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This thesis explores the surface assembly of mechanically interlocked molecular architectures at gold surfaces for potential applications in molecular switches, anion sensing and stimuli (redox and optical) responsive molecular films. <b>Chapter One</b> introduces the field of mechanically interlocked molecules focusing on rotaxane and catenane surface assemblies in the form of single molecule thick self-assembled monolayers. A review of the surface-attached characteristics of mechanically interlocked molecules is given before exploring specific anion template directed strategies for their construction. The potential to incorporate both redox-active and optically-active functional groups within these mechanically interlocked molecules is also discussed. <b>Chapter Two</b> provides the experimental details and procedures employed in this thesis to characterise the molecular systems under investigation. <b>Chapter Three</b> introduces several surface characterisation techniques such as; ellipsometry, contact angle, X-ray reflectivity and X-ray photoelectron spectroscopy, with a particular focus of applying these tools to probe the surface co-conformation of switchable and interlocked molecules at surfaces. Electroanalytical techniques such as cyclic voltammetry, chronoamperometry and electrical impedance spectroscopy are also introduced. <b>Chapter Four</b> details the surface assembly of a series of ferrocene containing anion templated catenane self-assembled monolayers on gold. Detailed electrochemical and angle resolved X- ray photoelectron spectroscopy characterisation elucidates the co-conformation upon surface attachment. <b>Chapter Five</b> details the anion templated surface assembly of a redox-active rotaxane self- assembled monolayer on gold. Subsequent electroanalysis and X-ray photoelectron spectroscopy characterisation confirms the structural integrity of the film and a possible co- conformation at the surface is discussed. <b>Chapter Six</b> describes efforts towards constructing optically responsive hybrid d-f lanthanide containing mechanically interlocked molecules. Initial work focuses on switching characteristics of a redox switchable antennae and its ability to modulate the luminescence of a series of lanthanide complexes in solution. Subsequent surface attachment of the lanthanide complexes in the form of emissive self-assembled monolayers is also investigated.

<p>A topologically interlocked material (TIM) system belongs to a class of architectured materials and is known to perform outstanding mechanical properties such as stiffness, strength, and toughness. TIM systems are assemblies of polyhedral or building blocks, where individual elements constrain each other on inclined sides of building blocks. This thesis first focuses on developing novel designs of TIM plates composed of building blocks that interact with each other. The resulting TIM systems can be characterized concerning their periodicity and symmetry. Consequently, this study investigates how the proposed geometric features enhance mechanical properties and contribute to emerging properties. Specifically, four research questions provide a clear direction and framework for the investigation. For efficient analysis, finite element calculations are employed, and physical validation methods are used to verify them.</p> <p>The first research question is how the mechanical properties of aperiodic systems differ from those of periodic systems. Aperiodic systems offer diverse possibilities in terms of forms and arrangements. In this thesis, aperiodicity is further divided into two aspects: disrupting symmetry and preserving symmetry. In the approach that disrupts symmetry, the shapes of the tiles are randomly generated. An aperiodic system does not necessarily possess inherently superior or inferior mechanical properties compared to a periodic system. However, the flexibility of aperiodic systems allows for numerous forms and arrangements, presenting promising alternatives to identify factors or patterns that contribute to improved mechanical performance. To simplify these complex configurations, network theory is employed.</p> <p>Each building and its contact interfaces are represented as nodes and links. By utilizing network theory, a focused analysis of the links is conducted, enabling a comprehensive understanding of force propagation across TIM systems. The quantification of the significance of each link assists in reinforcing critical links while potentially sacrificing less critical ones.</p> <p>This approach not only simplifies the research problem but also facilitates the creation of customized design systems by adjusting the links.</p> <p>The other approach to achieve aperiodicity while preserving symmetry utilizes quasicrystal structures. This is based on another research question: What are the benefits of creating TIM systems with quasi-crystal tilting? Quasi-crystals possess a unique characteristic of maintaining 5-fold rotational symmetry while breaking away from periodic patterns observed in traditional systems. The arrangement of elements in quasi-crystal structures extends in a non-repetitive pattern from the center outward, offering a multitude of potential possibilities for TIM systems. By incorporating quasi-crystal tiling, TIM systems are expected to open up exceptional mechanical properties and unconventional behaviors.</p> <p>The third research question investigates whether the influence on mechanical performance varies based on the symmetry level of TIM systems. Despite using identical unit blocks, the arrangement of an assembly can lead to different levels of symmetry. Furthermore, it is possible to modify the symmetry of the unit block, thereby impacting the overall symmetry of the assembly. To achieve this, the symmetry of a unit block is adjusted by modifying the angles of side faces, transitioning from larger angles to smaller angles or vice versa. This modification introduces directionality (rotational symmetry) to the unit block and creates a greater variety of symmetry levels depending on the arrangements of these blocks. By implementing a broader range of symmetry levels that conventional TIM systems cannot achieve, this research aims to investigate the relationship between these symmetries and mechanical properties.</p> <p>The fourth research question is about what emerging properties could be present in TIM systems. While the primary application of TIMs is to enhance the damage tolerance of brittle materials against an external load, there have been ongoing attempts to research emerging properties like negative stiffness, sound absorption, and chirality. Chirality, in particular, serves as a valuable geometric property to describe a circulation of force propagation. Generally, the ability of TIM systems to carry transverse loads is explained through equivalent Mises truss along x− and y − axis. However, chirality enables the representation of not only axial force paths but also circulations of forces within TIM systems. In addition, a rich variety of geometric patches are observed in quasi-crystal structures. In crystal structures, a limited number of patches are repetitively arranged, resulting in a restricted range of properties. However, quasi-crystals like Penrose are non-periodic and possess a greater capacity to generate diverse patches, allowing for the selection of various mechanical properties.</p>

I rotaxaner följs förflyttningen av makrocykeln vanligtvis med 1H-NMR spektroskopi. Målet med detta projekt är i stället att utveckla ett system som möjliggör att förflyttningen av makrocykeln kan observeras med hjälp av luminiscerande lantanid emission. Detta bör vara ett kraftfullt verktyg, då luminiscerande emission skulle möjliggöra att makrocykelns position längs med tråden kan avläsas direkt med blotta ögat. För att lantanid-baserade system ska kunna luminiscera krävs det att en aktiverande antennmolekyl finns i närheten av lantaniden. I detta projekt placerades en lantanidligand i den ena stoppande änden av en [2]rotaxan och en antennmolekyl sattes på den trådade makrocykeln. En förändring av pH:t medför att makrocykeln förflyttas närmre till lantanidliganden, vilket i sin tur medför att antennen aktiverar lantaniden och den luminiscerande emissionen startar. Baserat på styrkan av luminiscensen bör man då kunna avgöra makrocykelns position i rotaxanen. I framtiden hoppas vi kunna använda detta visualiseringsverktyg för att kunna börja använda rotaxaner som biosensorer för medicinsk diagnostik. / In rotaxanes, the movement of the macrocycle is usually tracked using 1H-NMR spectroscopy. The goal of this project is to instead develop systems so one can follow the macrocycle movement through luminescent lanthanide emission. This should be a powerful tool, as luminescence emission would allow for a direct visual readout of the macrocycle position along the thread with the naked eye. To allow luminescence in lanthanide-based systems, a sensitizing antenna molecule needs to be present in close proximity to the lanthanide. In this project, a lanthanide ligand was placed at the stoppered end of a [2]rotaxane, and a sensitizing antenna was attached to the threaded macrocycle. A change in pH induces the macrocycle to move closer to the lanthanide stopper, which causes the antenna to sensitize the lanthanide and start the luminescence emission. Based on the strength of the luminescence, one should then be able to determine the location of the macrocycle in the rotaxane. We hope to use this visual readout tool to eventually turn rotaxanes into useful point-of-care biosensors for medical diagnostics.

Des azobenzènes photochromiques ont été intégrés à des macrocycles synthétiques pour moduler photochimiquement la chélation de différents ions qui jouent un rôle essentiel dans les processus biologiques. La photocommutation de ces récepteurs a été étudiée (rendements quantiques, réversibilité, état photostationnaire) et les constantes de stabilité ont été déterminées. Le développement d’un récepteur biocompatible du Ca2+ (BAPTA) a permis de moduler la concentration de Ca2+ dans une solution aqueuse avec la lumière. Les molécules entrelacées sont également un sujet majeur dans le domaine de la chimie supramoléculaire. Une méthode de macrocyclisation photochimique, basée sur la dimérisation de l’anthracène, a été appliquée à des assemblages supramoléculaires dans le but de modifier leur topologie et de développer une nouvelle stratégie de photocaténation. En parallèle, un rotaxane a été réalisé en ajoutant des groupements encombrants sur les anthracènes par une réaction de Diels-Alder. / As the availability of ions plays a key role in biological processes, photochromic azobenzene macrocycles were synthetized to photochemically modulate chelation of different ions in various media. The photoswitching of these receptors was evaluated (quantum yields, reversibility, photostationary state) as well as binding constants. Integrating a biocompatible Ca2+ receptor (BAPTA) with azobenzene enabled the modulation of calcium concentration in aqueous solution and to reversibly switch the fluorescence emission of a molecular probe based on photoinduced electron transfer. Interlocked molecules are also a major topic in the field of supramolecular chemistry. A Photochemical macrocyclization method, based on the dimerization of anthracene, was applied to supramolecular assemblies in order to change their topology and develop a new strategy of photocatenation. In parallel, a rotaxane was achieved by adding bulky groups on anthracenes by a Diels-Alder reaction.

Molecular recognition plays an essential role in the self-assembly and self-organisation of biological and chemical systems alike—allowing individual components to form complex interconnected networks. Within these systems, the nature of the recognition and reactive processes determines their functional and structural properties, and even small changes in their identity or orientation can exert a dramatic effect on the observed properties. The rapidly developing field of systems chemistry aims to move away from the established paradigm in which molecules are studied in isolation, towards the study of networks of molecules that interact and react with each other. Taking inspiration from complex natural systems, where recognition processes never operate in isolation, systems chemistry aims to study chemical networks with the view to examining the system-level properties that arise from the interactions and reactions between the components within these systems. The work presented in this thesis aims to advance the nascent field of systems chemistry by bringing together small organic molecules that can react and interact together to form interconnected networks, exhibiting complex behaviour, such as self-replication, as a result. Three simple building blocks are used to construct a network of two structurally similar replicators and their kinetic behaviour is probed through a comprehensive kinetic analysis. The selectivity for one of the recognition-mediated reactive processes over another is examined within the network in isolation as well as in a scenario where the network is embedded within a pool of exchanging components. The interconnected, two-replicator network is examined under far-from-equilibrium reaction-diffusion conditions, showing that chemical replicating networks can exhibit signs of selective replication—a complex phenomenon normally associated with biological systems. Finally, a design of a well-characterised replicator is exploited for the construction of a network integrating self-replication with a another recognition-directed process, leading to the formation of a mechanically-interlocked architecture—a [2]rotaxane.

L’implémentation d’un agent structurant impliquant un macrocycle à 31membres et intégrant un récepteur de type Hamilton / bis(2,6-diamidopyridine) a permis deconcevoir des [2]rotaxanes via une réaction click catalysée par du cuivre(I), soit à partir d’unpseudorotaxane en présence d’un barbiturique fonctionnalisé, soit par une méthode de« gabarit actif ». Ces structures supramoléculaires ont été rendues photochimiquement activesen exploitant des analogues de récepteurs Hamilton incorporant des groupementsphotodimérisables de type 9-anthracène. La photodimérisation et la retrodimérisation de cesrécepteurs en présence d’un fil barbiturique comportant des groupements terminauxencombrants (bouchons) permettent l’assemblage et le désassemblage de rotaxanes via unprocessus de photocapture. Ces unités 9-anthracène jouent également le rôle de bouchonsphotoactifs dans la formation d’un [2]rotaxane composé d’un plus petit anneau de typedibenzo-24-couronne-8, dont la photoirradiation résulte en une interconversion topologiqueinhabituelle entre un rotaxane et un caténane. Deux approches photochimiques ont permis deréguler des machines moléculaires distantes par une communication chimiqueintermoléculaire, c’est à dire soit par un transfert de molécule photoguidée, soit par untransfert d’électron photoinduit exalté par la présence d’un transfert d’énergie électroniqueréversible. / A templating motif involving a 31-member macrocycle integrating a bis(2,6-diamidopyridine) / Hamilton-type receptor aided [2]rotaxane sythesis, via a copper(I)catalyzed Huisgen reaction, in the presence of a designer barbiturate or by functionalizationusing an active template synthesis. Homologous supramolecular structures were madephotochemically-active, harnessing Hamilton receptors incorporating photodimerizable 9-anthracene groups. Photodimerization and retrodimerisation of these receptors in the presence of a barbiturate thread bearing terminal bulky stopper groups permitted rotaxane assembly /disassembly. The 9-anthracene units serve as stoppers in the formation of a [2]rotaxanecompound comprising a smaller dibenzo-24-crown-8 ring. Photoirradiation of these photoactive stoppers results in an unusual all-optical topological rotaxane - catenaneinterconversion. Two approaches to photoregulate remote molecular machines byintermolecular chemical communication involving a photoguided molecule or by photoinduced electron transfer aided by reversible electronic energy transfer are considered.

The aim of the master´s thesis is to design a load bearing steel structure of a community centre in accordance with architectural requirements. The structure consists of a main aisle and two extensions beside. The length of the structure is 62 m, the width 42 m and maximum height 15 m. The main load bearing elements of the structure are transversal restrained columns and truss roof beams. The roof beam for the main aisle is made up of tubes and arched. The lower and upper beams of roof beams for the extensions are straight. The distance between the main columns in 12 m. The purlins for the main aisle are truss structures with arched lower beam, the purlins for the extensions have straight lower beams of truss. There is a storey in the extensions. The structure of ceiling consists of girders and interlocked concrete plate in trapezoid metal plate. The structure is designed for the district of Brno. It is designed in accordance with the ČSN EN 1993 standard.

Made available in DSpace on 2016-04-29T13:17:47Z (GMT). No. of bitstreams: 1 Carolina Krauter Kracker.pdf: 3705226 bytes, checksum: 2d14824d7cb8a26f483a95c38dd83639 (MD5) Previous issue date: 2013-05-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Metacontingencies are the product and the process of selection of cultural practices in the third level of selection by consequences, in which variation is a fundamental requisite for selection to occur. Three experiments were conducted with the objectives of investigate the effects of schemes analogous to differential reinforcement schemes of variability LAG, and CRF, upon the behavior variability in cultural selection processes, and to ascertain in which ways more or less variability along these processes would affect the selection of a new metacontingency, in the face of a change in the cultural consequences presentation criterion. In the Experiment I, 21 participants worked in trios, under the effect of schemes analogous to LAG 2 and LAG 1 for the products of responses of inserting numbers from 0 to 9 in spots placed in some computers´ screens. It was required, as a condition to the presentation of cultural consequences (bonus), that an aggregate product (PA) featured by an specific relation among the sums of the numbers inserted by the participants and by non-repetition of the sums between cycles, according to the n of the LAG contingence, was produced. It was observed that there wasn´t systematic production of this PA along more than two consecutive generations of participants and that only the specified relation among sums recurred along different generations. Stereotypies in the operant responses´ topographies and in the sums were found. In the face of the change in the criterion of presentation of the cultural consequences, featured by a different relation among the sums (new PA), the selection of/ by metacontingencies and cultural transmission occurred and the production of stereotypies was again observed. In the second experiment, that counted on 14 participants, similar experimental phases were conducted, except that there wasn´t a phase in which schemes analogous to LAG were in effect. The selection of/by metacontingencies and its transmission were verified in these conditions, and when the change in the criterion of presentation of the cultural consequences was made, a new cultural selection was observed in a similar moment of the occurrence of this phenomenon in the previous experiment; the practice was also transmitted. Behavior stereotypies were noticed, mainly in the first process of cultural selection that was described. There were 18 participants in the third experiment, in which a scheme analogous to LAG 1 for the sums was introduced; after 13 generations of participants the selection of/by metacontingencies was ascertained, as well as its transmission. It was observed that there was more variability in the responses topographies and in the sums, but patterns that indicated restrictions in the behavior variability were identified when the cultural selection occurred. It was concluded that the introduction of schemes analogous to LAG hampered the selection of/by metacontingencies and that a new cultural selection happened rapidly, despite of more or less behavioral variability in the microcultures´ stories previously the modification of the criterion related to the presentation of cultural consequences / Metacontingências são o produto e o processo de seleção de práticas culturais no terceiro nível de seleção por consequências, em que variação é requisito fundamental para ocorrência de seleção. Três experimentos foram conduzidos com os objetivos de investigar os efeitos de esquemas análogos a esquemas de reforçamento diferencial de variabilidade LAG e CRF em relação à variabilidade comportamental em processos de seleção cultural; e de averiguar de que maneira maior ou menor variabilidade ao longo desses processos afetariam a seleção de uma nova metacontingência, diante de uma mudança no critério de apresentação das consequências culturais. No Experimento I, 21 participantes trabalharam em trios, vigorando esquemas análogos a LAG 2 e LAG1 em relação a produtos das respostas de inserção de números de 0 a 9 em caselas dispostas nas telas de computadores. Exigiu-se, como condição para a apresentação de consequências culturais (bônus), que um produto agregado (PA) caracterizado por uma determinada relação entre as somas dos números inseridos pelos participantes e pela não-repetição das somas entre ciclos, de acordo com o n do LAG, fosse produzido. Observou-se que não houve produção sistemática desse PA por mais de duas gerações consecutivas de participantes e que apenas a relação entre as somas especificada recorreu por diversas gerações, observando-se estereotipias nas topografias das respostas operantes e nas somas. Diante da mudança no critério de apresentação da consequência cultural, caracterizada por uma relação diferente da anterior entre as somas (novo PA), ocorreu a seleção de/por metacontingências e transmissão cultural, novamente observando-se a geração de estereotipias. No segundo experimento, que contou com 14 participantes, fases experimentais semelhantes foram conduzidas, exceto que não houve uma fase em que esquemas análogos a LAG vigoraram. Averiguou-se que a seleção de/por metacontingências e sua transmissão ocorreram nessas condições e, diante de mudança no critério de apresentação da consequência cultural, nova seleção cultural foi observada em momento próximo ao verificado no experimento anterior, ocorrendo também a transmissão da prática. Estereotipias comportamentais foram notadas, principalmente no primeiro processo de seleção cultural descrito. Houve 18 participantes no terceiro experimento, em que se implementou um esquema análogo a LAG 1 para as somas; após 13 gerações de participantes, a seleção de/ por metacontingências com esse esquema em vigor pôde ser constatada, bem como sua transmissão. Foi observada maior variabilidade nas topografias de respostas e somas, mas padrões que indicaram restrição na variação comportamental foram identificados diante da ocorrência da seleção cultural. Constatou-se que a introdução de esquemas análogos a LAG teve como efeito dificultar a seleção de/ por metacontingências e que uma nova seleção cultural ocorreu rapidamente a despeito de haver maior ou menor variabilidade comportamental nas histórias de microculturas, anteriormente à mudança de critério para apresentação da consequência cultural de microculturas.