Dissertations / Theses on the topic 'Organic compounds'
To see the other types of publications on this topic, follow the link: Organic compounds.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Organic compounds.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
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.
Full textAbstract:
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.
2
Taylor, Paul. "Organic thionitroso compounds." Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6482/.
Full textAbstract:
A series of novel N-substituted phthalimide-2-sulplienamides was prepared. The N-aryl analogues were shown to be efficient precursors to thionitrosoarenes. Extension of the methodology to heteroaroraatic and acyl derivatives was unsuccessful, with the exception of 3-thionitroso- pyridine, the first known thionitrosoheteroarene. Thionitrosoarenes are shown to be versatile dienophiles and enophiles. Reactions with various substituted dienes proceeded with high stereoselectivity and some regioselectivity to afford 3,6-dihydro- 1,2-thiazines. Cycloadditions of thionitrosoarenes generated independently from imidosulphurous chloride precursors showed similar selectivities. The mechanism of cycloaddition is discussed in the light of molecular orbital calculations.
3
Hunter, James Freeman. "Oxidation of atmospheric organic carbon : interconnecting volatile organic compounds, intermediate-volatility organic compounds, and organic aerosol." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97794.
Full textAbstract:
Thesis: Ph. D. in Environmental Chemistry, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-110).
.Organic molecules have many important roles in the atmosphere, acting as climate and biogeochemical forcers, and in some cases as toxic pollutants. The lifecycle of atmospheric organic carbon is extremely complex, with reaction in multiple phases (gas, particle, aqueous) and at multiple timescales. The details of the lifecycle chemistry (especially the amount and properties of particles) have important implications for air quality, climate, and human and ecosystem health, and need to be understood better. Much of the chemical complexity and uncertainty lies in the reactions and properties of low-volatility oxidized intermediates that result from the oxidation of volatile organic precursors, and which have received comparatively little study thus far. This thesis describes three projects that link together the entire chain of oxidation (volatile to intermediate to condensed) in an effort to improve our understanding of carbon lifecycle and aerosol production. Laboratory studies of atmospherically relevant aerosol precursors show that the slow oxidation of intermediates is critical to explaining the yield and properties of aerosol under highly oxidized ("aged") conditions, and that the production of organic particles is significantly increased when intermediates are fully oxidized. This aging process is a strong function of molecular structure, and depends on aerosol concentration through the phenomenon of condensational trapping. Further laboratory studies of a series of (poly)cyclic 10 carbon alkanes show that structural effects are largely explained through fragmentation reactions, and that more generally, carbon-carbon bond scission is a ubiquitous and important reaction channel for oxidized intermediates. Finally, direct measurement of oxidized intermediate compounds in field studies shows that these compounds are abundant and important in the ambient atmosphere, with concentrations and properties in between those of volatile and particulate organic compounds. Together with other co-located measurements and complementary techniques, this enables estimates of emission, oxidation, and deposition to be constructed. The results from this thesis can be used to inform more sophisticated models of atmospheric organic carbon cycling, and to improve prediction of organic particulate matter concentrations.
by James Freeman Hunter.
Ph. D. in Environmental Chemistry
4
Szecsödy, James Edward. "Sorption Kinetics of Hydrophobic Organic Compounds onto Organic Modified Surfaces." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/219433.
Full textAbstract:
The sorption of five chlorinated benzenes and sixteen other organic solutes was investigated by determining the extent of sorption and the sorption rates in a series of 40 batch and 139 column experiments using surface-modified silica of known chemical composition. These surfaces were used to represent important functional groups in soil, and consisted of porous silica with patchy surface coatings of aliphatic chains (C₁, C₈, and C₁₈), and other substituent groups (phenyl, amine, alcoholic, and carboxylic). Three possible rate-limiting steps were examined: diffusion through immobile pore fluid, diffusion through bound organic matter, and the chemical binding and release rate. First-order desorption rate coefficients were observed to be 10⁻¹ to 10⁻² s⁻¹ on unbonded, and C₈, C₁₈, amine, and alcoholic modified surfaces, and 10⁻³ to 10⁻⁵ s⁻¹ on C₁ and phenyl-polymer modified surfaces. Diffusion through immobile pore fluid had only a minor effect on the sorption rate, as evidenced by similar rates on organic-bound porous and solid particles. The diffusion rate through the bound organic layer is not rate limiting due to the small organic layer thickness. The observed slow desorption on the phenyl-polymer surface is consistent with the rate limiting step being the chemical binding and release rate. The changes in the rate with temperature and within a series of chlorinated benzenes support this conclusion. The free energies for sorption onto the phenyl-polymer surface ranged from -4.0 kcal mol⁻¹ for chlorobenzene to -6.9 kcal mol⁻¹ for pentachlorobenzene, which are within the range expected for van der Waals interactions. The observed sorption energies are slightly stronger than predicted for hydrophobic surfaces, possibly reflecting strong binding due to multiple pi-pi electron interactions on the phenyl-polymer surface. Hydrophobic solute partitioning onto natural soils, as observed by others, is less than that observed on aliphatic and phenyl hydrophobic surfaces in this study, but greater than on amine or alcoholic modified surfaces. The sorption of di-, tri-, and tetra-chlorobenzenes onto the phenyl-polymer surface is apparently driven by the overall sorption enthalpy (ΔH° = -3.9 to -4.9 kcal mo1⁻¹) and to a lesser extent by the entropy (TΔS° = 0.5 to 1.5 kcal mol⁻¹). As equilibrium of the reactions observed in this study are reached within hours, these reactions are important at small field scales where residence times are hundreds of hours or less.
5
Sephton, Mark A. "Organic compounds in meteorites." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339860.
Full text
6
Oey, Ching-ching. "Organic-inorganic nanocomposites for organic optoelectronic devices." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35321222.
Full text
7
Oey, Ching-ching, and 黃晶晶. "Organic-inorganic nanocomposites for organic optoelectronic devices." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B35321222.
Full text
8
Sanders, Giles. "The dissolution of organic compounds." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362083.
Full text
9
Budd, Laura Elizabeth. "Polymorphism in small organic compounds." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/3967.
Full textAbstract:
The effect of temperature on the crystal structure of deuterated piperidine has been studied using neutron powder diffraction. Differential scanning calorimetry indicates that there are multiple phases accessible via changes in temperature however there is no evidence of this in the neutron powder diffraction study with only one phase observed in the range 2 – 250 K and under various crystallisation conditions. The effect of pressure up to 2.79 GPa has also been determined. The compression of the structure is facilitated through the closing up of voids in the structure and no phase transition is observed. Differential scanning calorimetry has shown N-methyl and N,N-dimethylformamide both exhibit a thermal event prior to melting. Low temperature neutron powder diffraction has shown these transitions are associated with the onset of methyl group rotation. Neutron powder diffraction studies show formamide exhibits remarkable polymorphism at ambient temperature and pressures between 0.1 GPa and 3.6 GPa, forming four new polymorphs. All the structures consist of N-H…O hydrogen bonded chains. The formation of the various polymorphs can be rationalised in terms of the orientation of the molecules within the hydrogen bonded chains and the resultant structures formed by further hydrogen bonds between the chains. This is in stark contrast to the effect of varying conditions of temperature where only one structure exists from 2 K right up to the melting point. The effect of temperature on the crystal structure of pyrazine in the range 8 – 315 K is described. At temperatures below 90 K the structure undergoes a phase transition to a previously uncharacterised phase, designated phase IV, which is closely related to the previously known phase I. The crystal structure of phase III has been determined at 315 K. The crystal structure of pyrazine has been determined at room temperature at pressures between 0.11 GPa and 9.36 GPa. At 0.94 GPa a transition from phase I to phase IV is observed. This is the same phase as observed at low temperatures. Crystal growth at 215 K results in the formation of two different phases of mesitylene; phase II and a new previously unknown phase designated phase IV. The structure of phase IV has been determined and found to be stable in the range 90 – 221 K. On cooling a crystal of deuterated mesitylene in phase II to 90 K a transition to phase III was observed and the resultant crystal structure is closely related to that of phase II.
10
Matqi, Khalil Yacoub. "Biodesulphurisation of organic sulphur compounds." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251215.
Full text
11
Compagnone, D. "Amperometric sensors using organic compounds." Thesis, Cranfield University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386197.
Full text
12
Ocampo, Ana Maria. "Persulfate activation by organic compounds." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Summer2009/A_Ocampo_083109.pdf.
Full textAbstract:
Thesis (Ph. D.)--Washington State University, August 2009.Title from PDF title page (viewed on Sept. 9, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references.
13
Shek, Lai Yung. "Hydrothermal crystallization of organic compounds /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202004%20SHEK.
Full text
14
Esfandiarfard, Keyhan. "Novel Organophosphorus Compounds for Materials and Organic Synthesis." Doctoral thesis, Uppsala universitet, Molekylär biomimetik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-328295.
Full textAbstract:
This thesis is devoted to the development of new organophosphorus compounds for potential uses in material science and as reagents in Organic Chemistry. Organophosphorus compounds in a single molecule or organic electronics context are appealing as the phosphorous centers perturb the electronic properties of the π-conjugated systems while at the same time provide synthetic handles for subsequent synthetic modifications. As such, new synthetic methodology to such compounds and the exploration of new building blocks is of considerable interest. In a different study, novel organophosphorus compounds are synthesized and shown to promote a reaction in Organic Chemistry that has previously not been possible, i.e. the stereoselective reductive coupling of aldehydes to alkenes. Such developments enlarge the toolkit of reactions that are available to Organic Chemists, and may impact the synthetic routes to pharmaceuticals and other important commodity chemicals. A general introduction of the key structural unit of this thesis, phosphaalkenes, is given in the first chapter. The synthesis, reactivity, properties and applications of these P=C double bond containing compounds are highlighted. The Wittig reaction and its variations as well as the phosphorus analogues that produce phosphaalkenes are outlined in detail. The second chapter is dedicated to the synthesis of a precursor that is used for the preparation of novel π-conjugated, organophosphorus compounds. C,C-Dibromophosphaalkenes are prepared and the halide substituents are used for the selective introduction of acetylene units. Besides the phosphaalkenes, the successful syntheses of two new diphosphenes is presented, indicating a broad applicability of the precursors. The third chapter is dedicated to the isolation of a metal-free phosphanylphosphonate that transforms aldehydes quantitatively to their corresponding E-phosphaalkenes in a transition metal-free phospha-HWE (Horner-Wadsworth-Emmons) reaction. The reaction benefits from mild conditions, high E-stereoselectivity, and a broad substrate scope. In the last chapter, a novel method for the reductive coupling of aldehydes to olefins is introduced. The reaction, which is a vast improvement over the McMurry coupling, allows for the selective synthesis of symmetrical and most importantly unsymmetrical E-alkenes. The phosphanylphosphonate mentioned above is the reagent that facilitates the coupling of the aldehydes via a phosphaalkene intermediate. This one-pot reaction benefits from mild conditions, good conversions, and high E-stereoselectivity. In summary, the thesis presents novel aspects of organophosphorus chemistry. These include the preparations and exploration of interesting precursors for the construction of π-conjugated organophosphorus compounds, and the use of organophosphorus reagents for unprecedented transformations in Organic Chemistry.
15
Amin, Hardik Surendra. "SPECIATION STUDIES FOR BIOGENIC VOLATILE ORGANIC COMPOUNDS AND SECONDARY ORGANIC AEROSOL GENERATED BY OZONOLYSIS OF VOLATILE ORGANIC COMPOUND MIXTURES." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/dissertations/528.
Full textAbstract:
Aerosols are either emitted directly into the atmosphere or are generated in the atmosphere; the latter process forms secondary organic aerosol (SOA). One of the important sources for SOA is the oxidation of volatile organic compounds (VOCs) by OH radicals, NOx, and O3. Aerosol can be visualized as suspended solid or liquid particle which is in equilibrium with surrounding gases. The products of SOA formation is a mixture of semi volatile organic compounds and a fraction of the products are condensable under atmospheric conditions. The condensable portion of aerosol is called particulate matter (PM) and these suspended particles can range in diameter from a few nanometers to microns. PM can impact climate through direct and indirect radiative forcing and can degrade air quality by reducing visibility and causing detrimental health effects. SOA can also form indoors, which also contributes to the health risk of PM. The severe impact of PM on human health and climate drives the scientific community to investigate the volatile organic compounds (VOCs) and their potential to form SOA, as well as the factors that alter the efficiency of SOA generation and the type of products. In a similar pursuit, the focus of this dissertation is the investigation of the SOA precursors that are emitted from trees and how they vary as a function of insect infestation. Also, the role of mixtures of VOCs as SOA precursors are investigated; commercial and lab made VOC mixtures are studied for SOA generation, product analysis, and absorption characteristics of aged SOA. Chapter 1 introduces PM, VOCs present in atmosphere, SOA generation, and speciation of products generated from the ozonolysis of VOCs. The impact of PM on human health and climate are summarized. A literature survey on the VOCs that are precursors to SOA and present in the outdoor and indoor environment is presented along with factors that may lead to variability in amount of VOCs. SOA generation from direct plant emissions and consumer products is surveyed. These studies show that VOC oxidation generate SOA which is important in the atmosphere due to climate and health effects and indoors due to health effects. A summary of SOA phase partitioning theories, the reaction mechanism for the formation of products from ozonolysis of the dominant biogenic SOA precursors (monoterpenes), and the factors that affect SOA generation is presented. Chapter 2 summarizes the results obtained from a field study assessing the impact of bark beetle infestation on SOA precursor emissions from forests in the Western United States. Samples of VOCs were collected by our collaborators from healthy and bark beetle infested trees using scent traps. We solvent extracted and analyzed by gas chromatography/mass spectrometry (GC/MS) nearly four hundred scent traps. An increase in the total and the individual VOCs emitted by infested trees was measured. A statistical analysis shows significant differences between the emissions from infested and healthy trees. A perspective is provided on potential impact of bark beetle infestation on regional SOA. The majority of the laboratory experiments for SOA generation have focused on individual VOCs as the single SOA precursor. However, as demonstrated in Chapter 2 for example, in a real environment multiple VOCs co-exist. Multiple SOA precursors undergo concurrent oxidation reactions, and it is not known if the products from concurrent oxidation of multiple precursors are the same as the sum of the products from individual SOA precursors. Mass closure analysis of field samples show that a significant fraction of the chemical identity of organic PM is unknown, but the chemistry impacts the toxicity of PM. Hence, it is important to understand SOA formation from realistic SOA mixtures. Chapter 3 describes the results of the SOA generation by ozonolysis of limonene and VOC mixtures containing limonene. We use an additive approach for building a surrogate VOC mixture close in composition to a commercially-available mixture. The yield of PM as a function of VOC precursor mixture was measured with respect to VOC composition using smog chamber SOA generation and scanning mobility particle sizing. PM in the chamber was collected onto filters and extracted, and the individual products of SOA were identified and quantified by GC/MS. The condensed-phase SOA products generated during these experiments for different VOC mixtures are compared. In Chapter 4, condensed-phase products sampled from SOA generated by the ozonolysis of α pinene and VOC mixtures containing α pinene, including two fir needle essential oils, are studied by extracting filter samples and analyzing the extracts by GC/MS. The products generated from VOC mixtures are characteristic of the most dominant VOC present in the mixture i.e. either limonene or α pinene. Some mixtures show the generation of new products which are not observed for corresponding individual VOC ozonolysis and hence can be used as marker for the corresponding VOC mixture. The distribution of α-pinene SOA products changes as the composition of the SOA precursor mixture changes. In Chapter 5, the UV visible absorption characteristics of ammonium ion aged SOA are discussed. Ammonium ion aging of aerosol leads impacts the radiative properties of aerosol and has the potential to impact aerosol's role in climate change. Filter samples containing SOA generated from two mixtures with different dominant monoterpenes (α-pinene-based Siberian fir needle oil and a limonene-based air freshener) were extracted. The absorption coefficients of the extracts were measured as a function of ammonium ion aging time using UV-visible absorption spectrometry. The conclusions from all above chapters are summarized in Chapter 6.
16
Carr, Gillian E. "Perfluoroalkylaromatic compounds." Thesis, Durham University, 1986. http://etheses.dur.ac.uk/7072/.
Full textAbstract:
Trifluoromethyl-substituted compounds find applications as both pharmaceutical and plant protection products. As these compounds have to undergo rigorous tests before being placed on the market, improved methods are required for the introduction of the trifluoromethyl group which could be applied to the production of ¹⁴C-labelled molecules for use in metabolic studies. Two sources of the trifluoromethyl group mentioned only briefly in the literature, bis(trifluoromethyl)mercury and sodium trifluoroacetate, were both developed as reagents for the synthesis of substituted trifluoromethylbenzenes. Trifluoromethylation with sodium trifluoroacetate was extended to the preparation of alkyl, alkenyl, and heterocyclic trifluoromethyl compounds, and up to three groups were introduced into an aromatic nucleus. The mechanism of this interesting copper-promoted reaction was investigated and an intermediate of the form [CF₃CuI]⁻ is proposed. Introduction of higher perfluoroalkyl groups from their respective sodium perfluoroalkanecarboxylic acids was attempted and the mechanistic features compared with those of the trifluoromethylation reaction. A poly-substituted trifluoromethyl aromatic compound, 1,3,5-tris(trifluoromethyl)benzene, was produced by fluorination of trimesic acid with sulphur tetrafluoride and its chemistry investigated. It is fairly unreactive but readily forms a sterically hindered lithium derivative which undergoes many reactions typical of an organolithlum compound. Mercury and copper derivatives were also prepared and used in coupling reactions with iodobenzene.
17
Schubert, Jeffrey W. "The structure of bromonium, chloronium, and oxonium ions." Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1537007641&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.
Full text
18
Öman, Cecilia. "Emissions of organic compounds from landfills /." Stockholm : Tekniska högsk, 1998. http://www.lib.kth.se/abs98/oman0604.pdf.
Full text
19
Greenacre, Caroline M. "Tropospheric chemistry of halogenated organic compounds." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404120.
Full text
20
Kinnison, David J. A. "Tropospheric chemistry of halogenated organic compounds." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240663.
Full text
21
Ntainjua, Ndifor Edwin. "Catalytic oxidation of volatile organic compounds." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54585/.
Full textAbstract:
Polycyclic aromatic hydrocarbons (PAHs) are an important class of volatile organic compounds (VOCs) which pose enormous health and environmental threats. This thesis investigates different catalyst formulations for the complete oxidation of naphthalene (Np). a model PAH. Low loadings of vanadium added during the impregnation step of catalyst preparation were found to enhance the naphthalene oxidation activity of Pd-alumina and Pt- alumina catalysts while higher loadings were detrimental to the catalysts' performance. The promotional effect has been attributed to the presence of a low concentration of a particular type of vanadium species which fosters the redox behaviour of the binary system (Pd/V or Pt/V) coupled with the change in the active metal (Pd or Pt) particle size (Pd or Pt dispersion). The presence of high concentrations of crystalline V2O5 species has been suggested to account for the lower activity observed for Pd/V and Pt/V catalysts with vanadium loadings in the range of 6 - 12% and 1 - 12 % respectively. It is postulated that the mechanism of naphthalene oxidation over Pd/V differs from the mechanism of oxidation over Pt/V catalysts. The nature of support material was established to be crucial for the activity of Pt- supported catalysts for naphthalene oxidation. The Pt dispersion, metal-support interaction (MSI) and oxidation state of Pt varied as a function of the nature of support and hence resulted in differences in the Np oxidation efficiency of five Pt- supported catalysts with equal Pt loading but different supports. Low Pt dispersion (high Pt particle size), weak MSI and metallic state of Pt favoured Np oxidation. Si02 proved to be the best amongst five Pt supports investigated for Np oxidation. A variation in the preparation method and preparation conditions of ceria affected the surface area, crystallite size, oxygen defect concentration, morphology and surface reducibility of the ceria catalyst and hence the Np oxidation activity. High surface area, small crystallite size, and high oxygen defect concentration of Ce02 favoured the activity of the catalyst for Np oxidation. The best preparation methods in this study were found to be homogeneous precipitation with urea (UR) and precipitation with the carbonate (CR). Optimum preparation conditions for ceria (UR) were established and a highly active nano-crystalline ceria catalyst for Np oxidation was derived. The addition of low and high loadings of Pt during the precipitation of this ceria (UR) catalyst resulted in less active naphthalene oxidation catalysts. The drop in activity of ceria with Pt doping has been attributed to a strong metal support interaction between Pt and ceria which limits the ease at which lattice oxygen is consumed in the Mars-Van krevelen redox cycle.
22
Reynolds, Stephen J. "Carbamoylcobalt (III) compounds in organic synthesis." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280294.
Full textAbstract:
This thesis describes the development and use of organocobalt (III) compounds in the formation of carbon-carbon and carbon-heteroatom bonds and, in particular, details the application of this chemistry for the synthesis of functionalised amides and ~, 1" and 8-lactams. Organocobalt chemistry was born from the isolation and characterisation of the vitamin B12 coenzyme (2) in the 1950s and early 1960s. The introduction to this thesis covers the search for vitamin B12 and briefly describes its biological role. Next, the considerable development of the simple vitamin B12 analogues, i.e. organocobalt (II) salophens (10), is outlined. Finally, the exploitation of organocobalt (III) complexes in synthetic organic chemistry is detailed. The preparation of nitrogen heterocycles is initially addressed, with a study of the viability of carbamoylcobalt (III) salophen compounds, i.e. (68), as sources of carbamoyl radicals, i.e. (73), in Chapter 1 of the thesis. Thus, radical quenching, employing several heteroatom trapping agents, successfully afforded the amide derivatives (74) and (75). In addition, carbamoyl radicals were induced to undergo intermolecular oxidative additions to deactivated alkenes, under both thermal and photolytic conditions, to secure the cinnamamides (77) and (78). A unique approach to /3-, y- and o-lactams using cobalt-mediated radical chemistry is described in Chapter 2. Thus, the carbamoylcobalt (m) salophen (111) underwent sequential homolysis, 4-exo-trigonal radical cyclisation, and radical-cobalt (II) recombination, to create the unusual azetidin-2-one (114), which was subsequently transformed into the alcohol (125). Computer generated molecular modelling calculations supporting the novel radical cyclisation are presented. Next, analogous cyclisations are described with the homologous carbamoylcobalt (III) salophens (138) and (150). Subsequent in situ dehydrocobaltation secured the y-lactams (140) and (141), and the 8-lactams (151) and (152). Results concerning the introduction of oxygenation in tandem with cyclisation are also presented in Chapter 2. Chapter 3 of the thesis describes a novel synthetic approach to the broad-spectrum antibiotic (+)-thienamycin (56), harnessing a cobaltmediated 4-exo radical cyclisation as the key step. Model studies showed that the cyclisation would tolerate a range of substitution around the precursor, i.e. (165) and (179), and that the stereochemical outcome delivers the required 3,4-trans geometry for thienamycin, i.e. (187)~(182). Our initial synthetic target towards (56) was the acid (196), but the route was abandoned when the carbamoyl chloride (193) failed to yield the organocobalt (III) compound (194) on treatment with sodium cobalt (I) salophen (12). However, our second approach was successful and culminated in the preparation of the /J-lactam (200), which constituted a fonnal synthesis of (+)-thienamycin. Our synthetic route to (200) involved: (i) the preparation of the amine (197) via Wittig methodology, i.e. (203)~(205); (ii) conversion of (197) to the radical precursor (198); (iii) a 4-exo radical cyclisation to afford the 3,4-transazetidin- 2-one (199) and finally, (iv) a two step sequence to yield the /3- lactam (200).
23
Allpress, James David. "Microbial transformation of halogenated organic compounds." Thesis, Manchester Metropolitan University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309883.
Full text
24
Kim, Byeongmoon 1957. "Asymmetric organic synthesis using organoboron compounds." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14679.
Full text
25
Phenix, Brian D. (Brian Dean) 1965. "Hydrothermal oxidation of simple organic compounds." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/38186.
Full text
26
Greyling, Guillaume Hermanus. "Negative thermal expansion of organic compounds." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/6896.
Full textAbstract:
Thesis (MSc)--Stellenbosch University, 2011.ENGLISH ABSTRACT: The primary objective of the work was to investigate the negative thermal expansion of organic materials and to determine the mechanisms governing this phenomenon by using the principles of crystal engineering. To this end, the following three compounds were studied in detail: • 4,4'-Diiodobiphenyl • 4-Iodobenzoic acid • Methyl Paraben The rationale behind this work was to determine the mechanisms responsible for the observed negative thermal expansion and to uncover the structural factors that induce negative thermal expansion. Single-crystal X-ray diffraction was employed as the primary analytical tool, owing to the unique information it can provide regarding intermolecular interactions in the solid state. A total of twenty organic compounds were analysed, of which three exhibited negative thermal expansion. Each compound employs a specific mechanism for negative thermal expansion, two of which are closely related and the third distinct.
AFRIKAANSE OPSOMMING: Die hoof doel van hierdie studie was om ondersoek in te stel in die verskynsel van ‘negative thermal expansion’ in organiese materiale en gevolglik die meganisme vas te stel deur die beginsels van kristalmanipulsie (‘crystal engineering’) te gebruik. Gevolglik was drie organise stowwe ondersoek: • 4,4'-Diiodobiphenyl /4,4'-Diiodobifeniel • 4-Iodobenzoic acid /4-Iodobensoësuur • Methyl Paraben Die redenasie hieragter is om die meganisme verantwoordelik vir die ‘negative thermal expansion’ vas te stel en die verskillende faktore wat bydra tot dit te bevestig. Enkel-kristal diffraksie word benut as die primêre analitiese tegniek as gevolg van die unieke inligting wat verkry kan word met betrekking tot die intermolekulêre interaksies. 'n Totaal van twintig stowwe is geanaliseer waarvan drie die spesifieke termisie eienskap besit. Elk van die drie stowwe het ‘n ander meganisme te vore laat kom waarvan twee baie ooreenstem en die derde verskil.
27
Haire, Geoffrey Robert. "Ruthenium catalysed oxidation of organic compounds." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272775.
Full text
28
Padden, Amena Nicole. "Microbial degradation of organic sulfur compounds." Thesis, King's College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264989.
Full text
29
Matsuda, Takanori. "Catalytic Silaboration of Unsaturated Organic Compounds." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149790.
Full text
30
Yang, Gang. "Aqueous solubility prediction of organic compounds." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/298795.
Full textAbstract:
Aqueous solubility is one of the most important physical properties to consider in drug discovery and development. Drug candidates with poor solubility often have poor bioavailability, which leads to increased developmental cost and efforts. Therefore, there is a strong trend to perform solubility screening of drug candidates as early as possible in the drug discovery and development process. While experimental methods are being developed to increase the throughput of solubility measurement, the development of aqueous solubility prediction methods can be a powerful complementary tool. This dissertation starts by compiling a large collection of aqueous solubility data for organic compounds covering diverse classes of structures. The data set is first used to critically evaluate the General Solubility Equation (Yalkowsky et al., 1980, 1999), one of the most widely used methods for aqueous solubility prediction. The General Solubility Equation performs very well overall as measured by the average absolute error (AAE) of 0.56 log unit. Detailed analyses indicate that it gives better predictions for non-electrolytes than some classes of weak electrolytes. This method is then compared with a method based on an amended solvation energy relationship, which considers the hydrogen bonding potentials of functional groups. It is shown that averaging the prediction results from the two methods gives better prediction than either method alone. Following the concept of the AQUAFAC model developed by Myrdal et al. (1992, 1993, 1995), an extended version of the original structural fragmentation scheme is developed. The model is trained on the data set and has an R2 value of 0.881 and a standard error of estimation of 0.819 log unit. Group contribution parameters for a set of 104 fragments are obtained. A new group contribution model is developed to suit the needs in the early drug discovery stage, when melting information is generally not available. Calculated octanol-water partition coefficient is included in the model. The model has a standard error of estimation of 0.814 log unit. When evaluated on independent test sets, the new model provides comparable prediction results with the other two models. The independence of the new model of experimental melting information makes it a suitable tool for aqueous solubility screening in early drug discovery.
31
Sharma, Y. "Continuous flow synthesis of organic compounds." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2017. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4520.
Full text
32
Brahme, K. C. "Studies in organic compounds containing nitrogen." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1987. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3282.
Full text
33
Ndamyabera, Christophe Adrien. "Porous metal-organic frameworks for sorption of volatile organic compounds." Doctoral thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33877.
Full textAbstract:
Metal-organic frameworks (MOFs) present potential for various applications such as gas sorption, gas storage, sensing, drug delivery, and catalysis. This attracts researchers to design and synthesize MOFs that can respond to a specific application. In this thesis, mixed ligands 34pba and 44pba ligands (34pba = 3-(4-pyridyl)benzoate, and 44pba = 4-(4-pyridyl)benzoate) and Co2+ metal salts were used to synthesize porous MOFs {[Co(34pba)(44pba)]·DMF}n (1) and {[Co(34pba)(44pba)]·(C3H6O)}n (2), with DMF = N,N'-dimethylformamide and C3H6O = acetone through solvothermal reaction. These two relate to each other through hinge-like expansion or contraction of the guest-accessible void. The use of Zn2+ as a metal ion led to an isostructural MOFs [Zn(34pba)(44pba)]·DMF}n (3) of 1. Using 34pba as a single ligand and Cu2+ as the metal ion led to the formation of a 2D [(Cu(34pba)2]·DMF) (4) while a little variation of solvent mixture resulted in a 3D {[CuCl2(34pba)2]∙solvent}n (7) structures. The functionalized ligands 44paba and 34paba (34paba = 3-(pyridyn-4-ylmethyl)aminobenzoate, 44paba = 4-(pyridyn-4- ylmethyl)aminobenzoate) were used with Cu2+ centre to prepare [Cu(44paba)·(H2O)·(DMF)]n (5) and {[Cu3(34paba)5(H2O)2]·(DMF)2}n (6), both of which are 1D structures. The activated MOFs 1d and 3d from (1 and 2) were used for the adsorption of volatile organic compounds (VOCs) and gases. In all tested guest molecules, there was higher sorption capacity in 1d which could be attributed to some gate opening process occurring which does not occur in 3d. Some effects responding to the sorption such as the change of colour in 1d were characterized. This colour change may be associated with the d-d, metal to ligand charge transfer, or π to π* transitions in coordination complex. Crystal structures and their stability, sorption properties and selectivity were characterized by single crystal X-ray diffraction, thermogravimetric analysis, differential scanning, hot stage microscopy, powder X-ray diffraction, infrared spectroscopy, and proton viii nuclear magnetic resonance (1H NMR) analysis. This thesis also reports the effect of methanol on discrete complexes of cis-dichloro-bis(ethylenediamine)cobalt(III) chloride (Coen) that led to the formation of a new crystal structure upon the removal of the water of hydration. The lattice energies calculated prove that Coen is more stable to allow a quick reversible sorption.
34
Ye, Penglin. "Semi-Volatile Organic Compounds: Behavior and Secondary Organic Aerosol Formation." Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/1046.
Full textAbstract:
This thesis mainly described the development of studying the behavior and secondary organic aerosol formation from semi-volatile organic compounds (SVOCs). SVOCs comprises a significant fraction of the organic mass in particulate matter (PM), which has shown important impacts on human health and also influences on Earth’s climate. SVOCs are thought to play essential roles in the formation of SOA, chemical aging and mixing processes. Smog chambers have been extensively used to study SOA formation, chemical reaction and physical properties. The interaction between SVOC vapor with Teflon chamber wall and suspended particles is a key factor influencing organic aerosol formations and behaviors in chamber experiments. We observed that pinanediol (PD) showed a large chamber wall deposition and reached a steady concentration, only around 14% of mass left in the gas phase. But we did not observe the release of PD from the chamber walls during isothermal dilution of the chamber with fresh air at 22 oC, which indicated there was no PD released from the chamber walls during the SOA formation. This clearly shows the vapor loss of SVOC precursors need to be considered when studying their SOA formation. The average carbon oxidation states the SOA from PD were calculated as around -0.7, which were similar to the value observed in CLOUD. Our data are consistent with ~10% of the SOA with low volatility that could drive new particle formation. It is challenging to measure SVOC vapor concentrations and properties. A new approach is discussed in this thesis, studying SVOC vapors from measuring the particles. The SVOCs coated particles sustained the SVOCs in the gas phase at or near their saturation concentration. The mass loss of SVOCs from the suspended particles thus reflects SVOCs vapor wall loss. Our results show the vapor wall loss rate of SVOC is consistently proportional to the SVOC vapor concentrations. We observed PEG400 seeds can sorb semi-volatile α-pinene SOA vapors. This allows us to trap semi-volatile α-pinene SOA into PEG400 seeds and then analyze their compositions and properties through measuring particles. PEG400 is liquid, water-soluble, nearly non-volatile, good solvent for SOA and relative stable during the oxidation with OH radicals and ozone. It can also be easily separated from the SOA mass spectrum with the unique fragment C4H9O2+ at m/z=89. The results demonstrated that SOA prepared from α-pinene reacted with OH produced more semi-volatile SOA vapors comparing to α-pinene ozonolysis. More semi-volatile SOA vapors were observed in the gas phase with higher SOA loadings. With well-built particle measurement methods, we may get more knowledge on the SVOC vapors.
35
Newington, Ian M. "Azo-anions in organic synthesis." Thesis, University of Oxford, 1985. http://ora.ox.ac.uk/objects/uuid:690ab891-be13-4582-a029-47974d20adac.
Full textAbstract:
Novel synthetic applications of ambident azo-anions derived from hindered hydrazones have been investigated. Reaction with electrophiles occurred predominantly at carbon as the N-addition pathway was sterically retarded. Trityl, diphenyl-4-pyridylmethyl (DPP) benzhydryl, and t-butyldiphenylmethyl (BDP) hydrazones of various aldehydes and ketones were prepared in good yields from the corresponding hydrazines and carbonyls in aqueous methanol. The lithium salts derived from trityl and DPP hydrazones, by treatment with methyl lithium at -55°C, reacted with aldehydes and ketones to generate azo-alkoxides. These could be diverted to alcohols,by sequential protonation and spontaneous homolysis (about -20°C) in the presence of ethanethiol, or to alkenes,by treatment with phosphorus trichloride at -78 G followed by azo-homolysis. The reactions enabled efficient reductive cross-coupling of aldehydes and ketones. The mechanism of the alkene forming reaction was investigated. Anions of benzhydryl hydrazones were found to react inefficiently by a G-addition pathway giving mainly N-addition products. Anions of BDP hydrazones conveniently gave excellent yields of azo-alkanes upon treatment with alkyl halides,but no products were obtained on reaction with carbonyl electrophiles. The azo-alkanes could be isolated and purified and acted as key intermediates for several synthetically useful transformations. Homolysis in refluxing benzene with thiophenol gave alkanes in good yields. Phenylselenenyl-, bromo-, and chloro-alkanes,and β-alkylstyrenes were generated when thiol was replaced by diphenyl diselenide, N-bromosuccinimide, N-chlorosuccinimide and β-nitrostyrene respectively. Treatment of the azo-alkanes with trifluoroacetic acid generated benzophenone alkylhydrazones. These were dissolved in ethanol with concentrated hydrochloric acid, thereafter hydrolysis yielded alkylhydrazines or treatment with hydrogen (1 atm., 50°C, 20h) over 10% Pd/C generated primary amines by a novel use of carbonyls as α-aminocarbanion equivalents.
36
Kou, Xiaodi. "Synthesis, characterization and reactivity of organic bismuth compounds." Fort Worth, Tex. : Texas Christian University, 2007. http://etd.tcu.edu/etdfiles/available/etd-07312007-125631/unrestricted/kou.pdf.
Full text
37
Wallner, Olov. "Palladium-Catalyzed Synthesis and Transformations of Organometallic Compounds." Doctoral thesis, Stockholm : Dept. of Organic Chemistry, Stockholm University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-804.
Full text
38
Faleni, Nobathembu. "Inclusion behaviour of related organic host compounds." Thesis, Cape Peninsula University of Technology, 2007. http://hdl.handle.net/20.500.11838/739.
Full textAbstract:
Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2007The inclusion behaviour of the two host compounds, 9-(4-methoxyphenyl)-9Hxanthen- 9-o1 (A1)• and 9-(4-methylphenyl)-9H-xanthen-9-o1 (A10) were investigated. These host compounds are large, bulky, rigid and they contain functionalities that allow them to selectively interact with other molecules, such as the guests in this work. The host molecules form inclusion complexes with small organic guest molecules. The host•••guest interactions are the interesting focus of this study. The host A1 included the guests: cyclohexane, 1,4-dioxane and N,N-dimethylformamide. Kinetics of desolvation were studied for the 1,4-dioxane and N,N-dimethylformamide compounds. Guest-exchange reactions were performed. The hostA1 was also used in the separation of 1, 4-dioxane and benzene. The host A10 included the guests; benzene, 1,4-dioxane, cyclohexane, cyclohexanone, N,N-dimethylacetamide and N,N-dimethylformamide. Kinetics of desolvation were studied for the benzene and cyclohexane compounds. The host A10 was used in the separation of the following pairs of guests: benzene and 1,4-dioxane; N,N-dimethylformamide and N,Ndimethylacetamide. The structures of the compounds were elucidated using single crystal X-ray diffraction. Thermal analysis was performed in order to determine the thermal stabilities of the complexes, including techniques such as thermogravimetry, differential scanning calorimetry and melting point measurement. The reactions in the guest exchange experiments were monitored using differential scanning calorimetry. Competition experiments were performed to determine the selectivity of a host for a series of related guests. These experiments were conducted between pairs of guests.
39
楊志雄 and Chi-hung Yeung. "Organic oxidation catalysed by ruthenium and manganese macrocycles." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233971.
Full text
40
Yeung, Chi-hung. "Organic oxidation catalysed by ruthenium and manganese macrocycles /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13883896.
Full text
41
Forsyth, Stewart Alexander 1975. "Novel organic salts." Monash University, School of Chemistry, 2003. http://arrow.monash.edu.au/hdl/1959.1/5833.
Full text
42
Comins, Stuart. "Myxothiazol and related compounds." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238235.
Full text
43
Frankowski, Kevin J. "Carbenes and carbenoids as powerful tools in organic synthesis." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 2.18 Mb., 94 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3205422.
Full text
44
Blasucci, Vittoria Madonna. "Organic solvents for catalysis and organic reactions." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31723.
Full textAbstract:
Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Charles Eckert; Committee Co-Chair: Charles Liotta; Committee Member: Amyn Teja; Committee Member: Christopher Jones; Committee Member: William Koros. Part of the SMARTech Electronic Thesis and Dissertation Collection.
45
Dutta, Somnath. "Alkylzirconium alkoxides in organic synthesis reactions with sigma- and pi-bonded organic substrates /." Online access via UMI:, 2005.
Find full text
46
Arsene, Cecilia. "Atmospheric degradation mechanisms of organic sulphur compounds." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=96417023X.
Full text
47
Granström, Karin. "Emissions of volatile organic compounds from wood." Doctoral thesis, Karlstads universitet, Institutionen för ingenjörsvetenskap, fysik och matematik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-2327.
Full textAbstract:
The central aim of this thesis is to support the efforts to counteract certain environmental problems caused by emissions of volatile organic compounds. The purpose of this work was (1) to develop a method to establish the amount of emitted substances from dryers, (2) to determine the effect of drying medium temperature and end moisture content of the processed material on emissions of monoterpenes and other hydrocarbons, (3) to examine the emissions of monoterpenes during production of pellets, and (4) to examine the natural emissions from forests with an eye to implications for modelling. The measurement method (1) resolves the difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapour to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted volatile organic compounds and to determine the moisture content of the drying medium. The method as used in this paper has an uncertainty of 13% using a 95% confidence interval. Emissions from a spouted bed (2) in continuous operation drying Norway spruce sawdust at temperatures of 140°C, 170°C or 200°C was analysed with FID and GC-MS. When the sawdust end moisture content was reduced below 10%wb, emissions of terpenes and volatile organic compounds per oven dry weight increased rapidly. Increased temperature of the drying medium increased the amounts of emitted monoterpenes when sawdust moisture content was below the fibre saturation point. Examination of sawdust and wood pellets from different pellets producers (3) revealed that most of the terpene emissions happened during the drying step, with rotary dryers causing higher emissions than steam dryers. Almost all of the volatile terpenes remaining in wood after drying were released during pelleting. When sawdust with higher moisture content was used in the pellets press, the terpene emissions were increased. Terpenes emitted naturally from vegetation can have an adverse environmental impact. Factors affecting terpene emissions from tree species in Sweden were reviewed (4). Models for prediction of terpene fluxes should include not only temperature but also light intensity, seasonal variation, and a base level of herbivory and insect predation. Prediction of high concentrations of ambient terpenes demand sufficient resolution to capture emission peaks e.g. those caused by bud break.
48
Bis, Joanna A. "Crystal engineering of organic compounds including pharmaceuticals." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001424.
Full text
49
Jain, Akash. "Estimation of Melting Points of Organic Compounds." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1303%5F1%5Fm.pdf&type=application/pdf.
Full text
50
Buckley, Anne Margaret. "Inorganic-organic layer compounds : synthesis and properties." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253398.
Full text