This dissertation focuses on the phosphorescence of organic chromophores using perfluoro-ortho-phenylene mercury (1) and bis(pentafluorophenyl)mercury (2) as external heavy atom effect inducers. To ascertain the suitability of these luminescent adducts for OLED applications, several research objectives have been investigated. To further shorten the triplet lifetimes of adducts involving 1, a strategy was developed which combines both internal and external heavy atom effects. Specifically, complexes involving 1 and N-methylcarbazole, N-methylindole and the 1- halonaphthalenes were investigated. The existence and stability of the complexes could be confirmed in solution by fluorescence spectroscopy. In the solid state, these adducts form supramolecular binary stacks where the molecules of 1 alternate with the aromatic substrate. As a result of the mercury external heavy atom effect, all of these adducts display intense room temperature phosphorescence of the free arene. With the Nheterocycles, the triplet lifetimes were drastically reduced to below 100 mu-s. To appreciate the origin of the unusual heavy atom effects observed in arene adducts with 1, 2 was studied as a monofunctional analog to 1. By utilizing fluorescence spectroscopy, naphthalene, biphenyl, and fluorene complexes of 1 and 2 have been detected in solution. The solid state structure of the adducts with 2 reveal supramolecular binary stacks. Comparison of the photophysical results supports the occurrence of cooperative effects between the Lewis acidic mercury centers of 1, which make it a more efficient external heavy-atom effect inducer. Polymeric materials which are amenable to deposition in thin layers were investigated as substrates for 1 and 2. Both poly(vinyl-2-naphthalene) and poly(vinylcarbazole) interact with 1 and 2 in solution as evidenced by fluorescence spectroscopy. With the solid blend 1•PVK, a small doping percentage of 1 results in white emission, while larger percentages of 1 yield bright orange emission. This dissertation presents the first structurally characterized ternary complex with 1, carbazole, and coordinating solvents THF and triethylamine. IR spectroscopy and short N···O and N···N distances in the solid state indicates that the acidic N-H moiety of carbazole interacts with the solvent by hydrogen bonding. In the extended structure, molecules of 1 and the hydrogen bonded complex alternate to form supramolecules.

The molecular recognition of fluoride and cyanide anions has become an increasingly pertinent objective in research due to the toxicity associated with these anions, as well as their widespread use. Fluoride is commonly added to drinking water and toothpastes to promote dental health, and often used in the treatment of osteoporosis, however, high doses can lead to skeletal fluorosis, an incurable condition. Cyanide is also an extremely toxic anion, which binds to and deactivates the cytochrome-c oxidase enzyme, often leading to fatality. The molecular recognition of these anions in water has proven to be challenging. For fluoride, the anion is small, and thus, efficiently hydrated (?H�hyd = -504 KJ/mol), making its complexation in aqueous environments particularly difficult. In addition to being small and efficiently hydrated like the fluoride anion, cyanide has a pKa(HCN) of 9.3 making its competing protonation in neutral water a further complication. Recent efforts to complex fluoride and cyanide have utilized triarylboranes, which covalently bind the anion. Monofunctional triarylboranes display a high affinity for fluoride with binding constants in the range of 105-106 M-1 in organic solvents, and chelating triarylboranes exhibit markedly higher anion affinities. These species, however, remain challenged in the presence of water. This dissertation focuses on the synthesis and properties of novel Lewis acids designed for the molecular recognition of fluoride or cyanide in aqueous environments. To this end, a group 15 element will be incorporated into a main group Lewis acidcontaining molecule for the purpose of: i) increasing the Lewis acidity of the molecule via incorporation of a cationic group, and ii) increasing the water compatibility of the host. Specifically, a pair of isomeric ammonium boranes has been synthesized. These boranes are selective sensors which selectively bind either fluoride or cyanide anions in water. The study of phosphonium boranes has revealed that the latent Lewis acidity of the phosphonium moiety is capable of aiding triarylboranes in the chelation of small anions. Finally, my research shows that Br�nsted acidic H-bond donors such as amides, when paired with triarylboranes, are capable of forming chelate complexes with fluoride.

Thèse de doctorat : Génie des procédés et des produits : INPL : 2008. / Titre provenant de l'écran-titre.

Thèse de doctorat : Chimie : Nancy 1 : 2009. / Titre provenant de l'écran-titre.

No description available.

Boron is an element distributed widely in environment mainly in the form of boric acid or borate salts. Boron is an element of demand because of its use in many high technology materials. Moreover boron is an essential element for growth of plants, but may also result in toxicity when present in excessive amounts. As the range between a deficient and toxic amount of boron is very narrow, imbalances in boron nutrition are well-known. For the removal of boron from aqueous solutions, various methods exist which are chemical coagulation, adsorption, solvent extraction and ion exchange processes. In this study, an alternative, energy efficient and easily scalable membrane based method, polymer enhanced ultrafiltration (PEUF) was developed for removal of boron from aqueous boron solutions. PEUF process consists of two steps: complexing boron with a water soluble polymer then removing the complex by ultrafiltration. Previously, boron removal from aqueous solutions was studied in a continuous process with a commercial ligand, polyvinyl alcohol (PVA). In our study, three newly developed polymers, which are derivatives of N-methyl-D-glucamine (P1) and iminodipropylene glycol(P2 and P2G) were used as the boron complexing ligand. P1 and P2 are linear polymers, while P2G is cross linked version of P2. The pilot scale system utilized for the PEUF process accommodates a spiral wound cellulose cartridge with 10000 Da molecular weight cutoffs (MWCO). The effects of operating parameters on performance of PEUF were investigated. The experimental parameters studied are metal/polymer ratio (loading) (0.01-1), pH (7-10). Boron analyses of the samples were made by using ICP-AES. Maximum removal (retention) was 90.1 %. The permeate flux remained constant at around 20 L/m2.hr and was not affected by the operating parameters. Decrease in loading caused the retention of boron to increase. Also at high pH values, retentions were relatively higher. Results showed that PEUF could be a successful alternative method for removal of boron.

In order to gain an understanding of the interaction of probe molecules with NaCh aggregates, steady-state and time-resolved photophysical methods were used. By employing several probe molecules, an understanding of how the structure of the probe affected binding to the two distinct sites in the aggregates was investigated. The first half of the thesis examined the reactivity of benzophenone (Bp) and 4,4-dimethylbenzophenone (DMBp) with NaCh aggregates by studying the kinetics of both the ketone triplet excited states and the ketone ketyl radicals. There were three species of triplet excited states observed in the presence of primary aggregates. One of the ketone triplet excited state species was located within the primary aggregate, and it reacted to form ketyl radicals. Other triplet states included in the primary aggregate were found to be long-lived, while a third species of triplet states was present in the aqueous phase. At higher bile salt concentrations, and in the presence of secondary aggregates, a layer of complexity was added. The binding dynamics for the triplet excited state with the secondary binding sites were much faster than those observed for the primary binding site. Hydrogen abstraction did not compete with other deactivation pathways in the presence of secondary aggregates, and thus only self-quenching and exit of the excited state probe from the secondary site were observed. Ketyl radical recombination took place in water and in the secondary sites. The second half of the research focused on the study a series of naphthalene (Np) derivatives in order to look at the effects of shape and hydrophobicity of probe molecules on the interactions between these probes and the host NaCh aggregates. 1-Ethylnaphthalene, 2-ethylnaphthalene, 1-acetonaphthone, 2-acetonaphthone, 1-naphthyl-1-ethanol and 2-naphthyl-1-ethanol were studied. 1-Ethylnaphthalene and 2-ethylnaphthalene were Ethylnaphthalene, 2-ethylnaphthalene, 1-acetonaphihone, 2-acetonaphthone, 1-naphthyl- 1-ethanol and 2-naphthyl-1-ethanol were studied. I-Ethylnaphthalene and 2- ethylnaphthalene were contained within the primary binding site, while 1-naphthyl-1-ethanol, 2-naphthyl-1-ethanol, 1-acetonaphthone and 2-acetonaphthone were contained within the secondary binding site. The effect of the position of the substituent was only noticed when the probe molecules formed weak interactions with the outside of the primary aggregate, and not when the probe was complexed to one of the binding sites present in the NaCh system. The naphthalene probe molecules were also used to study the effect of ionic strength on NaCh aggregate formation. It was found that primary aggregation occurred at lower NaCh concentration as the ionic strength was increased. No effect of ionic strength was observed on the formation of secondary aggregates. All the findings in this study are consistent with an aggregation model in which two distinct binding sites are present. The shape of the probe as well as its hydrophobicity are critical to its interaction with the NaCh aggregates. From these dynamic studies it was found that only a small number of NaCh monomers (6-13) are needed to define both the primary and secondary binding sites. / Graduate

Chlorite is a ferrous silicate mineral occurring as afracture filling mineral in the Swedish granite bedrock thatsurrounds the area of the candidate Swedish geologicalrepositories for nuclear waste. To investigate the importance of chlorites as a naturalbarrier for radionuclide migration sorption of Ni(II) onto anatural chlorite was chosen as the studied system. The sorptionbehaviour was studied using batch technique under differentexperimental conditions by varying the concentration ofbackground electrolyte, pH and initial nickel concentration.Our experiments showed that sorption is dependent of pH; belowpH 4 no sorption occurs and in the pH range 7-11 the sorptionmaxima was found. The sorption shows no dependence of ionicstrength in our experiments and together with pH dependency weconclude that the sorption of nickel to chlorite is mostlyoccurring through surface complexation. The distributioncoefficient, Kd, was determined for our results and in the range formaximal sorption the Kdis approximately 103cm3/g. Our experimental data were described using a diffuse doublelayer model, including strong and weak surface sites, in thesoftware PHREECQ and the results obtained from PHREEQC werealso used for a fit of the data in the software FITEQL. Thesurface complexes that dominate the sorption of nickel tochlorite from our model are Chl_ONi+(weak) and for pH above 9 Chl_ONi(OH)-(weak). Flow-through technique was used in ourinvestigations regarding the dissolution rate of a naturalchlorite and the experimental results show that the dissolutionrate of chlorite is strongly pH dependent and at pH 2 thehighest dissolution rate (RSi) could be determined to 7• 10-11mol/(m2s) based on silica data. Keywords:chlorite, nickel, sorption, surfacecomplexation, dissolution rate.

Nanoparticles have been found to have an increasingly wide range of applications including drug delivery systems, chemical sensors, biomolecule sensors, single electron devices, catalysis, Li-ionbatteries, andsolarcells. Avarietyofmethodshavebeenused to produce nanoparticles, but one widely used approach is the application of reverse micellenanoreactorswherebyblockco-polymersareusedtoencapsulateprecursorsalts and serve as a vessel for precursor salts to react. As the encapsulation of precursor salts can be a multi-step process, some nanoparticle formulations have proven difficult to make within the reverse micelle nanoreactor. To fully understand the difficulties in nanoparticle formation, we need to have a method to probe the internal structure of the reverse micelle. This thesis presents a novel method for probing the internal structure of the reverse micelle using a quantitative mechanical mapping (QNM) mode for atomic force microscopy (AFM). Unloaded reverse micelle nanoreactors were analyzed using the QNM AFM mode. A decrease of the Young’s modulus was noted through the centroid of the reverse micelle. Many models were applied to describe the noted decrease of Young’s modulus. The end result indicated that intrinsic differences between the mechanical properties of polystyrene and poly(2vinyl pyridine) and the co-polymer orientation lead to the measured decrease in Young’s modulus through the centroid. Results from the unloaded case were used to explain changes to the reverse micelle nanoreactor after loading with precursor salts. Across all precursor salts similar trends were noted, however there was no consistent relative Young’s modulus or molar salt loading ratio noted within the trends. Three distinct loading zones were consistent acrosstheprecursorsalts. Region I wastypifiedbyaslightdecreaseinrelativeYoung’s modulus with small resultant nanoparticles. Region II was typified by linear increases in relative Young’s modulus for increases in the molar salt loading ratio. Region III was found to have two possible outcomes, either the micelle reach a maximum effective infiltration, where the relative Young’s modulus ratio no longer increases for increased molar salt loading ratio, or the micelle would unravel for increased molar salt loading ratio. Further studies should be done to confirm the existence of the universal loading regions across further co-polymers, solvents, and precursor salts. / Thesis / Master of Applied Science (MASc)

La flottation ionique est un procédé de séparation permettant d'extraire et de concentrer des ions dans une mousse formée à l'aide d'un tensioactif. Pour les systèmes classiques, la forte interaction entre les ions et le tensioactif collecteur entraîne généralement la formation de précipités. Une fois la mousse collapsée, le résidu solide récupéré nécessite un traitement particulier pour permettre sa valorisation ou son conditionnement. Afin de remédier à cet inconvénient, ce travail propose d'utiliser comme collecteur un tensioactif carboxylique polyéthoxylé, l'AKYPO® RO 90 VG, ayant la particularité de former des complexes ion-tensioactifs solubles, et ce également avec des ions multichargés. Ce travail présente une étude poussée des mécanismes fondamentaux qui régissent l'extraction d'ions par formation de mousses. Dans une première partie, les propriétés tensioactives et acide base du collecteur en solution sont étudiées en combinant nombre de techniques indépendantes que sont le dosage pHmétrique, la tensiométrie et la diffusion aux petits angles. L'évolution de ces propriétés en présence de différents sels de nitrates (Nd, Eu, Ca, Sr, Cu, Li, Na, Cs) couplée à des mesures électrophorétiques donneront une première approche de la sélectivité. Enfin, l'ensemble de ces données associées à une étude de la formation des complexes tensioactif/ion permettra d'établir la spéciation du système Nd/AKYPO® en fonction du pH. Dans une seconde partie, l'analyse de la conductimétrie et de la diffusion de neutron aux petits angles permettront d'établir les paramètres régissant la formation et stabilité des mousses de flottation. Le pH et la nature des ions ajoutés, leur nombre de charge ainsi que leur nature chimique, apparaissent ainsi comme les paramètres majeurs gérant l'humidité et l'épaisseur de film des mousses. La dernière partie est dédiée à la compréhension des expériences d'extraction/séparation ionique par flottation en s'appuyant sur l'ensemble des résultats obtenus précédemment. Il est montré que la flottation du néodyme est fortement liée à sa spéciation, pouvant conduire à sa dés-extraction ou sa flottation sous forme particulaire. Il est également montré que le néodyme induit un phénomène de déplétion des ions monovalents dans la mousse. Cette spécificité ionique permet d'envisager le système étudié pour la séparation d'ions par le procédé de flottation. / Ion foam flotation allows to concentrate ions in a foam phase formed by a soap. For classical systems, the strong interaction between ions and surfactant generally leads to the formation of precipitates and of froth. When the froth collapses, the solid residue thus recovered requires a recycling or conversion. In order to remedy this, the present work uses as collector a polyethoxylated carboxylic surfactant, AKYPO® RO 90 VG, which forms soluble ion/surfactant complexes, even with multi-charge ions. This work presents a detailed study of the fundamental mechanisms that govern the extraction of ions by foaming. In the first part, surface activity and acid/base properties of the surfactant in solution are determined by combining numerous independant techniques which are pHmetric dosage, tensiometry and small angle scattering. The evolution of these properties in the presence of different nitrate salts (Nd, Eu, Ca, Sr, Cu, Li, Na, Cs) coupled with electrophoretic measurements give a first approach to selectivity. Finally, all of these data combined with a study of the formation of surfactant/ion complexes allow us to determine the speciation of Nd/AKYPO® system as a function of pH. In the second part, the analysis of the foam by conductivity and neutron scattering provides information on the wetness and foam film thickness, parameters governing foam stability. The pH and the nature of the added ions, their number of charge and also their chemical nature thus appear to be major parameters that governed wetness and foam film thickness. The last part is devoted to the understanding of the ion extraction/separation experiments by flotation based on all previous results. It is shown that the flotation of neodymium is strongly related to its speciation, which could lead to its re-extraction or its flotation in precipitated form. It is shown that, neodymium induces a phenomenon of mono-charge ion depletion in the foam. This ionic specificity allows to consider the studied system for ion separation by the flotation process.