Das Ziel dieser Arbeit bestand in der Synthese neuartiger homochiraler Molekülstrukturen, welche nach Konzepten des Crystal Engineering über ein starres Grundgerüst sowie koordinationsfähige Haftgruppen verfügen sollten. Unter Verwendung von Wein- und Milchsäure, als Vertreter der natürlich vorkommenden, enantiomerenreinen α-Hydroxycarbonsäuren, konnten die entsprechenden Derivate mit aromatischen und/oder acetylenischen Spacerelementen hergestellt und umfassend charakterisiert werden. Die synthetisierten Wein- und Milchsäureverbindungen sowie die sich von den jeweiligen Weinsäureestern ableitenden TADDOLe wurden außerdem auf ihre optische Aktivität, ihre Affinität gegenüber verschiedenen Lösungsmitteldämpfen, ihr Einschlussverhalten gegenüber achiralen und chiralen Lösungsmitteln sowie ihre Eignung als organische Linker bei der Synthese von metallorganischen Gerüststrukturen untersucht. Mittels Röntgeneinkristallstrukturanalyse konnten die Festkörperstrukturen einiger Derivate aufgeklärt und diese hinsichtlich ihrer Konformation verglichen werden.

Self-assembly processes were used to construct supramolecular architectures based on metal-ligand interactions. The structures formed strongly depend on the used metal ion, the ligand type, the chosen counter ion and solvent as well as on the experimental conditions. The focus of the studies was the design of multifunctional N-donor ligands and the characterization of their complexing and structural properties. This work was divided into three distinct main parts: The bis(2-pyridylimine), the bis(2-hydroxyaryl) imine and the tripodal imine / amine ligand approach. In the first part a series of bis(2-pyridylimine) derivatives having different linking elements were employed as building blocks for novel supramolecular architectures. Reaction of individual d-block metal salts with these ligands has led to the isolation of coordination polymers, a metallamacrocycle, double-stranded helicates, triple-stranded helicates as well as of circular meso-helicates. The nature of the spacer in the Schiff base ligands, the noncovalent weak interactions, such as hydrogen bond, face-to-face π-π and edge-to-face CH-π interactions, are all important factors influencing the architecture of the final products. Topological control of the assembly process of the hexanuclear meso-helicates is clearly associated with the bidentate coordination of the sulfate anion which directs the formation of a double- rather than a triple-stranded helicate around the octahedrally coordinated Cu(II). Surprisingly, the variation of the linker function in the ligands, which significantly changes the linking angle of the pyridylimine strands, has only a little influence of the resulting structure. Also the use of a mixture of ligands does not influence the meso-helicate topology; the result is the symmetrically mixed meso-helicate. The new iron(II) triple helicate [Fe2(L5)3](PF6)4 14 {L5 = bis[4-(2-pyridylmethyleneimino)phenyl]-1,1-cyclohexane} in its chloride form binds strongly to DNA as confirmed by induced circular dichroism signals in both the metal-to-ligand charge transfer (MLCT) and in-ligand bands of the helicate. The induced CD spectrum gives some evidence that [Fe2(L5)3]4+ interacts with the DNA in a single binding mode, which is consistent with major groove binding. The cytotoxicity of the new iron(II) triple helicate 14 was evaluated on human lung cancer A549 cells and compared with that of cisplatin and that of the previously reported iron(II) triple helicate [Fe2(L1)3]4+{L1 = bis[4-(2-pyridylmethyleneimino)phenyl]methane}. The first results show some distinguishing features for 14 obviously caused by the existing structural differences of the complexes. In the second part of the thesis, novel uranyl complexes of the bis(2-hydroxyaryl) imine ligands have been synthesized and characterized. 1D coordination polymers and mononuclear structures were formed. In all complexes a distorted hexagonal bipyramidal coordination geometry around the uranyl centre is observed. The imine nitrogen atoms of the ligands do not bind to the metal centre but interact strongly with the hydroxy group via H-bonding. DFT calculations made with L8 ( α,α’-Bis(salicylimino)-m-xylene) are in good agreement with the X-ray crystal structure data. Liquid-liquid extraction studies involving selected ligands and Eu(III) or U(VI) indicate remarkably high selectivity for U(VI) over Eu(III) at weak acidic pH conditions. We believe that the study made opens up new possibilities for uranyl ion extraction which could be interesting in view of the treatment of nuclear waste. In the third part of the thesis, a series of multifunctional tripodal ligands with different N-donor centres were used for U(VI) and lanthanide, Nd(III), Eu(III) and Yb(III), binding and extraction. Reaction of these metal ions with selected tripodal ligands afforded complexes which were characterized by ESI mass spectroscopy. The complex composition was found to be 1:1 in all cases. The extraction behaviour of the tripodal ligands towards Eu(III) and U(VI) was studied both in the absence and presence of octanoic acid as co-ligand using the extraction system Eu(NO3)3 or UO2(NO3)2–buffer–H2O/ ligand–CHCl3. These separation systems show a remarkably high selectivity for U(VI) over Eu(III). It is interesting to note that the addition of the octanoic acid to the extraction system leads to high synergistic effects. A series of Eu(III) extraction experiments were done to clarify the composition of the extracted complexes. The results clearly point to the formation of various species with changing composition.

<p>  </p> <p>Experimental and computational techniques are used to study physico-chemical phenomena occurring in water on which hydrophobic interactions play a role. In particular, hydrophobic self-aggregation, including host-guest binding, and the affinity of ions to oil/water interfaces are investigated. Raman multivariate curve resolution (Raman-MCR) spectroscopy was the experimental technique used to unveil intermolecular interactions through the analysis of solute-correlated (SC) vibrational spectra. Molecular simulations, including molecular dynamics (MD) simulations, quantum-mechanical calculations, or a combination of both, were carried out to assist with the molecular-level interpretation of the experimental SC spectra.</p>

Indiana University-Purdue University Indianapolis (IUPUI) / In this research thesis, copper indium gallium selenium (CIGS) nanoparticles were synthesized from metal chlorides, functionalized to disperse in water, and further used in layer by layer (LbL) nanoassembly of CIGS films. CIGS nanoparticles were synthesized through the colloidal precipitation in an organic solvent. The peak and average sizes of the synthesized particles were measured to be 68 nm and 75 nm in chloroform, and 30 nm and 115 nm in water, respectively. Two methods were used to disperse the particle in water. In the first method the stabilizing agent oleylamine (OLA) was removed through multiple cleaning processes, and in the second method ligand exchange was performed with polystyrene sulfonate (PSS). Zeta potential of CIGS nanoparticles dispersed in water was measured to be +61 mV. The surface charge of the nanoparticles was reversed by raising the pH of the solution, which was measured to be −43.3 mV at 10.5 pH. In a separate process, the CIGS nanoparticles dispersed in water were coated with PSS. The resulting dispersion was observed to be stable and the surface charge was measured to be −56.9 mV. The LbL deposition process of CIGS nanoparticles was characterized by depositing thin films on quartz crystal microbalance (QCM). LbL depositions was conducted using (i) oppositely charged CIGS nanoparticles, (ii) positively charged CIGS nanoparticles and PSS, and (iii) PSS-coated CIGS (CIGS-PSS) and polyethyleneimine (PEI). The average thickness of each bi-layer of the above mentioned depositions were measured to be 2.2 nm, 1.37 nm, and 10.12 nm, respectively. The results from the QCM have been observed to be consistent with the film thickness results obtained from atomic force microscopy (AFM). Various immersion times versus thickness of the film were also studied. For electrical characterization, the CIGS films were deposited on indium tindioxide (ITO)-coated glass substrates. Current versus voltage (I/V) measurements were carried out for each of the films using the Keithley semiconductor characterization instruments and micromanipulator probing station. It was observed that the conductivity of the films was increased with the deposition of each additional layer. The I/V characteristics were also measured under the light illumination and after annealing to study the photovoltaic and annealing effects. It was observed that under light illumination, the resistivity of a 12-layer CIGS film decreased by 93% to 0.54 MΩ.m, and that of the same number of layers of PSS-coated CIGS and PEI film decreased by 60% to 0.97 MΩ.m under illumination. The resistivity of an 8-layer CIGS and PSS film decreased by 76.4% to 0.1 MΩ.m, and that of the same layers of PSS-coated CIGS and PEI decreased by 87% to 0.07 MΩ.m after annealing. The functionalized nanoparticles and the LbL CIGS films were implemented in the solar cell devices. Several configurations of CIGS films (p-type), and ZnO and CdS films (n-type) were considered. Poly(3,4-ethylenedioxythiophene) (PEDOT), molybdenum (Mo), and ITO were used as back contacts and ITO was used as front contact for all the devices. The devices were characterized the Keithley semiconductor characterization instruments and micromanipulator probing station. For a CIGS and n-ZnO films device with PEDOT as back contact and ITO as front contact, the current density at 0 V and under light illumination was measured to be 60 nA/cm2 and the power density was measured to be 0.018 nW/cm2. For a CIGS and CdS films device with ITO as both back and front contact, the current density at 0 V and under light illumination was measured to be 50 nA/cm2 and the power density was measured to be 0.01 nW/cm2. For a drop-casted CIGS and CdS films device with Mo as back contact and ITO as front contact, the current density of 50 nA/cm2 at 0 V and power density of 0.5 nW/cm2 under light illumination was measured. For the LbL CIGS and chemical bath deposited CdS films device with ITO as both back and front contact, the current density of 0.04 mA/cm2 at 0 V and power density of 1.6 μW/cm2 under light illumination was measured. Comparing to Device-III, an increase by 99% in the power density was observed by using the CIGS LbL film in the device structure. The novel aspects of this research include, (i) functionalization of the CIGS nanoparticles to disperse in water including coating with PSS, (ii) electrostatic LbL deposition of CIGS films using oppositely charged nanoparticles and polymers, and (iii) the utilization of the fabricated LbL CIGS films to develop solar cells. In addition, the n-type cadmium sulfide film (CdS) and zinc oxide (ZnO) buffer layer were also deposited through LbL process after the respective particles were functionalized with PSS coating in separate experiments.

La synthèse de l'hydrogène est une alternative viable à l'utilisation du pétrole. Les méthodes telles que l’électrocatalyse font appel à une source d’énergie primaire, ce qui favorise les déchets générés par ces méthodes, de même que le gaspillage d’énergie. Bien qu’ayant de très faibles rendements, les systèmes photocatalytiques permettent la synthèse d’un hydrogène propre et quasi sans déchets. Une perspective permettant d’améliorer encore leur potentiel serait d’éliminer les solvants organiques tels que le DMF, qui sont nocif pour l’environnement et la santé des êtres vivants. Étant donné que le solvant doit être changé, il faut prendre garde à modifier le donneur d’électron sacrificiel et le photosensibilisateur en conséquence. La production de tels solvants est également source de pollution, ce qui atténue le potentiel environnemental de ces méthodes. L’objectif de ce travail est de développer et de tester de nouveaux catalyseurs hydro-solubles variés permettant une amélioration des performances photo-catalytiques actuelles ainsi qu’une performance acceptable dans l’eau. L’étude des propriétés catalytiques est réalisée par l’étude de systèmes homogènes conjugués principalement avec le [Ru(bpy)3]2+ en tant que photosensibilisateur et avec le triethanolamine (dans le DMF) et l’acide ascorbique (dans l’eau) en tant que donneur d’électron sacrificiel. Les catalyseurs présentés lors de ce travail sont des catalyseurs à base de polypyridyl, de cobaloximes et de N-imidoylamidine. Les catalyseurs à base de poly-pyridyl ont d’abord été étudiés puisqu’ils sont réputés pour leur performance en milieux aqueux. La seconde approche consistait à produire des catalyseurs à base de cobaloxime qui aient une performance relativement constante tout d’abord dans les solvants organiques, puis d’adapter ces performances en milieu aqueux. La troisième approche a été de tester des catalyseurs à base de N-imidoylamidine, ce type de catalyseurs n’ayant jamais été testé pour la production d’hydrogène, puis d’en étudier les performances dans l’objectif de paver la voie pour de futures recherches sur le sujet. / The synthesis of hydrogen is a viable alternative to the use of petroleum. Methods such as electrocatalysis use a primary energy source, which reduces the waste generated by these methods, as well as the waste of energy. Although having very low yields, photocatalytic systems allow the synthesis of clean hydrogen with virtually no waste. One prospect to further improve their potential would be to eliminate organic solvents such as DMF, which are harmful to the environment and the health of living beings. Giving the fact that we change the solvent, we need to change the electron sacrificial donor and the photosensitizer as well. The production of such solvents is also a source of pollution, which reduces the environmental potential of these methods. The objective of this work is to develop and test various new water-soluble catalysts allowing an improvement of the current photo-catalytic performances as well as an acceptable performance in water. The study of the catalytic properties is carried out by the study of homogeneous conjugated systems mainly with [Ru(bpy)3]2+ as photosensitizer and with triethanolamine (in DMF) and ascorbic acid (in water) as a sacrificial electron donor. The catalysts presented during this work are catalysts based on polypyridyl, cobaloximes, and N-imidoylamidine. Poly-pyridyl-based catalysts were first studied because they are known for their performance in aqueous media. The second approach was to produce cobaloxime-based catalysts that had relatively constant performance first in organic solvents and then to match this performance in aqueous media. The third approach was to test catalysts based on N-imidoylamidine, as this type of catalyst have never been tested to produce hydrogen, then to study their performance to pave the way for future research on the subject.

La presente tesis doctoral titulada ¿Materiales funcionales híbridos para el reconocimiento óptico de explosivos nitroaromáticos mediante interacciones supramoleculares¿ se basa en la combinación de principios de Química Supramolecular y de Ciencia de los Materiales para el diseño y desarrollo de nuevos materiales híbridos orgánico-inorgánicos funcionales capaces de detectar explosivos nitroaromáticos en disolución. En primer lugar se realizó una búsqueda bibliográfica exhaustiva de todos los sensores ópticos (cromogénicos y fluorogénicos) descritos en la bibliografía y que abarca el periodo desde 1947 hasta 2011. Los resultados de la búsqueda están reflejados en el capítulo 2 de esta tesis. El primer material híbrido preparado está basado en la aplicación de la aproximación de los canales iónicos y, para ello, emplea nanopartículas de sílice funcionalizadas con unidades reactivas y unidades coordinantes (ver capítulo 3). Este soporte inorgánico se funcionaliza con tioles (unidad reactiva) y una poliamina lineal (unidad coordinante) y se estudia el transporte de una escuaridina (colorante) a la superficie de la nanopartícula en presencia de diferentes explosivos. En ausencia de explosivos, la escuaridina (color azul y fluorescencia intensa) es capaz de reaccionar con los tioles anclados en la superficie decolorando la disolución. En presencia de explosivos nitroaromáticos se produce una inhibición de la reacción escuaridinatiol y la suspensión permanece azul. Esta inhibición es debida a la formación de complejos de transferencia de carga entre las poliaminas y los explosivos nitroaromáticos. En la segunda parte de esta tesis doctoral se han preparado materiales híbridos con cavidades biomiméticas basados en el empleo de MCM-41 como soporte inorgánico mesoporoso (ver capítulo 4). Para ello se ha procedido al anclaje de tres fluoróforos (pireno, dansilo y fluoresceína) en el interior de los poros del soporte inorgánico y, posteriormente, se ha hidrofobado el interior de material mediante la reacción de los silanoles superficiales con 1,1,1,3,3,3-hexametildisilazano. Mediante este procedimiento se consiguen cavidades hidrófobas que tienen en su interior los fluoróforos. Estos materiales son fluorescentes cuando se suspenden en acetonitrilo mientras que cuando se añaden explosivos nitroaromáticos a estas suspensiones se observa una desactivación de la emisión muy marcada. Esta desactivación de la emisión es debida a la inclusión de los explosivos nitroaromáticos en la cavidad biomimética y a la interacción de estas moléculas (mediante interacciones de ¿- stacking) con el fluoróforo. Una característica importante de estos materiales híbridos sensores es que pueden ser reutilizados después de la extracción del explosivo de las cavidades hidrofóbicas. En la última parte de esta tesis doctoral se han desarrollado materiales híbridos orgánicoinorgánicos funcionalizados con ¿puertas moleculares¿ que han sido empleados también para detectar explosivos nitroaromáticos (ver capítulo 5). Para la preparación de estos materiales también se ha empleado MCM-41 como soporte inorgánico. En primer lugar, los poros del soporte inorgánico se cargan con un colorante/fluoróforo seleccionado. En una segunda etapa, la superficie externa del material cargado se ha funcionalizado con ciertas moléculas con carácter electrón dador (pireno y ciertos derivados del tetratiafulvaleno). Estas moléculas ricas en electrones forman una monocapa muy densa (debida a las interacciones dipolo-dipolo entre estas especies) alrededor de los poros que inhibe la liberación del colorante. En presencia de explosivos nitroaromáticos se produce la ruptura de la monocapa, debido a interacciones de ¿-stacking con las moléculas ricas en electrones, con la consecuencia de una liberación del colorante atrapado en el interior de los poros observándose una respuesta cromo-fluorogénica / Salinas Soler, Y. (2013). Functional hybrid materials for the optical recognition of nitroaromatic explosives involving supramolecular interactions [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31663 / Premios Extraordinarios de tesis doctorales

<p>This dissertation describes how the surface chemistries of 2D nanomaterials can be modified to alter overall material properties. Specifically, through a focus of the ligand-surface atom bonding in addition to the overall ligand structure we highlight the ability to direct morphological outcomes in lead free halide perovskites, maximize optoelectronic responses in substoichiometric tungsten oxide, and alter physicochemical properties titanium carbide MXenes.   </p>

The self-assembly of structured particles into monodisperse clusters is a challenge on the nano-, micro- and even macro-scale. While biological systems are able to self-assemble with comparative ease, many aspects of this self-assembly are not fully understood. In this thesis, we look at the strategies and rules that can be applied to encourage the formation of monodisperse clusters. Though much of the inspiration is biological in nature, the simulations use a simple minimal patchy particle model and are thus applicable to a wide range of systems. The topics that this thesis addresses include: Encapsulation: We show how clusters can be used to encapsulate objects and demonstrate that such `templates' can be used to control the assembly mechanisms and enhance the formation of more complex objects. Hierarchical self-assembly: We investigate the use of hierarchical mechanisms in enhancing the formation of clusters. We find that, while we are able to extend the ranges where we see successful assembly by using a hierarchical assembly pathway, it does not straightforwardly provide a route to enhance the complexity of structures that can be formed. Pore formation: We use our simple model to investigate a particular biological example, namely the self-assembly and formation of heptameric alpha-haemolysin pores, and show that pore insertion is key to rationalising experimental results on this system. Phase re-entrance: We look at the computation of equilibrium phase diagrams for self-assembling systems, particularly focusing on the possible presence of an unusual liquid-vapour phase re-entrance that has been suggested by dynamical simulations, using a variety of techniques.

This thesis explores the capacity of sterically and electronically unsaturated boranes to bind substrates of biological and environmental interest, and transduce such binding events into a photo-physical and/or electrochemical response, hence reporting the presence of these substrates. Chapter three details the synthesis of a range of novel ferrocenyl boranes featuring either a proximal hydrogen-bond donor or a second Lewis acidic centre. These novel boranes were shown to be competent at binding both cyanide and fluoride anions, with the role played by a proximal hydrogen-bond donor or a second Lewis acidic centre in anion binding investigated by both NMR and crystallographic studies. Chapter four reports the synthesis of novel pyridinyl and related boronic esters, as well as unexpected mixed alkenyl/aryl boranes. The capacity of both types of system to bind fluoride or cyanide anions in solution was investigated by UV-Vis and NMR studies. The photo-physical responses to these anions were also probed, leading to the establishment of both switch-on and switch-off fluorescent responses. Chapter five extends the knowledge derived from selective anion receptor design and combines this with recent developments in the field of frustrated Lewis pairs (FLPs) to activate, bind and report the presence of nitrous oxide (N₂O) molecule. Thus, the syntheses of novel, highly Lewis acidic ferrocenyl boranes that incorporate a high degree of steric loading around the boron centre are reported. The electrochemical and photo-physical response of an FLP system to the presence of N₂O was investigated leading to the development of a novel N₂O reporting system.

Les propriétés des matériaux moléculaires proviennent à la fois de la structure des composantes individuelles et de la façon dont elles s’associent. Ce dernier aspect reste difficile à contrôler, malgré de grandes avancées en science des matériaux. Pour mieux comprendre la relation structure-propriétés, nous avons entrepris une étude systématique de l'hexaphénylbenzène et de ses dérivés, qui offrent une charpente symétrique et rigide. En premier lieu, nous avons attaché six groupements diaminotriazinyles sur l’hexaphénylbenzène afin de produire des réseaux tridimensionnels hautement poreux maintenus par des ponts hydrogène. En modifiant systématiquement le coeur moléculaire, nous avons excisé près du tiers de la molécule-mère, générant des réseaux supramoléculaires dont la porosité s’est élevée graduellement jusqu’à 75%, équivalant ainsi le record pour ce type de matériaux. Ensuite, nous avons étudié le comportement de l’hexakis(4-nitrophényl)benzène. Dans les structures cristallines obtenues, des interactions non-covalentes entre groupements nitro démontrent leur potentiel en chimie supramoléculaire. Le coeur moléculaire ne joue qu’un rôle secondaire dans l’empilement des molécules : seules quelques interactions C-H•••π impliquant le cycle aromatique central de l’hexaphénylbenzène sont évidentes. Cette dernière observation nous a poussés à étudier le comportement à l’état cristallin de l’hexaphénylbenzène et ses dérivés. En scrutant attentivement neuf structures cristallines de ces composés, nous avons décerné la présence récurrente d’interactions C-H•••π impliquant le cycle aromatique central. Cette association caractéristique a été exploitée pour créer des réseaux supramoléculaires maintenus par des interactions C-H•••π sélectives entre un groupement éthynyle et le cycle aromatique central de l’hexaphénylbenzène. Finalement, nous avons joint le côté sombre de l’ingénierie cristalline en utilisant nos connaissances dans le but d’empêcher la formation d’interactions directionnelles. En protégeant le cycle aromatique central de l’hexaphénylbenzène à l’aide de groupements alkyles, les interactions C-H•••π ont été pratiquement éliminées. Ces résultats offrent la possibilité de créer de nouveaux matériaux amorphes. Dans ces études, focalisées sur le système hexaphénylbenzène, nous avons mis en relief des phénomènes qui sont obscurcis dans d'autres familles de molécules. De plus, ce système a grandement facilité l’utilisation d’une approche méthodique pour explorer la relation structure-propriétés. Nos travaux nous ont amenés à des conclusions de valeur universelle en science des matériaux moléculaires. / The properties of molecular materials depend on the identity of individual components and on their organization. Unfortunately, it remains difficult to control molecular organization, despite advances in materials science. To better understand the relationship between molecular structure and collective properties, we undertook a systematic study of hexaphenylbenzene and its derivatives, which possess a rigid symmetric framework. Our first study focused on using hydrogen bonds to control self-assembly in the solid state. By installing six diaminotriazinyl groups on a hexaphenylbenzene core, we predictably obtained highly porous three-dimensional hydrogen-bonded networks. Through systematic structural modifications of the molecular core, we excised nearly a third of the parent molecule, and the porosity of the networks gradually increased, matching the record of 75% previously obtained for this type of material. We then turned to weaker interactions to control organization, as revealed by the packing of hexakis(4-nitrophenyl)benzene. In the crystal structures analyzed, non-covalent interactions between nitro groups were observed, demonstrating their potential in supramolecular chemistry. Careful examination of the structures showed that the hexaphenylbenzene moieties play only a secondary role in determining the overall packing; however, C-H•••π interactions involving the central aromatic ring of hexaphenylbenzene were also observed. To further document this unexpected behavior, we analyzed nine crystal structures of hexaphenylbenzene and derivatives, which showed that a C-H•••π recognition pattern involving the central aromatic ring occurs consistently throughout the series. This motif was used to prepare supramolecular networks based exclusively on selective and directional C-H•••π interactions involving ethynyl groups and the central aromatic ring of hexaphenylbenzene. Finally, we joined the dark side of crystal engineering by using our knowledge of supramolecular chemistry to prevent the formation of directional interactions. By installing alkyl groups near the central aromatic ring of hexaphenylbenzene, C-H•••π interactions were practically eliminated. These results were then used to devise new amorphous materials. The hexaphenylbenzene system permitted a methodical analysis of structure-property relationships in molecular materials. This particular system exposed phenomena normally obscured in other families of molecules, and our analysis of its behavior has yielded conclusions of universal value in materials science.