Three norbornane fused dihydro-tetrathiafulvalene derivatives which contained the thiol, disulfide and acetylthio functionalities were synthesised. Cyclic voltammetry was used to measure the redox properties of the compounds, which showed that the molecules were able to undergo two reversible, one electron oxidation processes. X-ray structures of all three functionalities were obtained. The three compounds were sublimed onto Au(111) surfaces, and characterised using a number of surface science techniques. Disordered structures are formed initially for all three compounds when adsorbed at room temperature. Following progressive annealing of the substrate, highly ordered adlayer structures are formed that are believed to be bound to the surface via a gold adatom. Van der Waals and hydrogen bonding interactions are shown to play an important role in the formation of these ordered structures. The adsorption of triphenylphosphine sulfide on Au(111) is also investigated, using a combination of RAIRS and STM experiments. Here an extremely ordered (2√3×2√3)R30º structure is formed immediately upon deposition at 298 K. From the experimental data and DFT calculations, the orientation of the molecule is deduced. The attempted synthesis of a thiol functionalised donor-acceptor compound is also described, with a few previously unknown intermediate compounds being synthesised. Finally, a series of four known aryl amidoximes were synthesised. These were subsequently deposited on a Cu(111) crystal and studied using a vibrational spectroscopy. Three of the compounds were found to decompose to varying degrees during the sublimation process. The possible conformations of the amidoxime group on the copper surface are discussed.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

No description available.

Les travaux de cette thèse concernent la compréhension à l'échelle atomique des processus physico chimiques intervenant aux interfaces et dans des phases diluées. Pour commencer, nous avons étudié l'interaction entre la molécule 1,4-diazabicyclo [2.2.2]octane (DABCO) et un atome de gaz rare (He, Ne, Ar, Kr). Nous avons effectué une analyse systématique de ces systèmes, et nous en avons conclu que la méthode MP2 associée à une base diffuse est suffisamment précise pour décrire le système DABCO – Ar. Les surfaces d'énergie potentielle des complexes DABCO – gaz rare ont été calculées, ce qui nous a permis de réattribuer les spectres expérimentaux de ces espèces. Ensuite, nous nous sommes concentré sur les complexes DABCO – Arn (avec n = 2, 3, 4) neutres et ioniques. Nous avons montré que le DABCO interagi avec les atomes d'argon, et subit des déformations dues à l'effet de cette interaction faible sur ses modes de vibration. Par la suite, nous avons étudié les plus bas états électroniques du DABCO – Arn (n = 1, 2, 3). Nos résultats pourront être étendus à l'interprétation qualitative des études spectroscopiques et dynamiques des molécules de DABCO absorbés dans de grands agrégats d'argon. Enfin, nous avons étudié l'interaction entre l'imidazole et une couche d'or en présence de CO2. Nous avons montré que la molécule d'imidazole se fixe à l'agrégat d'or par une liaison covalente entre l'atome d'azote et un atome d'or, ainsi que des interactions faibles de type van der Waals entre les atomes d'hydrogène et la surface d'or. Nous avons déterminé que le site préférentiel pour l'interaction imidazole – or est le site top. Cette interaction permet un transfert de charge de l'imidazole vers la surface d'or, ce qui affecte la capture du CO2 (environ 50% plus faible par rapport à l'interaction Im(seule) – CO2). Mais l'augmentation du nombre de molécules d'imidazole à la surface de la couche d'or pourrait permettre une liaison plus forte entre le CO2 et l'imidazole / This thesis concern the understanding at the atomic level of physicochemical processes occurring at interfaces and dilute phases. First, we studied the interaction between the 1,4- diazabicyclo [2.2.2] octane (DABCO) molecule and a rare gas atom (He, Ne, Ar, Kr). We conducted a systematic analysis of these complexes, and we concluded that the MP2 method with a diffuse basis set is accurate to describe the system DABCO – Ar. The potential energy surfaces of DABCO – rare gas complexes were calculated, which allowed us to reatribuate the experimental spectra of these species. Then, we focused on DABCO – Arn (n = 2, 3, 4) neutral and ionic clusters. We have shown that the DABCO interacted with argon atoms and undergoes deformation due to the effect of the weak interaction on his vibrational modes. Subsequently, we studied the lowest electronic states of DABCO – Arn (n = 1, 2, 3). Our results can be extended to the qualitative interpretation of spectroscopic and dynamic studies of absorbed DABCO in large argon clusters. Finally, we studied the interaction between imidazole and a gold surface with CO2. We have shown that the imidazole molecule binds to the gold surface by a covalent bond between the nitrogen atom and a gold atom, and van der Waals interactions between hydrogen atoms and the gold surface. We determined that the preferred site for the imidazole – gold interaction is the top site. This interaction allows a charge transfer from the imidazole to the gold surface, which affects the capture of CO2 (about 50% lower compared to the interaction Im – CO2). But increase number of imidazole molecules on the gold surface could lead to a stronger bond between CO2 and imidazole

Polymer brushes represent a relatively new class of materials and are referred to an assembly of polymer chains tethered by one of their extremities to a surface by a chemical bond. Different techniques to produce polymer brushes exist but our privileged choice was about the ¡§grafting from¡¨ method due to the better control over the types of grafted polymer, the surface-grafting density, and the chain-lengths. In our project, we focused on polymerizations from self-assembled monolayers of thiol chemisorbed on gold surface, bearing end-group functions as anchoring sites. The main objective of this work is to develop multifunctional polymeric surfaces composed by micro-domains of diverse compounds, which contain opposite features. Poly(ƓÕ-caprolactone) and poly(L,L-lactide)-based brushes both known for their high degree of crystallinity and hydrophobicity, and poly(dimethylamino ethyl methacrylate) (PDMAEMA)-based brushes for their hydrophilicity and external stimuli responsive characteristics were investigated. Moreover, the design of these advanced materials can be achieved with patterning technique such as micro-contact printing, leading to a spatial confinement of the polymer brushes. In order to reach our objective, the thesis was decomposed in different parts. First, the preparation of homogeneous and heterogeneous monolayers derived from thiols on gold surface will be investigated. Secondly, the ¡§grafting from¡¨ synthesis of homo-polymers from thiol end group will be carried out. This part required the development of synthesis conditions for both types of homopolymer brushes. Subsequently, these parameters were applied to the creation of a binary system by the growth of two different macromolecular chains on the same substrate. Finally, upon the ¡§smart¡¨ behavior of PDMAEMA, the potential of the polymer as chemical sensor was evaluated with single walled and multi walled-carbon nanotubes (SW- and MW-CNTs) as interesting conductive (nano)fillers.

No description available.

No description available.

This thesis focuses on the design, synthesis and development of dynamic multivalent nanostructures such as supramolecular dendrimers, liposomes and gold-functionalized nanostructures. These structures can be used for drug delivery and molecular sensing applications. This thesis is divided into three parts: In part one, a general introduction to self-assembly, dynamic systems, metalligand exchange, nanostructured dendritic scaffolds, liposomes and gold nanostructures is given. In part two, a microwave approach is presented as an efficient method for the regioselective deuteration of bipyridine scaffolds. Dynamic systems based on transition metal-bipyridine coordination complexes were investigated. The compositional self-adaptation and kinetics of these dynamic systems were successfully assessed by ESI-MS. Based on this amphiphilic dendrimers/metallodendrimers were also designed and synthesized via  a convergent strategy. Their ability to self-assemble into supramolecular assemblies and their controlled disassembly was effectively demonstrated. In part three, two types of drug delivery systems based on dynamic multivalent nanostructures of glycodendrimers/metalloglycodendrimers and drugpresenting liposomes were developed. The dynamic self-assembly of these architectures into supramolecular nanostructures with site-specific functionality through interacting carbohydrate or cholesterol moieties was assessed. The host-guest interaction/encapsulation and controlled release with external stimuli were studied using a fluorescent probe, as well as selected drug molecules. The antibacterial property of the drug delivery systems was also evaluated, demonstrating an enhanced bactericidal activity. A new, rapid and simple approach for the functionalization of plasmonic gold nanostructured surfaces was also developed. The optical performance and light-specific sensitivity of the fluorescent probe on the resulting nanostructures were also presented. / <p>QC 20151119</p>

Δύο από τα πιο γνωστά μη γραμμικά οπτικά φαινόμενα που λαμβάνουν χώρα κατά την ακτινοβόληση επιφανειών χρυσού με ισχυρούς παλμούς laser είναι η γένεση πολλαπλών αρμονικών και η πολυφωτονική φωτοηλεκτρική εκπομπή. Οι διεργασίες αυτές αποτελούν το αντικείμενο της παρούσας διδακτορικής διατριβής. Κατ' αρχήν η προσπάθεια επικεντρώνεται στην ανάπτυξη ρεαλιστικών μοντέλων περιγραφής των συγκεκριμένων φαινομένων. Εν συνεχεία πραγματοποιούνται αριθμητικοί υπολογισμοί με στόχο την αναπαραγωγή πρόσφατων πειραματικών δεδομένων μέσω της οποίας προτείνονται νέες ιδέες αξιοποίησης των εν λόγω διεργασιών. / Multiple harmonic generation and multiphoton photoelecton emission are the most important nonlinear optical phenomena that take place when a metal surface is illuminated with intense laser pulses. The main objective of this work is the development of realistic theoretical models for these processes. Numerical calculations for several pulse widths are also presented. Through these calculations the validity of the models is checked and new experimental perspectives are proposed.

La microscopie SEEC (Surface Enhanced Ellipsometric Contrast) est une technique inventée au mans, il y a une dizaine d’années. Elle permet de visualiser des objets de taille nanoscopique entre polariseur et analyseur croisés en utilisant les propriétés non dépolarisantes de surfaces multicouches. Jusqu’au début de la thèse, seules des observations à l’air étaient possibles. Le but de cette thèse a consisté à adapter cette technique à l’observation in-situ d’objets en immersion dans l’eau.Pour cela, il a fallu inventer de nouvelles surfaces propres à ce nouveau milieu. Les calculs ont montrés que des surfaces fines d’or révélaient un bon contraste pour des objets de 1 nm en immersion dans l’eau. Expérimentalement, nous avons montré que pour exploiter au maximum le contraste SEEC, il est nécessaire de modifier l’éclairage. En parallèle de ces travaux expérimentaux, de nouveaux calculs ont montrés que l’utilisation d’épaisseurs encore plus fines permettait de visualiser ces objets avec un bon contraste et sans aucune modification de l’éclairage. Nous avons appelé cette nouvelle technique : la microscopie CONE. Nous avons découvert deux modes de mesure. Après avoir réalisé des fonctionnalisations homogènes et hétérogènes des surfaces d’or. Ces surfaces ont été utilisées en résonance plasmonique de surface (SPR) pour l’étude de fixation de protéine (adsorption et immobilisation) puis d’interaction protéine/protéine. Ces expériences ont ensuite servies de référence pour évaluer les microscopies SEEC et CONE. Par cela, nous avons prouvé que ces microscopies présentent de forts intérêts pour la détection in-situ de protéines avec un faible coût. / This thesis was supported by National Agency for Research with the project: ANR PNANO-07 SEEC. The Surface Enhanced Ellipsometric Contrast (SEEC) microscopy has invented in 2000 at Le Mans (France). This technique allows the visualization of nanoscopic object between crossed analyzer and polarizer. It’s possible if some special multilayer surfaces are used. There surfaces must have the particularity to not change the polarization of light during the reflection. Until the beginning of the project the SEEC microscopy was useful only for air observations. The goal of the thesis was to adapt this technique to observe on gold surfaces immerged in water and to compare the performance of the SEEC microscopy with Surface Plasmonique Resonance (SPR) in that configuration. The SPR is a biomolecular interaction study reference technique. SEEC microscopy lateral resolution was evaluate by fluorescence microscopy. Next, we realize two model experiments monitor in parallel by SEEC microscopy and by SPR: BSA immobilization and biotinylated IgG fixation by immobilized streptavidine. To compare measurements efficiently we did a huge preparation work (surface functionalizations and microfluidic) to have exactly same conditions in both techniques.Our results show SEEC microscopy cannot replace SPR for biomolecular interaction studies but it can be used as cheap immunological diagnostic technique. This work gives the path to follow on that direction.