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Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

The gas chromatograms of crude oil hydrocarbons reveal both resolved and unresolved components. The unresolved feature is commonly referred to as the unresolved complex mixture (UCM). UCMs are thought to result from the co-elution of complex mixtures of hydrocarbons with similar chemical properties and become more obvious as resolved components are removed by processes such as weathering and refining. Consequently UCMs are a prominent feature in oil-polluted sediments, biodegraded crudes and refineiT products. The characterisation of both aliphatic and aromatic unresolved complex mixtures (UCMs) of hydrocarbons, as well as their possible effects on the environment, is described. An aliphatic hydrocarbon UCM isolated from the base oil of Silkolene 150 lubricating oil was characterised by a combination of micro vacuum-distillation and oxidative degradation. Vacuum-distillation produced six distillate cuts and a residue which were all highly unresolved by GC (ca. 951/6). The average molecular weight of each cut was determined by probe CIMS (310 - 440 Daltons), and varied by -20 Daltons. Cr03 oxidation of each fraction yielded similar distributions of n-monocarboxylic acids, ketones and lactones as well as C02 (ca. 6%). The resolved products of oxidation suggest that the aliphatic UCM is a rather homogeneous mixture of highly branched alkanes. However a significant amount of the products remain unresolved (UCMox.; ca. 70-95%). A retro -structural analysis approach, using an aromatic UCM oxidant (Ru04), combined with a mass balance approach, was used to characterise aromatic UCMs. Following reproducibility studies and the analysis of authentic aromatic compounds, the method was applied to the characterisation of unresolved aromatic refinery oil fractions and a suite of aromatic UCM distillate fractions. Selected refinery oils were separated into mono-, di-, tri- and tetraaromatics by BPLC and shown to be mainly unresolved by GC (ca. 80%). Ru04 oxidation of these fractions yielded DCM soluble products (24 - 74%), water soluble products (0 - 10%) and C02 (12 -78%). The principal resolved products in each oxidation were monocarboxylic acids and dicarboxylic acids which were used to reconstruct precursor compounds. Vacuum-distillation of Tia Juana Pesado crude (Venezuela) gave six cuts and a residue which were analysed by GC, 1H NMP, UV and probe CIMS to obtain molecular weight (171 - 301 Daltons) and broad structural information whilst Ru04 oxidation was used to obtain molecular information via the retro -structural analysis approach. This showed that the aromatic UCM was in fact highly aliphatic and contained alkyl and cycloalkyl tetralins. A significant advancement in the quantitative characterisation of UCMOx. and subsequently the characterisation of aromatic UCMs was made. Ion cyclotron resonance spectrometry (ICR) was used to characterise the Ru04 oxidation products of selected refinery fractions. Analysis of the oxidation products of a monoaromatic refinery fraction indicated the presence of monocarboxylic acids (Cl - C21; 58%) and alicyclic carboxylic acids (C7 - C19; 16%), a hydrogenated monoaromatic sample contained monocarboxylic acids (Cl - C20; 30%), dicarboxylic acids (C2 - C11,7%) and alicyclic carboxylic acids (C7 - C18; 11%) , whilst a diaromatic fraction contained monocarboxylic acids (C10 - C19; 7%), alkyl phthalic acids (C8 - C17', 17%) and cycloalkyl phthalic acids (C11 - C15; 3%). Retro -structural analysis suggests that the nonhydrotreated monoaromatic UCM is mainly comprised of alicyclic and alkyl substituted benzenes, the monoaromatic UCM isolated from the hydrotreated oil of alky'l and cycloalkyl substituted tetralins and the diaromatic fraction of alkyl and cycloalkyl naphthalenes. This was supported by, FIMS analysis of the fractions prior to oxidation. As an investigation of the environmental toxicity of UCMs, the effect of a saturated aliphatic UCM, and its chemical oxidation products, on the feeding rate of mussels (Mytilus edulis), was investigated. The UCM had little effect, whilst oxidation resulted in an increase in toxicity. The non-toxic nature of the hydrocarbons was attributed to their low aqueous solubility, whilst oxidation resulted in the formation of products NNith a greater solubility, which were sufficiently hydrophobic to be narcotic toxicants. Parts of this work have been published [Thomas et al., (1993) Organic Geochemistry, Falch Hurtigtrykk, Non%-ay(A bstract), 717-719; Thomas et al., (1995) [Vater Research. 29,371-382]. iv

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Donald L. Sparks, Dept. of Plant & Soil Sciences. Includes bibliographical references.

The hydrocarbons of recent polluted sediments, in-reservoir and laboratory biodegraded crude oils, and certain petroleum products (e.g. lubricating oils) often display 'humps' or Unresolved Complex Mixtures (UCMs) when analysed by gas chromatography (GC). Although widespread and often abundant, to date little is known of their detailed molecular composition. Standard chromatographic methods of isolation of model aliphatic and aromatic hydrocarbon UCMs from lubricating oils followed by conventional methods of analysis provided little compositional detail. Thus GC and GC-electron impact mass spectrometry (GC-EIMS) was limited to an estimate of carbon number ranges and to the identification of certain series of 'biological marker' compounds. However, these were well resolved and were estimated to account for <10% of the total detector response. Further analyses were performed by chemical ionisation-MS (CI-MS), probe distillation EI-MS, field ionisation-MS (FIMS), and elemental analysis; yet the information provided by each was limited to a few 'average' molecular types. In view of the limitations of conventional methods of analysis, alternative methods were adopted. These utilised novel chemical and pyrolytic degradations of the UCM hydrocarbons. Chemical oxidation with Cr03 in glacial acetic acid produced reasonable yields of total recoverable material (40-80%). Furthermore, a high proportion were functionalised (>90%), and many resolved, which allowed their identification by EI and CI GC-MS. Surprisingly, the most abundant products of oxidation of hydrocarbon UCMs were straight chain monocarboxylic acids. This appeared to contradict literature consensus on UCM composition, namely a predominance of highly branched and/or cyclic hydrocarbons. However, from literature reported CrO oxidations of hydrocarbons, potential precursor compounds were proposed. These were monoalkyl substituted 'TO-branched acyclic and monocyclic alkanes for the aliphatic UCM and alkyl 'TO-branched monoaromatic hydrocarbons for the aromatic UCM. Proposed precursor UCM hydrocarbons were confirmed by synthesis and chemical oxidation under the same conditions. Thus each of the synthetic candidate UCM hydrocarbons [7-n-hexylnonadecane, 9-(2-phenylethyl)-heptadecane and 9-(2- cyc 1 ohexyl ethyl j--hep tade cane] produced n-acids on oxidation with Cr03- Further correlations were found for products of other synthetic alkanes and less abundant UCM oxidation products. For example, n-alkan-2-ones. iso alkan-2- ones, and 7-methyl--y-lactones could all be correlated with methyl substituted acyclic alkyl linkages on UCM hydrocarbons. The application of chemical oxidation to aliphatic UCMS of varied origin showed the technique has great potential for fingerprinting such samples. GC-MS analysis of a selected series of resolved product compounds (alkyl ketones, -y-methyl--y-lactones) showed good correlations for samples of the sane origin, yet distinct differences for UCHs from different sources. Biodegradation of the three candidate UCM hydrocarbons alongside acyclic isoprenoid alkanes and normal and monomethyl alkanea showed the UCM hydrocarbons were at least as resistant to microbial degradation as the isoprenoid alkanes. In this context it is therefore concluded that the candidate UCM compounds serve as good molecular models for hydrocarbon UCMs.

New methodologies have been developed for the determination of organotin and organolead compounds in environmental samples. Several high performance liquid chromatographic separations of organotin compounds have been tested and the best system (cation-exchange chromatography with methanol and a citrate buffer) employed for the determination of tributyltin (TBT), triphenyltin (TPhT), dibutyltin (DBT) and monobutyltin (MBT) in environmental samples. The coupling between high performance liquid chromatography (HPLQ and the inductively coupled plasma-mass spectrometer (ICP-MS) for this application has been modified to yield limits of detection of 0.44,0.26,1.4 and 0.23 ng. g-' as Sri for TBT, TPhT, DBT and MBT respectively. Different extraction procedures have been tested for the determination of organotin species in samples of environmental interest, such as sediments and biological materials. The values obtained for TBT, TPhT and DBT in the analysis of a mussel candidate reference material, CRM 477, have been incorporated in the certification campaign of this material. A liquid chromatographic separation for trimethyllead (TML) and triethyllead (TEL) has also been developed. Artificial rain water has been analysed for TML. The system proved to be valid for the determination of TML in this sample, even in the presence of high amounts of inorganic lead. Finally, isotope dilution analysis (IDA) was incorporated in the method. Tributyltin iodide (TBTI) and trimethyllead chloride (TMLCI), isotopically enriched in &quot;Sn and &quot;Pb, respectively, were synthesised. The mussel tissue CRM 477 was analysed with IDA-HPLC-ICPMS for TBT. As for the analysis without isotope dilution, the result obtained was incorporated in the certification campaign. The analysis with this methodology gave a better precision in the overall determination than external calibration analysis. Artificial rain water, at two different concentration levels, was analysed for TML with IDA-HPLC-ICP-MS. Better precision and accuracy was obtained for the analysis of this material with this method than when external calibration procedures were employed. IDA-HPLC-ICP-MS has proved to be a valid technique for the analysis of environmental samples. The technique simplifies the procedure, compensates for different sources of variability and, thus, the overall precision obtained in the analysis is improved compared to other calibration techniques.

Dyestuffs are widely used industrial chemicals, yet surprisingly little is known about their fate in the environment. The potential modes of transformation and removal of reactive dyes in treatment and in the environment are principally through anaerobic and aerobic biodegradation and photodegradation. The research herein describes the use of LC-MS analysis with laboratory simulations to develop a better understanding of the occurrence and fate of reactive dyes and their degradation products in the aquatic environment. One reason for the lack of information on the environmental fate of reactive dyes has been the paucity of robust analytical methods suitable for the determination of dyes in aqueous samples. Robust analytical methods were optimised to provide LC-MS and MSMS identification of degradation products. Additionally, interpretation of the MSMS spectra of known reactive dyes provided novel characteristic fragment ions indicative of the triazine reactive group of reactive dyes . Fibre reactive dyes are designed to have a degree of photostability and therefore their photodegradation behaviour has not been widely investigated. Little is known of their stability to daylight over prolonged periods of irradiation in dilute aqueous solutions and in the presence of humic substances. The kinetics of photodegradation of an anthraquinone dye (Reactive Blue H4R) and azo dye (Reactive Yellow P5G) were evaluated. The former underwent rapid and extensive degradation 01/2 1.5 h). The major products formed were identified using LC-MSMS and a photodegradation pathway proposed. By comparison, the photodegradation of the azo dye was significantly slower, 01/2 30 h). The addition of humic substancesa ppearedt o have little effect on the rate of photodegradationu nder the conditions used. The reduction of azo dyes under anaerobic treatment has been extensively studied, but the subsequent fate of the initial reduction products when exposed to air are not understood. Three relatively simple azo dyes, Amaranth, Sunset Yellow and Naphthol Blue-Black, were reduced and their autoxidation products identified by LC-MS. These were subsequently used to predict the autoxidation products of a more complex azo reactive dye: Reactive Red 3.1. Additionally, a persistent degradation product from the anaerobicaerobic treatment of Reactive Red 3.1 was identified from LC-MS data. Azo reactive dyes are generally regarded as being resistant to aerobic degradation and there are few published data regarding degradation pathways for reactive anthraquinone dyes. Pure cultures of Pseudomonas docunhae, A 9046 and A texaco and mixed bacterial consortia (semi-continuous activated sludge, SCAS) aerobic degradation of azo and anthraquinone reactive dyes was studied. Two azo dyes were degraded by pure cultures of A docunhae and A 9046, suggesting that azo dyes can be aerobically degraded given favourable conditions. The antraquinone dye was extensively degraded by SCAS and pure culture biodegradation. Metabolites were identified by LC-MS and a degradation pathway proposed.

This is a field study describing seven backwaters in the floodplain of the Luznice river. The backwaters include alluvial pools, river arms and oxbows which differ in their genesis, morfology, hydrological régime, macrophyte vegetation and chemistry of water and sediments. This study was carried out in the Trebonsko - Protected Landscape Area and Biosphere Reserve, South Bohemia, Czech Republic. The data of species composition of the vegetation on transects of the backwaters are supplemented by water and sedimet analyses.

Les travaux de thèse présentés dans ce manuscrit portent essentiellement sur la préparation, le criblage et l’utilisation des catalyseurs hétérogènes à base de polysaccharides. L’objectif principal du projet de thèse a plus particulièrement consisté à évaluer deux polysaccharides : les alginates et le chitosane en tant que supports renouvelables pour la catalyse hétérogène. Ces deux types de polysaccharides ont des structures et des propriétés physico-chimiques très différentes : les alginates sont connus pour être de bons complexants de métaux di ou trivalents de par la présence des fonctions carboxylates dans leur matrice, le chitosane résulte quant à lui de l’assemblage d’unités N-glucosamine pouvant être facilement modifiées chimiquement.Dans un premier temps, nos travaux ont essentiellement portés sur des catalyseurs bimétalliques Mn+ Pd supportés sur alginate dont nous avons évalué l’activité catalytique dans les réactions de couplage C—C de Mizoroki-Heck, Sonogashira et Suzuki-Miyaura. D’une manière générale, seuls les catalyseurs à base de nanoparticules de palladium ont montré une réactivité intéressante pour la catalyse de la réaction de Suzuki-Miyaura. Par la suite, nous avons également étudié les réactions d’oxydations d’alcools catalysées par du palladium (II) complexé à l’alginate. Cette étude nous a permis d’identifier deux catalyseurs actifs vis-à-vis de l’oxydation d’alcools allyliques et benzyliques.Dans un deuxième temps, nous avons développé de nouveaux ligands de type NHC en vue de les greffer sur la matrice chitosane : un ligand NHC pour les réactions de métathèse d’oléfines, et plusieurs ligands NHC de type pincer CNC pour les réactions de couplage C—C dans l’eau. Bien que les performances catalytiques des systèmes hétérogènes correspondant soient limitées, ces travaux ont conduit à l’élaboration de nouveaux ligands amphiphiles construits autour d’un noyau pyrazine porteurs de quatre ligands carbéniques. Après complexation de métaux tels que le palladium ou l’or, ces systèmes conduisent à des nanocatalyseurs ayant des performances catalytiques intéressantes. Enfin, dans un troisième temps, nous avons développé une nouvelle réaction de cyanation décarboxylante pallado-catalysée permettant de transformer en une étape des acides carboxyliques aromatiques en benzonitriles correspondants. Outre son intérêt synthétique, cette réaction présente un grand intérêt pour le marquage isotopique. / This work describes the preparation, screening and use of heterogeneous catalysts based on polysaccharides. The main goal of our project was to evaluate two polysaccharides: alginates and chitosan as renewable supports for heterogeneous catalysis.Alginates are known to form gels with most di- and multivalent cations due to the presence of the carboxylate functions of their matrix. And chitosan is an attractive polysaccharide for application in catalysis owing to the presence of readily functionalizable amino group and its insolubility in organic solvents.First, our work focused on evaluating the catalytic activity of bimetallic Mn+-Pd catalysts supported on alginate in C—C coupling reactions. Among them, one system demonstrated remarkable catalytic properties for the Suzuki-Miyaura coupling. Then, the oxidation of alcohols catalyzed by Alginate-Mn+-Pd2+ catalyst was investigated. Two catalysts demonstrated good activity for oxidation of benzylic and allylic alcohol.In a second time, we developed new NHC ligands in order to anchor them on chitosan: two new NHC ligands for olefin metathesis and several NHC pincer CNC ligands for C—C coupling reactions in water. A palladium complex obtained with one our new ligand bearing long alkyl chains showed good activity in the Suzuki-Miyaura coupling in pure water.Finally, a new palladium (II) catalyzed decarboxylative cyanation reaction was investigated. This methodology is the first example of direct conversion of aryl carboxylic acid into the corresponding aryl nitrile. This reaction is well adapted to labeled compound synthesis.

Les phosphines sulfonées sont les ligands hydrosolubles les plus utilisés en catalyse organométallique aqueuse. La méthode la plus courante d’introduction des groupements sulfonate sur une arylphosphine consiste en la réaction de celle-ci avec l’oléum sulfurique. Dans ce contexte, la première partie de cette thèse a été consacrée à la synthèse de nouvelles triarylphosphines sulfonées encombrées possédant des groupements naphtyle. Plus précisément, les phosphines sulfonées synthétisées ont été du type [(1 ou 2-naphtyl)x(phényl)3-x]phosphine (x = 1, 2, 3) avec en moyenne, deux groupes sodium sulfonate par molécule. Dans la seconde partie de cette thèse, le développement d’une nouvelle voie d’accès à des phosphines du type R-diphénylphosphines disulfonées, où R est un groupement sensible aux conditions drastiques de sulfonation a été mis en œuvre. Ce protocole met en jeu deux étapes : la première étape implique l’alkylation de la benzyldiphénylphosphine trisulfonée (BDPPTS) ou du 1,2-bis(diphénylphosphino)éthane tétrasulfoné (DPPETS) par un dérivé halogéné (RX) apportant le groupement R sensible. La seconde étape consiste en le clivage réducteur par l’aluminohydrure de lithium (LiAlH4) des sels de phosphonium ou de bis-phosphonium ainsi obtenus et conduit à la R-diphénylphosphine disulfonée. Les phosphines qui ont été synthétisées par cette méthode sont les n-octyl-, n-dodécyl-, n-hexadécyl-, phénéthyl- et but-3-ényl-diphénylphosphines disulfonées. Les phosphines sulfonées synthétisées dans le cadre de cette thèse ont été valorisées en tant que ligands dans la réaction d’hydroformylation du déc-1-ène catalysée au rhodium et assistée ou non par des cyclodextrines. / Sulfonated arylphosphanes are the most applied water-soluble ligands in aqueous organometalliccatalysis. Sodium sulfonate groups are commonly introduced on an arylphosphane by using sulfuric oleum(SO3/H2SO4) followed by neutralization with aqueous sodium hydroxide. In this context, the first part of thiswork was focused on the synthesis of new bulky sulfonated triarylphosphanes with naphtyl groups. Moreprecisely, sulfonated [(1 or 2-naphtyl)x(phenyl)3-x]phosphane (x = 1, 2, 3) with an average sulfonation degreearound two have been prepared. In the second part, a new and convenient synthesis pathway to disulfonatedR-diphenylphosphanes with R an oleum-sensitive group was developed. This route involves two steps: thefirst step is the alkylation of trisulfonated benzyldiphenylphosphane (BDPPTS) or tetrasulfonated 1,2-bis(diphenylphosphanyl)ethane (DPPETS) with an halide compound (RX) bearing the sensitive group R. Inthe second step, the synthetized trisulfonated phosphonium or tetrasulfonated bis-phosphonium salt aresubsequently cleaved by lithium aluminium hydride (LiAlH4) to give the corresponding disulfonated Rdiphenylphosphanes.The phosphanes obtained by this new methodology are the disulfonated n-octyl-, ndodecyl-,n-hexadecyl-, phenethyl-, and but-3-enyl-diphenylphosphanes. Most of the synthetized phosphanesin this work have then been tested as ligand in the rhodium catalyzed dec-1-ene hydroformylation assisted ornot by cyclodextrins.