Dissertations / Theses on the topic 'Host-guest interaction'
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Löffler, Susanne. "Host-Guest Chemistry of Acridone-based Coordiantion Cages." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E415-6.
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Biplab, Rajbanshi. "Investigation of host- guest inclusion complexation of some biologically potent molecules and solvent consequences of some food preservations with the manifestation of synthesis, characterization and innovative applications." Thesis, University of North Bengal, 2020. http://ir.nbu.ac.in/handle/123456789/3963.
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Applegarth, Lucas M. S. G. A. "Towards engineering and understanding of guest host interaction between dopants and liquid crystals in liquid crystal displays." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/169/.
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Liquid crystal displays are intricate devices which consist of many cells that are filled with liquid crystal hosts. The operation of the liquid crystal cell is to modulate the polarisation of light, by varying their birefringence, which in turn can be used to control the intensity of light and colour as a function of time. Many individual cells grouped together can be controlled to give specific intensity of light and colour, to build up images that are viewed on displays, i.e. pictures on TV’s. The properties of the liquid crystalline material used in a cell dictate the performance of the device which they are used. Commercially used liquid crystal material is typically a multi-component system that exhibits many physical properties such as birefringence, dielectric anisotropy, voltage holding ratio, visco-elastic, guest-host effect and the kinetic switching response time of the cell between the on state and off state. By manipulating the physical properties we can exert specific control over the properties of the cell of particular importance in display applications is the speed with which cells can be turned between the on and off state; these are known as the rise and decay response times respectively. Introducing guest molecules into the liquid crystal host may alter the dielectric anisotropy which potentially increases the speed of the switching process, making the device faster. Guest molecules must be compatible with the dielectrically positive or negative liquid crystal host allowing good mixing of the components and alignment between the guest molecule and liquid crystal molecule. This compatibility is important as it allows both, guest and host, to align with the applied electric field when turned on giving the on state of the cell and when turned off allowing both to re-align with the alignment layer in the cell bringing to the cell order of the medium back to the off state of the cell. The time taken for the cell to reach the on state and off state is an important part of this study. Dopants have been designed with a head, tail and linker core moiety that are compatible with dielectrically positive and negative liquid crystals. Head groups will have polar substituents such as heteroarenes, fluorine and bromine, to exert control over the dielectric anisotropy. Alkoxy or alkyl tails were selected to increase solubility and size compatibility with the liquid crystal hosts. The linkers between the two arenes were selected as acetylene (linear, large Raman cross-section) and ether, methylene and propylene (to bring about a bend in the molecule). The switching times for liquid crystal devices are studied using an electro-optic method developed in conjunction with SONY MSL (Stuttgart). These studies enable analysis of the transmission of light through the cell as it goes from the on/off state as a function of time and applied potential. By comparison with the currently used liquid crystal materials our work shows that the level of doping, the length of the tail and the nature of the linker do affect the switching time significantly. It is shown that a non-linear linker, which introduces a ‘bite angle’ within the guest molecule brings about the best increase in response times. Time-Resolved Raman spectroscopy studies of a liquid crystal cell during the turn on/off process were made. These demonstrate the capability of this technique to measure the orientation of the molecules as a function of time as well allowing the independent motion of the guest and host molecules during the switching process. Raman spectroscopy gives a useful insight into the behaviour of the guest and host materials in an operating liquid crystal cell.
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Xu, Yeping. "Synthesises of mesoporous materials and studies of host-guest interaction in mesoporous carbon by solid state NMR." Berlin mbv, Mensch-und-Buch-Verl, 2009. http://d-nb.info/995894957/04.
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Takacs, Zoltan. "Chloromethane Complexation by Cryptophanes : Host-Guest Chemistry Investigated by NMR and Quantum Chemical Calculations." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81472.
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Host–guest complexes are widely investigated because of their importance in many industrial applications. The investigation of their physico–chemical properties helps understanding the inclusion phenomenon. The hosts investigated in this work are cryptophane molecules possessing a hydrophobic cavity. They can encapsulate small organic guests such as halo–methanes (CH2Cl2, CHCl3). The encapsulation process was investigated from both the guest and the host point of view. With the help of Nuclear Magnetic Resonance (NMR), the kinetics of complex formation was determined. The information was further used to obtain the activation energies of the processes. Having done this on five different cryptophanes, it is possible to relate the energies to structural differences between the hosts. Via the dipolar interaction between the guest’s and host’s protons, one can get information on the orientation of the guest inside the cavity. Moreover, the dynamics of the guest can be further investigated by its relaxation properties. This revealed restricted motion of the guest inside the host cavity. Not only the nature of the guest plays an important role. The host is also changing its properties upon encapsulation. All the cryptophanes investigated here can exchange rapidly between many conformers. These conformers have different–sized cavities. Quantum chemical optimization of the structure of the conformers makes volume estimation possible. Not only the cavity volumes, but also the quantum-chemically obtained energies and the calculated chemical shifts of the carbon–13 atoms can be helpful to follow the changes of the host upon complex formation. The host cannot be considered as a rigid entity. Analysis of variable temperature proton and carbon-13 spectra shows that the encapsulation can be considered as a mixture of conformational selection and induced fit. The structures of the formed complexes are further investigated by means of two-dimensional nuclear Overhauser spectroscopy (NOESY). The complex formation, its kinetics and thermodynamics are found to be a complicated function of structure elements of the host, the cavity size and the guest size and properties.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Accepted. Paper 5: Manuscript.
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Chen, Zhibing. "Synthesis and host-guest interaction of cage-annulated podands, crown ethers, cryptands, cavitands and non-cage-annulated cryptands." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4229/.
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Symmetrical cage-annulated podands were synthesized via highly efficient synthetic strategies. Mechanisms to account for the key reaction steps in the syntheses are proposed; the proposed mechanisms receive support from the intermediates that have been isolated and characterized.
An unusual complexation-promoted elimination reaction was studied, and a mechanism is proposed to account for the course of this reaction. This unusual elimination may generalized to other rigid systems and thus may extend our understanding of the role played by the host molecules in "cation-capture, anion-activation" via complexation with guest molecules. Thus, host-guest interaction serves not only to activate the anion but also may activate the leaving groups that participate in the complexation.
Complexation-promoted elimination provides a convenient method to desymmetrize the cage while avoiding protection/deprotection steps. In addition, it offers a convenient method to prepare a chiral cage spacer by introducing 10 chiral centers into the host system in a single synthetic step.
Cage-annulated monocyclic hosts that contain a cage-butylenoxy spacer were synthesized. Comparison of their metal ion complexation behavior as revealed by the results of electrospray ionization mass spectrometry (ESI-MS), alkali metal picrate extraction, and pseudohydroxide extraction with those displayed by the corresponding hosts that contain cage-ethylenoxy or cage-propylenoxy spacers reveals the effect of the length of the cage spacer upon the host-guest behavior. A series of cage-annulated cryptands, cavitands and the corresponding non-cage-annulated model compounds have been synthesized. These host molecules display unusual behavior when examined by using ESI-MS techniques, i.e., they bind selectively to smaller alkali metal ions (i.e., Li+ and Na+), a result that deviates significantly from expectations based solely upon consideration of the size-fit principle. It seems likely that this behavior results from the effect of the host topology on host-guest behavior. A series of non-cage-annulated cryptands also have been synthesized. These compounds can serve as starting materials for cavitand construction.
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Adams, Gareth. "Quantification of interaction energies for host/guest peptides with a hydrated DMPC bilayer : a step towards membrane protein folding." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311177.
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Von, Lengeling Volkher Heinrich Christoph. "The nexilitas factor: host-guest relationships in small owner managed commercial accommodation facilities in contemporary South Africa." Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1002656.
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The commercialization of hospitality established arguably the oldest profession. Historically small commercial hospitality establishments, known as inns in the western world, were of ill repute. Perhaps connected to their reputation, this category of accommodation facility has been seriously neglected as an area of academic inquiry, particularly from the perspective of the host. While there has been a huge growth in the interdisciplinary field of tourism studies in recent decades, little attention has been paid to the role of the host in the host-guest relationship at whatever level of analysis. This thesis seeks to redress the balance. Hospitality is a basic form of social bonding. This type of bonding, where a hierarchy between strangers is implicit (as with hosts and guests), may be termed ‘nexilitas’; nexilitas is a form of social bonding in liminal circumstances. To that extent it is comparable to ‘communitas’ which describes social bonding between equals in certain liminal circumstances. The difference is that nexilitas is a form of bonding between individuals in a complex power relationship. The host controls the hospitality space, but custom also empowers the guest with certain expectations, especially in the commercial context. The thesis identifies the various forms of hospitality – traditional ‘true’ or ‘pure’ hospitality, social hospitality, cultural hospitality and commercial hospitality – and discusses these critically in their historical and cross-cultural contexts, with emphasis on the perspective of the host. The passage of hospitality is then traced through the three phases of preliminality, liminality and post-liminality and discussed along the themes anticipation, arrival and accommodation and finally departure of the guest. While the historical and ethnographic review is mainly based on written histories and the experiences of other anthropologists as guests as well as ethnographers, the passage of hospitality draws on the multi-sited auto-anthropological experiences of the author, both as host and as ethnographer of contemporary South African hosts in small owner-managed commercial hospitality establishments.
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Pembouong, Gaëlle. "Caractérisation de polymères supramoléculaires hiérarchiques à base de cyclodextrines fonctionnalisées." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS005/document.
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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 hiérarchiquesMolecular 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
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Pembouong, Gaëlle. "Caractérisation de polymères supramoléculaires hiérarchiques à base de cyclodextrines fonctionnalisées." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS005.
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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 hiérarchiquesMolecular 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
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Antoniuk, Iurii. "Elaboration de nanoparticules auto-assemblées par interaction hote-invité." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1082/document.
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Ce travail de thèse concerne le développement de nouvelles architectures hôte et invité à base de polysaccharide et leur application dans la conception de nanoparticules molles à structure hiérarchique et d’hydrogels supramoléculaires pour l’encapsulation et la libération de médicaments. Dans la première partie du manuscrit, nous décrivons une voie de synthèse de polymères hôtes et invités comprenant des chaînons espaceurs poly(éthylène glycol) hydrophile (PEG) entre le squelette de dextrane et soit le groupement b-cyclodextrine (bCD)(polymère hôte) ou le groupement adamantane (Ada) (polymère invité). La présence des bras espaceurs PEG a conduit à une amélioration substantielle de la disponibilité des groupes Ada du polymère invité par rapport à la situation avec un bras espaceur court et hydrophobe. Nous avons ensuite étudié la formation de nanoassemblages entre les différents types de polymères hôtes et invités. Une fois de plus, les espaceurs PEG ont eu un impact significatif sur la taille et la structure interne des nanoassemblages. La deuxième partie de ce travail décrit la synthèse d’une nouvelle série de dextranes greffés par des chaînons PEG et Ada, préparés par réactions de cycloaddition d'azoture-alcyne catalysées le cuivre (I) (CuAAC). Les degrés substitution (DS) en chaînons PEG greffés (5000 g/mole) sont de l’ordre de 20 mol.% tandis que les DS par les groupements Ada sont variés de 0 à 10 mol.%. L’affinité de ces polymères pour la bCD native, ainsi que leur capacité à former des couches superficielles avec des polymères de b-cyclodextrine (pbCD et pbCDN+), s'avèrent dépendre fortement du DS en groupements Ada, ce qui résulte de la coopérativité des interactions impliquées. Dans la dernière partie, nous avons décrit une stratégie de modification non covalente de microgels sensibles à la température à base de poly (N- isopropylacrylamide) (pNIPAm), pour les recouvrir d’une couronne de pbCDN+. Cette stratégie s'appuie sur l’auto-assemblage électrostatique entre pbCDN+ et les chaînes de poly(acide acrylique) chargés négativement (pAAc) et greffées à la surface des microgels. Dans le cas d’une charge globalement neutre des microgels pNIPAm/bCDN, la stabilisation colloïdale a pu être réalisée à l’aide de dextranes greffés (PEG, Ada) en utilisant une procédure d’assemblage hiérarchique. Enfin, à l'aide de dextrane modifié par des groupements Ada (DT-Ada), les microgels pNIPAm/bCDN ont pu être associés pour produire des hydrogels 3D hiérarchiques (10wt %). Leur température de transition sol-gel est décalée vers le bas pour atteindre la gamme des températures physiologiques (37-41°C) par rapport à celle observée dans un hydrogel hôte-invité uniforme bCDN/DT-Ada (51°C)This PhD work is based on the development of new architectures of polysaccharide-based host and guest polymers and their application in the design of hierarchically structured soft nanoparticles and supramolecular hydrogels with interesting drug delivery profiles. In the first section of the manuscript we describe a synthetic pathway to host and guest polymers with hydrophilic poly(ethylene glycol) PEG spacer between the dextran backbone and either b-cyclodextrin (bCD) host or adamantane (Ada) guest grafted groups. The presence of the PEG spacer led to a substantial improvement of the availability of Ada groups of the guest polymer as compared to its counterpart, where Ada are linked to the backbone with a short hydrophobic spacer. This was followed by the study of nanoassemblies formation between the different types of host and guest polymers. Once again, PEG spacer had a significant impact on the size and internal structure of the resulting nanoassemblies. The second part of this work describes synthesis of a series of new (PEG, Ada)-grafted dextrans prepared by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The degrees of substitution (DS) by PEG grafts (5000 g/mole) are close to 20 mol% while the DS by Ada-groups are varied from 0 to 10 mol.%. The affinity of these polymers to monomeric bCD, as well as their ability to form superficial layers with b-cyclodextrin polymers (pbCD, pbCDN+), are strongly dependent on the DS by Ada, giving an indication of cooperativity effects between them. In the last part we described a strategy to a non-covalent modification of thermoresponsive poly(N-isopropylacrylamide) (pNIPAm)-based microgels with a pbCDN+ host polymer shell. It uses on electrostatic self-assembly between pbCDN+ and negatively charged poly(acrylic acid) (pAAc) chains grafted to the surface of microgels. The resulting pNIPAm/bCDN microgels with neutral overall charge could be colloidally stabilized with (PEG, Ada)-grafted dextrans via a hierarchical self-assembly procedure. Finally, using Ada-modified dextrans (DT-Ada), pNIPAm/bCDN microgels could be physically cross-linked to yield hierarchical 3D hydrogels (at 10 wt%). Their gel-sol transition temperature is shifted down to the physiological temperature range (37-41°C) as compared to uniform pbCDN/DT-Ada host-guest hydrogels (51°C
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Zhang, Jiaying, and jiaying zhang@rmit edu au. "Understanding Host Community Attitudes towards Tourism and Resident-Tourist Interaction: A Socio-Behavioural Study of Melbourne's Urban-Rural Fringe." RMIT University. Management, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080801.144715.
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The fast development of the tourism industry has created both positive and negative impacts on host communities. Reacting to these impacts, host residents hold various attitudes towards tourism and tourists. It has come to common agreement that a supportive host community plays a vital role in the successful and long-term development of community tourism. In order to explain the antecedents of community attitudes towards tourism, researchers have investigated the topic from both the extrinsic perspective (such as stage-based models) and the intrinsic perspective (such as the Social Exchange Theory). Nevertheless, there are still several important research gaps and deficiencies within the existing literature. First, the influence of psychological factors (personality) on attitudes towards tourism is somewhat neglected. Second, when examining the relationship between community attitudes towards tourism and the influential factors, the majority of previous studies do not distinguish the orthogonal dimensions of attitudes (such as positive dimension and negative dimension). Third, the existing literature has not addressed the issue of whether specific attitudes towards tourism will lead to a corresponding behaviour when interacting with tourists, and what other factors are determinant in host-guest interactive behaviour. Aiming to address such research gaps and deficiencies, this study has a major objective of developing a theoretical model (encompassing attitude element) to understand the antecedents of host-guest interaction. A quantitative approach was employed for the entire project. A self-administrated questionnaire survey was used to collect primary data. A total of 878 useful questionnaires were returned for analyses. Stratification sampling methods were utilized in communities where population database was accessible, while random sampling methods were used in other communities. The findings from this study confirmed the two major hypotheses in terms of community attitudes towards tourism. First, there was a significant relationship between an individual's personality and his/her attitudes towards tourism. Residents being high on Openness, Conscientiousness, Extraversion and Agreeableness traits and low on the Neuroticism trait tended to be more positive towards tourism than their counterparts. Second, while some factors were found to be influential on both positive and negative dimensions of attitudes towards tourism, others only demonstrated influences on one dimension. The Resident-Tourist Interaction Model developed in this study provided a comprehensive theoretical framework in modelling and predicting host residents' interactive behaviour towards tourists. Drawing on the evaluation results of three leading behavioural theories belonging to the school of cognition, the Model identified attitudinal, volitional, social, motivating and habitual factors for the prediction of resident-tourist interactive behaviour. Motivating factor (intention) was the critical and immediate element for action, which, in turn, was best predicted by subjective norms. External factors (gender, age and personality traits) only moderated the predictive power of the Model by less than two percent. The Model was valid and reliable for the current data. The present study advanced resident-tourist interactive behavioural study by establishing a sound theoretical framework. It also consolidated the body of knowledge in understanding community attitudes towards tourism. Findings from this study have significant practical implications for community tourism planning and management.
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Wuttke, Axel. "Computational Study of Dispersion Interactions through Local Orbital Analysis." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://hdl.handle.net/11858/00-1735-0000-002E-E606-7.
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Yu, Zutao. "The design, synthesis and evaluation of synthetic transcription factors (Syn-TFs)." Kyoto University, 2018. http://hdl.handle.net/2433/235052.
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Dorner, R. W. "Host-guest interactions in microporous aluminophosphates." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445422/.
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Microporous materials have attracted considerable interest from the scientific community leading to studies to understand the mechanism involved in the crystallisation of these materials. Most preparations of these materials require a specific organic template (amine or ammonium salt), which acts as a structure directing agent (SDA). The exact behaviour of templates during crystallisation and their role in controlling selectivity to form specific microporous materials is still not completely understood. In previous work carried out at the Royal Institution of Great Britain, the most specific SDA for the synthesis of AlP04-5 (AFI), i.e. Af-Methyldicyclohexylamine (MCHA) had been found. In this thesis, using high-resolution powder X-ray diffraction and Rietveld analysis it was possible to locate the template within the channel system. Employing Monte Carlo docking calculations, the results obtained experimentally were corroborated. Comparing the position of the MCHA within the AFI channel system with the position of other SDAs that form the A1PO-5 topology, a relationship between a template's pKb value and its ability to form the AFI topology could be proposed. Based on the results from the location of MCHA within the framework, it was possible to synthesis a novel layered aluminophosphate material, using phenylethylamine as SDA. The material's structure was solved by single crystal diffraction. Having located several organic molecules within the inorganic framework, experiments were conducted to test microporous aluminophosphates as hydrocarbon traps in cold start emission control. Several different substituted materials of the AFI and ATS topology were tested in dry and wet conditions. To gain further insight into the material's ability to store toluene, the organic molecule was located through X-ray diffraction. The results were again corroborated through computational methods. Overall the thesis has led to a better insight into organic-inorganic interactions within microporous aluminophosphates.
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Séon, Lydie. "Polymer multilayers : fundamental aspects and application for biomaterials." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAE014/document.
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La surface d'un matériau est le lieu privilégié des interactions entre le matériau et son environnement. La technique couche-par-couche, qui consiste en un dépôt alterné de polyanions et de polycations, ouvre de nouvelles perspectives dans le domaine des biomatériaux pour le contrôle de ces interactions. La cohésion des films multicouches de polyélectrolytes est principalement assurée par des interactions électrostatiques mais a été étendue à d'autres forces motrices telles que les interactions hôte-invité. Nos travaux s’articulent autour de deux axes principaux. D’une part, nous nous sommes intéressés aux films multicouches de polymères neutres basés sur des interactions hôte-invité et en particulier à l'influence de la force du complexe d’inclusion b-cyclodextrine/ferrocène sur la topographie de ces films. La force de l’interaction hôte-invité a d’abord été modulée en associant différents invités (l’adamantane, le ferrocène et le pyrène) avec la β-cyclodextrine. La force du complexe b-cyclodextrine/ferrocène a été ensuite modulée par la présence de différents sels de sodium à différentes forces ioniques au cours de la construction du film. Une force d'interaction intermédiaire du complexe semble être nécessaire pour former des films continus, tandis que, si elle est trop faible, la force d'interaction limite la construction du film.D’autre part, motivé par le fait que la prévention des infections microbiennes des dispositifs médicaux implantables constitue un problème médical et financier majeur, nous avons développé de nouveaux revêtements antimicrobiens grâce à la technique couche-par-couche. Des films multicouches à base de polysaccharides contenant la cateslytine, un peptide antimicrobien, permettent l’inhibition en 24h du développement de Candida albicans et Staphylococcus aureus, qui sont des agents pathogènes communs et virulents rencontrés dans les maladies nosocomiales. La libération des peptides antimicrobiens est déclenchée par la dégradation enzymatique du film en présence des agents pathogènes. Le revêtement est ainsi qualifié d’auto-défensif. La non-cytotoxicité du film vis-à-vis des cellules humaines permet une application cliniquement pertinente pour prévenir les infections sur les cathéters. Des dimères à base de cateslytine de différentes longueurs et un dendrimère ont été synthétisés afin d'améliorer l'activité biologique du peptide d'origine, i.e. ses propriétés antimicrobiennes et antiinflammatoires. Afin d’élaborer des films antimicrobiens mécaniquement robustes, le polyuréthane (polymère entrant dans la composition des cathéters) a été fonctionnalisé par une couche de polydopamine qui peut ensuite réagir avec des groupements thiol ou amine, permettant la fixation covalente des films de polysaccharides antimicrobiens réticulés étape par étapeThe surface of a material is the privileged location, where the interactions between the material and its environment take place. In the field of biomaterials, the challenge is to control these interactions. A very versatile coating technique is the layer-by-layer deposition, which consists in the alternated deposition of polyanions and polycations. The cohesion of polyelectrolyte multilayer films is primarily ensured by electrostatic interactions but was extended to other driving forces such as host-guest interactions. Our work was constituted of two main parts.In the first part, the buildup of neutral polymer multilayer films based on host-guest interactions was studied and in particular the influence of β-cyclodextrin/ferrocene interaction strength on the topography of these films. The host-guest interaction strength was first modulated by involving different guests (adamantane, ferrocene and pyrene) in the buildup. Then, β -cyclodextrin/ferrocene interaction strength was tuned by the presence of different types and concentrations of salts during the multilayer buildup. Intermediate interaction strength seems to be required to form continuous films, whereas, if too low, the interaction strength limits the film buildup.In the second part, motivated by the fact that the prevention of pathogen colonization of implantable medical devices constitutes a major medical and financial issue, polyelectrolyte multilayers were used as tools to develop new antimicrobial coatings. Polysaccharide multilayer films containing cateslytin, an antimicrobial peptide, fully inhibited in 24h the development of Candida albicans and Staphylococcus aureus, which are common and virulent pathogens agents encountered in care-associated diseases. The release of the antimicrobial peptides was triggered by the enzymatic degradation of the film due to the pathogens themselves introducing the concept of self-defensive coating. The non-cytotoxicity of the film, towards human cells, highlights a medically relevant application to prevent infections on catheters. Different cateslytin based dimers with various lengths and one dendrimer were synthesized in order to improve the bioactivity of the original peptide, i.e. antimicrobial and anti-inflammatory properties. In order to obtain mechanically robust antimicrobial films, polyurethane (polymer that composes catheters) was functionalized with a polydopamine layer that can further react with thiol or amine groups, allowing the covalent attachment of step-by-step cross-linked antimicrobial polysaccharide films
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Amombo, Noa Francoise Mystere. "Halogen···Halogen interactions in host - guest systems." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27462.
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For a few decades now, halogen bonds which are non-covalent interactions, have gained a lot of interest in the science community due to their applications in diverse research areas. Halogen bonding (XB) is an interaction that occurs between electron deficient halogen compounds and electron donors. This is an established non-covalent interaction in the solid and gaseous phase. In this thesis, the work presented deals with the investigation of halogen bond interactions in host-guest complexes utilising both experimental and theoretical techniques. Two host compounds, tetrakis-4-(bromophenyl)ethylene and its iodo-analogue were synthesised for the studies reported in Chapter 3, 4 and 5. Chapter 3, deals with the classification of halogen···halogen interactions using halogenated methanes as guest solvents. Here, the inclusion complexes can be classified into different types of halogen bonds depending on their geometry. Type I, which are of van der Waals in nature usually have X···X distances greater than the sum of their van der Waals radii. Type IIa and IIb are interactions which are considered to be attractive and their X···X distances are usually shorter than those of type I. The compounds obtained in Chapter 3 were used to study both the kinetics of desolvation and the kinetics of enclathration for the solid host-methyl iodide vapour reactions, to obtain their rate law and determine activation energies. In Chapter 4, the two hosts mentioned above were utilised to form inclusion compounds with a series of halogenated compounds for guest exchange reactions. The structures of the starting inclusion compounds were exposed to the vapours of the second incoming guests to form intermediate complexes and final compounds, which were used to analyse the halogen···halogen interactions in their structures. NMR spectroscopy was performed on selected crystals to monitor the guest exchange experiment and the rate law of each exchange reaction was established. Tetrakis-4-(bromophenyl)ethylene and its iodo-analogue were also used as host compounds in Chapter 5. Here, halogen···halogen interactions are also classified and two novel polymorphs of tetrakis-4-(iodophenyl)ethylene with 3-picoline (3PIC) are reported. Kinetics of enclathration by suspension was conducted on two of the bromohost inclusion compounds (with 3-bromopyridine and 3-picoline) at 25 °C and 35 °C. Competition between hydrogen and halogen bonding was performed in Chapter 6, using three similar but subtly different host compounds with halogenated substituted pyridines as guests. IR spectroscopy and Hirshfeld surface analysis were utilised for further characterisation of these inclusion compounds. The synthesis of halogenated Werner clathrates containing Cl-, Br- and I- in Chapter 7, was conducted with various guests of substituted pyridines. Compounds, which were derived from NiI₂ yielded ionic complexes, forming iodide anions. Iodine was added to these complexes to form tri-iodide anions. The Werner clathrates obtained with the 4-picoline (4PIC) could also be directly synthesised by the exposure of NiCl₂/NiBr₂ to the vapour of 4PIC. Kinetics of enclathration of these two solid-vapour reaction compounds were also analysed. All the structures in this study were elucidated using single crystal X-ray diffraction. Thermal analyses such as thermogravimetry (TG), hot stage microscopy (HSM) and differential scanning calorimetry (DSC) were used for the determination of the thermal behaviour of the new compounds. Variable temperature powder X-ray diffraction was also carried out for the characterisation of the new compounds.
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Hua, Weijie. "Structure and spectroscopy of bio- and nano-materials from first-principles simulations." Doctoral thesis, KTH, Teoretisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-31944.
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This thesis is devoted to first-principles simulations of bio- and nano-materials,focusing on various soft x-ray spectra, ground-state energies and structures of isolated largemolecules, bulk materials, and small molecules in ambient solutions. K-edge near-edge x-ray absorption fine structure (NEXAFS) spectra, x-ray emission spectra, andresonant inelastic x-ray scattering spectra of DNA duplexes have been studied by means oftheoretical calculations at the density functional theory level. By comparing a sequence of DNAduplexes with increasing length, we have found that the stacking effect of base pairs has verysmall influence on all kinds of spectra, and suggested that the spectra of a general DNA can bewell reproduced by linear combinations of composed base pairs weighted by their ratio. The NEXAFS spectra study has been extended to other realistic systems. We have used cluster modelswith increasing sizes to represent the infinite crystals of nucleobases and nucleosides, infinitegraphene sheet, as well as a short peptide in water solution. And the equivalent core holeapproximation has been extensively adopted, which provides an efficient access to these largesystems. We have investigated the influence of external perturbations on the nitrogen NEXAFSspectra of guanine, cytosine, and guanosine crystals, and clarified early discrepancies betweenexperimental and calculated spectra. The effects of size, stacking, edge, and defects to theabsorption spectra of graphene have been systematically analyzed, and the debate on theinterpretation of the new feature has been resolved. We have illustrated the influence of watersolvent to a blocked alanine molecule by using the snapshots generated from molecular dynamics. Multi-scale computational study on four short peptides in a self-assembled cage is presented. It isshown that the conformation of a peptide within the cage does not corresponds to its lowest-energyconformation in vacuum, due to the Zn-O bond formed between the peptide and the cage, and theconfinement effect of the cage. Special emphasis has been paid on a linear-scaling method, the generalized energy basedfragmentation energy (GEBF) approach. We have derived the GEBF energy equation at the Hartree-Focklevel with the Born approximation of the electrostatic potential. Numerical calculations for amodel system have explained the accuracy of the GEBF equation and provides a starting point forfurther refinements. We have also presented an automatic and efficient implementation of the GEBFapproach which is applicable for general large molecules.QC 20110404
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Wajs, Ewelina Maria. "Supramolecular nanoarchitectures based on cyclodextrin host-guest interactions." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/277426.
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La química supramolecular s'ha convertit en una eina molt poderosa en la construcció de noves arquitectures de mida nanomètrica amb propietats singulars. La combinació de modificacions covalents amb una àmplia gamma d'interaccions no covalents permet l'ajust de les propietats dels nanomaterials i la creació de materials innovadors i avançats amb aplicacions diverses. L'objectiu principal d'aquest treball és explorar la possibilitat de combinar les propietats úniques de les ciclodextrines amb materials polimèrics per crear noves nanoarquitectures.
La present tesi descriu el desenvolupament d'una nova classe de nanomaterials polimèrics basats en interaccions supramoleculars. Aquests nanomaterials es van preparar d'una manera controlada per deposició capa a capa en solucions aquoses i es van aplicar amb èxit en biosensors per millorar el senyal anaítica i també podrien ser utilitzats per a diferents aplicacions biomèdiques. A més, s'han preparat nanocebes de carboni altament solubles basades en nanoestructures polimèriques, la qual cosa obre noves possibilitats en diverses aplicacions com l'energia fotovoltaica o l'electrònica molecular, on la dispersió de molècules acceptores té un paper important en la fabricació i el rendiment del dispositiu.La química supramolecular se ha convertido en una herramienta muy poderosa en la construcción de nuevas arquitecturas de tamaño nanométrico con propiedades singulares. La combinación de la modificación covalente con una amplia gama de interacciones no covalentes permite el ajuste de las propiedades de los nanomateriales y la creación de materiales innovadores y avanzados con aplicaciones diversas. El objetivo principal de este trabajo es explorar la posibilidad de combinar las propiedades únicas de las ciclodextrinas con materiales poliméricos para crear nuevas nanoarquitecturas . La presente tesis describe el desarrollo de una nueva clase de nanomateriales poliméricos basados en interacciones supramoleculares. Estos nanomateriales se prepararon de una manera controlada por deposición capa a capa en soluciones acuosas y se aplicarion con éxito en biosensores para mejorar la señal anaítica y también podrían ser utilizados para diferentes aplicaciones biomédicas. Además, se han preparado nanocebollas de carbono altamente solubles basadas en nanoestructuras poliméricas. lo cual abre nuevas posibilidades en diversas aplicaciones tales como la energía fotovoltaica o la electrónica molecular, donde la dispersión de moléculas aceptoras juega un papel importante en la fabricación y el rendimiento del dispositivo.
Supramolecular chemistry has emerged as a very powerful tool in the construction of novel nanometer-sized architectures with remarkable properties. The combination of covalent modification with a wide range of non-covalent interactions allows the fine tuning of nanomaterial properties and the creation of innovative and advanced materials with distinct applications. The main objective of this work it to explore the possibility to combine the unique guest-complexing properties of cyclodextrins with polymeric materials to create novel nanoarchitectures. The present thesis describes the development of a new class of polymeric nanomaterials based on supramolecular host-guest interactions. These well-organized nanomaterials were prepared in a controlled manner by simple layer-by-layer deposition technique in aqueous solutions. They were successfully implemented in enzyme-encapsulating particle-based signal enhancement tools in biosensors and also could be used for different biomedical applications. Moreover, the prepared highly soluble carbon based polymeric nanostructures opens up new possibilities for many other applications such as photovoltaics or molecular electronics where the dispersion of acceptor molecules plays an important role in device fabrication and performance.
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Rühle, Bastian. "Structure, dynamics and interactions in porous host-guest systems." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-169902.
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Alves-Areias, A. "Investigation of host-guest interactions by x-ray crystallography." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395365.
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Schoonover, Daniel Vernon. "The Chemistry of Fullerenes, Polymers, and Host/Guest Interactions." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/72841.
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The exploitation of the relationship between the chemical and physical properties of materials is the hallmark of advancing science throughout the world. The basic understanding of how and why molecules react and interact with each other in different environments allows for the discovery and implementation of new materials and devices that not only advance the state of human life but continually change the planet. The work described in this dissertation generally falls under three diverse categories: functionalization of fullerenes, investigation of host/guest interactions in solution, and the synthesis and characterization of ion containing polymers.
The separation and functionalization of fullerenes is a recent and exciting area of research. The separation methods outlined are intended to increase the availability of endohedral metallofullerenes by decreasing their cost of production. Functionalized fullerene species were achieved through Bingel and Prato reactions to provide materials with novel functional groups. These materials may be further utilized in photovoltaic or other organic electronic devices.
The characterization of noncovalent interactions between different molecules in solution is the focus of supramolecular chemistry. Isothermal Titration Calorimetry stands out as one of the best, among the many methods used to elucidate the characteristics of these systems. The binding of bis- imidazolium and paraquat guests with macrocyclic host molecules has been explored in this work. The measurements of the association constants for these systems will aid in the ongoing synthesis of new host/guest systems.
Ion containing polymers were synthesized and characterized for their use in electroactive devices. Imidazolium containing polymers with bulky anions were synthesized on low glass transition polymer chains. These materials had enhanced ion conductivity and may eventually be used in electronic actuator materials.Ph. D.
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Rizzuto, Felix. "Allosteric interactions in coordination cages." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/278963.
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Biomolecular receptors can catalyse reactions, alter their geometry, and inhibit their activity in response to molecules binding around their periphery. Synthetic receptors that can mimic this allosteric binding behaviour extend the potential applications of host-guest chemistry to programmable molecular systems. Modulating the degree and magnitude of interaction between components within these systems enables the design of chemical behaviour akin to biological complexity. With a view to developing artificial guest-binding regulation systems, a series of metal-organic cages capable of both the peripheral and internal encapsulation of guests are presented: octahedra capable of accommodating two guests in different locations simultaneously; cuboctahedral receptors that bind fullerenes with all-or-nothing positive cooperativity and assemble supramolecular entities internally; a heteroleptic triangular prism capable of recognising steroids and enantiopure natural products; and a tetrahedron that binds fullerene clusters. Each of these architectures employs one or more binding site to either: a) template specific products; b) regulate the cooperativity of binding of large anionic guests; c) assemble coordination complexes and interlocked species inside their cavities; d) alter their morphology in well-defined ways; or e) form assemblies with new electronic and electrochemical functionality. In all cases, chemical systems that respond to multiple stimuli simultaneously are explored, and new applications for bringing multiple species into proximity are detailed. The allosteric binding motifs described herein can be extended to sort reaction mixtures, generate specific isomeric forms, stabilise labile species and promote tuneable modes of intermolecular cooperativity.
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Meyer, Andrew James. "A calorimetric study of host-guest and protein-substrate interactions." Thesis, University of Leicester, 1997. http://hdl.handle.net/2381/30009.
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This thesis describes a study of molecular recognition processes involving - and - cyclodextrins, and the enzymes chloramphenicol acetyltransferase and DNA gyrase.;An isothermal titration calorimeter of high sensitivity was used to investigate the binding of a number of relatively small guest molecules with much larger host molecules. The calorimetric technique allows the direct determination of the apparent binding enthalpy bindH0', the evaluation of the apparent association constant Ka' and hence evaluation of the apparent Gibbs energy and entropy of binding, bindG0' and TbindS0'.;The energetics of association for p-nitrophenol and 1-adamantane carboxylic acid in neutral and anionic forms, binding to - and - cyclodextrins were measured, and the results compared with those from previous studies. Binding of p-fluoronitrobenzene, p-nitrobenzyl alcohol and the antibiotic chloramphenicol to the cyclodextrins was also studied and the thermodynamic binding parameters identified. The results showed that where there is a close fit of the guest molecule inside the cyclodextrin cavity, the binding is enthalpy driven. Where there is a loose fit the binding is entropically favourable, but is still enthalpy dominated.;Binding of hydrophobic derivatives of the antibiotic chloramphenicol (CM), to the enzyme chloramphenicol acetyltransferase (CAT), was investigated. Six CM analogues were prepared with substitutions made at the 3-hydroxy group of CM, and enthalpies of binding to CAT determined by calorimetry. Comparison of calorimetric data with Gibbs energies of binding determined previously, showed that the binding is enthalpy driven.;Binding of coumarin drugs to the 43-kDa and 24-kDa protein fragments of the enzyme DNA gyrase was studied using titration calorimetry. The energetics of binding obtained from the calorimetric technique were compared with those obtained from rapid gel filtration (spin-column) studies. Titration calorimetry shows that the Ka' for coumarins binding to both proteins is of the order of 108 mol-1dm3 and that the binding is enthalpy driven.
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Yasmin, Ananya. "Investigation of Host Guest Inclusion Complexations and Diverse Interactions of Some Industrially and Biologically Potent Molecules in Assorted Phases by Physicochemical Methodologies." Thesis, University of North Bengal, 2019. http://ir.nbu.ac.in/handle/123456789/2854.
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Nouvel, Nicolas. "Lewis acid-base pairs and host-guest interactions : towards dynamic functional materials." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609310.
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Norrehed, Sara. "Modulation of Molecular Properties : Host–Guest Interactions for Structural Analysis and Chemical Reactions." Doctoral thesis, Uppsala universitet, Syntetisk organisk kemi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-207138.
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This thesis concerns the construction, use and modulation of various host–guest systems, from small bispidines for binding of inorganic ions to bisporphyrin clips for supramolecular systems. Small flexible molecules undergo fast conformational movements when in solution. These conformational movements generate time-averaged population-weighted chemical shifts, coupling constants and NOEs when analysed by NMR spectroscopy. A bisporphyrin clip was designed to be used as a host for restriction of conformational movements of small flexible molecules by ditopic metal-ligand binding. Based on conformational analysis in combination with NMR analysis of molecular flexibility in solution (NAMFIS), the relative stereochemistry of flexible alditol-derived diamines containing three or four consecutive stereocentres could be determined. To further explore the idea of conformational deconvolution via host–guest binding, two flexible molecular tweezers with photoswitchable moieties were developed. Upon photoswitching cis/trans isomerisation facilitates the opening and closing of these bisporphyrin hosts. A guest molecule could then be exposed to a “catch and stretch” or “catch and release” effect. Preliminary studies have shown that photoisomerisation of the constructed systems is possible without photodecomposition and preliminary binding studies have been conducted. Controlled modulation of molecular conformations is of interest especially if the conformational steering activates a unit working as a nucleator in a larger structure or facilitates a reaction. The protonation-triggered modulation of bispidine conformations has been investigated. In addition to previously reported conformations we have observed that upon diprotonation a bispidine derivative can be driven into the unusual boat-boat conformation. Finally, the unexpected formation of persistent organic radicals with a cyclophane motif from the reaction of N,N´-diphenyl-1-5-diazacyclooctane and AgBF4 is described. Interestingly, these diradicals exhibit features such as intramolecular π-stacking without lateral displacement and also intramolecular spin pairing.
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Ng, Joe Cho Yan. "Host-guest chemistry : physicochemical aspects of cyclodextrin-drug and lithium-crown ether interactions." Thesis, University of Surrey, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308555.
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Blackett, P. M. "A thermodynamic study of host-guest interactions in aqueous and non-aqueous media." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/843879/.
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Thermodynamic parameters for the complexation process involving substituted sodium benzoates with a, 13 and 7 cyclodextrins have been determined in water and in N,N-dimethylformamide at 298.15 K. The increasing negative enthalpies of complexation in N,N-dimethylformamide moving from a to 7-cyclodextrin reflects the effects of substituting the cyclodextrin ligand as the cyclodextrin cavity size increases. Single-ion parameters of the new benzoate-cyclodextrin anions have been derived and the results show that these anions are solvated much better in water than in N,N-dimethylformamide. Thermodynamic parameters for the complexation of 1:1 monosaccharide-cyclodextrin complexes have been determined in water at 298.15 K. The data show the ability of the cyclodextrins to selectively distinguish between the aldopentoses and aldohexoses. Thermogravimetric analysis and differential scanning calorimetry of an isolated monosaccharide-cyclodextrin complex reveal that N,N-dimethylformamide is interacting with cyclodextrin. nuclear magnetic resonance (NMR) and spectrophotometric studies together with computer modelled calculations suggest the formation of exclusion type complexes. stability constants, free energies, enthalpies and entropies of complexation of the D-amino acids and D-amino acid trifluoromethanesulphonates in methanol at 298.15 K are discussed. No significant variations were found in the free energies of complexation of the amino acids as a result of an entropy-enthalpy compensation effect. The transfer enthalpy of the amino acid cations are negative implying that these cations are enthalpically more stable in methanol than water. However, no complexation in water was found between these guest species and 18-crown-6. This is attributed to an interaction between 18-crown-6 and water as reflected in the transfer enthalpy of this ligand from water to methanol. Electrochemical, spectrophotometric, nuclear magnetic resonance and calorimetric studies on the interaction of a resorcinol-based calix[4]arene with amines in non-aqueous media (chloroform and benzonitrile) are reported as a contribution to the area of calixarene chemistry involving the generation of new electrolytes, resulting from a combination of proton transfer and hydrogen bonding from the calixarene to the amine. A summary and suggestions for further work are also given.
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Rühle, Bastian [Verfasser], and Thomas [Akademischer Betreuer] Bein. "Structure, dynamics and interactions in porous host-guest systems / Bastian Rühle. Betreuer: Thomas Bein." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/1051580129/34.
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Reyzer, Michelle Lee. "Evaluation of metal binding interactions in host-guest chemistry using quadrupole ion trap mass spectrometry /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004364.
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Cametti, Massimo. "Salophen-Uranyl Complexes as Supramolecular Receptors." Doctoral thesis, La Sapienza, 2005. http://hdl.handle.net/11573/917517.
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Rahaman, Habibur. "Diverse Interactions of Some Significant Compounds Prevailing in Different Solvent Systems with the Manifestation of Solvation Consequence by Physicochemical Investigations." Thesis, University of North Bengal, 2019. http://ir.nbu.ac.in/handle/123456789/2814.
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Rydzek, Gaulthier. "Assemblage de films polymères par réaction click électrocontrôlée." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00756082.
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Les multicouches de polyélectrolytes, systèmes auto-assemblés par adsorptions successives de polycations et polyanions, peinent à trouver des applications concrètes en raison de leur fragilité mécanique et du temps nécessaire à leur assemblage. Pour améliorer leur tenue mécanique, nous avons développé une méthode d'assemblage couche-par-couche par liaisons covalentes de films polymères. Des films formés de polymères portant des groupements alcynes et azides ont ainsi été réticulés par une réaction click catalysée par les ions Cu+ obtenus par voie électrochimique. Pour améliorer le mode d'assemblage, l'auto-construction en une seule étape de films par approche morphogénique, a été développée. Cette approche, confinée à la surface et caractérisée par la présence en solution de l'ensemble des constituants, marque une rupture. Elle permet ainsi un contrôle spatial de l'assemblage des films et la combinaison de plusieurs modes d'interactions pendant leur assemblage. Des films dont la cohésion repose sur des interactions covalentes, hôtes-invités et supramoléculaires, ont ainsi été assemblés. L'introduction de nanoparticules métalliques dans les films (multicouches et auto-construits) a également été effectuée dans le but de développer des électrodes de grande surface spécifique.
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Brunet, Gabriel. "Investigating the Single Crystal to Single Crystal Transformations of Highly Porous Metal-Organic Frameworks Through the Crystalline Sponge Method." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34308.
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The development of a new technique capable of analyzing compounds crystallographically without first needing to crystallize them has been recently described. The present thesis aims to demonstrate the potential of such a technique, which utilizes crystalline sponges, in order to regularly order guest compounds in a porous media. The structural stability of the molecular sponges, which are highly porous metal-organic frameworks (MOFs), is first investigated, revealing that the Co-based MOF, 1, undergoes two remarkable transformations. This thesis also demonstrates how the technique can be employed to visualize the motion and occupancy of gaseous guests in a MOF. The Zn-based MOF, 4, was found to physisorb and chemisorb molecular iodine, leading to the formation of a variety of polyiodide species. The flexible nature of the host was determined to be an essential component in the exceptionally large iodine uptake capacity of the MOF. These results illustrate that the crystalline sponge method can be an effective strategy for directly visualizing guest molecules and obtaining vital information on the interactions formed between the host and guest.
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Roy, Niloy. "Synthesis, characterization and innovative applications of inclusion complexes and nanocomposites of some biologically potent molecules." Thesis, University of North Bengal, 2022. http://ir.nbu.ac.in/handle/123456789/4754.
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Chaffee, Kathleen Elizabeth. "'Amplifying' the NMR signatures of host-guest interactions and molecular structure using liquid-crystalline matrices and polarization enhancement of nuclear spins." OpenSIUC, 2008. https://opensiuc.lib.siu.edu/dissertations/250.
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Nuclear magnetic resonance (NMR) spectroscopy has been extensively used to investigate the structure and dynamics of host-guest systems. NMR spectroscopy has gained attention because of its high spectral information content for studies of molecules in the solid state and in solution. However, the main weakness of NMR is the inherent low detection sensitivity. Host-guest interactions are weak; therefore these interactions can be particularly difficult to study due to weak spectral response. NMR methods are currently the best solution for measuring these responses with atomic-scale precision. Improving upon these limitations is the main goal of this dissertation research using laser-polarized xenon, liquid crystals, and polarization exchange pulse sequences. The first five chapters review the basics of NMR spectroscopy that is used throughout this dissertation. Chapters one and two concern the fundamental elements of liquid-state and liquid-crystal NMR spectroscopy. The third chapter deals with the properties of organic thermotropic and lyotropic liquid crystals including the ZLI 1132 and PBLG. Chapter four presents the theoretical and experimental aspects of optical pumping laser-polarized xenon and properties of xenon. An overview of the dissertation research is described in chapter six. Chapter seven describes the procedures for synthesizing many of the cryptophanes used in the NMR experiments in this dissertation. The cryptophanes synthesized include cryptophane-A, cryptophane-223, and cryptophane-E as well as the water-soluble derivatives of each. The eighth and ninth chapters investigate the binding kinetics of hydrocarbon and hydrogen gases to cryptophane-111 in organic solutions. Chapter ten illustrates the utility of liquid crystalline-aligned cryptophanes (bis- and cryptophane-A) reintroducing dipolar couplings in solution. Chapter eleven describes the exploitation of the reintroduced dipolar coupling of the guest molecule to transfer the abundant 1H nuclear spin magnetization to the rare 13C spins to enhance NMR detection sensitivity using an adiabatic Hartmann-Hahn cross polarization pulse sequence. Chapter twelve describes cryptophanes of varying cavity size to probe the host-guest dynamic coupling (with chloroform as a guest ligand) aligned in PBLG. Finally, chapter thirteen introduces preliminary xenon @ cryptophanes aligned in liquid crystals to achieve intermolecular polarization transfer.
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Ghosh, Indrajit [Verfasser], Werner [Akademischer Betreuer] Nau, Mathias [Akademischer Betreuer] Winterhalter, and Uwe [Akademischer Betreuer] Pischel. "Bio-Mimetic Supramolecular Host–Guest Interactions / Indrajit Ghosh. Betreuer: Werner Nau. Gutachter: Werner Nau ; Mathias Winterhalter ; Uwe Pischel." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2013. http://d-nb.info/1087285070/34.
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Han, Kang Verfasser], Martin [Akademischer Betreuer] [Möller, and Felix [Akademischer Betreuer] Plamper. "Supracolloidal co-assemblies of microgels based on orthogonal host-guest interactions / Kang Han ; Martin Möller, Felix Alois Plamper." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1156924383/34.
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Han, Kang [Verfasser], Martin [Akademischer Betreuer] Möller, and Felix [Akademischer Betreuer] Plamper. "Supracolloidal co-assemblies of microgels based on orthogonal host-guest interactions / Kang Han ; Martin Möller, Felix Alois Plamper." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1156924383/34.
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Ioup, Sarah E. "Water-Soluble Deep-Cavity Cavitands: Synthesis, Molecular Recognition, and Interactions with Phospholipid Membranes." ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1572.
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Water-soluble deep-cavity cavitands provide a rare opportunity to study self-assembly driven by the hydrophobic effect. These molecular hosts dimerize in the presence of certain guest molecules to form water-soluble molecular capsules. These systems have given rise to numerous novel chemical phenomena and have potential use in drug delivery. The host octaacid (OA) has been particularly well-characterized, but studies are limited to basic pH because of limited host solubility.
Herein we report an improved synthesis of OA and the syntheses of three new water-soluble deep-cavity cavitands. The new hosts are soluble at neutral pH, increasing relevance for biological studies. The new syntheses are versatile enough to apply to the synthesis of additional water- soluble cavitands in the future. We also describe preliminary characterization of the molecular recognition properties of the new hosts. Binding of organic guest molecules to form 1:1 host:guest complexes and 2:1 host:guest capsules was qualitatively similar to that of OA. However, binding of anions spanning the Hofmeister series revealed interesting new behavior. The new hosts bound a wider range of anions inside the hydrophobic pocket with much higher association constants. Moreover, external binding of several anions to the cavitand pendant feet was observed.
Looking towards biological applications, we desired to learn how these molecules interact with phospholipid membranes. Six water-soluble cavitands were tested for their ability to permeabilize liposomal POPC membranes. One host showed very high potency in permeabilizing membranes, while three other hosts showed moderate activity. Host binding of POPC was found to be at least one factor in host-induced permeabilization. A requenching assay to determine leakage mechanism strongly supported all-or-none leakage, whereby some vesicles lose all contents while others lose none. These results suggest that these cavitands induce partial transient leakage of vesicles by the formation of transient membrane pores. These findings show potential for the use of these hosts as drug delivery carriers, antimicrobial compounds, and tools in membrane alteration studies.
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Moser, Arvin. "Conformational studies of host-guest interactions in calixarenes using dynamic NMR spectroscopy, X-ray crystallography and pseudo-cavity volume analysis." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9447.
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The compound 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis( N,N-diethylaminocarbonyl)methoxycalix[4]arene, 1, forms a 1:1 complex with both the sodium and potassium cations in a binary mixture of chloroform-d and acetonitrile-d3. Kinetic and mechanistic solution studies are analyzed using 1H, 23Na and 39K NMR in order to compare the binding modes of the guests Na+ and K+. Both the sodium and potassium complexes exhibit a quantitative complexation (Kf > 10 4 M-1) in the temperature range of 238 to 320 K. The exchange between the complexed and solvated sodium cations is very slow on the 23Na NMR time scale at 320 K. Similarly, results for the exchange between the complexed and solvated potassium cations at 320 K were found to be slow to moderately slow on the 39K NMR time scale. Dynamics of the ethyl moiety are probed using 1H NMR and EXSY techniques. Analysis of 2-D EXSY 1H NMR data for the interconversion of the methylene protons from the N(CH2CH3)2 moiety of the (Na,1)+ and (K;1) + complexes exhibit slow exchange at 320 K. (Abstract shortened by UMI.)
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Chaffee, Kathleen E. "'Amplifying' the NMR signatures of host-guest interactions and molecular structure using liquid-crystalline matrices and polarization enhancement of nuclear spins /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1674093171&sid=7&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Thesis (Ph. D.)--Southern Illinois University Carbondale, 2008."Department of Chemistry and Biochemistry." Keywords: Cross-polarization, Cryptophanes, Host-guest chemistry, Liquid crystals, Supramolecular, Host-guest interactions, Polarization, Nuclear spins. Includes bibliographical references (p. 172-185). Also available online.
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Hazlewood, Anna. "Synthesis and properties of novel cage-functionalized crown ethers and cryptands." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2896/.
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A novel cryptand was synthesized which contained a 3,5-disubstituted-4- oxahexacyclo[5.4.1.02,6.03,10.05,9.08,11] dodecane "cage" moiety. In alkali metal picrate extraction experiments the cryptand exhibited high avidity towards Rb+ and Cs+, when compared with the corresponding model compound. A computational study of a series of cage-functionalized cryptands and their alkali metal-complexes was performed. The X-ray crystal structure of a K+-complexed bis-cage-annulated 20-crown-6 was obtained. The associated picrate anion was found to be intimately involved in stabilization of the host-guest complex. The interaction energy between the host-guest complex and picrate anion has been calculated, and the energy thereby obtained has been corrected for basis set superposition error.
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Polavarapu, Anjaneya Prasad. "Exploring Molecular Interactions : Synthesis and Studies of Clip-Shaped Molecular Hosts." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8220.
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Bouchet, Aude. "Étude des propriétés chiroptiques de cryptophanes hydrosolubles lors de l’encapsulation de molécules invitées." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14344/document.
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Les cryptophanes constituent une famille de molécules chirales qui comportent une cavité dans laquelle elles peuvent accueillir des espèces invitées de taille et de nature variables (halogénométhanes, xénon, cations). Nous nous sommes intéressés aux propriétés d’encapsulation présentées par trois espèces solubles dans l’eau : le cryptophane-A hexa-hydroxyle, le cryptophane-A penta-hydroxyle et le cryptophane-A hexa-acide carboxylique. La chiralité de ces systèmes a été utilisée pour en étudier les propriétés de complexation au moyen de techniques chiroptiques : la polarimétrie, le dichroïsme circulaire électronique (ECD) et le dichroïsme circulaire vibrationnel (VCD), cette dernière technique étant associée à des calculs de chimie théorique. Les effets de différents paramètres, tels que le pH de la solution et la nature des contre-ions, sur la complexation de molécules invitées ont été analysés. Les modifications conformationnelles induites sur les cryptophanes lors de l'encapsulation ont également été déterminées. De plus, des propriétés d'énantiodiscrimination de ces cryptophanes hydrosolubles énantiopurs vis-à-vis de petites molécules invitées chirales ont été mises en évidence. Enfin, ces cryptophanes ont montré une affinité exceptionnelle pour le cation césium Cs+ en solution aqueuse. Ces deux derniers résultats permettent d’envisager des applications intéressantes de ces systèmes en chromatographie chirale d’une part, et en chimie de l’environnement pour la détection de césium radioactif d’autre partCryptophanes derivatives are a family of chiral molecules containing a cavity which enables them to encapsulate guest species with variable size and nature (halogenomethanes, xenon, cations). We have been interested in the encapsulation properties of three different water soluble cryptophanes: hexa-hydroxyl cryptophane-A, penta-hydroxyl cryptophane-A and hexa-carboxylic acid cryptophane-A. The chirality of these systems have been exploited to study their complexation properties using chiroptical techniques: polarimetry, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD), the latter being associated with theoretical calculations. The effects of different parameters such as the pH of the solution and the nature of the counter-ions on the complexation of guest molecules have been analyzed. The conformational changes induced on the cryptophanes upon encapsulation have been also determined. In addition, enantiodiscrimination properties of these enantiopure water soluble cryptophanes toward small chiral guest molecules have been evidenced. Finally, these cryptophanes have shown an exceptional affinity for the cesium cation Cs+ in aqueous solution. These last two results allow to consider interesting applications of these systems in chiral chromatography and environmental chemistry, in particular for the detection of radioactive cesium, respectively
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Chopade, Prashant D. "From supramolecular selectivity to nanocapsules." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/13529.
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Doctor of PhilosophyDepartment of Chemistry
Christer B. Aakeroy
A family of three 2-aminopyrazine derivatives were prepared and co-crystallized with thirty carboxylic acids. Our theoretical charge calculations and experimental results from 90 reactions demonstrated that decreasing the charge on the hydrogen-bond acceptor sites results in a decrease of the supramolecular yield (the frequency of occurrence of the desired outcome). However, synthon crossover (undesired connectivity) was observed 7/12 times and was unavoidable due to competitive binding sites present in the N-heterocyclic bases chosen. To avoid synthon crossover, we used a strategy based on geometric bias. We utilized hydrogen-bonding two-point contacts and halogen-bonding single-point contacts for supramolecular reactions with the 2-aminopyrazine family of compounds. The desired two-point contact and single-point contact (N•••I or N•••Br) appeared in 9/9 times even in the presence of other potentially interfering intermolecular interactions. In addition, the role of charge in controlling the presence/absence of proton transfer was also highlighted. To establish a hierarchy in halogen-bonding interactions we designed and synthesized a library of eight molecules equipped with two different halogen bond donors and combined with variety of halogen-bond acceptors. 11 Halogen-bonded co-crystals were obtained; however, positional disorder of I/Br atoms obscures a complete analysis. This problem was solved by introducing asymmetry in the halogen-bond donor molecules. Finally, successfully demonstrated an unprecedented hierarchy in halogen-bond interactions based on electrostatics. We developed high-yielding Suzuki-Miyaura coupling reactions of tetraboronic pinacolyl ester cavitand to iodoarenes with a range of functional groups (electron withdrawing/donating group and a heterocycle) that show robustness and versatility, making it a ‘launch pad’ for the synthesis of many new cavitands in a facile manner. We have also successfully demonstrated cavitand functionalization from tetraaldehyde to tetraoximes using ‘solvent assisted grinding’, irrespective of the position of the aldehyde. Finally, we prepared tetra-substituted pyridyl and carboxylic acid cavitands having an ellipsoidal cavity capable of encapsulating asymmetric guest molecules and was subsequently obtained the first of its kind, C[subscript]2v symmetric molecular capsule with encapsulated asymmetric guest molecule.
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Kai, Sze-fai Alex. "Design and synthesis of luminescent Rhenium(I) and Ruthenium(II) Diimine complexes for the recognition of ions and small molecules by host-guest interactions /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20567091.
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Li, Chi-kwan, and 李志君. "Gold(I) and Gold(II) phosphine complexes exhibiting weak AuI... AuI interactions and unsupported AuII-AuII bonds: syntheses, spectroscopy, host-guest chemistry and reactivity studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31243332.
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Li, Chi-kwan. "Gold(I) and Gold(II) phosphine complexes exhibiting weak AuI ... AuI interactions and unsupported AuII-AuII bonds : syntheses, spectroscopy, host-guest chemistry and reactivity studies /." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25155295.
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