Les complexes de coordination supramoléculaires constitués de briques moléculaires chirales sont bien décrits dans la littérature. En revanche, les systèmes combinant briques moléculaires chirales et chiralité inhérente restent encore très peu explorés. C'est dans ce contexte que s'inscrit ce travail de recherche. Nous avons étudié de nouveaux ensembles supramoléculaires de coordination tridimensionnels chiraux pour des applications potentielles en catalyse. La synthèse a été développée par auto-assemblage de briques moléculaires différentes : ligands azotés bitopiques, ligands tritopiques et complexes de coordination. Neuf auto-assemblages différents ont été réalisés avec les ligands bitopiques dérivés de l'imidazole et de complexes de Pd (II) et de Pt (II). Les auto-assemblées triangulaires T-7, T-9, T-10, T-12, T-13 et T-15 ont été obtenues majoritairement alors que les structures T-11, C-11a et C-11b ou encore T-14 et C-14, ont été obtenues sous la forme d'un mélange triangle-carré dont les proportions dépendent de la concentration et de la nature du solvant. Leur caractérisation et l'étude de leur structure en solution ont permis de mettre en évidence une chiralité inhérente à leur structure. A notre connaissance, l'auto-assemblée T-7 est la première structure triangulaire chirale, composée de briques moléculaires achirales, complètement caractérisée en solution. A partir de l'auto-assemblage ligand tritopique / ligand bitopique / complexe métallique, trois structures prismatiques chirales ont été synthétisées grâce à l'encapsulation d'un invité pyrènecarboxaldéhyde (I-8). La structure Prism-2 a été obtenue avec un excellent rendement et une très bonne pureté. Sa caractérisation par spectroscopie RMN en solution et son analyse en DFT ont permis de déterminer la chiralité inhérente de la structure obtenue comme un racémique P-(Prism-2⊃(I-8)2) et M-(Prism-2⊃(I-8)2). L'analogue énantiopur Prism-3 est obtenu par l'auto-assemblage de L4Me, 4tpt et du complexe énantiopur Pd-5 en présence de I-8. La spectroscopie RMN en solution a permis de déterminer la configuration de l'énantiomère obtenu, (λ,P)-(Prism-3⊃(I-8)2), et confirme la chiralité inhérente de ces structures prismatiques. / Supramolecular coordination complexes, constituted of chiral molecular bricks, are well described in the literature. However, supramolecular complexes combining chiral building blocks and inherent chirality are underexplored. In this context, we have undertaken the synthesis of novel chiral three-dimensional supramolecular coordination complexes for their potential uses in catalysis. Their synthesis have been carried out by self-assembly of different molecular bricks: ditopic and tritopic nitrogen-ligands, and coordination complexes. Nine different self-assemblies have been synthesized with imidazole-based ditopic ligands and palladium(II), or platinum(II), coordination complexes. On the one hand, the triangular self-assemblies T-7, T-9, T-10, T-12, T-13 and T-15 have been obtained as the major component. On the other hand, structures T-11, C-11a-b or T-14 and C-14 have been obtained as a mixture of triangular and square structures in a ratio depending on the concentration and the solvent. The full characterization of these structures in solution has shown their inherent chirality. To our knowledge T-7 is the first triangular supramolecular coordination complex constituted of achiral components shown to be chiral in solution. Self-assembly syntheses of tritopic and ditopic ligands as well as palladium(II) coordination complexes were carried out, in the presence of pyrenecarboxaldehyde (I-8). Three chiral prismatic structures have been obtained. Prism-2 has been characterized by NMR spectroscopy in solution and DFT analysis which supports its inherent chirality. The racemic (P-(Prism-2⊃(I-8)2) / M-(Prism-2⊃(I-8)2)) has been isolated with an excellent yield and a very good purity. Prism-3, an enantiopure analog of Prism-2, was obtained by self-assembly synthesis of L4Me, 4tpt and the enantiopure coordination complex Pd-5 in the presence of I-8. The configuration of the isolated enantiomer was carried out by NMR spectroscopy in solution and assigned to (λ,P)-(Prism-3⊃(I-8)2), confirming the inherent chirality of the different prismatic structures.

Les matériaux chiraux peuvent avoir une forte influence sur la propagation de la lumière et ont attiré l'attention de la communauté des nanosciences. Les nanoparticules d'or, matériaux plasmoniques stables ayant une activité dans le visible (400 à 800 nm), sont des objets attrayants en tant que blocs de construction pour la formation de matériaux optiques. Précédemment, nous avons conçu et obtenu des Goldhelices en greffant des nanoparticules d’or sur des nano structures hélicoïdales de silice. Le travail présenté dans cette thèse vise à développer et à organiser les Goldhelices de manière à améliorer, modifier, réduire, voire même éliminer les propriétés chiroptiques. Les détails des nanostructures ainsi que la cinétique de formation de l'auto-assemblage organique utilisé comme support pour la formation de Goldhelices sont étudiés. Des Goldhelices sont ensuit organisées hiérarchiquement à l’aide de trois techniques : la microfluidique, le « dip coating » et le « Grazing Incidence Spraying ». Enfin, l’effet de ces organisations sur les propriétés optiques sont caractérisées par spectroscopies chirales et ellipsométrie. Nous démontrons qu'un tel système peut être utilisé pour la création de polariseur linéaire ou circulaire où une telle polarisation est uniquement dépendant par l'organisation des Goldhelices. / Chiral materials can have strong influence on the propagation of light and have attracted attention in the nano-science community. Gold nanoparticles (GNPs), stable plasmonic materials in the visible range (400-800 nm), are attractive objects as building blocks for optical materials. We have designed and obtained Goldhelices by grafting GNPs on silica nano-helical structures. The work presented in this thesis aims at developing tunable Goldhelices and organizing them in order to enhance, modify, reduce or even eliminate the chiroptical properties. The details of the nanostructures as well as the kinetics of formation of organic self-assembly which is used as templates for the formation of Goldhelices are fully studied. The hierarchical organization of the Goldhelices is investigated by the use of three techniques, the microfluidics, the dip-coating and the grazing incident spraying. Finally, the effect of the organization on their optical properties are characterized by chiral spectroscopies and Mueller matrix polarization ellipsometry. We demonstrate that such a system can be used for the creation of linear or circular polarizer where such polarization is solely tunable by the organization of the Goldhelices.

One-dimensional (1D) nanomaterial self-assembly offers an excellent approach to the fabrication of highly complex nanodevices. Despite considerable effort and research, precisely controlling the orientation and positioning of nanowires (NWs) on a large-scale area and assembling into a functional device is still a state of the art problem. This thesis focuses on the dimensionally controlled copper nanowires (Cu NWs) synthesis, and magnetic field assisted self-assembly of cupronickel nanowires (Cu/Ni NWs) into interconnect structures on a carbon doped silicon dioxide (CDO) wafer. CDO is a low dielectric constant (k) material used for copper interconnects in multilayered complex integrated circuits (ICs). Here, a strong affinity of copper (Cu) and nickel (Ni) to thiol (-SH) functional groups were exploited to strongly adhere the nanowires (Cu/Ni NWs) onto the CDO substrate. Thiol (-SH) functionalization of the CDO surface was achieved via a series of reactions involving (1) esterification of the surface exposed ≡Si-OH functional group to its triflate (≡Si-O-Tf), (2) reduction of triflate to ≡Si-H using DIBAL-H, and (3) hydrosilylation of ≡Si-H using 2-propene thiol (≡Si-(CH2)3-SH) in a photochemical reaction. The thiol functionalization of CDO surface enhances the interaction of Cu/Ni NWs with strong chemical bonds. The same reaction scheme was also used in the functionalization of the hydrophilic (Si-OH) surface to the hydrophobic long alkyl chain derivatized (≡Si-CH2-(CH2)16-CH3) surface. This long alkyl chain modified surface acts as an excellent moisture resistant film, which helps to maintain the low-k value of CDO. The dimensionally controlled Cu NWs were synthesized by a wet chemical approach. Optimization of the reducing agent, hydrazine (N2H4), controlled the surface morphology of nanowires (NWs). Interestingly, the high concentration of reducing agent produced particle decorated and/or with a rough NW surface, and conversely decreasing its concentration resulted in a comparatively thin, particle-free and smooth surface. The reaction temperature affected the aspect ratio (Length/Diameter) of the NWs. As the reaction temperature increased from 60 to 90 °C, the aspect ratio decreased from 140 to 21. Controlling the orientation of Cu NWs in a magnetic field was accomplished by coating them with a thin layer (~20 nm) of ferromagnetic nickel (Ni). This Ni-coated NWs showed an excellent degree of alignment (half-width ≈10 degrees) in the direction of an applied magnetic field over a large surface area at field strength as low as 2500 Gauss. Also, the Ni coating helped in protecting the copper core from oxidation resulting in better electrical wire-to-wire contacts. A nanowire-based interconnect channel was fabricated by combining magnetic field assisted alignment and deposition of aligned NWs on a thiol-modified and photolithography patterned CDO substrate. The NWs, deposited in the trenches, strongly bonded to the thiol-derivatized CDO substrate while an acetone wash removed loosely bound NWs on the photoresist surface. In electrical characterization, the directionally well-aligned Cu/Ni NWs channel displayed surprisingly two-fold higher conductivity than randomly arranged NWs channel.

Ce travail traite de la synthèse et de la caractérisation de nouvelles cages moléculaires discrètes riches en électrons préparées via la méthodologie d'auto-assemblage dirigée par les métaux, ainsi que de leurs propriétés redox et d’encapsulation. Les concepts généraux guidant la méthodologie d’auto-assemblage pilotée par les métaux sont présentés. Trois types de ligands tétratopiques rédox-actifs (L) constitués de tétrathiafulvalène (TTF), de dithiol-fluorène (DTF) ou de tétrathiafulvalène π étendu (exTTF) ont été conçus. Leur capacité à générer des cages auto-assemblées avec divers complexes (M) a été étudiée. Dans le premier cas, des métallacages M8L2 dont la géométrie offre une opportunité unique de favoriser des interactions inter-TTF étroites au cours du processus d’oxydation ont été décrites. Ces interactions ont été confirmées par des études électrochimiques ainsi que par DRX à partir d’un sel oxydé électrocristallisé. Dans le second cas, plusieurs auto-assemblages discrets MxLy (cages, clips) ont été obtenus à partir de nouveaux ligands électroactifs basés sur l'unité 9- (1,3-dithiol-2-ylidène) fluorène (DTF). Leurs propriétés rédox ainsi que leur capacité à complexer des unités électro-déficientes sont fortement dépendantes de la géométrie de l’auto-assemblage. Concernant le ligand exTTF, de grandes métallacages électroactives M12L6 (environ 4 000 Å3) ont été obtenus par combinaison avec des complexes trans de palladium ou d'argent. Ces dernières se désassemblent lors de l'oxydation, donnant lieu à une transformation sans précédent d'une cage métallique discrète en un polymère de coordination. Enfin, un nouveau squelette aromatique benzo[1,2-b:4,5-b'] dithiophène est décrit en tant qu’alternative aux dérivés riches en électrons π étendus. Le rôle critique des interactions non-covalentes 1,5 S ···S est démontré par une approche combinée expérimentale et théorique. / This work deals with the synthesis and characterization of new electron-rich discrete molecular cages, prepared via the coordination-driven self-assembly methodology, as well as on evaluating their redox and host-guest properties. The general concepts guiding the metal-driven self-assembly methodology are presented. Three types of redox-active tetratopic ligands (L) featuring either a tetrathiafulvalene (TTF), a dithiol-fluorene (DTF) or a π-extended tetrathiafulvalene (exTTF) have been designed. Their ability to generate self-assembled cages upon combination with various metal complexes (M) has been studied. In the first case, M8L2 metallacages were obtained, whose geometry offers a unique opportunity to promote close inter-TTF interactions upon oxidation, as confirmed through electrochemical studies as well as from single-crystal DRX from an electrocrystallized oxidized salt. In the second case, several discrete self-assemblies MxLy (cages, clips) were obtained and characterized from new electro-active ligands based on the 9-(1,3-dithiol-2-ylidene)fluorene (DTF) unit. Their redox properties as well as their binding ability towards electro-deficient planar species show a strong dependence to the self-assembly geometry. Considering the exTTF ligand, large (ca. 4000 Å3) electroactive M12L6 metallacages were obtained from combining with trans palladium or silver complexes. Le latter exhibits a disassembling process upon oxidation, giving rise to an unprecedented redox-triggered transformation of discrete metalla-cage into a coordination polymer. Finally, a new benzo[1,2-b:4,5-b'] dithiophene aromatic scaffold is investigated as an alternative π-extended electron-rich derivative. The critical role of non-covalent 1,5 S···S interactions is demonstrated by a combined experimental and theoretical approach.

With recent advancements in the synthesis and characterization of polymeric materials, scientists are able to create multi-scale novel polymers with various cases of chemical functionalities, diversified topologies, as well as cross-linking networks. Due to those remarkable achievements, there are a broad range of possible applications of smart polymers in catalysis, in environmental remediation, and especially in drug-delivery. Because of rising interest in developing therapeutic drug binding to specific treating target, polymer chemists are in particular interests in design and engineering the drug delivery materials to be not only bio-compatible, but also to be capable of self-assembly at various in-vivo physiological stimulus. Both experimental and theoretical work indicate that the thermodynamic properties relating to the hydrophobic effect play an important role in determining self-assembly process. At the same time, computational simulation and modeling are powerful instruments to contribute to microscopic thermodynamics' understanding toward self-assembly phenomenon. Along with statistical approaches, constructing empirical model based on simulation results would also help predict for further development of tailored nano-structured materials. My Research mainly focused on investigating physical and chemical characteristics of polymer materials through molecular dynamics simulation and probing the fundamental thermodynamic driving force of self-assembly behavior. We tried to surmount technological obstacles in computational chemistry and build an efficient scheme to identify the physical and chemical Feature of molecules, to reproduce underlying properties, to understand the origin of thermodynamic signatures, and to speed up current trial and error process in screening new materials. / acase@tulane.edu

Les systèmes moléculaires de taille nanométrique sont impliqués dans une grande variété de procédés et de fonctions biologiques. La compréhension des mécanismes permettant le contrôle de leur structure à plusieurs échelles présente un grand intérêt. Par exemple, malgré le défi que cela représente, il n'existe actuellement aucun système synthétique permettant la formation d'objets fibrillaires de diamètre monodisperse et modulable en milieu aqueux. L'objectif de ce travail est de développer une boite à outils moléculaires de cyclodextrines (CDs) sélectivement di-fonctionnalisées de façon à pouvoir s'auto-assembler sous forme de fibres pouvant ensuite s'associer pour former des assemblages hiérarchiques via des interactions secondaires. L'étude de la formation du premier niveau d'assemblage de ces composés par viscosimétrie, ITC et SANS a montré que l'utilisation de CDs pontées permet de favoriser la polymérisation de ces composés en supprimant le phénomène d'auto-inclusion. Cette étude a permis de développer deux polymères supramoléculaires (PSM) cationiques à base de ?-CDs fonctionnalisées possédant un degré de polymérisation plus élevé que ceux existant actuellement. Leur capacité à former des PSM hiérarchiques en présence de polyanions rigides a ensuite été évaluée par analyses DLS, spectroscopie et cryo-MET. Dans des conditions de concentration en CDs et de rapport en charges optimisées, trois différents assemblages hiérarchiques solubles dans l'eau ont été formés. Nous avons montré que le premier niveau d'association ainsi que la directionnalité des interactions secondaires étaient des paramètres clés pour la formation d'assemblages hiérarchiques stables et de morphologies bien définies. Ces structures modulables nous serviront donc de plateformes pour étudier et mieux comprendre les mécanismes impliqués dans la formation des assemblages hiérarchiques. / Molecular systems with nanometer-sized dimensions are involved in a wide variety of processes and biological functions. Understanding the mechanisms controlling their multi-lengthscale structure presents a major interest. For instance, despite this challenge, there is so far no reliable synthetic system forming well-defined tunable fibrillar objects with a monodisperse diameter in aqueous solution. The aim of this work is to develop a tool box of di-functionalized cyclodextrins (CDs) specifically designed to self-assemble into supramolecular rods that could then reach higher levels of hierarchy via interactions mediated by the secondary functionalization. The study of the first level of association of these compounds by viscosimetry, ITC and SANS showed that the use of bridged CDs allows the polymerization by suppressing the self-inclusion phenomenon. As a result, we developed two tunable cationic supramolecular polymers (SMP) based on functionalized β-CD with relatively high polymerization degrees. Their ability to form hierarchical SMP with rigid polyanionic species was then assessed by DLS, spectroscopy and cryo-TEM. In optimized concentration and charge ratio conditions, three different water-soluble hierarchical assemblies were formed. We showed that the first level of association and the high directionality of the secondary interactions are key parameters to achieve these stable, well-defined, hierarchical assemblies. These tunable structures will be therefore used as a platform to get greater insight into hierarchical assembling processes.

Nature has inspired chemists to develop complex assemblies that perform functions in biologically relevant solutions. Yet this is not a trivial task. Not only does water act as a competitive medium but the salts that are inevitably present hamper supramolecular hosts from properly binding and carrying out their programmed function. This work was inspired by a serendipitous discovery of water-soluble functionalized calix[4]arenes that self-assemble into homodimers in salty water, mock serum and real urine. This thesis aims to explore this homodimerizing motif to learn more about self-assembly in salty water and to develop useful supramolecular tools. First the structural limits of the calixarene motif was explored by the transformation into a clip-like host that assembled similarly in water. NMR titrations revealed that the homodimers responded to hydrophobic cationic guests by dissociating to form new host-guest complexes. The resilience of the self-assembling motif was then tested against extreme co-solute conditions. In this part of the study, reversible covalent bonds were introduced within the dimer scaffold to afford a dynamic library of exchangeable hosts. Quantitative NMR was used to monitor each host in response to molar concentrations of urea and salt. This work also reports on a new class of salt-tolerant supramolecular chemosensors, called DimerDyes. These sensors form quenched homodimers in water but dissociate in the presence of hydrophobic cations to form new emissive complexes. Its mode of action was characterized by DOSY, 1H NMR and fluorescence spectroscopy. DimerDyes successfully monitored enzymatic reaction in real-time despite the presence of competitive salts and co-factors. The DimerDye concept was quickly expanded by the parallel synthesis of crude DimerDyes and efficient testing for illicit drugs without the need for purification. “Hit” dimers were then purified, characterized and were able to detect multiple different drug classes in real saliva. / Graduate / 2020-09-19

Elastin-like peptide (ELP) fusions promote therapeutic delivery and efficacy. Recombinant proteins, like neurotrophins, lack bioavailability, have short in vivo half-lives, and require high manufacturing costs. Fusing recombinant proteins with genetically encodable ELPs will increase bioavailability, enhance in vivo solubilization, as well as provide a cost-effective method for purification without the need for chromatography. During expression of neurotrophin-ELP (N-ELP) fusions, dense water-insoluble aggregates known as inclusion bodies (IBs) are formed. Inclusion bodies are partially and misfolded proteins that usually require denaturants like Urea for solubilization. Strong denaturants arrest ELPs stimuli-responsive property and increase unwanted aggregation, making purification difficult, yet possible. The current field of study exhibit issues with protein recovery due to solubility issues and aggregation. This study examines the solubility challenges of inclusion body proteins and the role ELP fusion tags play on IBs solubility. Elastin-like peptides are a class of stimuli-responsive biopolymers whose biocompatibility and limited toxicity are attractive for biological applications. ELPs are tunable polymers, which consist of peptide repeat units (VPGXG), where X is any amino acid except Proline while the guest residue or length of the sequence can be chosen. ELPs have uniquely tunable phase transitioning properties that allow the protein to undergo molecular self-assemblies into different nanostructures in response to the changes in their environment (e.g. pH or temperature). Optimizing the purification process via suppressing aggregation during the refolding process has increased protein recovery slightly however, more work is needed to attain 90 percent recovery. Usage of ELPs has increased the solubility of N-ELP fusions, specifically for brain-derived neurotrophic factor ELP fusions.

Virus-like particles (VLPs) are elegant functional architectures formed by the self-assembly of viral structural proteins. VLPs have been developed as vaccines against hepatitis B and cervical cancer, and have recently been shown in animal studies to provide protection against both seasonal and avian influenza following intranasal administration. This new class of vaccines offers unprecedented immunoprotection, inherent safety, and a simple route of administration. To realize the full potential of VLP technology as an efficient and responsive vaccine platform, this project exploits the parallel advancements in recombinant technology, analytical techniques and colloidal science to facilitate the swift and economical delivery of candidate VLP vaccines from laboratory to clinical trials, and ultimately into commercial production. Three areas of VLP production are specifically targeted in this work, i.e., VLP subunit production, particle characterisation and assembly. The major research outcomes in this work are: (i) establishment of a simple and economical VLP subunit production method which eliminates inefficient and complicated purification procedures necessitated by the current in vivo production methods; (ii) development of a high-resolution and high-throughput analytical method for rapid and reliable quality control check of VLP products; and (iii) establishment of the foundation to predict optimal VLP self-assembly conditions through molecular thermodynamics. These research outcomes collectively enhance the quantitative knowledge base in VLP assembly and may ultimately enable the development of a mechanistic and descriptive modelling approach to optimize VLP production. From a fundamental perspective, this work introduces the first experimental technique to measure protein interactions of viral subunits undergoing rapid, irreversible assembly reaction. Such information, when correlated with molecular details and assembly conditions may provide unique insights into the molecular switches responsible for viral assembly, unveiling the fundamental mechanism underpinning viral self-assembly.

This paper describes recent progress in a continuing program to develop and apply RM³ (recess mounting with monolithic metallization) technologies for heterogeneous integration. Particular emphasis is placed on the APB (aligned pillar bonding) and MASA (magnetically assisted statistical assembly) technologies. Next, ongoing research on applications of RM3 integration to produce optoelectronic integrated circuits (OEICs) for optical clock distribution, diffuse optical tomography, and smart pixel arrays are described. Finally, potential new applications of these technologies in intra- and interchip optical signal interconnects, in fluorescent dye detection and imaging for biomedical applications, and in III-V mini-IC integration on Si-CMOS for enhancing off-chip drive capabilities are outlined. / Singapore-MIT Alliance (SMA)