Les microcapteurs implantables sont des outils de choix pour l’étude du système nerveux central. Ils permettent d’analyser en temps réel la composition du milieu interstitiel du cerveau et les variations de concentration de neurotransmetteurs et de substrats métaboliques dans l’espace extracellulaire. La procédure d’immobilisation de l’enzyme sur l’électrode est une étape cruciale déterminant les performances du biocapteur. Nous avons développé une méthode d’immobilisation simple, non-toxique et peu chère en utilisant une molécule de poly(ethyleneglycol) diglycidyl éther (PEGDE) qui répond bien aux critères des applications cliniques. La méthode a été étudiée et optimisée sur trois enzyme: la Glucose oxydase, la D-amino acide oxydase et la Glutamate oxydase. Les capteurs développés se caractérisent par une forte sensibilité et un temps de réponse suffisamment court pour la détection des événements biologiques en temps réel. Les capteurs à base de PEGDE ont démontrés une bonne stabilité dans le temps et leur capacité de suivre en temps réel la variation de concentration de glucose dans le SNC du rat suite à l’injection d’insuline ou de glucose. Nous avons également adapté les méthodes d’immobilisation d’enzyme les plus utilisées dans le domaine des neurosciences: immobilisation par réticulation dans des vapeurs de Glutaraldéhyde ou par PEGDE, piégeage dans une matrice de sol-gel ou de polypyrrole dérivé, ou immobilisation dans une matrice d’hydrogel. Nous avons comparé les biocapteurs ainsi obtenus en termes de sensibilité, de stabilité in vivo, de temps de réponse et aussi de toxicité. Cette étude comparative nous a permis de conclure que le PEGDE représente un procédé d’immobilisation optimal car il ne demande pas de synthèse organique, contrairement à l’hydrogel, il n’est pas toxique contrairement au glutaraldehyde et il assure une immobilisation covalente plus stable que le piégeage dans des sol-gel ou polypyrrole. Cette étude comparative a mis également en évidence l’effet de la procédure de fixation de l’enzyme sur la spécificité du biocapteur. Nous avons montré que l’immobilisation par glutaraldehyde provoque une importante perte de sélectivité de l’enzyme. Quant au PEGDE, son immobilisation est assez douce pour préserver la spécificité naturelle de l’enzyme. Nous avons montré que la procédure d’immobilisation a un impact important sur la quantification des molécules dans les échantillons biologiques et in vivo. La validité des mesures sur nos capteurs a été contrôlée par HPLC ou électrophorèse capillaire. Nous avons également développé des sondes multisensibles en utilisant les techniques de microfabrication sur silicium. Le dispositif comporte une aiguille de 6mm en longueur, 100µm en largeur et 50 µm en épaisseur. Elle porte trois électrodes de taille 40x200µm. Ces dispositifs, optimisés pour réduire les effets d’interférence entre les électrodes, ont été pour le suivi simultané de glucose et lactate dans le SNC de rats anesthésiés. / Identification, monitoring and quantification of biomolecules in the CNS is a field of growing interest for identifying biomarkers of neurological diseases. In this thesis, silicon needle-shaped multi-molecules sensing microprobes were developed. Our microelectrode array design comprises a needle length of 6mm with 100x50 µm2 cross-section bearing three platinum electrodes with a size of 40x200 µm and 200µm spacing between them. We have used these microprobes for simultaneous glucose and lactate monitoring, using the third electrode for control of non-specific current variations. Local microdroplet protein deposition on the electrode surface was achieved using a pneumatic picopump injection system. Enzyme immobilization on the electrode surface is a key step in microelectrode biosensor fabrication. We have developed a simple, low cost, non-toxic enzyme immobilization method employing poly(ethyleneglycol) diglycidyl ether (PEGDE). Successful biosensor fabrication was demonstrated with glucose oxidase, D-amino acid oxidase, and glutamate oxidase. We found that these biosensors exhibited high sensitivity and short response time sufficient for observing biological events in vivo on a second-by-second timescale. PEGDE-based biosensors demonstrated an excellent long-term stability and reliably monitored changes in brain glucose levels induced by sequential administration of insulin and glucose solution. We then carried out a comparative study of five enzyme immobilization procedures commonly used in Neuroscience: covalent immobilization by cross-linking using glutaraldehyde, PEGDE, or a hydrogel matrix and enzyme entrapment in a sol-gel or polypyrrole-derived matrices. Enzymatic microelectrodes prepared using these different procedures were compared in terms of sensitivity, response time, linear range, apparent Michaelis-Menten constant, stability and selectivity. We conclude that PEGDE and sol-gel techniques are potentially promising procedures for in vivo laboratory studies. The comparative study also revealed that glutaraldehyde significantly decreased enzyme selectivity while PEGDE preserved it. The effects that immobilization can have on enzyme substrate specificity, produce dramatic consequences on glutamate detection in complex biological samples and in the CNS. Our biosensor’s results were systematically controlled by HPLC or capillary electrophoresis. The highly selective PEGDE-based biosensors allowed accurate measurements glutamate concentrations in the anesthetized and awaked rats at physiological conditions and under pharmacological and electrical stimulations. The microfabricated multielectrodes based on silicon needles coupled to the simple, non-toxic and mild immobilization method based on PEGDE, open new possibilities for specific neurotransmitter detection in the central nervous system and the study of cell-cell communication in vivo.

<p>Cellulose ethers and polyethylene glycols are used in drug formulations as water swelling or water soluble matrices. Polar lipids, for example monoglycerides, and surfactants can be used to solubilise hydrophobic or amphiphilic drugs and to formulate potential drug delivery vehicles such as emulsions, liposomes and cubic phases. In this thesis mixtures of these excipients are characterised in various environments, from dilute aqueous solutions to solid dispersions. Special focus has been on the understanding of the associating processes involved.</p><p>Detailed understanding of the association of cellulose ethers, of varying hydrophobicity, and amphiphilic substances is presented. The hydrophobicity of the polymer was found to have an impact on the interaction scheme. The amphiphiles were found to bind at lower amphiphile concentrations to a more hydrophobic polymer thus influencing both micro- and macroscopic structure of the aggregates. </p><p>The choice of counterion to the amphiphile has a small but significant effect on the interaction and the structure of the aggregates. Also amphiphilic drug molecules can interact with nonionic polymers in a similar way as surfactants in aqueous solution. Due to the higher cmc of the drug ibuprofen the interaction is largely influenced by the ionic strength of the solution. The type of amphiphile also influences the cooperativity of the amphiphile-polymer binding.</p><p>In more concentrated systems liquid crystals are formed into which the polymer interact with the amphiphiles. Both cubic and sponge phases were found with relatively large polymers interacting with polar lipids. These phases were found to swell and shrink mainly controlled by the amount of polymer inside them. Also membrane interacting substances added to the sponge phase could influence the size of the water channels in the phase. </p><p>In water free systems polymers and polar lipids were found to interact as well as forming solid dispersions. The behaviour of the phase separation between polymer and lipid depended on the concentration of the dispersed phase. The polar lipid was found to be distributed in the lamellar part of the semicrystalline polymer influencing the polymer folding.</p>

Today, assessment of the health of coastal waters is recognized as being important for both the conservation of nature and well-being of humans. Anthropogenic pollution has been the focus of extensive research for some time and a variety of programs for the monitoring and assessment of environmental pollution have been developed. Determination of the levels of pollution in sensitive ‘sentinels’ such as mussels, allows monitoring of these levels in a given area over a prolonged period of time. Furthermore, the biological effects of pollution are reflected in a series of biomarkers, none of which provides a general picture of the sentinel’s state of health and all of which are individually specific for certain pollutants and influenced by both biotic and abiotic factors. In an attempt to improve biomonitoring of marine pollution, we have developed two proteomic approaches here. In the first portion of the thesis, a proteomic analysis was performed on peroxisomes isolated from mussels exposed either to one of three model anthropogenic pollutants, or two different types of crude oil, or from mussels exposed to the Prestige oil spill. Application of two-dimensional electrophoresis (2-DE) provided protein expression signatures (PES) for exposure to these different pollutants.Furthermore, several individual protein components of these PES could be putatively identified. In the second portion of this work, such analysis of subproteomes was developed further in order to improve the applicability of this approach to biomonitoring. A simple fractionation procedure in combination with liquid chromatography and 2-DE provided samples from mussels residing in different regions of a pollution gradient around the harbor of Gothenburg, as well as from mussels exposed to two types of fuel oil similar to that of the Prestige that were suitable for environmental proteomics. In addition, we constructed a model for this approach that can be cross-validated in the future and applied to assess sources of fuel oil pollution in connection with biomonitoring programs.

Mixtures of chlorinated organic pollutants can be found in the soils at chlorophenol-contaminated sawmill, including (inter alia) polychlorinated phenols (CPs), phenoxyphenols (PCPPs), diphenyl ethers (PCDEs), dibenzofurans (PCDFs) and dioxins (PCDDs). These hydrophobic compounds have low water solubility and hence low mobility as truly dissolved compounds. However, they may migrate through the soil at significant rates via co-transport with dissolved organic matter (DOM) and colloids of fine, waterborne particulate matter. In the work underlying this thesis the distribution of chlorinated hydrophobic pollutants between these two mobile fractions in soil samples from five sawmill sites was studied Soils at five sites at which CPs were formerly used were characterized, and found to have complex profiles of chlorinated hydrophobic pollutants. CPs, PCPPs, PCDEs and PCDD/Fs were present at up to ppm-levels. Furthermore, the relative proportions of the pollutants differed from their relative proportions in the preservatives used at the sites, indicating that they have been transported from, and/or degraded in, the soil at different rates. These organic pollutants have low water solubility and strong affinity for soil organic matter (SOM). The importance of SOM for the fate of CPs, PCPPs, PCDEs, PCDFs and PCDDs in soil was investigated by examining the distribution of compounds between the mobile DOM and the immobile particulate organic matter (POM). The partitioning of CPs between DOM and POM was found to be approximately equal. However, the relative strength of association with POM of groups of chlorinated organic pollutants was positively correlated with their hydrophobicity, and thus increased in the order CP &lt; PCPP &lt; PCDE &lt; PCDF &lt; PCDD. Despite the weak association of PCDD/Fs with DOM our investigations found that considerable concentrations of these pollutants were bound to mobile fractions (DOM and colloids, &gt;0.2 µm) in both a groundwater analysis and a leaching test. CPs and PCPP were present at up to ppm- and ppb-levels, respectively, and PCDEs and PCDD/Fs at up to ppt-levels. The importance of transport in association with the mobile fraction (DOM and colloids) increased with increasing hydrophobicity e.g. PCDDs were almost entirely associated with fine particulate matter, while CPs were largely found in the water phase and only minor proportions were associated with colloids.

The present dissertation covers the total synthesis of viridiofungin triesters and studies toward the total synthesis of xeniolide F. In both cases, sigmatropic rearrangements of α-allyloxy substituted α,β-unsaturated esters are employed: for the viridiofungin ester synthesis a [2,3]-Wittig rearrangement and for the xeniolide F synthesis a catalytic asymmetric Claisen rearrangement CAC. For both rearrangement reactions the historical development, main characteristic and important variations are discussed. The viridiofungin triester synthesis represents a convergent and highly flexible route toward these natural products. The [2,3]-Wittig rearrangement allowed the diastereoselective synthesis of the polar head group with two adjacent stereogenic centers. The E-configured double bond was formed by a Julia-Kocienski olefination. During the studies toward the total synthesis of xeniolide F a new, diastereoselective strategy for the generation of allyl vinyl ethers with E-configured vinyl ether double bond was established employing rhodium catalyzed OH-insertion and an E-selective Horner-Wadsworth-Emmons olefination. Under the conditions of the catalytic asymmetric Claisen rearrangement (CAC) this highly substituted allyl vinyl ether rearranged diastero- and enantioselectively to the corresponding a-keto ester. This example clearly illustrates the high potential of the CAC as synthetic tool for natural product synthesis. / In der vorliegenden Arbeit wird die Totalsynthese von Tirestern der Viridiofungine A, A2 und A4 sowie die Synthese eines Schlüsselintermediates für die Totalsynthese von Xeniolid F dargestellt. In beiden Fällen wird ausgehend von einem α-allyloxysubstituierten α,β-ungesättigten Ester eine Umlagerungsreaktion als Schlüsselschritt eingesetzt: im Falle der Viridiofunginester eine diastereoselektive [2,3]-Wittig-Umlagerung, bei den Arbeiten zur Totalsynthese von Xeniolid F eine diastero- und enantioselektive, katalytische Claisenumlagerung. Für beide Umlagerungsreaktionen werden ausführlich die theoretischen Hintergründe sowie die historische Entwicklung und wichtige Varianten besprochen. Mit der Viridiofungintriestersynthese wird eine konvergente und bezüglich der lipophilen Seitenkette sehr flexible Syntheseroute vorgestellt. Die [2,3]-Wittig-Umlagerung konnte dabei erfolgreich für die diastereoselektive Synthese der hochsubstituierten, polaren Kopfgruppe der Viridiofunginester mit zwei benachbarten stereogenen Zentren (davon eines quartär) eingesetzt werden. Zur Bildung der E-konfigurierten Doppelbindung wurde die Julia-Kocienskie-Olefinierung ausgenutzt. Bei den Arbeiten zur Totalsynthese von Xeniolid F wurde eine neuartige Strategie zur diastereoselektiven Synthese eines Allylvinylethers mit E-konfigurierter Vinyletherdoppelbindung eingesetzt. Die Horner-Wadsworth-Emmons-Olefinierung (HWE-Olefinierung) generierte dabei E-selektiv die Vinyletherdoppelbindung. Das für die HWE-Olefinierung benötigte Phosphonat wurde durch rhodiumkatalysierte OH-Insertion aus einem Allylalkohol und einem Diazaphosphonoacetat hergestellt. Der hochsubstituierte Allylvinylether wurde unter den Bedingungen der katalytisch asymmetrischen Claisenumlagerung umgesetzt und führte mit exzellenter Diastereo- und Enantioselektivität zum entsprechenden α-Ketoester. Anhand dieses Beispiels konnte das Potential der katalytisch asymmetrischen Claisenumlagerung zum Aufbau von hochfunktionalisierten Bausteinen für die Naturstoffsynthese verdeutlicht werden.

Cellulose ethers and polyethylene glycols are used in drug formulations as water swelling or water soluble matrices. Polar lipids, for example monoglycerides, and surfactants can be used to solubilise hydrophobic or amphiphilic drugs and to formulate potential drug delivery vehicles such as emulsions, liposomes and cubic phases. In this thesis mixtures of these excipients are characterised in various environments, from dilute aqueous solutions to solid dispersions. Special focus has been on the understanding of the associating processes involved. Detailed understanding of the association of cellulose ethers, of varying hydrophobicity, and amphiphilic substances is presented. The hydrophobicity of the polymer was found to have an impact on the interaction scheme. The amphiphiles were found to bind at lower amphiphile concentrations to a more hydrophobic polymer thus influencing both micro- and macroscopic structure of the aggregates. The choice of counterion to the amphiphile has a small but significant effect on the interaction and the structure of the aggregates. Also amphiphilic drug molecules can interact with nonionic polymers in a similar way as surfactants in aqueous solution. Due to the higher cmc of the drug ibuprofen the interaction is largely influenced by the ionic strength of the solution. The type of amphiphile also influences the cooperativity of the amphiphile-polymer binding. In more concentrated systems liquid crystals are formed into which the polymer interact with the amphiphiles. Both cubic and sponge phases were found with relatively large polymers interacting with polar lipids. These phases were found to swell and shrink mainly controlled by the amount of polymer inside them. Also membrane interacting substances added to the sponge phase could influence the size of the water channels in the phase. In water free systems polymers and polar lipids were found to interact as well as forming solid dispersions. The behaviour of the phase separation between polymer and lipid depended on the concentration of the dispersed phase. The polar lipid was found to be distributed in the lamellar part of the semicrystalline polymer influencing the polymer folding.

Brominated flame retardants (BFRs) are chemicals used in e.g. electronic equipment, textiles and plastics for the prevention of fire. Over recent decades, concern has been raised regarding some heavily used BFRs, since the levels in the environment have been increasing. In the present thesis, persistent, bioaccumulative, and toxic (PBT) properties were studied for a structurally varied set of BFRs selected to represent more than 60 organic BFRs. The studied BFRs include: 2,4,4'-tribromodiphenyl ether (BDE 28), 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE  183), decabromodiphenyl ether (BDE 209), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), tetrabromobisphenol A 2-hydroxyethyl ether (TBBPA OHEE), 2,4,6-tribromophenol (246BrPh), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), and hexabromobenzene (HxBrBz). It is likely that soil will act as a sink for BFRs. Therefore, studies of BFRs were performed on persistence in soil, and on bioaccumulation from soil in the earthworm Eisenia fetida. Large variation in the biodegradability in soil among the tested BFRs was observed. The studied brominated diphenyl ethers (BDE 28 and BDE 209) were very persistent under both aerobic and anaerobic conditions, while 246BrPh and TBECH degraded quickly in both aerobic and anaerobic soil. The bioaccumulation in earthworm from soil was high for HxBrBz, TBECH and for tested brominated diphenyl ethers with 4-6 bromine atoms (BDE 47, BDE 99, and BDE 153). Bioaccumulation was also studied in zebrafish after dietary exposure to a mixture of BFRs. It was shown that several metabolites were formed and retained in zebrafish, which highlights the importance of also searching for and identifying persistent degradation products. Maternal transfer was shown for all BFRs present in the female zebrafish. This shows that zebrafish young (fry) are exposed to these BFRs at approximately the same concentrations as female zebrafish during the early-life stages, when fish are usually most sensitive to organic contaminants. Toxicity of individual BFRs and a BFR mixture was studied in Nitocra spinipes using a silica gel-based system. Highest toxicities were observed for BDE 28, TBBPA, and TBBPA OHEE. In the mixture toxicity study, simultaneous exposure to low concentrations (individually causing no significant effect) of six BFRs significantly affected the survival of Nitocra spinipes. The results from the PBT studies presented in the thesis and literature data were compared with the criteria for PBT classification, as set in the European REACH legislation. Further, some BFRs with physico-chemical properties similar to those of identified PBTs were suggested to be prioritized for future PBT testing.

L’électrofilage est un procédé permettant de préparer des fibres possédant un diamètre de l’ordre du micromètre ou de quelques centaines de nanomètres. Son utilisation est toutefois limitée par le manque de contrôle sur la structure et les propriétés des fibres ainsi produites. Dans ce travail, des fibres électrofilées à partir de mélanges de polystyrène (PS) et de poly(vinyl méthyl éther) (PVME) ont été caractérisées. La calorimétrie différentielle à balayage (DSC) a montré que les fibres du mélange PS/PVME sont miscibles (une seule transition vitreuse) lorsque préparées dans le benzène, alors qu'une séparation de phases a lieu lorsque le chloroforme est utilisé. Les fibres immiscibles sont néanmoins malléables, contrairement à un film préparé par évaporation du chloroforme qui a des propriétés mécaniques médiocres. Des clichés en microscopies optique et électronique à balayage (MEB) ont permis d’étudier l'effet de la composition et du solvant sur le diamètre et la morphologie des fibres. Des mesures d’angles de contact ont permis d’évaluer l’hydrophobicité des fibres, qui diminue avec l’ajout de PVME (hydrophile); les valeurs sont de 60° supérieures à celles des films de composition équivalente. Un retrait sélectif du PVME a été réalisé par l’immersion des fibres dans l’eau. La spectroscopie infrarouge a montré que la composition passe de 70 à 95% de PS pour une fibre immiscible mais seulement à 75% pour une fibre miscible. Ces résultats indiquent que la phase riche en PVME se situe presque uniquement à la surface des fibres immiscibles, ce qui a été confirmé par microscopie à force atomique (AFM) et MEB. Finalement, l’effet du mélange des deux solvants, lors de l’électrofilage du mélange PS/PVME, a été étudié. La présence du chloroforme, même en quantité réduite, provoque une séparation de phases similaire à celle observée avec ce solvant pur. / Electrospinning is a simple method for the preparation of polymer fibers with diameters of hundreds of nanometers to a few micrometers. Although it is a versatile method, some issues remain in the control of the structure and properties of electrospun fibers. In this study, fibers electrospun from polystyrene (PS)/poly(vinyl methyl ether) (PVME) blends were characterized. Differential scanning calorimetry (DSC) revealed that fibers electrospun from benzene are miscible while a phase separation occurs when the fibers are electrospun from chloroform. While films cast from chloroform show poor mechanical properties, immiscible fibers are ductile. The effects of the blend composition and the solvent on the fiber diameter and morphology were observed by scanning electron microscopy (SEM) and optical microscopy. Afterwards, contact angle measurements were made to evaluate the hydrophobicity of the fibers which decreases as hydrophilic PVME is added to the blend; the values for the fibers were found to be 60° higher than their equivalent in films. PVME was selectively removed from the immiscible fibers by complete immersion into water. Infrared spectroscopy revealed that this process increases the PS content from 70 to 95% for immiscible fibers but only to 75% for miscible fibers. These results show that the PVME-rich phase is almost completely distributed on the fiber surface, which was confirmed by atomic force microscopy (AFM) and SEM. Finally, the electrospinning of PS/PVME blends from chloroform/benzene solutions was studied. The presence of chloroform, even as a residual amount, causes a phase separation just as it does in fibers electrospun from pure chloroform.

Cette thèse est une enquête épistémologique qui s’interroge sur la persistance de « l’éther » dans le champ de la technologie. De façon générale, le mot « éther » évoque un modèle conceptuel de la physique pré-einsteinienne, celui d’un milieu invisible permettant la propagation de la lumière et des ondes électromagnétiques. Or, ce n’est là qu’une des figures de l’éther. Dans plusieurs mythologies et cosmogonies anciennes, le nom « éther » désignait le feu originel contenu dans les plus hautes régions célestes. Aristote nommait « éther », par exemple, le « cinquième être », ou « cinquième élément ». La chimie a aussi sa propre figure de l’éther où il donne son nom à un composé chimique, le C4H10O, qui a été utilisé comme premier anesthésiant général à la fin du XIXe siècle. L’apparition soutenue dans l’histoire de ces figures disparates de l’éther, qui a priori ne semblent pas entretenir de relation entre elles, est pour nous la marque de la persistance de l’éther. Nous défendons ici l’argument selon lequel cette persistance ne se résume pas à la constance de l’attribution d’un mot ou d’un nom à différents phénomènes dans l’histoire, mais à l’actualisation d’une même signature, éthérogène. À l’invitation d’Agamben et en nous inspirant des travaux de Nietzsche et Foucault sur l’histoire-généalogie et ceux de Derrida sur la déconstruction, notre thèse amorce une enquête historique motivée par un approfondissement d’une telle théorisation de la signature. Pour y parvenir, nous proposons de placer l’éther, ou plutôt la signature-éther, au cœur de différentes enquêtes historiques préoccupées par le problème de la technologie. En abordant sous cet angle des enjeux disparates – la légitimation des savoirs narratifs, la suspension des sens, la pseudoscience et la magie, les révolutions de l’information, l’obsession pour le sans-fil, l’économie du corps, la virtualisation de la communication, etc. –, nous proposons dans cette thèse autant d’amorces pour une histoire autre, une contre-histoire. / This dissertation stands as an epistemological inquiry into the persistence of the notion of ether within technology’s discursive field. Most often, the word “ether” is understood as a conceptual model in pre-einsteinian physics which designates the medium responsible for the propagation of electromagnetic waves and light. However, this proves to be only one of the many figures of ether. In multiple mythologies and cosmogonies, ether was also the name employed to refer to a sublime and pure fire filling the highest spaces of the universe. Aristotle, for example, named “ether” what he considered to be the “fifth being,” or the “fifth element.” Chemistry also makes use of ether, where the name denominates the compound C4H10O, used as the first general anaesthetic agent at the end of the nineteenth century. From our point of view, the sustained occurrences of ether in these different figures, so disparate indeed that they appear unrelated, marks the manifestation of its persistence. We argue that this persistence should not be narrowed down to a constant attribution of a “word” or a “name” to several historical phenomenons, but rather should be viewed as the actualization of a same etherogeneous “signature.” Responding to an invitation by Italian philosopher Agamben, and building on Nietzsche’s and Foucault’s history-genealogy as well as on Derrida’s deconstruction, our dissertation proposes an historical program oriented towards a theorization of the signature. To do so, we suggest locating the ether, or rather the ether-signature, at the heart of several historical inquiries concerned with the contemporary problem with technology. Approaching some of theses issues –the legitimating of narrative knowledge, the suspension of the senses, pseudoscience and mysticism, information and industrial revolutions, wireless obsessions, body and corporeality, virtualization of communication, etc. –, our dissertation aims at locating and articulating as many baits towards an-other history, a counter-history.

Les sels d’imidazolium ont un rôle important dans certaines protéines et acides nucléiques et ont été utilisés à de nombreuses reprises dans des assemblages supramoléculaires en raison de leurs propriétés uniques. Les sels de diimidazolium dérivés sont toutefois moins connus. Ils ont pour l’instant uniquement été utilisés comme des précurseurs de carbènes N-hétérocycliques. Ils sont donc à la base de plusieurs catalyseurs utilisés pour des réactions de couplage croisés mais leurs propriétés sont toutefois méconnues dans le cadre de la chimie supramoléculaire. Cette classe de composés a nottament attiré notre attention en raison de la facilité de modification de leurs propriétés physico-chimiques par modification de leur structure chimique. L’objectif général des travaux présentés dans cette thèse est l’étude des propriétés supramoléculaires des sels de diimidazolium disubstitués en solution (aqueuse ou organique), ainsi qu’en phase solide ou cristal-liquide. L’influence de l’espaceur entre les deux noyaux imidazolium ainsi que l’influence des substituants latéraux et des contre-ions a été étudiée. Dans un premier temps, les propriétés de complexation des sels de diimidazolium à des macrocycles sont étudiées. Les sels bromure sont étudiés en solution aqueuse avec plusieurs cyclodextrines et le cucurbit[7]uril, et les sels hexafluorophosphate sont étudiés en solution organique pour leur complexation avec l’éther couronne DB24C8 et un calix[4]arène. Cette nouvelle classe de composés a montré de très bonnes propriétés de complexation à ces différents macrocycles en solution et a également permis de contrôler différents assemblages supramoléculaires à l’interface air-eau. Dans un deuxième temps, l’étude des sels de phénylènediimidazolium a permis de modifier les propriétés de complexation en solution pour obtenir la formation de complexes multiples avec le cucurbit[7]util en solution aqueuse. Cette même famille de composés a également permis la formation de cristaux liquides ioniques lorsque les substituants sont des chaînes alkyles plus longues. La résolution de plusieurs structures cristallines de différents sels de diimidazolium a finalement permis de comprendre la nature des interactions intermoléculaires à l’état cristallin. La recherche présentée dans cette thèse a donc permis une étude détaillée des propriétés supramoléculaires des sels de diimidazolium dans tous les états de la matière qui leur sont accessibles. / Imidazolium salts play an important role in different proteins and nucleic acids and have been used many times in supramolecular assemblies due to their unique properties. Diimidazolium salts derived from imidazolium salts are less known. To date, they have only been used as precursors for N-heterocyclic carbenes, which are used to catalyze various cross-coupling reactions. Their properties are not well known in supramolecular chemistry. This class of compounds attracted our attention because of the ease of tuning their properties by modifying their chemical structure. The main goal of the research presented in this thesis was to study the supramolecular properties of disubstituted diimidazolium salts in solution (aqueous or organic solution), in the solid state and in the liquid-crystalline state. The role of the spacer between the two imidazolium moieties, of the sidechains and of the counterions was studied. Firstly, the complexation between diimidazolium salts and various macrocycles was studied. Bromide salts were studied in aqueous solution with cyclodextrins and cucurbit[7]uril, while hexafluorophosphate salts were studied in organic solution with a DB24C8 crown ether and a calix[4]arene. This novel class of compounds showed very promising complexation properties with these macrocycles in solution and also allowed us to control the formation of various supramolecular assemblies at the air-water interface. Secondly, phenylenediimidazolium salts were studied and allowed the modification of the complexation properties in aqueous solution. Multiple complexes can be formed simultaneously with cucurbit[7]uril in aqueous solution. The same class of compounds also has the ability to yield ionic liquid crystals when the alkyl sidechains are long. The resolution of the crystalline structures of some synthesized diimidazolium salts allowed us to understand the nature of the intermolecular interactions in the solid state. The research presented in this thesis is a complete study of the supramolecular properties of diimidazolium salts in every accessible state of matter.