Previous studies of supramolecular association through chalcogen-centred secondary bonding interactions (SBIs) demonstrated the versatility of 1,2,5-telluradiazoles and their annulated congeners, the benzo-2,1,3-telluradiazoles, as supramolecular building blocks. Key to the properties of those compounds is their propensity to undergo auto-association through the [Te-N]2 supramolecular synthon leading to dimers or supramolecular ribbon polymers. Moderate steric repulsion induces structural distortions of [Te-N]2 without dissociation and, in doing so, enables properties of practical interest such as chromotropism and second-order non-linear optical responses. However, moisture sensitivity discourages wide-spread application of these compounds. While being more tolerant of the atmosphere, the analogous selenadiazoles form weaker intermolecular interactions. Using a combined experimental and computational approach, this thesis investigates methods by which the selenium-centred supramolecular interactions can be enhanced and applied in the construction of supramolecular architectures. The quantum mechanical description of the SBIs formed by 1,2,5-chalcogenadiazoles was updated with the application of modern dispersion corrections to relativistic density functional theory calculations (PBE-D3, ZORA). While in all cases the dispersion effect on optimized SBI distances is small (< 0.03 Å), the dispersion corrections to the calculated interaction energy range from 6 to 10 kJ mol-1 and increase with the weight of the chalcogen. The total interaction energy increases faster, however, therefore the relative weight of dispersion for the telluradiazole (10%) is significantly less than for the sulfur analogue (40%). The same dispersion-corrected functional was applied to the identification of the secondary ions observed in the Laser Desorption Ionization mass spectrum of benzotelluradiazoles. The most stable structure of the [2M+H]+ ion was shown to feature the [Te-N]2 supramolecular synthon and would be preferred over alternatives held by hydrogen bonding alone, one TeN SBI, a combination of the two or -stacking. The [2M]+ would also feature the [Te-N]2 supramolecular synthon. Shortening of the TeN distances in these ions implies that electron withdrawing groups strengthen the SBIs. The updated computational method was also applied to characterize the bonding in the adducts of a N-heterocyclic carbene with benzo-2,1,3-telluradiazole and 3,4-dicyano-2,1,5-telluradiazole recently prepared by the Zibarev group. The long TeC distances (2.53 and 2.34 Å) correspond to fractional bond orders (<0.6) but display a significant covalent character. Attachment of the carbene nearly erases the remaining σ-hole on tellurium, raises the LUMO energy and consequently prevents the dimerization of these adducts, in contrast to what has been observed with the pyridine and DMSO adducts of other telluradiazoles. Benzo-2,1,3-selenenadiazole reacted with boranes (BR3, R = Ph, F, Cl, Br) yielding 1:1 (R = Ph, F, Cl, Br) and 1:2 (R = Cl) adducts. The crystal structure the BPh3 adduct features molecules organized in pairs connected by long SeC SBIs but no SeN SBIs. The BF3 and BCl3 1:1 adducts dimerize forming the [Se-N]2 supramolecular synthon. In contrast, the BBr3 adduct does not dimerize although SeBr, BrBr SBIs are formed through the lattice. The 1:2 adduct displays SeCl SBIs accompanied by distortion of the N-B-Cl bond angle due to the enhanced electrophilicity of the chalcogen. DFT calculations were performed to evaluate the energies of dimerization of the 1:1 adducts, the calculated SBI energies are greater than those for the dimer of the parent heterocycle (benzo-2,1,3-selenadiazole, 3b). The products of the combination of benzo-2,1,3-selenenadiazole with chloride salts of divalent Mn, Fe, Co, Ni, and Cd crystallized from DMSO in two distinct structural types. While the smaller ions (FeII, CoII and NiII) form infinite chains of metal atoms N,N’-bridged by the heterocycle΄ the larger ions (MnII and CdII) stabilize infinite chains of metal atoms bridged by 2 halide ions. In the latter case, two heterocycle molecules cap each metal ion and are able to establish a link to the next chain in the lattice through the [Se‑N]2 supramolecular synthon. Despite the large (>9.2 Å) distance between [M(-Cl)2]∞ chains, the manganese derivative is only paramagnetic, not ferromagnetic. Symmetry-broken DFT calculations for small models were unable to quantitatively reproduce the measured couplings (J) but do indicate that the heterocycle acquires significant spin density in the MnII compound enabling paramagnetic coupling through the [Se‑N]2 supramolecular synthon. General methods for the synthesis of N-alkylated selenadiazolium cations were investigated. Methyl, iso-propyl and tert-butyl benzo-2,1,3-selenadiazolium cations were prepared by direct alkylation or cyclo-condensation of the alkyl-phenylenediamine with selenous acid. While the former reaction only proceeds with the primary and tertiary alkyl iodides, the latter is very efficient. Difficulties reported in earlier literature are attributable to the formation of adducts of benzoselenadiazole with its alkylated cations and side reactions initiated by aerobic oxidation of iodide. However, the cations themselves are resilient to oxidation and stable in acidic to neutral aqueous media. X-ray crystallography was used in the identification and characterization of the following compounds: [C6H4N2(R)Se]+X-, (R = CH(CH3)2, C(CH3)3; X = I-, I3-), [C6H4N2(CH3)Se]+I-, and [C6H4N2Se][C6H4N2(CH3)Se]2I2. Formation of SeN SBIs was only observed in the last structure because anion binding to selenium is stronger. The relative strengths of those forces and the structural preferences they enforce were assessed with DFT-D3 calculations supplemented by AIM analyses of the electron density. The methods developed for the preparation of N-alkyl benzoselenadiazolium cations were extended to the syntheses of dications intended for use as building blocks of supramolecular polymers. The structure of several salts was established by single-crystal X-ray diffraction. [H4C6NSeN-CH2-CH2-NSeNC6H4]Cl2 crystallized forming a macrocyclic structure in which two dications are bridged by SeCl SBIs; a third halide anion sits at the centre of the macrocycle. [1,2-(H4C6NSeN)2-C6H10]Cl2 features two selenadiazolium cations bridged by a 1‑(R),2‑(R)‑substituted cyclohexane and short SeCl SBIs. [1,4-(H4C6NSeN-CH2)2-C6H4](BF4)2, featuring a p-xylene bridge, crystallizes in two pseudopolymorphs; with dications in anti or syn conformations making SeF contacts. [H4C6NSeN-CH2-CH2-NSeNC6H4](CF3SO3)2 does dimerize though the [Se-N]2 supramolecular synthon, although SeO interactions with the anions cap the second selenium atom. In contrast, [H4C6NSeN-CH2-CH2-CH2-NSeNC6H4](CF3SO3)2 only displays SeO contacts. An oligonucleotide analogue containing N-substituted selenadiazolium cations was designed to create foldamers with structures controlled by main-group secondary bonding. The target structures take advantage of the methods developed in this thesis for the functionalization of selenadiazoles and is meant to be compatible with automated methods for oligonucleotide synthesis. The proposed synthesis begins with the preparation of 1-(α,β)-O-methyl-2-deoxy-D-ribose, which was chlorinated and treated with phenylenediamine. High-resolution mass spectrometry confirmed the attachment of the diamine to the ribose, however, the yield was too low to continue this synthetic project. A ground-breaking development in the application of secondary bonding in supramolecular chemistry is the discovery of the reversible auto-association of iso-tellurazole N-oxides through TeO SBIs into annular structures. These rings are persistent in solution and behave as actual macrocycles able to complex transition metal ions, form adducts with fullerenes, and host small molecules. Single-crystal X-ray diffraction was critical to the characterization of these structures and required careful disorder modelling for tetrahydrofuran molecules included in a macrocyclic hexamer and the occupational disorder of CH2Cl2 and BF4- anions due to metal depletion in the crystal of a PdII complex. / Thesis / Doctor of Philosophy (PhD) / Supramolecular chemistry is a prominent area of research that pursues the construction of large structures by the spontaneous assembly and organization of molecular building blocks. Its fundamental premise is that the judicious use of intermolecular forces allows the design of a structure and control of its properties. Most of the work in supramolecular chemistry has relied on hydrogen atoms bridging molecules and the bonding of metal ions to atoms rich in electrons. This thesis pursued the use of a different type of intermolecular force, termed “secondary bonding”, which is characteristic of the heaviest elements at the right of the periodic table (the “main-group” of elements). Previous work at McMaster demonstrated that cyclic molecules containing carbon, nitrogen and tellurium were particularly efficient as supramolecular building blocks. However, they are easily degraded by atmospheric water, this fact severely limits practical applications of these compounds. In this thesis, the tellurium atoms are replaced by selenium, a lighter element in the same family. The resulting molecules are more tolerant of atmospheric conditions but form weaker intermolecular links. Through a combination of quantum mechanical, synthetic, spectroscopic and structural studies, it is shown that certain modifications to the molecular structure increase the affinity of the selenium atoms for electrons. In this way, it is possible to strengthen the intermolecular interactions and promote the spontaneous assembly of supramolecular structures. These investigations eminently fall in the category of fundamental research but have broad-reaching implications for practical applications in optical and electronic technologies.

Groundbreaking progress in molecule-based optoelectronic devices for lighting, display and energy-harvesting technologies demands highly efficient and easily processable functional materials with tunable properties governed by their molecular/supramolecular structure variations. To date, functional coordination compounds whose function is governed by non-covalent weak forces (e.g., metallophilic, dπ-acid/dπ-base stacking, halogen/halogen and/or d/π interactions) remain limited. This is unlike the situation for metal-free organic semiconductors, as most metal complexes incorporated in optoelectronic devices have their function determined by the properties of the monomeric molecular unit (e.g., Ir(III)-phenylpyridine complexes in organic light-emitting diodes (OLEDs) and Ru(II)-polypyridyl complexes in dye-sensitized solar cells (DSSCs)). This dissertation represents comprehensive results of both experimental and theoretical studies, descriptions of synthetic methods and possible application allied to monovalent coinage metal-based functional materials. The main emphasis is given to the design and synthesis of functional materials with preset material properties such as light-emitting materials, light-harvesting materials and conducting materials. In terms of advances in fundamental scientific phenomena, the major highlight of the work in this dissertation is the discovery of closed-shell polar-covalent metal-metal bonds manifested by ligand-unassisted d10-d10 covalent bonds between Cu(I) and Au(I) coinage metals in the ground electronic state (~2.87 Å; ~45 kcal/mol). Moreover, this dissertation also reports pairwise intermolecular aurophilic interactions of 3.066 Å for an Au(I) complex, representing the shortest ever reported pairwise intermolecular aurophilic distances among all coinage metal(I) cyclic trimetallic complexes to date; crystals of this complex also exhibit gigantic luminescence thermochromism of 10,200 cm-1 (violet to red). From applications prospective, the work herein presents monovalent coinage metal-based functional optoelectronic materials such as heterobimetallic complexes with near-unity photoluminescence quantum yield, metallic or semiconducting integrated donor-acceptor stacks and a new class of Au(III)-based black absorbers with cooperative intermolecular iodophilic (I…I) interactions that sensitize the harvesting of all UV, all visible, and a broad spectrum of near-IR regions of the solar spectrum. These novel functional materials of cyclic trimetallic coinage metal complexes have been characterized by a broad suit of spectroscopic and structural analysis methods in the solid state and solution.

No / The increasing prevalence of poorly soluble drugs in development provides notable risk of new products demonstrating low and erratic bioavailabilty with consequences for safety and efficacy, particularly for drugs delivered by the oral route of administration. Although numerous strategies exist for enhancing the bioavailability of drugs with low aqueous solubility, the success of these approaches is not yet able to be guaranteed and is greatly dependent on the physical and chemical nature of the molecules being developed. Crystal engineering offers a number of routes to improved solubility and dissolution rate, which can be adopted through an in-depth knowledge of crystallisation processes and the molecular properties of active pharmaceutical ingredients. This article covers the concept and theory of crystal engineering and discusses the potential benefits, disadvantages and methods of preparation of co-crystals, metastable polymorphs, high-energy amorphous forms and ultrafine particles. Also considered within this review is the influence of crystallisation conditions on crystal habit and particle morphology with potential implications for dissolution and oral absorption.

Understanding the supramolecular interactions governing the self-assembly of molecular building blocks upon surfaces is fundamental to the design of new devices such as sensors or catalysts. Successful heterogeneous enantioselective catalysts have relied upon the adsorption of ‘chiral modifiers’, usually chiral amino acids, onto reactive metal surfaces. One of the most researched examples is the hydrogenation of β-ketoesters using nickel-based catalysts. The stability of the chiral modifiers upon catalyst surfaces is a major obstacle to the industrial scale-up of this reaction. In this study, the replacement of conventional modifiers with porous, chiral and functionalised self-assembled networks is investigated. Perylene-3,4,9,10-tetracarboxylic diimide (PTCDI) and melamine (1,3,5-triazine,-2,4,6-triamine) have been shown to form hydrogen bonded networks on Ag-Si(111)√3x√3R30° in ultra-high vacuum (UHV) and Au(111) substrates in UHV and ambient conditions, these networks are capable of hosting guest molecules. These networks are investigated further in this study. In UHV, the behaviour of the components and network formation on Ni(111) is probed using scanning tunnelling microscopy (STM) and temperature-programmed desorption (TPD). The stability of the PTCDI-melamine network on Au(111) was analysed using TPD. Metal coordination interactions between each of the network components and nickel upon the Au(111) surface were examined by STM before testing the ability of the network to act as a template for metal growth. Finally, a number of polymerisation reactions are investigated with a view to replacing chiral modifiers with porous, chiral, functionalised covalent networks. Periodic covalent networks should possess the greater chemical and thermal stability required for more widespread use. In UHV and ambient conditions, STM is used to monitor the progress of surface-confined reactions on Au(111) and characterise the resultant covalent structures.

Ce travail s'inscrit dans le cadre de la chimie supramoléculaire, domaine s'intéressant à l'étude d'édifices moléculaires liés par des interactions non-covalentes, fréquemment rencontrés dans le monde du vivant. Afin de mieux comprendre les phénomènes de complexation, de nombreux récepteurs moléculaires synthétiques ont été développés depuis ces cinquante dernières années. Dans le cadre de la reconnaissance moléculaire, les calix[6]arènes s'avèrent être des plateformes idéales puisqu'ils sont aisément fonctionnalisables et possèdent une cavité hydrophobe propice à l'inclusion de petites molécules organiques. D'ailleurs de nombreux récepteurs calix[6]aréniques ont déjà été développés et ont été étudiés pour leur aptitude à complexer des molécules neutres, des anions, des paires d'ions ou des ions métalliques. Cependant, ils souffrent de certaines limitations puisqu'ils ne sont pas hydrosolubles et sont difficilement post-fonctionnalisables limitant de ce fait leur applicabilité. Nous nous sommes donc intéressés à la synthèse de récepteurs calix[6]aréniques fonctionnalisés ainsi qu'à l'étude de leurs propriétés réceptrices vis-à-vis d'entités chargées ou de molécules neutres. Les études de ces systèmes ont été réalisées essentiellement par spectroscopie de Résonance Magnétique Nucléaire (RMN).<p>Dans le cadre de ce travail, des récepteurs ditopiques mono- et trisfonctionnalisés de type calix[6]cryptamide ont tout d'abord été développés. Ces récepteurs présentent un motif trenamide qui constitue un second site de reconnaissance, distinct mais proche du premier formé par la cavité calix[6]arénique. Ces récepteurs se sont révélés capables de complexer les molécules neutres polaires ainsi que des entités chargées avec une grande sélectivité en milieu aprotique mais également en présence d'un solvant protique. Le chapeau trenamide étant relativement contraint et bien préorganisé, il assure un fort effet chélate et permet une sélectivité de taille pour l'anion fluorure. La proximité des deux sites de reconnaissance ainsi que la sélectivité pour l'anion fluorure permettent à ces récepteurs de reconnaître des ammoniums sous forme de paires d'ions de contact uniquement avec le fluorure comme partenaire anionique. Les résultats obtenus ont démontré que l'introduction de fonctionnalisations soit au niveau du chapeau trenamide, à proximité du site de reconnaissance, soit au niveau du petit col du calix[6]arène n'inhibait pas les propriétés de complexation de ces récepteurs. Les premiers essais d'introduction de groupes hydrosolubilisants ont alors été réalisés et se sont révélés très prometteurs. En effet, l'introduction de groupements PEG sur un calix[6]cryptamide trisfonctionnalisé a permis de démontrer l'aptitude de ce récepteur à complexer des molécules neutres en milieu aqueux (CD3OD/D2O).<p>Dans un second temps, des récepteurs mono- et trisfonctionnalisés de type calix[6]tren ont été développés. Les études préliminaires réalisées ont permis de mettre en évidence que, comme le calix[6]tren non fonctionnalisé, ces récepteurs étaient capable de complexer de petites molécules organiques lorsqu'ils sont polarisés, soit sous leur forme per-protonnée soit sous la forme d'un complexe métallique (Zn2+ ou Cun+). <p><p>L'ensemble de ces travaux a ainsi permis de valider la stratégie de synthèse visant à introduire des bras fonctionnels sur des récepteurs ditopiques calix[6]aréniques et de démontrer que ces nouveaux récepteurs fonctionnalisés conservaient des propriétés de reconnaissance. Ces travaux permettent donc d'envisager de multiples applications pour ce type de récepteurs.<p>This work falls within the field of supramolecular chemistry, a field concerned with the study of molecular structures linked by non-covalent interactions. Such weak interactions are frequently encountered in the living world and in particular in molecular recognition processes. In order to better understand and exploit these recognition processes, many synthetic molecular receptors have been developed over the last fifty years. In this regard, calix[6]arenes have proved to be ideal platforms because they can be easily functionalized and they possess a hydrophobic cavity suitable for the inclusion of small organic molecules. Hence, many calix[6]arene based receptors have been studied for their ability to complex neutral molecules, anions, ion pairs or metal ions. However, most of these receptors suffer from major limitations that limit their applicability: they are not water soluble and hardly post-functionalizable. In the frame of this thesis, we were therefore interested in the synthesis of functionalized calix[6]arene based receptors and in the study of their host-guest properties toward charged species or neutral molecules. Studies of these host-guest systems have been carried out mainly by Nuclear Magnetic Resonance spectroscopy (NMR).<p><p>First, mono- and trisfunctionalized ditopic receptors based on a calix[6]cryptamide skeleton were synthesized. These receptors possess two binding sites in close proximity: a trenamide subunit and the calix[6]arene cavity. They have proved to be capable of complexing neutral polar molecules as well as charged species with high selectivity in aprotic solvents but also in a protic environment. The trenamide cap being relatively constrained and well pre-organized, it provides a strong chelate effect and allows a selectivity of size for the fluoride anion. Remarkably, the proximity of the two recognition sites allow these receptors to recognize ammonium ions in the form of contact ion pairs but only with a fluoride anion as the partner. The results have shown that the introduction of functionalizations at the trenamide cap or at the narrow rim of the calix[6]arene do not inhibit the complexation properties of these receptors. First attempts in order to introduce water-solubilizing groups have been undertaken and promising results have been obtained. Indeed, the introduction of PEG groups on a trisfunctionalized calix[6]cryptamide has led to a receptor able to complex neutral molecules in an aqueous environment (CD3OD/D2O).<p><p>In a second step, mono- and trisfunctionalized receptors derived from calix[6]tren have been synthesized. Preliminary studies have highlighted that, similarly to the parent calix[6]tren, these receptors are able to complex small organic molecules when they are polarized either in their per-protonated form or in the form of a metal complex (Zn2+ or Cun+).<p><p>All this work validates the synthetic strategy that consists of introducing functional arms on ditopic calix[6]arene based receptors and opens new perspectives for the elaboration and study of molecular receptors in an aqueous environment. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

<div>Surface level molecules act as an interface that mediates between the surface and the environment. In this way, interfacial molecules are responsible for conferring characteristics of relevance to many modern material science problems, such as electrical conductivity and wettability. For many applications, such as organic photovoltaics and nanoelectronics, macroscopic placement of chemical patterns at the sub-10 nm must be achieved to advance next generation device applications.</div><div><br></div><div>In the work presented here, we show that sub-10 nm orthogonal features can be prepared by translating the building principles of the lipid bilayer into striped phase lipids on 2D materials (e.g. highly ordered pyrolytic graphite (HOPG), MoS2). Macroscopic patterning of these nanoscopic elements is achieved via Langmuir Schafer deposition of polymerizable diyne amphiphiles. On the Langmuir trough, amphiphiles at the air water interface are ordered into features that can be observed on the macroscale using Brewster angle microscopy. Upon contact of the 2D material with the air-water interface the macroscopic pattern on the trough is transferred to the 2D material creating a macroscopic pattern consisting of sub-10 nm orthogonal chemistries. We also show here how hierarchical ordering can be accomplished via noncovalent microcontact printing of amphiphiles onto 2D materials. Microcontact printing allows a greater measure of control over the placement and clustering of interfacial molecules.</div><div><br></div><div>The alkyl chain/surface enthalpy has a great deal of influence over the ordering of amphiphiles at the sub-nm scale. Here, we examine this influence by depositing diyne amphiphiles onto MoS2 which has a weaker alkyl adsorption enthalpy compared to HOPG. We found that dual-chain amphiphiles deposited on MoS2 adopt a geometry that maximized the molecule-molecule interaction compared to the geometry adopted on HOPG.</div><div><br></div><div>Finally, we show how the hierarchical pattern of diyne amphiphiles can be transferred off of the 2D material onto an amorphous material. This is done by reacting the amorphous material with the conjugated backbone of the diyne moiety through a hydrosilylation reaction to exfoliate the film from the 2D crystalline material. The resulting polymer ‘skin’ has many applications were controlling interfacial properties of an amorphous material is important.</div>

<p>As global population continue to rise, the demand for energy is slated to increase substantially. To combat climate change, large amounts of renewable energy will be needed to feed this growing demand. Of renewable energy sources, photovoltaics are well positioned to meet this increasing demand due to the immense abundance of solar energy incident on earth. However, existing energy intensive, low throughput, and costly manufacturing techniques for photovoltaics may pose a barrier to continued large scale implementation.</p> <p>Solution processing has emerged as a promising photovoltaics fabrication technique with high throughput, high materials utilization, and lower cost than existing vacuum-based methods. Thin film photovoltaic materials such as Cu(In,Ga)(S,Se)₂ and CdTe have both been fabricated using various solution processing methods. Of the various solution processing routes, colloidal metal chalcogenide nanoparticles have demonstrated promise as a hydrazine-free route for the solution processing of high efficiency Cu(In,Ga)(S,Se)₂ solar cells. However, conventional solution processing with colloidal nanoparticles has long suffered from anionic and carbonaceous impurities, stemming from legacy synthesis methods. The work in this dissertation aims to solve these issues through the development of novel synthetic methods, ligand engineering, and ultimately improved scalability through slot-die coating.</p> <p> Typical colloidal syntheses rely on the use of metal salts as precursors such as metal halides, nitrates, acetates, and so forth, where the anions may incorporate and alter the electrical properties of the targeted nanomaterials. In this work, the recent advances in amine-thiol chemistry and its unique ability to solubilize many metal containing species are expanded upon. Alkylammonium metal thiolate species are easily formed upon addition of monoamine and dithiol to elemental Cu, In, Ga, Sn, Zn, Se, or metal chalcogenides such as Cu₂S and Ag₂S. These species were then used directly for the synthesis of colloidal nanoparticles without the need for any additional purification. The metal thiolate thermal decomposition pathway was studied, verifying that only metal chalcogenides and volatile byproducts are formed, providing a flexible route to compositionally uniform, phase pure, and anionic impurity-free colloidal nanoparticles including successful syntheses of In₂S₃, (In_xGa_1–x)₂S₃, CuInS₂, CuIn(S_xSe_1–x)₂, Cu(In_xGa_1–x)S₂, Cu₂ZnSnS₄, and AgInS₂. </p> <p>However, further impurities from deleterious carbonaceous residues originating from long chain native ligands were still a persistent problem. This impurity carbon has been observed to hinder grain formation during selenization and leave a discrete residue layer between the absorber layer and the back contact. An exhaustive hybrid organic/inorganic ligand exchange was developed in this work to remove tightly bound oleyalmine ligands through a combination of microwave-assisted solvothermal pyridine ligand stripping followed by inorganic capping with diammonium sulfide, yielding greater than 98% removal of native ligands via a rapid process. Despite the aggressive ligand removal, the nanoparticle stoichiometry remained largely unaffected when making use of the hybrid ligand exchange. Scalable blade coating of the ligand exchanged nanoparticle inks from non-toxic dimethyl sulfoxide inks yielded remarkably smooth and crack free films with RMS roughness less than 7 nm. Selenization of ligand exchanged nanoparticle films afforded substantially improved grain growth as compared to conventional non-ligand exchanged methods yielding an absolute improvement in device efficiency of 2.8%. Hybrid ligand exchange nanoparticle-based devices reached total-area power conversion efficiencies of 12.0%.</p> <p>While extremely effective in ligand removal, ligand exchange pathways increase process complexity and solvent usage substantially, which may limit the cost advantage solution processing aims to provide. Further synthesis improvement was developed through a ligand exchange free, direct sulfide capped strategy. Using sulfolane as a benign solvent, CuInS₂ nanoparticles with thermally degradable thioacetamide ligands were synthesized using thermal decomposition of isolated metal thiolates from Cu₂S and In precursors. Through gentle thermal treatment, these ligands decomposed into non-contaminating gaseous byproducts leaving carbon free nanoparticle films without the need for ligand exchange.</p> <p>With the development of virtually contamination free colloidal nanoparticle inks, focus was shifted to scalability using slot die coating. Unlike typical lab-scale coating techniques such as spin coating, slot die coating is a widely used industrial coating technique with nearly 100% materials utilization, and high throughput roll-to-roll compatibility. A custom lab-scale slot-die coater was used to rapidly proof coating conditions, which were rapidly analyzed for uniformity using absorbance scanning in conjunction with profilometry. A cosolvent chlorobenzene/dichlorobenzene ink was developed to yield highly uniform, crack free thin films from non-ligand-exchanged Cu(In,Ga)S₂ nanoparticles, which were finished into devices with champion total are efficiencies of 10.7%. To the best of our knowledge, this represents the first report of slot die coated Cu(In,Ga)(S,Se)₂ photovoltaics. The methods presented in this work offer a pathway towards low impurity, high efficiency, scalable solution processed Cu(In,Ga)(S,Se)₂ photovoltaics to enable low cost renewable energy.</p>

This thesis describes the synthesis of halogen bonding receptors for integration within interlocked anion host systems. Chapter 1 introduces the field of supramolecular chemistry, with a particular focus on anion recognition and sensing, halogen bonding, and the synthesis of mechanically interlocked structures. Chapter 2 describes the preparation and anion binding properties of carbazole-based receptor molecules. A systematic anion binding study on a series of halogen- and hydrogen-bonding 3,6-bis-triazolium carbazole acyclic receptors is described initially, followed by the development of a halogen bonding rotaxane. The anion and metal complexation properties of acyclic and macrocyclic systems incorporating the 1,8-bis-triazole carbazole motif are also presented. Chapter 3 details the synthesis and anion complexation investigations of halogen and hydrogen bonding naphthalene-based acyclic and interlocked rotaxane host molecules. Chapter 4 presents receptors based on the 4,4'-bis-triazole-2,2'-bipyridyl motif. A halogen bonding rhenium(I) bipyridyl complex is exploited in the development of a rotaxane host system which optically senses anions via luminescence purely through halogen bonding interactions. The anion recognition and sensing properties of diquat-based receptors are also investigated, and shown to exhibit optical and electrochemical responses to anions. Chapter 5 summarises the major conclusions from Chapters 2-4. Chapter 6 describes the experimental procedures used in the work, and includes characterisation data for the synthesised compounds. Supplementary information relating to crystallographic data, and absorption, luminescence and electrochemical studies, is provided in the Appendices.

This thesis investigates the design and synthesis of macrocycles and examines their ion-pair recognition, anion recognition and interpenetrative assembly capabilities. Chapter One introduces the field of supramolecular chemistry. Key concepts in host–guest complexation and self-assembly are outlined, with particular emphasis on the design of host systems for anion and ion-pair recognition. Chapter Two details the synthesis and binding properties of a heteroditopic 1,2,3-triazole- containing macrocycle that exhibits cooperative ion-pair recognition. Solution and solid-state evidence shows that the triazole motif simultaneously binds anions and cations. The exten- sion of this work towards the formation of interlocked structures containing an expanded heteroditopic macrocycle and threading components is explored. Chapter Three discusses the design and syntheses of series of electron-deficient macrocycles based on imidazolium, pyridinium and triazole. These are investigated for anion binding ability and assembly of interpenetrative assemblies with electron-rich threading components. Chapter Four describes research into the formation of interpenetrative assemblies using neutral components. Their design is based around aromatic donor–acceptor interactions and halogen bonding. Chapter Five presents some conclusions from the research undertaken. Chapter Six provides titration protocols, Job plot approximations, experimental procedures and characterisation of the compounds described in this thesis. Appendix details additional X-ray crystallographic data.

The synthesis, characterisation and anion binding properties of a series of mono- and bifunctional Lewis acidic borylferrocene compounds are described within this thesis. The original parent compound FcBMes₂ (3.1), revealed a versatile route for the synthesis of such borylferrocenes and subsequently the analogous compound Fc*BMes₂ (3.2) was synthesised. The anion binding properties of (3.1) and (3.2) were investigated and both were shown to bind one equivalent of cyanide. The binding event was signalled by an electrochemical shift (ca. -560 mV) and a quenching of bands at 510 or 542 nm respectively in the UV/Vis spectrum, while the mode of anion binding in the solid state was established by X-ray crystallography for [ⁿBu₄N]⁺[(3.1)·CN]⁻. Incorporation of a suitable redox active dye (i.e. tetrazolium violet for 3.2) allowed conversion of the electrochemical response to a colorimetric change on cyanide binding. However, a competing response for fluoride is also seen for (3.1) and (3.2). Thus a two component system is reported involving (3.2) and the boronic ester FcB(OR)₂ (3.4), [where (OR)₂ = OCH(Ph)CH(Ph)O], which from previous research is known to selectively bind fluoride, and allows for selective colorimetric cyanide sensing by simple Boolean AND/NOT logic. 1,4-C₆H₄(BMes₂)[B(OR)₂] (3.5), 4,4-C₁₂H₈(BMes₂)[B(OR)₂] (3.6) and 1,1′-fc(BMes2)(B(OR)2) (3.7) were synthesised as possible single molecules for discrimination between cyanide and fluoride. (3.5) and (3.6) proved only capable of binding one equivalent of either anion, (3.7) showed some ability to bind two equivalents of fluoride however based on ESI-MS studies although only in the presence of a large excess of anion. Systematic variation of the para-boryl substituent was investigated by synthesis of compounds FcB(Xyl^F)₂ (4.1), FcB(Xyl)₂ (4.2) and FcB(Xyl^OMe)₂ (4.3). Anion binding studies reveal a linear increase in fluoride binding affinity consistent with that expected based on the para,/em>-Hammett parameters, however with only minor differences, while no pattern is observed with respect to their cyanide binding capabilities. The addition of neutral and cationic peripheral substituents has been investigated through synthesis of [1,2-fc(CH₂NMe₂)BMes₂] (4.6) and [1,2-fc(CH₂NMe₃)BMes₂]⁺ (4.7). Subsequent binding studies revealed (4.6) to be moisture sensitive, however reaction of (4.7) with fluoride and cyanide led to formation of the adducts [(4.7)·F]⁻ and [(4.7)·CN]⁻. The anion affinity of (4.7) exhibits a substantial increase when compared to the parent compound (3.1). Even when compared to the isomeric 1,1′ system an increase of approximately three orders of magnitude is seen attributed to the closer nature of the cationic charge and in the fluoride adduct the presence of a cooperative intramolecular hydrogen bond. The 1,1′-bifunctional analogues of the mono-substituted systems were synthesised [e.g. 1,2-fc(BMes₂)₂ (5.1)] and shown to complex two equivalents of fluoride or cyanide in acetonitrile. The 1:1 cyanide adduct of (5.1) was isolated in chloroform however, no evidence for chelation was observed. The analogous systems 1,2-fc(BMes₂)₂ (5.5), 1,2-fc(BXyl₂)2 (5.7), and 1,2-fc(BMes₂)(BXyl₂) (5.8) were also investigated. Reaction of (5.5) with fluoride and cyanide revealed it to bind only one equivalent of either anion, neither however was bound in a chelating fashion although X-ray crystallography revealed cyanide binds exo whilst fluoride binds endo to the B···B cavity. Finally the kinetics of fluoride binding were studied by UV/Vis spectroscopy and showed a systematic increase in rate constant upon reduction of steric bulk.