosynthèse de stéroïdes a conduit à l'élaboration d'analogues azotés de ces derniers. Pour étudier les relations structure-activité des molécules potentiellement inhibitrices, des pipéridines et des quinolizidines fonctionnalisées ont été synthetisées. Plusieurs stratégies ont été envisagées et la stéréochimie étudiée. Ce travail décrit également l'étude de plusieurs voies d'accès à des systèmes tricycliques de type azaphénanthrénique saturé dans le but de mimer de façon plus précise le squelette des intermédiaires à structure stéroïdique
20
Freeman, David John. "Polycyclic aromatic compounds in flames." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308234.
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Laws, Andrew Peter. "The quantitative electrophilic aromatic reactivity of some novel aromatic compounds." Thesis, University of Sussex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328304.
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Timmerman-Vaughan, David J. "Photonitration of aromatic compounds by tetranitromethane." Thesis, University of Canterbury. Chemistry, 1996. http://hdl.handle.net/10092/7833.
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This thesis describes the photochemical reactions of tetranitromethane with aromatic compounds. These reactions are known to occur by initial formation of a triad consisting of an aromatic radical cation, trinitromethanide ion and nitrogen dioxide and the subsequent reactions which occur involve the recombination of these species of the triad.
This thesis is in three major parts. In the first (Chapter 2) the photochemical reactions of tetranitromethane with 1,4,6,7-tetramethylnaphthalene (56), 2,6-dimethylnaphthalene (57) and 1,3-dimethylnaphthalene (58) are described. In all cases the initial recombination step involves the aromatic radical cation and trinitromethanide ion and the reactions of these three naphthalene derivatives further documents the importance of the energy of the delocalized carbon radical formed in the first recombination step. A number of hydroxy/trinitromethyl adducts (84), (98), (102)-(1 04), (114), (115) and nitro/trinitromethyl adducts (75), (94)-(97), (99)-(101), (110)-(113), (122) were isolated as part of this study.
In the second part of this thesis (Chapter 3) the analogous reactions of 1,2,3-trimethylbenzene (137), 1,2,4,5-tetramethylbenzene (134), pentamethylbenzene (135) and hexamethylbenzene (136) are described. In the photolysis of 1,2,3-trimethylbenzene ( 137) with tetranitromethane a variety of nitronic esters (159)-(162) are formed in addition to "double" adducts (139), (157), (158) which arise by subsequent addition of nitrogen dioxide to initially formed hydroxy/trinitromethyl adducts (176), (177) and nitro/trinitromethyl adducts (152), (175), and the more usual "single" nitro/trinitromethyl adducts (151)-(156). In the reactions of 1,2,4,5-tetramethylbenzene (134), pentamethylbenzene (135) and hexamethylbenzene (136) evidence was obtained which pointed to increasing instability of initially formed adducts. In particular for pentamethylbenzene (135), nitro/trinitromethyl adducts (244), (245) were formed at -20, -50 and -78° in dichloromethane but rearranged rapidly in solution. For hexamethylbenzene (136) direct evidence of the formation of nitro/trinitromethyl adducts could not be obtained because of the insolubility of the substrate, hexamethylbenzene (136), in the photolysis solvents. However rearrangement products (279)-(282), (287), (288), analogous to those from pentamethylbenzene (135), were obtained from the photolysis of hexamethylbenzene (136) with tetranitromethane.
The final part of this thesis (Chapter 4) describes the photolysis of 2,3-dimethylanisole (307) with tetranitromethane. The purpose of this section of the work was to explore the effect of replacing one of the flanking methyl groups in 1,2,3-trimethylbenzene (137) with a methoxy group. In the event "single" hydroxy/trinitromethyl adducts (316), (317) and nitro/trinitromethyl adducts (314), (315) were formed but nitronic esters and "double" adducts, characteristic of the reactions of 1,2,3-trimethylbenzene (137), were notably absent from among the products.
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Butts, Craig P. "Photonitration of aromatic compounds by tetranitromethane." Thesis, University of Canterbury. Chemistry, 1996. http://hdl.handle.net/10092/8550.
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This thesis describes the photochemical reactions of aromatic substrates with tetranitromethane. These reactions are known to proceed via the initial formation of a triad of species; the aromatic radical cation, trinitromethanide ion, and nitrogen dioxide. The chemistry of these systems involves the recombination of this triad.
This thesis consists of five major parts. In the first (Chapter 2), the photochemical reactions of 1,5-dimethylnaphthalene with tetranitromethane are described. The initial step in the recombination of the triad is the reaction of trinitromethanide ion with the aromatic radical cation and this work highlights the importance of the resultant carbon radical stability to the reaction pathway. The isolation of a number of nitro-trinitromethyl adducts 221-224, 228-229, and hydroxy-trinitromethyl adducts 225-227, in addition to the thermal allylic rearrangement of adduct 228 to adduct 221 is documented.
The second part (Chapter 3), discusses the photochemical reactions of 1-methoxynaphthalene with tetranitromethane. The effect of the methoxy substituent on the aromatic substrate is examined and the likely mode of formation of the trinitromethyl aromatic compound 309 and the nitro aromatic compound 306 via highly unstable intermediate adduct species is described. The identification of two labile nitro-trinitromethyl adducts 314 and 315 is also documented.
The third part of this thesis (Chapter 4) describes the photochemical reactions of 4-methylanisole with tetranitromethane. A solvent induced change in the regiochemistry of trinitromethanide ion attack on the radical cation is rationalised in terms of the stabilisation of the trinitromethanide ion by more polar solvent environments. Evidence was obtained indicating that the nitrotrinitromethyl adducts 423 and 424 are formed via an allylic rearrangement of initially formed adducts 435 in competition with the formation of the observed nitro aromatic compound 420.
The fourth part of this thesis (Chapters 5 and 6) describes the photochemical reactions of 2-methylanisole, 2,4-dimethylanisole, 4-fluoroanisole, and 4-fluoro-3-methylanisole with tetranitromethane. The effect of substitution of the aromatic substrate was explored and nitro-trinitromethyl adducts 518-519, 521-522, 617-623, and 634-636 identified.
The final section of this thesis (Chapter 7) examines the effect of ethanol in the photolysis medium. The photochemical reactions of tetranitromethane with 1,2-dimethoxybenzene, 1,4-dimethoxybenzene, and 1,2-methylenedioxybenzene are described in addition to re-examination of the photochemical reactions of tetranitromethane with 1-methoxynaphthalene and 2-methylanisole in the presence of ethanol in the photolysis solution. Ethanol solvation of the trinitromethanide ion appears to retard nucleophilic attack on the aromatic radical cation in addition to introducing a sterically mediated change in the regiochemistry of trinitromethanide ion attack on the radical cation. A final feature of interest, the identification of highly labile nitro-trinitromethyl adducts 724 and 725 in the photolysis product mixtures of 1,4-dimethoxybenzene and tetranitromethane is also documented.
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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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Close, Adam James. "Regioselective routes to tetrasubstituted aromatic compounds." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/64912/.
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Polysubstituted aromatics are highly desirable in medicinal chemistry for library generation and the tetrasubstituted aryl motif appears in many pharmaceuticals. Current methods to access 1,2,4,5- and 1,2,3,4- tetrasubstituted aromatics are problematic. Therefore new routes giving defined regiochemical outcomes with four different orthogonal functionalities were sought. This work took two directions; 1) the bromination and nitration of trisubstituted aryl MIDA boronates, and 2) the nitration of trisubstituted aryl bromides, both leading to the desired tetrasubstituted aromatics. MIDA boronates are boronic acids masked with N-methyliminodiacetic acid (MIDA). This allows for iterative palladium cross-coupling reactions. The first step in the work was developing a new rapid microwave-mediated method (5-15 min) towards MIDA boronates using ether poly-ethylene glycol 300, acetonitrile or dimethylformamide as a solvent. This methodology gave a library of over 20, mainly aryl or heteroaryl MIDAboronates.1,2 Trisubstituted aryl-MIDAboronates were then brominated or nitrated giving 6 novel tetrasubstituted aromatic compounds. The 3 new tetrasubstituted aryl-MIDAboronates bromides were then used in a selection of iterative Suzuki–Miyaura cross coupling reactions (SM) to show the potential uses of the compound in library generation. Three different bromo-fluorobenzaldehyde regioisomers were nitrated giving 3 different tetrasubstituted aromatics. These 3 compounds were then subjected to several different conditions to modify them i.e. nitro reduction, Sonogashira couplings, reductive aminations, Clauson-Kaas pyrrole synthesis. A number of tetrasubstituted anilines were reacted with 4-chloro-6,7-dimethoxyquinazoline to afford novel, potential kinase inhibitors.
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Blumire, Nigel James. "Intramolecular radical additions to aromatic compounds." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/420074/.
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This thesis is concerned with the development of cyclisation strategies that allow entry to polycyclic heterocycles and medium sized ring systems. Radical additions to pyridines are developed and methodologies explore the differences between the homolysis of C-Br and C-I bonds. Mechanisms are described for the unexpected ipso additions to the pyridines. Work towards the synthesis of the stegnans and dimethylgomisin illustrates the attempts to utilise the ipso addition to form medium sized ring systems. A new method of synthesising these medium sized ring systems is discussed. Progress towards a general methodology is described and shows the opportunities for which it could be utilised. A literature review of the synthesis of heterocycles via radical cyclisations is presented.
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Tucker, Sheryl A. (Sheryl Ann). "Spectroscopic Properties of Polycyclic Aromatic Compounds." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc278682/.
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The fluorescence spectrum of many polycyclic aromatic compounds (PACs) depends upon solvent polarity. The emission spectrum of PAC monomers consists of several major vibronic bands labeled I, II, etc., in progressive order. Emission intensity enhancement of select bands is observed in polar solvents.
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Wong, Sang K. "Pharmaceutical studies on aromatic azido compounds." Thesis, Aston University, 1986. http://publications.aston.ac.uk/12461/.
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Nicolson, Iain Sinclair. "Catalytic pyrolysis of nitro aromatic compounds." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/15526.
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The work contained in this thesis was intended to study the rearrangement of o-nitrotoluene to anthranil which has previously been shown to occur under a variety of conditions. Flash Vacuum Pyrolysis (FVP) of nitrotoluene over zeolite 13X was carried out. o-Nitrotoluene was found to give conversion to toluene in 5.5% yield with recovery of starting material (12%). FVP of m-nitrotoluene gave recovery of toluene in 8% yield and starting material (7%). FVP of p-nitrotoluene gave only a trace of toluene with mainly recovery of unreacted starting material (12%). FVP of 1-ethyl-2-nitrobenzene over zeolite 13X gave conversion to ethylbenzene in 13% yield and styrene in 4% yield along with recovery of a trace of starting material. FVP of nitrotoluene was also carried out over the zeolites A, Y, ZSM-5 and mordenite as well as alumina and silica. o-Nitrotoluene was found to give conversion to aniline by a combined reduction and dealkylation in yields from 5-41% with unreacted starting material (0-515); o-toluidine and toluene were identified as minor products in several of the pyrolyses. m-Nitrotoluene over alumina gave aniline and m-toluidine. p-Nitrotoluene over zeolite Y alumina gave conversion to aniline and p-toluidine. FVP of 1-ethyl-2-nitrobenzene over these zeolites, silica and alumina gave conversion to aniline and indole in varying amounts; minor products of styrene, 2-vinylaniline and ethylaniline were also observed. FVP of 3-methylanthranil with no catalyst at 700°C gave conversion to 1H-indol-3(2H)-one in 86% yield. FVP of 3-methylanthranil over zeolite mordenite at 500°C gave conversion to 1H-indol-2(2H)-one in 11% yield along with unreacted starting material (6%). FVP of 1H-indol-3(2H)-one over zeolite mordenite at 500°C gave rearrangement to 1H-indol-2(2H)-one in 37% yield. FVP of anthranil over zeolite Y at 500°C gave conversion to aniline in 28% yield.
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Deng, Yifan. "Flavin-dependent hydroxylation of aromatic compounds." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS601.
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Le marché mondial des enzymes industrielles, estimé à 17 milliards USD en 2025, continue à croître. La forte demande attire de plus en plus l'attention en raison des avantages de ces enzymes à efficacité élevée, faible coût et respect de l'environnement. Les biocatalyseurs sont développés en raison de la demande dans les domaines pharmaceutique, de la recherche, de la biotechnologie et du diagnostic. L'objectif de ce projet est de réaliser un système in vitro capable de catalyser une réaction d'hydroxylation aromatique. Ce projet est principalement divisé en deux parties. Après une introduction, les détails de l’établissement du système seront décrits et suivis d’une étude sur les propriétés biochimiques. Afin d’obtenir un rendement plus élevé en produits à haute valeur ajoutée, l’activité sur des substrats non naturels doit être renforcée. Une approche cristallographie-structure-mutagenèse est appliquée, basée sur la structure modèle de l'enzyme, certains résidus sont mutés en acide aminé spécifique et l'activité de ces mutants est testée sur des non-substrats. L'hydroxylation est une réaction redox, des cofacteurs sont nécessaires. Pour un système in vitro, il faut réduire les coûts de production en évitant d’utiliser des cofacteurs de forme réduite qui est à prix élevé. Un système de régénération sera introduit. Le système de régénération enzymatique actuellement utilisé dans la production industrielle reste une méthode efficace. De nouvelles méthodes telles que la régénération électrochimique, la régénération catalysée par des complexes organométalliques montrent une activité comparable au système enzymatique. Afin de faciliter le recyclage du catalyseur, un processus d’hétérogénéisation du catalyseur est appliqué. Un exemple d'immobilisation d'un complexe organométallique à base de Rh sur une Bipyridine-Périodique Mésoporeuse Organosilica (Bpy-PMO) est étudié. Ce catalyseur hétérogène montre une activité de régénération et une recyclabilité relativement intéressanteThe growing global market of industrial enzymes is estimated to attain 17 billion USD in 2025. The strong demand and many advantages such as high efficiency, low cost, environmentally friendly procedures draw more attention to its use. Besides the regular utilization, specialty enzymes including biocatalysts are quickly developing due to the demand in pharmaceutics, research & biotechnology, and diagnostics. The objective of this project is to realize an in vitro system which can catalyze an aromatic hydroxylation reaction. This project is divided into two parts. After an introduction, the details of system establishment will be described, followed by a study on biochemical properties. In order to achieve a higher yield on high added value products, activity on non-natural substrates needs to be enhanced. A crystallography-structure-mutagenesis approach is applied, based on the model structure of the enzyme, chosen residues are mutated into specific amino acids and activity of these mutants is tested on non-substrates. Considering hydroxylation is a redox reaction, cofactors are needed. For an in vitro system, in order to lower production cost by avoiding using high price reduced cofactors, a regeneration system will be introduced. The enzymatic regeneration system currently used in industrial production is still considered to be an efficient method. Nevertheless, new methods such as electrochemical regeneration, organometallic complexes catalyzed regeneration show a comparable activity to the aforementioned enzymatic regeneration system. With the goal of facilitating catalyst recycling, a catalyst heterogenization process is applied. Immobilization of a Rh based organometallic complex on Bipyridine-Periodic Mesoporous Organosilica (Bpy-PMO) is investigated as an example. This heterogeneous catalyst shows relatively interesting cofactors regeneration activity and recyclability
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Arvapally, Ravi K. "Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc28388/.
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The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter metal like potassium. Dynamic quenching as the predominant phenomenon was noticed.
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Montagu, Angélique. "Composants aromatiques nano-encapsulés : une alternative face à la résistance aux antibiotiques : Démonstration des effets biologiques seuls ou nano-encapsulés de l’in vitro à l’in vivo Prevention of Bacterial Infections Using Encapsulated Phytophenolic Actives Aromatic and terpenic compounds loaded in lipidic nanocapsules: activity against multi-drug resisant Acinobacter baumannii assessed in vitro and in a murine model of sepsis Demonstration of the interactions between aromatic compound-loaded lipid nanocapsules and Acinetobacter baumannii bacterial membrane." Thesis, Angers, 2016. http://www.theses.fr/2016ANGE0072.
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Face à la montée en puissance des bactéries multi-résistantes, la découverte de nouvelles stratégies antibactériennes s’impose. Une alternative est l’utilisation de substances actives antibactériennes issues d’huiles essentielles. Ces actifs de nature lipophile, ont été encapsulés via les nanocapsules lipidiques (NCL) pour une utilisation par voie systémique. L’efficacité de ces NCL chargées en actifs a été montrée dans un modèle de sepsis à Acinetobacter baumannii avec un taux de survie de 45% à 55%. Notre étude a montré le pouvoir d’attraction et de pénétration du carvacrol (Car) encapsulé via les fonctions hydroxyles vis-à-vis de la membrane bactérienne. Les effets biologiques de ces actifs ont été caractérisés par une dégradation de l’ARNr et une surexpression des gènes codant pour des heat shock protein. Une surexpression de la catalase due au Car est également observée, en lien avec le stress oxydatif (rôle de détoxification). Nos travaux ont montré que les bactéries pourraient utiliser dans ce processus une stratégie de défense contre le Car en utilisant les ROS endogènes lors d’une réponse au stress environnemental. Ces effets biologiques sont conservés après l’encapsulation des actifs par les NCL. Dans un modèle in vivo de pneumopathie, aucune survie animale n’a été constatée, malgré la post-insertion des NCL, qui est censée augmenter leur furtivité dans le sang. L’infection pulmonaire n’a pas favorisé d’accumulation des NCL dans les poumons. Ce phénomène pourrait s’expliquer par la métabolisation du Cin en acide cinnamique dans le sang, forme oxydée de l’actif qui réduirait drastiquement l’activité antibactérienne des NCL chargées en Car-CinFaced with the rise of multidrug-resistant bacteria, the discovery of new antibacterial strategies is imperative. An alternative is the use of antibacterial active substances from essential oils. These lipophilic compounds were encapsulated via lipidic nanocapsules(LNC) allowing a use by systemic way. The efficacy of actives loaded LNC has been showed in a murine model of sepsis against Acinetobacter baumannii with a survival rate of 45% to 55%. Our study showed the power of attraction and penetration of the encapsulated carvacrol (Car) via the hydroxyl functions. The biological effects of these compounds were characterized by a degradation of rRNA, an over expression of genes encoding heat shock proteins. A catalase overexpression was also observed which is related to an oxidative stress (role of detoxification). Our works showed that bacteria could use in this process, a defense strategy against Car using the endogenous reactive oxygen species in response to environmental stress. These biological effects are preserved after encapsulation by LNC. In an in vivo model of pneumonia, no animal survival has been observed, despite the use of pegylated LNC, which is supposed to increase their stealth in the blood. Pulmonary infection did not promote the LNC accumulation in the lungs. This phenomenon could be explained by the metabolization of Cin in cinnamic acid in the blood, the oxidized form ofthe compound which would drastically reduce the antibacterial activity of Car-Cin loaded LNC
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Yuan, Tao 1968. "Dechlorination of environmentally recalcitrant chlorinated aromatic compounds." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79208.
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Chlorinated aromatic compounds are an important group of compounds. Many of them have been produced in large quantities and they are indispensable to technological and societal benefits. But regulatory agencies have tightened regulations on the use and release of chlorinated aromatic compounds because of the scientific understanding of their toxicity, persistence, behavior in the environment and their potential to cause adverse effects on the ecosystem and human health.Pentachlorophenol (PCP), octachloronaphthalene and decachlorobiphenyl are all highly chlorinated aromatic compounds, of which, PCP has been used mainly as a biocide. Octachloronaphthalene and decachlorobiphenyl don't have practical use, but their congeners have been used widely as chemicals in industry. These compounds are toxic, recalcitrant and bio-accumulated within organisms. As the conventional treatment, incineration of these compounds can cause more serious problems, so that suitable alternatives need to be developed for their detoxification.
When compared with biodegradation or the thermal treatment of these compounds, chemical degradations have several merits. (Abstract shortened by UMI.)
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Warner, Stephanie D. "Photochemical degradation of selected polycyclic aromatic compounds." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84446.
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Polycyclic aromatic hydrocarbons and many of their derivatives are considered to be ubiquitous environmental pollutants, which often exhibit mutagenic and/or carcinogenic activity. In the atmosphere, photolysis is generally considered to be the dominant degradation pathway for these pollutants. The photochemical behaviours of benzo(a)pyrene, benzo(b)fluoranthene and benzo(k)fluoranthene have been examined in the laboratory. This study was complemented by an analysis of ambient air samples collected in the vicinity of a Horizontal Stud Soderberg aluminum smelter in Beauharnois, Quebec. Benzo(a)pyrene is much more reactive in the presence of light when compared to the fluoranthene compounds. The products were identified as the 1,6-, 3,6- and 6,12-benzo(a)pyrenediones. An analysis of the ambient air samples revealed the prevalence of benzo(b)fluoranthene in the emissions from the aluminum smelter. Its relatively high abundance and resistance to degradation indicates that it will be a suitable indicator to represent total polycyclic aromatic hydrocarbon levels at the smelter. The photochemical behaviour of a series of nitropolycyclic aromatic hydrocarbons has also been investigated. The photoreactivity of these compounds in solution and adsorbed onto a surface has previously been associated with the torsion angle of the nitro group with respect to the aromatic moiety. Initially, through a combination of spectroscopic techniques and semi-empirical calculations, the orientation of the nitro group in each compound was determined. Solution studies were inconclusive in determining the role of the torsion angle of the nitro group in influencing the photochemical degradation. However, when the compounds were adsorbed onto a surface, no relationship could be established between photoreactivity and the orientation. The stability of these compounds was also examined during the sampling process. In an effort to further examine the relationship between th
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Morris, Kenneth Robert. "Solubility of aromatic compounds in mixed solvents." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184324.
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The solubilities of benzene, naphthalene and anthracene were measured in five binary solvent systems. These systems consised of water and one of the following water miscible organic solvents: acetone, acetonitrile, methanol, ethanol, and isopropanol. The measurements were made at intervals of 0.1 volume fractions of the organic cosolvent. Solubility data were also collected for the above solutes in mixed cosolvents. solvent systems containing three In addition, the solubilities of and six five other aromatic solutes were measured in the binary solvent systems of methanol/water and acetone/water. The data was used to test the log-linear solubility model of Yalkowsky (1981). The model predicts a linear relationship between the solubility of a solute in a binary solvent system (S(m)) and the volume fraction of cosolvent present (f(c)) log S(m) = σf(c) + log S(w) Where S(w) is the solubility of the solute in water and σ is the proportionality constant and slope of the curve. The model is easily extended to multiple mixed solvents by combining the σ values from the binary solvent systems. log (S(m)/S(w)) = Σ₁ (σ₁£₁) A method was developed to estimate σ in a given binary solvent system from the octanol-water partition coefficient of the solute. Combining this method with the generalized solubility equation of Yalkowsky to estimate S(w), allows a priori estimates of solubility in mixed solvents. Maximum deviations in the binary solvent systems studied were related to maxima in excess density. In the alcoholic binary solvent systems the minima were related to minima in the heats of mixing of the two cosolvents. The herbicide atrazine deviated dramatically from the model. The system was examined for possible changes in the crystal structure of atrazine. It was found that some crystal modification occured in the presence of mixed solvents. The rate of the change appears to be dependant on the concentration of the cosolvent. A change or modification in the crystal violates one of the basic assumptions of the log-linear model. The assumption is that the crystal contributes equally to the solubility behavior irrespective of the solvent system. It was determined that atrazine undergoes a polymorphic transition in the systems studied. It is postulated that this polymorphism is responsible for the anomolous solubility behavior observed for atrazine.
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Williams, Marilyn M. "Phytodegradation of petroleum aromatic compounds in soil." Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1180784.
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Lunt, P. "Microbial communities growing on chlorinated aromatic compounds." Thesis, Cardiff University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376824.
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Jones, Kerina Helen. "The metabolism of aromatic compounds by fungi." Thesis, Aberystwyth University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309993.
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Williams, Alvin Scott. "Charge transfer induced osmylation of aromatic compounds." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309472.
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Melhuish, M. W. "Nitration and chlorination of deactivated aromatic compounds." Thesis, University of Exeter, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379462.
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Fermi, Andrea <1985>. "Polysulfurated aromatic compounds: preparation and photophysical properties." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5720/.
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The aim of this thesis was the synthesis and photophysical characterization of some new polysulfurated aromatic compounds: this class of molecules can offer intriguing properties, potentially useful for the construction of
new materials for optoelectronic devices.
Two main families of compounds have been synthesized: the first is represented by a series of small molecular asterisks, with peripheral aromatic units, showing luminescence in solid phase or in highly rigid conditions.
All compounds with peripheral substituents display an AIE behavior (Aggregation Induced Emission) with radiative deactivation of the triplet states.
Taking inspiration from these smaller asterisks, a larger molecule with the same geometry has been designed, decorated with terpyridyl moieties as the outermost units: this compound shows great affinity for the coordination
of several transition metal ions, changing luminescence properties after the interaction with zinc ions.
With the same intentions, a tetrasulfurated pyrene-core molecule with terpyridyl external units has been synthesized and isolated: this ligand exhibits good coordination capabilities towards transition metal ions, giving rise to luminescent nanoaggregates upon addition of zinc(II), characterized by DLS and AFM microscopy. In addition a NIR emission is recorded after coordination of neodymium(III), showing evidence of an intramolecular
energy transfer process.
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Fermi, Andrea. "Polysulfurated aromatic compounds : Préparation and photophysical properties." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4124.
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Durant mon Doctorat de Sciences Chimiques, effectué en cotutelle entre l'Université de Bologne et l'Université de Aix-Marseille, j'ai pris en charge la synthèse et la caractérisation d'une série de composés aromatiques soufrés qui bénéficient de propriétés photophysiques intéressantes. Ce travail de thèse a été concentré sur deux classes de composés : la première s'apparente à des astérisques moléculaires contenant un coeur benzénique persoufré, fonctionnalisé avec des unités périphériques aromatiques. Dans chaque cas, des groupes stériquement encombrants ont été greffés sur les unités aromatiques situées à la périphérie des molécules. Ces molecules offrent la capacité de fonctionner comme luminophore AIE (Emission Induite par l'Agrégation) à l'état solide ou dans des milieux à haute rigidité. La deuxième famille de molécule est basée sur la même géométrie en astérisque. Cependant, chaque ligand de cette série utilise des unités terpyridyles comme unité périphérique, capables d'interagir avec des métaux de transition comme le fer(III) et le zinc. Suite à la complexation du zinc les propriétés photophysiques peuvent être modulées en fonction de la rigidité du système. Enfin, on a synthetisé un troisième type de système qui a été obtenu par le remplacement du coeur benzénique des astérisques par une fonction pyrene polysoufrée, en conservant les mêmes unités périphériques. Ce composé a montré des propriétés photophysiques intéressantes mais aussi des capacités de coordinations vers les ions métalliques (Fe(III), Zn(II) et le Nd(III)), ce qui a permis la génération d'émission dans le domaine du proche infrarougeThe aim of this thesis was the synthesis and photophysical characterization of some new polysulfurated aromatic compounds: this class of molecules can offer intriguing properties, potentially useful for the construction of new materials for optoelectronic devices. Two main families of compounds have been synthesized: the first is represented by a series of small molecular asterisks, with peripheral aromatic units, showing luminescence in solid phase or in highly rigid conditions. All compounds with peripheral substituents display an AIE behavior (Aggregation Induced Emission) with radiative deactivation of the triplet states. Taking inspiration from these smaller asterisks, a larger molecule with the same geometry has been designed, decorated with terpyridyl moieties as the outermost units: this compound shows great affinity for the coordination of several transition metal ions, changing luminescence properties after the interaction with zinc ions. With the same intentions, a tetrasulfurated pyrene-core molecule with terpyridyl external units has been synthesized and isolated: this ligand exhibits good coordination capabilities towards transition metal ions, giving rise to luminescent nanoaggregates upon addition of zinc(II), characterized by DLS and AFM microscopy. In addition a NIR emission is recorded after coordination of neodymium(III), showing evidence of an intramolecular energy transfer process
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Seo, Sangwon. "Decarboxylative and direct functionalisations of aromatic compounds." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/decarboxylative-and-direct-functionalisations-of-aromatic-compounds(a9ddab1b-86a0-491e-a95b-d6b40c8bd7ab).html.
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Aromatic rings are privileged structures found in a diverse range of natural and synthetic compounds, thus synthetic methods for their functionalisations are important in organic synthesis. Despite significant advancements made, especially in the field of transition metal catalysis, work still continues for the development of milder, more efficient, and more atom economical reactions. We describe here our efforts towards the development of decarboxylative/direct C(aryl)–N and C(aryl)–C bond forming reactions using aromatic carboxylic acids and unfunctionalised arenes as cheap and widely available aromatic sources. The investigations into copper-catalysed and copper/palladium-catalysed intermolecular and copper/silver/palladium-catalysed intramolecular decarboxylative amination of aromatic carboxylic acids are reported. A new approach to decarboxylation of benzoic acids is also described. The reaction uses silver (I) catalyst and peroxydisulfate salt to generate aryl radicals via oxidative decarboxylation. The applications of this approach in intra- and intermolecular decarboxylative C–H arylation, and protodecarboxylation are described. Also described is the development of silver-catalysed trifluoromethylation of simple arenes and heteroarenes. The reaction proceeds via radical trifluoromethylation using trimethyl(trifluoromethyl)silane as the trifluoromethyl radical source. This method has been applied to the trifluoromethylation of complex agrochemical molecules, proving its synthetic utility in late-stage functionalisation. Furthermore, we describe the exploitation of trifluoroacetate derivatives as cheap trifluoromethylating reagents in copper-mediated decarboxylative C–H trifluoromethylation of 2-phenylpyridine.
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Landera, Alexander. "Formation of Polycyclic Aromatic Hydrocarbons and Nitrogen Containing Polcyclic Aromatic Compounds in Titan's Atmosphere, the Interstellar Medium and Combustion." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/991.
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Several different mechanisms leading to the formation of (substituted) naphthalene and azanaphthalenes were examined using theoretical quantum chemical calculations. As a result, a series of novel synthetic routes to Polycyclic Aromatic Hydrocarbons (PAHs) and Nitrogen Containing Polycyclic Aromatic Compounds (N-PACs) have been proposed. On Earth, these aromatic compounds originate from incomplete combustion and are released into our environment, where they are known to be major pollutants, often with carcinogenic properties. In the atmosphere of a Saturn’s moon Titan, these PAH and N-PACs are believed to play a critical role in organic haze formation, as well as acting as chemical precursors to biologically relevant molecules. The theoretical calculations were performed by employing the ab initio G3(MP2,CC)/B3LYP/6-311G** method to effectively probe the Potential Energy Surfaces (PES) relevant to the PAH and N-PAC formation. Following the construction of the PES, Rice-Ramsperger-Kassel-Markus (RRKM) theory was used to evaluate all unimolecular rate constants as a function of collision energy under single-collision conditions. Branching ratios were then evaluated by solving phenomenological rate expressions for the various product concentrations. The most viable pathways to PAH and N-PAC formation were found to be those where the initial attack by the ethynyl (C2H) or cyano (CN) radical toward a unsaturated hydrocarbon molecule led to the formation of an intermediate which could not effectively lose a hydrogen atom. It is not until ring cyclization has occurred, that hydrogen elimination leads to a closed shell product. By quenching the possibility of the initial hydrogen atom elimination, one of the most competitive processes preventing the PAH or N-PAC formation was avoided, and the PAH or N-PAC formation was allowed to proceed. It is concluded that these considerations should be taken into account when attempting to explore any other potential routes towards aromatic compounds in cold environments, such as on Titan or in the interstellar medium.
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Reginato, Nada McGlinchey Michael J. "Polycyclic compounds of manganese /." *McMaster only, 2003.
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Berryman, Orion Boyd. "Anions and electron-deficient aromatic rings /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2008. http://hdl.handle.net/1794/8159.
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Thesis (Ph. D.)--University of Oregon, 2008.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 265-281). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
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Rautenbach, Daniel. "The electrochemical hydroxylation of aromatic substrates." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/94.
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The electrochemical hydroxylation of aromatic substrates was investigated in some detail, with the view to develop a method, which could produce dihydroxybenzenes in acceptable yields. Of particular interest was the selectivity and yield of the 1,4-dihydroxybenzenes. Two distinctly different methods were investigated in order to achieve this goal, acyloxylation and direct electrochemical hydroxylation. Acyloxylation is the process where radical cations generated at the anode undergoes nucleophilic attack by acetate anions. The resulting aromatic acetates so produced can then be hydrolysed to the phenolic compounds. Two nucleophile systems were considered in the investigation, acetates (acetoxylation) and trifluoro-acetates (trifluoro-acetoxylation). These investigations were conducted under a variety of conditions using phenol and phenyl acetate as starting materials. From the results it was, however, concluded that the acetoxylation of these aromatic compounds occurs in unacceptable product and current yields. Trifluoro-acetoxylation on the other hand showed promise, but due to the nature and cost of the reagents it was deemed to be an impractical process. Direct electrochemical hydroxylation: in which the radical cations produced at the anode undergoes nucleophilic attack by water producing the corresponding dihydroxybenzenes. These dihydroxybenzenes are then further oxidised to the benzoquinones, which then undergo reduction at the cathode in order to produce the corresponding dihydroxybenzene. In this process phenol, 2-tert-butylphenol and 2,6-di-tert-butylphenol were investigated as substrates. The results indicated that the yield towards the 1,4-dihdroxybenzenes increased as the degree of substitution on the ring increased.
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Navarro, Brigitte. "Application de la réaction de cycloaddition [2+2] du dichlorocétène sur les oléfines en synthèse." Grenoble 1, 1990. http://www.theses.fr/1990GRE10114.
Full textAbstract:
Des ,-dichlorocyclobutanones (produit de cycloaddition (2+2) entre le dichlorocetene et des olefines) ont ete dans un premier temps converties efficacement et rapidement en -chloroenones. Une nouvelle methode rapide et flexible a ete ainsi realisee donnant des intermediaires tres interessants en synthese. Comme application directe de cette homologation de 2 carbones a partir d'olefines, la synthese courte en 6 etapes de la muscone racemique a ete realisee a partir de la cyclotridecanone avec un rendement global de 50%. Enfin l'utilisation des dienes, derivants de l'ouverture des cyclobutenes fonctionnalises (obtenus de facon rapide et quantitative a partir des ,-dichlorocyclobutanones) dans des reactions de diels-alder, donnent des cycloadduits permettant ensuite d'acceder directement a des composes aromatiques polyfonctionnalises, voire des paracyclophanes
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Belson, D. J. "Aromatic nitration using aqueous nitric acid." Thesis, Loughborough University, 1989. https://dspace.lboro.ac.uk/2134/11976.
Full textAbstract:
The rates of nitration of benzene, toluene, anisole, p-xylene and mesitylene in aqueous nitric acid have been determined for concentratians in the range 24-41 mol % HNO3 and at temperatures between 293 and 333K. Correlation of rate constants with values of acidity function confirms that the mechanism of nitration in aqueous nitric acid is similar to that in aqueous Sulphuric acid.
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Martin, Peter Arnold. "Nucleophilic substitution reactions of some polyhalogenated compounds." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6876/.
Full textAbstract:
Rate measurements for the reactions of a series of polyfluoro - and polychloro - pyridines with aniline and ammonia in 60/40 dioxan/water at 25ºC has shown that chlorine, when ortho and para to the position of attack, is activating with respect to fluorine, but at the position meta to the point of attack, chlorine and fluorine are virtually equivalent in their effect on reaction rate. The trifluoromethyl and nitrile groups were found to be activating relative to fluorine when ortho and para to the position of substitution and the nitrile group was thus found to be ortho/para directing. The ortho/para orienting effect of ring nitrogen was shown to be dominant in heterocyclic systems. It has been demonstrated for several different nucleophiles that nucleophilic attack in polyfluorinated heterocycles occurs so as to maximise the number of ortho and meta fluorines with fluorine being of little significance. Of the nucleophiles examined aniline and ammonia were found to be similar in their behaviour. Benzylamine however showed some propensity for substitution at positions ortho to ring nitrogen whilst N-methylaniline showed strong steric effects due to the N-methyl group, most notably when the heterocylic ring substituents were chlorine, trifluoromethyl and nitrile. Sodium was shown to have a 'salt effect' in the reactions of methoxide and phenoxide, and, a catalytic effect on the reactions of aniline affecting both the rate and position of substitution. The use of transition state, and molecular orbitals to explain the patterns of substitution is discussed. The trifluoromethylsilyl group was found to undergo nucleophilic attack at silicon and the series of mono, di and tri-fluoromethyl-pentafluorobenzenes were used to examine the concept of negative ion hyperconjugation.