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Metherell, A. J. "Self-assembly and host-guest studies of heteronuclear coordination complexes." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/7365/.
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This thesis is primarily concerned with the synthesis and characterisation of heterometallic polynuclear coordination structures, but also contains host-guest studies of mononuclear complexes. Chapter One consists of an introduction to self-assembly and supramolecular chemistry. Recent examples of coordination cages are given along with previous work from the Ward group. An introduction to recent efforts in the field of heterometallic supramolecular chemistry is also given. Chapter Two describes the use of a series of mononuclear Ru(II) complexes to act as models for the vertices of coordination cages. A simple and general synthetic procedure is described which will allow access to a wide range of substituted analogues of [Ru(LH)3]2+ as their pure fac and mer isomers. It has been shown that the fac-[RuL3]2+ complexes bind to isoquinoline N-oxide more strongly than the mer isomer, but much less strongly than the complete cage complex due to the presence of competing anions, which are excluded from the cage cavity. Chapter Three describes the formation of a series of heteronuclear coordination cages from inert and labile subcomponents. The synthesis of a range of mononuclear [RuL2]2+ and [RuL3]2+ complexes as either a mixture of mer and fac isomers or pure fac is discussed, followed by the self-assembly of two heterometallic cubes [Ru4Cd4(L1,5-nap)12]16+ and [Ru4Co4(Lm-Ph)12]16+, a [Ru4Cd12(Lp-Ph)12(L1,4-nap)12]32+ cage, the adamantoid cage [{Ru(Lp-Ph)3}4Ag6]14+, and the trinuclear [{Ru(Lo-Ph)2}2Ag]5+. Chapter Four describes the syntheses and characterisation of a family of asymmetric ligands based upon pyrazolyl-pyridine and catecholamide binding moeties connected by aromatic spacers. The synthesis and structural determination of a tetrameric hetero-octanuclear cyclic helicate [Ti4Zn4(L1,3)8(μ-OMe)8] with the ligand H2L1,3 is described. Chapter Five describes the efforts towards functionalising the exterior of M8L12 cages. The synthesis of the aniline functionalised ligand Lan is discussed, which self-assembles with Co(II) to form a [Co8(Lan)12]16+ cube. Functionalising the ligand with ferrocene to form LFc results in the self-assembly process with Co(II) now forming a [Co6(LFc)9]12+ structure.
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Jordan, Brian J. "Directed assembly host-guest chemistry, nanowires, and polymeric templates /." Amherst, Mass. : University of Massachusetts Amherst, 2009. http://scholarworks.umass.edu/dissertations/AAI3359899/.
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Zarra, Salvatore. "Water-soluble metal-organic architectures : self-assembly and host-guest behaviour." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648397.
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MacGillivray, Leonard R. "Self-assembly for the construction of discrete and infinite host-guest architecture /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924903.
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Hall, Benjamin R. "Investigating the self-assembly and host-guest chemistry of inorganic polyhedral cages." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/2554/.
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Supramolecular cage complexes are of great interest, not only for their structural elegance, but also for their applications. Chapter 1 describes a collection of the many types of cage complexes based on three-dimensional polyhedral shapes and the host-guest chemistry that some cages complexes, enabled by their central cavities, are able to exhibit as they encapsulate small molecules. This thesis contains a number of studies, starting with an investigation into the host-guest chemistry of the tetrahedral cage complex [M4(Lbip)6⊃(BF4)](BF4)7 [where M = Co(II) or Cd(II)]. Anion exchange is able to take place in these complexes, replacing tetrafluoroborate counterions for 1-naphthyl sulfonate or tetraphenylborate molecules. This is summarised in Chapter 2. Chapter 3 details three experiments that look into the stability and the self-assembly process of tetrahedral cage complexes in solution. Two experiments involve the use of electrospray mass spectrometry, one to monitor the exchange of ligands between two tetrahedral cages, and the other to monitor the exchange of metal(II) ions between two isostructural cages. The third study follows the self-assembly of a tetrahedral cage by employing UV/vis spectroscopic titrations and uses equilibrium-restricted factor analysis to model the additive factors in the data as definite chemical species. Chapters 4 and 6 describe new ligands and modifications to ligands by altering the pyrazolyl-pyridine binding units. It has been discovered that using pyrazine in place of pyridine (Chapter 4) on the ligands has a dramatic effect on the construction of the final product. The encapsulation of neutral molecules by the cubic cage complex [Co8(L1,5-nap)12](BF4)16 is investigated in Chapter 5 and it has been discovered that coumarin binds to the internal cavity of the cage. The paramagnetic Co(II) metal centres cause the signals of the cage protons in the 1H NMR spectrum to be spread over a wide range (± 100 ppm). This makes it easy to see the guest signals and to identify any changes due to host-guest binding.
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Shin, Du Hyun. "Host-Guest Assemblies for Functional Interfaces via Langmuir-Blodgett and Self-Assembly Technique." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/54573.
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Various technologies depend on interfacial events that are influenced by various molecular interactions at a solid-liquid interface. The functionality of a surface plays an important role in many applications such as catalysis, sensing, and bio-compatibility, which can benefit from distinctive chemical and physical surface properties. To create tailor-made functional surfaces, surface host-guest assemblies based on Langmuir-Blodgett and self-assembly technique have been employed as a model system as they may offer the potential ability to regenerate surface properties via intercalation of various functional guest molecules. This thesis ranges over the development and characterization of host-guest assemblies and their feasibilities for the regeneration of surface properties via intercalation of functional guests. In our work, 3-dimensional host structures with cavities are constructed on a targeted solid substrate using Langmuir-Blodgett and self-assembly techniques. In particular, by adopting the fundamental concept of host-guest interaction in supramolecular chemistry, we expect that structurally homologous guest molecules where functional groups are anchored can be intercalated into the cavities between hydrophobe arrays at the liquid-solid interface from solution under well-controlled conditions. This approach offers the potential of separating the functional of the monolayer from the inherent structure of the host.
The first part of this thesis details two-dimensional host-guest assemblies consisting of guanidinium (G), octadecylsulfonate (S) and various functional alkane guests at the air-aqueous interface and following deposition onto solid substrates via the Langmuir-Blodgett technique. In particular, we evaluated the stability of the host-guest assemblies and the feasibility of exchanging molecular guests under exposure to various organic solvent environments. Analysis of X-ray reflectivity measurements of the thin films showed that good stability of the host-guest assembly could not be achieved due to weak interactions between the host monoalyer and the solid surface. In addition, no evidence of intercalation of guest molecules into guest-free host-cavities was observed.
The second part of this thesis discusses the effective methodologies to prepare low-density self-assembled monolayers (LDSAMs) with cavities on silicon substrates. We employed a step-wise reaction based on hydrolytic or silane chemistry: integral spacer molecules such as anthracene-derivatives were anchored to the Si substrate and then long alkane chains were appended to the spacer molecules. The results showed that LDSAMs using an anthryl spacer are attached at the SAM/Si interface via a Si-O-C linkage, and the films do not exhibit a densely packed monolayer quality as would be expected for a non-sterically hindered alkyltrichlorosilane on Si. Thus, the resulting LDSAMs (with cavities) may be capable of accommodating other guest molecules with hydrocarbon chains through intercalation in order to form host-guest assemblies.
The third part of this thesis demonstrates the ability of LDSAMs to produce functional surfaces via the intercalation of various functional guest molecules. Self-assembled monolayers of (10-octadecyl)-9-anthracenethiol (host-SAMs) on Au substrates were prepared. Quartz crystal microbalance with dissipation (QCM-D) measurements was used to demonstrate the capacity of LDSAMs to confine guest molecules in the cavities and to probe the structural changes of the host-guest assembly during guest intercalation from ethanol solution. X-ray photoelectron spectroscopy (XPS) measurements were then used to probe host-guest monolayers formed by immersing the host monolayer in solutions in a variety of other solvents. A combined study of QCM-D and XPS showed that guest molecules were intercalated into host-cavities. The reversibility of the intercalation process allows a guest already situated in a host-cavity to be replaced with second guest under well-regulated solvent conditions.<br>Ph. D.
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Mejuto, Nieblas Carmen. "Poly-N-Heterocyclic Carbene Ligands with Polyaromatic Linkers. Self-Assembly and Host-Guest Chemistry." Doctoral thesis, Universitat Jaume I, 2017. http://hdl.handle.net/10803/404306.
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In summary, a series of polytopic ligands based on NHC and MIC ligands have been synthesized in this Doctoral Thesis by means of different synthetic routes that gave rise to systems with very sophisticated architectures. A large variety of metal complexes have been formed based on these salt precursors that allowed the preparation of homo and heteroleptic mono-, di- and tri-metal complexes with different geometries. The luminescence properties of various imidazolium salts, the catalytic activity of some of the metal complexes obtained, and host-guest molecular recognition studies have been analyzed.<br>En esta Tesis Doctoral se ha sintetizado una serie de ligandos politópicos basados en ligandos NHC y MIC mediante diferentes rutas sintéticas que dieron lugar a sistemas con arquitecturas muy sofisticadas. Se ha procedido a la formación de una gran variedad de complejos metálicos basados en dichas sales precursoras que permitieron la obtención de complejos mono-, di- y tri-metálicos homo y heterolépticos con diferentes geometrías. Se han analizado las propiedades luminiscentes de varias sales de imidazolio, la actividad catalítica de algunos de los complejos metálicos obtenidos y se han llevado a cabo estudios de reconocimiento molecular host-guest.
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Meng, Wenjing. "Metal-organic polyhedra : subcomponent self-assembly, structural properties, host-guest behavior and system chemistry." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610719.
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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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SMUKSTE, INESE. "ARTIFICIAL RECEPTORS FOR MOLECULAR RECOGNITION OF AMINO ACIDS, PEPTIDES AND CARBOHYDRATES." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1029757614.
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Zayed, Jameel Majed. "Self-assembly of synthetic and biological components in water using cucurbit[8]uril." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/242016.
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This thesis discusses progress made towards assembling molecular building blocks in the presence of our molecular host of choice, cucurbit[8]uril (CB[8]). Our studies on the self-assembly of synthetic and biological components in water bridge overlapping conceptsand techniques drawn from the fields of synthetic organic chemistry, supramolecular self-assembly, and applied NMR techniques. Chapter 1 introduces the reader to chemical complexity, and how supramolecular chemistshave advanced in their capability of assembling more complex molecular architectures. The discussion focusses particularly on self-assembly carried out in the aqueousphase, and how, like in biology, molecular design of the building blocks become criticalin enabling non-covalent assembly to occur in this dynamic, and relatively competitiveenvironment. The cucurbit[n]uril family of molecular hosts are then introduced with anoverview of their modes of binding, and affinities towards typical guests. Finally, a practicalintroduction to NMR methods gaining prominence in supramolecular chemistry ispresented. In particular, the use of diffusion NMR, a key tool for probing the solutiondynamics of molecular assemblies, is highlighted. Chapter 2 details work carried out on the CB[8]-mediated self-assembly of supramolecularblock copolymers from polymeric, and small molecule building blocks. Here, endgroup-functionalised polymer guests were shown to assemble with small molecule ditopicguests in the presence of CB[8] to form block copolymers. Copolymers of various molecularweights were assembled, and the supramolecular complexes were studied usingsolution viscometry and diffusion NMR. This study represented the first use of diffusionNMR for probing the assembly of polymeric guests with CB[8].Chapter 3 describes the self-assembly of CB[8] with complementary ditopic guests. Highmolecular weight supramolecular polymers are known to form through the step-growthassembly of complementary ditopic building blocks. Here we sought to probe CB[8]?sability to drive supramolecular polymerisation. Solution viscometry, ESI-MS, and diffusionNMR were used to investigate the self-assembly process, which indicated that cyclicoligomers had formed. The relatively low solubility of CB[8] in water was thought to bea major limitation to polymer formation in this instance. Important observations relating to the effect of salts on the solution viscosities and stabilitiesof the complexes, are also discussed. Chapter 4 places emphasis on the synthetic methods employed towards preparing multivalentguests for CB[8] binding studies. Our synthetic guests were based on watersolubleoligomers of ethylene glycol. A bidirectional elongation route is presented foraccessing higher molecular weight, and monodisperse ethylene glycol oligomers (n = 12)in suitable purity. Chapter 5 describes the assembly of protein-polymer conjugates, and the versatility ofdiffusion NMR as a means to probe the assembly process. Here, end group-functionalisedpoly(ethylene glycol) guests were appended to bovine serum albumin (BSA) through amixed chemical ligation-self assembly protocol. The NMR studies conducted are emphasisedhere, which served to complement other characterisation methods used thatare reported elsewhere. Chapter 6 discusses ongoing work on lipid-based guests, and the resulting liposome assembliesformed. Head group-functionalised phospholipid guests, and cholesterol-basedguests were synthesised. Phospholipid guests were obtained through an enzymatic route,a novelty in our group. Dye-encapsulated liposomes were then assembled, purified, andcharacterised by fluorescence microscopy. Finally, we sought to optimise lipid formulationsto enhance liposome stability, towards conducting molecular recognition studies inthe presence of CB[8].Chapter 7 then closes the thesis with concluding remarks that summarise the describedresearch, while highlighting points of note.
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García, Simón Cristina. "Synthesis of molecular nanocapsules for supramolecular host-guest chemistry and enzyme-like catalysis." Doctoral thesis, Universitat de Girona, 2015. http://hdl.handle.net/10803/289567.
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Coordination-driven self-assembly has led to the realization of an increasing number of elegant and sophisticated functional structures, the structural complexity of which would be difficult to achieve using conventional covalent chemistry. The synthesis of three-dimensional coordination capsule-like structures is of particular interest due to their multiple potential applications, particularly their use in selective molecular recognition (host-guest chemistry), reactivity modulation (nanoreactors), molecular sensors or biological applications.
The main goal of this doctoral thesis, performed in the QBIS-CAT group from the University of Girona, is the preparation of coordination nanocapsules of different sizes (1 and 2) and their application in the selective recognition of specific molecular substrates. On one hand, the smaller capsule (1) displays high selectivity towards anionic, planar-shaped -guests, whilst on the other hand, the larger nanocapsule (2) is able to encapsulate fullerenes in a rapid manner at room temperature, by simply soaking a solid sample of the capsule in a fullerene containing solution. Strikingly, the larger nanocapsule is shown to be effective for the selective separation of C60 from a mixture of fullerenes using a straightforward washing protocol of a solid sample of fullerene containing nanocapsule. Nowadays, the applications of fullerenes (i.e. in solar cells or in medicine) are limited in origin by their purification which is often tedious and expensive. The results of this investigation may pave the way for the future development of new methodologies for the purification of fullerene mixtures.
Finally, the confined inner cavity of the larger nanocapsule, 2, was used to encapsulate a chiral rhodium catalyst which gave amongst the highest selectivities in the asymmetric hydroformylation of styrene for a monoligated rhodium catalyst. The results obtained demonstrate a substantial increase in stereoselectivity upon encapsulation of the catalyst, providing evidence of a selectivity-inducing effect by the secondary coordination sphere reminiscent of enzymatic active sites.<br>La química d’autoacoblament dirigida per enllaços de coordinació ha facilitat l’obtenció d’una gran varietat d’estructures químiques molt sofisticades, la complexitat de les quals hagués estat molt difícil d’aconseguir mitjançant la convencional química covalent. La síntesis de càpsules de coordinació tridimensionals rep un interès especial degut a la multitud d’aplicacions que aquestes ofereixen, destacant la seva aplicació en el reconeixement selectiu de molècules (química receptor-substrat), modulació de la reactivitat (nanoreactors), sensors moleculars o les seves aplicacions biològiques.
El principal objectiu d’aquesta tesi doctoral, que ha estat realitzada al grup QBIS-CAT de la Universitat de Girona, és la preparació de nanocàpsules de coordinació de diferents mides (1 i 2), i la seva aplicació en el reconeixement selectiu de substrats moleculars específics. Per una banda, la nanocàpsula més petita (1) és altament selectiva per substrats plans, aniònics amb sistemes . Per altra banda, la nanocàpsula de majors dimensions (2) pot encapsular ful·lerens de manera ràpida i a temperatura ambient, simplement amarant una mostra sòlida de la nanocàpsula en una dissolució de ful·lerens. A més, la nanocàpsula més gran es va emprar amb èxit en la separació selectiva de C60 d’una barreja de ful·lerens utilitzant un senzill protocol experimental basats en rentats del sistema nanocàpsula-ful·lerè en estat sòlid. Actualment, les aplicacions dels ful·lerens (ex. en cel·les solars o en medecina) es veuen limitades per la purificació d’aquestes molècules, que generalment s’aconsegueix mitjançant processos tediosos i costos. Els resultats d’aquesta investigació podrien facilitar el desenvolupament de noves metodologies per la purificació de barreges de ful·lerens.
Finalment, la cavitat interior de la nanocàpsula de majors dimensions, 2, es va utilitzar per encapsular un catalitzador de rodi quiral que va donar alts valors de selectivitat, dels més alts que s’han observat per a un catalitzador de rodi monolligat. Els resultats obtinguts demostren que l’encapsulació del catalitzador incrementa notablement l’estereoselectivitat de la reacció, i indiquen que el confinament del catalitzador dins la caixa causa un efecte d’inducció de la selectivitat similar al que té lloc en els centres catalítics dels enzims.
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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 hiérarchiques<br>Molecular systems with nanometer-sized dimensions are involved in a wide variety of processes and biological functions. Understanding the mechanisms controlling their multi-lengthscale structure presents a major interest. For instance, despite this challenge, there is so far no reliable synthetic system forming well-defined tunable fibrillar objects with a monodisperse diameter in aqueous solution. The aim of this work is to develop a tool box of di-functionalized cyclodextrins (CDs) specifically designed to self-assemble into supramolecular rods that could then reach higher levels of hierarchy via interactions mediated by the secondary functionalization. The study of the first level of association of these compounds by viscosimetry, ITC and SANS showed that the use of bridged CDs allows the polymerization by suppressing the self-inclusion phenomenon. As a result, we developed two tunable cationic supramolecular polymers (SMP) based on functionalized β-CD with relatively high polymerization degrees. Their ability to form hierarchical SMP with rigid polyanionic species was then assessed by DLS, spectroscopy and cryo-TEM. In optimized concentration and charge ratio conditions, three different water-soluble hierarchical assemblies were formed. We showed that the first level of association and the high directionality of the secondary interactions are key parameters to achieve these stable, well-defined, hierarchical assemblies. These tunable structures will be therefore used as a platform to get greater insight into hierarchical assembling processes
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Huang, Feihe. "Host-Guest Systems Based on Crown Ether, Cryptand, and Pseudocryptand Hosts with Paraquat, Diquat, Secondary Ammonium, and Monopyridinium Salt Guests." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/26490.
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Supramolecular host-guest chemistry is a topic of great current interest. However, the further development of host-guest chemistry is still limited by the number of available host-guest recognition motifs. This makes it necessary and valuable to find new host-guest recognition motifs and apply known host-guest recognition motifs in the preparation of novel supramolecular systems.
By comparing the crystal structures of the host and its taco complex, we proved that folding is a necessary step during the formation of taco complexes. Based on the known bis(m-phenylene)-32-crown-10/paraquat recognition motif, the first solid-state supramolecular poly(taco complex) was prepared.
We demonstrate not only that bis(m-phenylene)-32-crown-10-based cryptands are powerful hosts for paraquat derivatives compared with the simple crown ether, but also that cooperative complexation can be obtained with the cryptand structure. It was shown that the significant improvement in complexation was the result of the combination of the preorganization of the cryptand hosts and the introduction of additional and optimized binding sites. Furthermore, it was demonstrated that improved complexation of bis(secondary ammonium) and bisparaquat salts could also be achieved by the formation of the pseudocryptand structure. We also prepared two dimers of inclusion cryptand/paraquat complexes driven by dipole-dipole and face-to-face p-stacking interactions.
An interesting complex based on dibenzo-24-crown-10 and diquat was prepared. In its crystal structure the diquat guest lies in the concave cavity provided by two dibenzo-24-crown-8 hosts.
Monopyridinium-based [2]- and [3]-pseudorotaxanes were prepared based on the newly discovered bis(m-phenylene)-32-crown-10/monopyridinium salt and cryptand/monopyridinium salt recognition motifs.
Inspired by the formation of solid-state taco complexes between bis(m-phenylene)-32-crown-10 and paraquat derivatives, we designed and synthesized the first cylindrical bis(crown ether) host for paraquat derivatives and studied its complexation with paraquat.
We prepared three slow-exchange C3-symmetric inclusion complexes based on a newly discovered cryptand/trispyridinium recognition motif, in which 1,3,5-trispyridiniumbenzene salts act as guests.
Finally the application of several new and known recognition motifs in the preparation of a supramolecular poly[3]pseudrotaxane, and the first pseudorotaxane-type supramolecular star-shaped polymer, and the first supramolecular hyperbranched polymer was discussed.<br>Ph. D.
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Lee, Minjae. "Design, Synthesis and Self-Assembly of Polymeric Building Blocks and Novel Ionic Liquids, Ionic Liquid-Based Polymers and Their Properties." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77166.
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The convergence of supramolecular and polymer sciences has led to the construction of analogs of traditional covalently-constructed polymeric structures and architectures by supramolecular methods. Host-guest complexations of polymers are also possible through well-defined synthesis of polymeric building blocks, for novel supramolecular polymers.
Monotopic polymeric building blocks were synthesized by controlled radical polymerizations with a crown or paraquat initiator. The combinations of terminal and central functionalities of host and guest polymeric building blocks provided chain-extended and tri-armed homopolymers, and diblock and tri-armed copolymers.
A supramolecular graft copolymer was formed from a main-chain poly(ester crown ether) and a paraquat terminated polystyrene. This comb-like copolymer was characterized by a large viscosity increase. A four-armed polystyrene-b-poly(n-butyl methacrylate) was synthesized from a pseudorotaxane macroinitiator derived from a complex of a crown-centered polystyrene and a dufunctional paraquat compound. A single peak with higher molecular weight from size exclusion chromatography proved the copolymer formation.
Supramolecular interactions enhance the ionic conductivity of semi-crystalline ionic polymers; the ionic conductivity of a C₆-polyviologen and dibenzo-30-crown-10 mixture was 100 times higher than the polyviologen itself. However, ionic conductivities of amorphous polyviologens with polyethers were influenced only by glass transition temperature changes.
New imidazolium ionic liquid monomers and imidazolium based polymers were synthesized for potential applications in electroactive devices, such as actuators. Structure-property relationships for pendant imidazolium polyacrylates and main-chain imidazolium polyesters were investigated. Terminal ethyleneoxy moeties enhanced ionic conduction 2~3 times; however, the alkyl chain length effect was negligible. For the imidazoium polyesters, higher ion conductivities result from 1) mono-imidazolium over bis-imidazolium, and 2) bis(trifluoromethanesulfonyl)imide polymers over hexafluorophosphate analogs. A semi-crystalline hexafluorophosphate polyester with C₁₀-sebacate-C₁₀, displayed 400-fold higher ionic conductivity than the amorphous C₆-sebacate-C₆ analogue, suggesting the formation of a biphasic morphology in the former polyester.
New dicationic imidazolium salts have interesting features. 1,2-Bis[N-(N'-alkylimidazoilum)]ethane salts stack well in the solid state and possess multiple solid-solid phase transitions. They complex with dibenzo-24-crown-8 and a dibenzo-24-crown-8 based pyridyl cryptand with <i>K<sub>a</sub></i> = ~30 and 360 M¹, respectively. Some of these dicationic imidazolium salts have low entropies of fusion, typical of plastic crystals.
These newly discovered imidazolium homopolymers have ionic conductivities up to 10⁴ (S cm⁻¹); however, better properties are still required. Well-designed block copolymers should provide both good electrical and mechanical properties from bicontinuous morphologies, such ion channels.<br>Ph. D.
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Yeung, Ching-lam Margaret, and 楊靖琳. "Design and synthesis of luminescent alkynylplatinum (II) terpyridine complexes and their function as optical probes for biomolecules and ions : from self-aggregarion, supramolecular assembly to host-guest chemistry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/208590.
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A number of cationic water-soluble alkynylplatinum(II) terpyridine complexes, [Pt(tpy){C≡CCH2OC6H3-(CH2OH)2-3,5}]OTf, [Pt(tBu3tpy){C≡CCH2OC6H3- (CH2OH)2-3,5}]Cl, [Pt(tpy){C≡CCH2OC6H4-(CH2OH)-4}]OTf, [Pt(tpy){C≡CC6H3- (CH2OH)2-3,5}]OTf, [Pt(tpy){C≡CC6H4-(CH2OH)-4}]OTf, [Pt(tpy)(C≡C－C≡CH)]OTf and [Pt(tpy){C≡CC6H4(CH2NMe3)-4}](OTf)2, have been synthesized. Phosphate anion derivatives of polyanionic nature, e.g. adenosine triphosphate and tyrosine-containing phosphopeptide, were employed to investigate the induced supramolecular helical assembly behaviors of several of the water-soluble platinum(II) complexes through the study of their UV-vis absorption, emission and circular dichroism (CD) spectroscopies. The extent of such induced self-aggregation properties has been shown to be dependent on the concentration of substrates and capable of screening their respective structurally similar analogues. Two of the complexes were further explored for their use as label-free detection probes for real-time monitoring of the conversion of these phosphate anion derivatives to their metabolic products catalyzed by several biologically important enzymes. Michaelis-Menten analyses have been performed to determine the kinetic parameters.
Supramolecular self-assembly and disassembly behaviors of water-soluble platinum(II) complexes have also been explored for their sensing applications for biomacromolecules with quantitative analyses based on UV-vis, emission and CD spectral titration studies. Making use of the selective binding affinity of aptamers towards their target substrates, the extent of self-assembly of the platinum(II) complexes in the presence of lysozyme and thrombin, which arose from their electrostatic interactions with the negatively charged aptamers, could be modulated for the quantification of these substrates. The potential applicability of this probing strategy in real biological environment has been assessed. Other than that, CD spectroscopic studies revealed the formation of supramolecular helical assembly of the platinum(II) complexes upon electrostatic interaction with heparin. Such helical conformation of the heparin–complex mixture together with the distribution of the negatively charged functionalities on the heparin have endowed the complex with high differentiating power for screening possible interfering analogues. Insulin has also been employed as a template for inducing the self-assembly of the platinum(II) complex. Changes in negative surface charge distribution on insulin, brought about by its conformational changes upon conversion to insulin amyloid under destabilizing conditions, have resulted in different extent of induced self-assembly of the metal complex. Spectral changes of the platinum(II) complex has provided a convenient monitoring of insulin amyloid formation, with kinetic parameters determined.
A number of platinum(II) complexes with nucleobase-functionalized alkynyl ligands, [Pt(tpy)(C≡CCH2-T-1)]OTf, [Pt(tBu3tpy)(C≡CCH2T-1)]OTf, [Pt(tpy)(C≡C– CH2-A-9)]OTf, [Pt(tpy)(C≡CCH2-C-1)]OTf and [Pt(tpy)(C≡CCH2-G-9)]OTf (T = thymine; A = adenine; C = cytosine; and G = guanine), and amide-functionalized terpyridine ligands, [Pt{tpy–(CONHPh)2}(C≡CPh)]PF6 and [Pt{tpy–(CONHC6H13)2} (C≡CPh)]PF6, have been synthesized. Cation-binding properties of [Pt(tpy)(C≡CCH2-T-1)]OTf have been examined using UV-vis and emission spectroscopies, and ESI-MS. Pronounced selectivity towards Hg2+ ions was obtained due to the formation of thymine–Hg2+–thymine base pair, through which the Pt… Pt interactions were turned on. Such binding mechanism has been confirmed with the use of a control complex [Pt(tBu3tpy)(C≡CCH2T-1)]OTf and resonance light-scattering experiments. Anion-binding properties of the complexes with amide-functionalized terpyridine moieties towards spherical and non-spherical anions have been examined with UV-vis and emission spectral titration studies. Drastic color changes were observed for [Pt{tpy–(CONHC6H13)2} (C≡CPh)]PF6 in acetone upon F– ion addition, which was attributed to the F– ion-induced deprotonation of the amide functionalities.<br>published_or_final_version<br>Chemistry<br>Doctoral<br>Doctor of Philosophy
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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)<br>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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Han, Muxin. "Construction of Low‐Symmetric and Light-Switchable Coordination Cages for Guest Uptake and Catalysis." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-87A6-D.
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Khutia, Anupam [Verfasser], Bernhard [Akademischer Betreuer] Lippert, and Jens [Gutachter] Müller. "Supramolecular Chemistry of Metal Ions and Nitrogen Based Ligands including Pyrimidine Nucleobases : Self-assembly, Metallacalix[n]arenes, Host-Guest Chemistry, Hydrogen Bonding, pKa Values / Anupam Khutia. Betreuer: Bernhard Lippert. Gutachter: Jens Müller." Dortmund : Universitätsbibliothek Dortmund, 2011. http://d-nb.info/1103231626/34.
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Espelt, Ripoll Mónica. "Reversible molecular encapsulation in self-assembled and mechanically locked containers with polar interior." Doctoral thesis, Universitat Rovira i Virgili, 2013. http://hdl.handle.net/10803/275961.
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The present thesis work dealt with the study of the polar interiors of self-assembled homocapsules based on aryl-extended calix[4]pyrrole scaffolds, as well as the anisotropic polar interior of a mechanically locked calix[4]arene-calix[4]pyrrole heterocapsule. The properties of the internal cavities of the receptors were probed through the inclusion of different molecules known as guests. Homologous series of aliphatic N-oxides were used in encapsulation experiments to evaluate the size modification and adaptability exhibited by the aromatic cavity enclosed in both systems.
Moreover, new super aryl-extended calix[4]pyrroles were synthesized by the elongation of the aromatic walls of aryl-extended calix[4]pyrroles yielding a substantial increased volume of the internal cavity.
Additionally, the preparation of an unprecedented calix[4]pyrrole – calix[4]pyrrole molecular container having the two hemispheres mechanically linked was achieved. This capsule features a sizeable increase of its internal volume when compared to the previous calix[4]arene-calix[4]pyrrole molecular container. Both mechanically locked capsules displayed a bis-[2]-catenane topology. Furthermore, the new mechanically locked homo-dimer possesses polar functionalization at the closed ends of both hemispheres.<br>En la presente tesis se han estudiado las cavidades polares de cápsulas autoensambladas basadas en estructuras de calix[4]pirrolesaril-extendidos, así como también las cavidades de cápsulas formadas por dos hemisferios distintos, uno de calix[4]areno y otro de calix[4]pirrol que se encuentran mecánicamente entrelazados, mediante la encapsulación de distintos tipos de moléculas a las cuales llamamos huéspedes. Series homólogas de N-óxidos alifáticos se utilizaron en los experimentos de encapsulación para evaluar la modificación del tamaño de cavidad y la adaptabilidad exhibida por la cavidad aromática en los dos sistemas capsulares. Además, se ha sintetizado nuevoscalix[4]pirroles super extendidos mediante la elongación de las paredes aromáticas de los anteriormente conocidoscalix[4]pirroles aril-extendidos, lo que ha repercutido en un considerable incremento del volumen de interno de la cavidad. Asimismo, se ha logrado sintetizar un contenedor molecular basado en dos moléculas de calix[4]pirroles en el cual los dos hemisferios están mecánicamente unidos, del mismo modo que lo estaban en la anterior cápsula formada por un calix[4]areno y un calix[4]pirrol. La obtención de esta nueva cápsula molecular ha supuesto un aumento de volumen con respecto a la anterior cápsula también enlazada mecánicamente. Los dos contenedores moleculares descritos presentan una topología de bis-[2]-catenano. La nueva cápsula molecular posee una funcionalización polar interior en los dos hemisferios, una diferencia con respecto a la anterior.
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Wang, Xiang. "Orchestration de l'auto-assemblage et des mouvements moléculaires de pseudo-rotaxanes helicoïdaux." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0076/document.
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L’orchestration des mouvements directionnels d’architectures supramoléculaires s’avère cruciale pour la préparation de machines moléculaires artificielles. Les oligomères d’amides aromatiques (i.e. foldamères) peuvent adopter des conformations stables capables de se complexer à des tiges moléculaires pour former des (pseudo)-rotaxanes. Un contrôle fin des cinétiques d’association et de dissociation de l’hélice autour de la tige permet à l’oligomère hélicoïdal de glisser le long de celle-ci sans dissociation. Des études RMN et cristallographiques ont montré que des tiges moléculaires possédant plusieurs sites de reconnaissance pour des hélices permettaient l’élaboration d’architectures supramoléculaires hélicoïdales chirales avec une haute-fidélité. Chaque station possédant une longueur et une chiralité définie peut induire la complexation de foldamères de taille et d’hélicité concordante. Le glissement directionnel d’une double hélice le long d’une tige possédant plusieurs stations a également été investigué. Insérer un espaceur encombrant (i.e. plus large que la cavité de l’hélice) sur le chemin du foldamère le force à se déplier et se replier pour atteindre le site le plus favorable thermodynamiquement. Un oligomère asymétrique montrant de hautes affinités et de fortes sélectivités pour des tiges asymétriques a été préparé. L’enfilement de cet oligomère sur des tiges asymétriques a été étudié. Des données cinétiques (RMN) indiquent que l’enfilement de celui-ci s’effectue de façon polarisée en fonction de la nature de la tige<br>The directional motion orchestration of supramolecular architectures is crucial for the construction of artificial molecular machines. Aromatic amide oligomers (i.e. foldamers) can adopt stable helical conformations able to wind around dumbbell-like guests to form (pseudo)-rotaxanes. A fine control of the association-dissociation kinetics allows the oligomers to slide along the rods without dissociation. In this thesis, based on the segregation of the kinetics of association-dissociation and sliding, helical oligomer motions were orchestrated to form complex self-assemblies and to perform directional motion. NMR and crystallographic studies showed that multistation rod guests can template the formation of well-defined multi-helical supramolecular polymers with high fidelity. Each station possessing a defined length and chirality can induce the complexation of oligomers presenting matching length and chirality. Directional sliding of a double helical oligomer along linear multistation rod guests was investigated. Placing a bulky spacer on the rod prohibits the sliding process, forcing the oligomer to dissociate and reassociate onto the thermodynamically favored station. An asymmetrical oligomer was prepared showing highly selective binding toward asymmetrical rod guests. The threading of this oligomer onto linear asymmetrical guests was investigated. Kinetic data indicated that the threading orientation of this asymmetrical oligomer was polarized by its passage along guest molecules
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Jao, Meng-Hsuan, and 饒孟璇. "Synthesis and Self-assembly Behaviors of POSS-based Host-Guest complex." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/p4bz3u.
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碩士<br>國立交通大學<br>應用化學系碩博士班<br>105<br>POSS is considered to be the smallest silicon oxide nanoparticles (NPs) and the molecular shape is close to a cube (side length ~ 0.5-0.7 nm). Attaching conjugated arms to the eight vertices of a POSS core resulting in a 3D conjugated giant molecule. Our previous studies have showed that through conformational isomerization, POSS derivatives can adopt a rod-like conformation, which contain two empty cavities above and below the POSS core. The diagonal distance of the cavity is about 0.8 nm, making the conjugated POSS a suitable building-block in host-guest chemistry. We wondered whether or not conjugated POSS can properly work as a host. To look into this issue, POSS-derivative with electron-rich pyrene unit attached to the eight vertices of POSS core was synthesized to be a host. Electron-deficient naphthalene diimide derivatives such as hex-NDI and Di-NDI were synthesized to be guest. In this work, we will try to perfect the supramolecular structure of the POSS-py/hex-NDI and POSS-py/Di-NDI complex.
The solid-state characterization including DSC, X-ray diffraction showed that hex-NDI molecules can be trapped within the POSS cavities at the molar ratio of POSS-py:hex-NDI = 1:4, and formed a new smectic liquid crystal phase; on the other hand, POSS/Di-NDI will form an ordered structure in molar ration of 1:2. In solution phase, the results provide that adding of hex-NDI will help to contract the arms of POSS-py, forming a more specific shape of the cylindrical particles.
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Yang, Woei-Chyan, and 楊偉權. "Self-Assembly , Characterization and Host-Guest Interaction of Nanoscale Rhenium (I) Rectangles." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/86961381028863879440.
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碩士<br>國立臺北科技大學<br>化學工程系碩士班<br>91<br>Abstract：
key words: self-assembly, supramolecules, host-guest interaction.
In the first of this thesis, the rational design and synthesis of self-assembled rhenium-based rectangular boxes has been performed. Characterization by single- crystal X-ray diffraction, NMR, and UV-visible analyses have been carried out. Their molecular recognition property has been examined. The second research topic concerns with the copper-mediated catalytic transformation of organic compounds at ambient temperature.
（I）Synthesis of Novel Rectangular Supramolecules
The synthesis and characterization of novel rectangular host-guest supramolecules are reported. The self-assembly of rhenium-based nanohost with a rectangular inner cavity can be achieved via a simple one-step synthetic route. The rational selection of fac-(CO)3Re as corners, the judicial choice of a chelating three-electron donor, chloranilic acid (CA), and a two-electron donor, 4, 4’-bipyridyl (bpy), or, trans-1, 2 bis(4-prydyl)-ethylene (bpe) as a spacer bridging ligand can fulfill the eighteen-electron configuration around the rhenium center. As a result, self-assembly of novel molecular rectangle possessing a large cavity could be obtained instead of two thermodynamically favored molecular squares. Three rectangular supramolecular nanohosts: Re4(CA)2(bpy)2•(p-xylene)2 (1.1), Re4(CA)2(bpy)2•(mesitylene) (1.2) and Re4(CA)2(bpy)2•(THF)4 (3) have been successfully prepared and characterized. Their structures have been analyzed by X- ray crystallography. Crystal data for 1.1: space group P , a = 9.884(1) Å, b = 13.020(1) Å, c = 13.739(1) Å, α = 106.13(4), β = 105.95(5), γ = 96.56(5), V = 1597.95(2) Å3, Z = 1. Crystal data for 1.2: space group P21/n, a = 11.020(2) Å, b = 18.442(5) Å, c = 14.944(4) Å, α = 90.00, β = 104.02(11), γ = 90.00, V = 2946.75(12) Å3, Z = 2. Crystal data for 3: space group C2/m, a = 17.660(9) Å, b = 25.049(15) Å, c = 10.907(6) Å, α = 90.00, β = 120.95(3), γ = 90.00, V = 4137.9(4) Å3, Z = 2.
（II） Catalytic transformation of a organic compound catalyzed by Cu(II), Ni(II) at ambient temperature
A one-step Cu(II)-catalyzed transformation of organic compound 3,6-di-2-pyridyl-4-{[(2-pyridyl)carbonyldiazenyl]-(2-pyridyl)methyl}-1H-1,2,4,5-tetrazine （4） has been achieved at ambient temperature by using 3,6-Di-2-pyridyl-1,2,4,5-tetrazine（DPTZ） as starting material. In addition to Cu(II) ion, Ni(II) is also capable of mediating the chemical transformation of DPTZ molecule. The plausible self-assembly catalytic reaction has been purposed reasonably for compound 4. The molecular structure of 4 has been characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in a triclinic crystal system with space group P , a = 7.9380(2) Å, b = 11.5280(4) Å, c = 12.0990(4) Å, α = 83.372(2)°, β = 86.127(2)°, γ = 77.4690(10)°, V = 1072.54 (6) Å3, Z = 2.
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Wang, Ruibing. "Cucurbit[n]uril host-guest complexes: the effects of inclusion on the chemical reactivity and spectroscopic properties of aromatic guest molecules." Thesis, 2007. http://hdl.handle.net/1974/502.
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This thesis deals primarily with supramolecular chemistry based on cucurbit[n]uril (CB[n], n = 7 and 8) host molecules. The research has been focused on the synthesis and characterization of host-guest complexes CB[n] with aromatic guest molecules, and the study of the effects of the host-guest complexation on the chemical reactivity and spectroscopic properties of the included guests, such as their photoreactivity and their UV-visible absorption and emission properties, in aqueous solution.
The [4+4] photodimerization of protonated 2-aminopyridine (APH+) occurs stereoselectively to give the anti-trans product as the result of a preferred orientation of two APH+ guests in the cavity of CB[7]. The CB[7] host inhibits photohydration in the course of the photoisomerizations of protonated trans-1,2-bis(4-pyridyl)ethylene and trans-1,2-bis(1-methyl-4-pyridinium)ethylene by including the (4-pyridyl)ethylene portion of the guest, while this is not observed with trans-1,2-bis(1-hexyl-4-pyridinium)ethylene, as preferential inclusion of the hexyl groups leaves the vinyl group vulnerable to photohydration. Very strong CB[7] complexation of (E)-1-ferrocenyl-2-(1-methyl-4-pyridinium)ethylene completely inhibits the (E)→(Z) photoisomerization process.
The H/D exchange rates and acidities of the C(2)-proton of cationic imidazolium and thiazolium (including thiamine and thiamine phosphates) carbon acids are decreased upon their complexation with CB[7]. Inclusion of protonated aromatic amines (and aromatic alcohols) in the cavity CB[7] significantly decreases their ground and excited state acidities, such that the emission is switched from the neutral amine to the protonated amine excited state, resulting in changes in the color of fluorescence. The fluorescence of acridizinium cations can be switched off by the formation of 2:1 complexes with CB[8] and then switched back on again by the addition of CB[7] or a competing guest molecule.
The stabilization of the deep blue color of the 4,4’-bis(dimethylamino)diphenyl carbonium ion, upon complexation of the corresponding carbinol with CB[7], results from a complexation-induced shift in the carbinol/carbonium ion equilibrium. A dramatic purple to blue color change in pinacyanol chloride upon addition of CB[7] is due to a partial breakup of dye aggregates, upon the interactions of the dye with the host molecule. The CB[n] complexation-induced emission and/or absorption color switch have the potential to be employed in molecular switches and in chemical sensing.<br>Thesis (Ph.D, Chemistry) -- Queen's University, 2007-08-07 09:21:06.553
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"DNA self-assembly and host-guest chemistry for programmed photonic nanostructures and switches." Tulane University, 2020.
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Nguyen, Pham Bich Tram. "Construction of Multidimensional Metal-organic Framework via Self-assembly Approach: the Harvest of Interesting Molecular Textures." Thesis, 2008. http://hdl.handle.net/1807/11157.
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Metal organic framework (MOF) has emerged as a new class of porous, thermally stable material which has attracted great attention due to their wide applications in gas storage, separation, catalysis etc. Self-assembly is the operative mechanism of MOFs syntheses; however, the control of MOF self-assembly is still a challenge in the construction of predetermined, structurally well-defined MOFs. The goal of the research is to arrive at multidimensional, highly porous and functional MOFs via hierarchical assembly of smaller molecular building blocks and, at the same time, to examine the possibilities for different interesting molecular textures. This goal is to be accomplished by the knowledge of ligand coordination mode, and geometry as well as logical choices of ligands and metals from which the MOFs are to be constructed from. Preparations of novel frameworks as well as other interesting molecular architectures are highlighted with their structures characterized.
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Ferreira, João Miguel Pimenta. "Osmium tetroxide in a dynamic supramolecular system." Master's thesis, 2018. http://hdl.handle.net/10773/25638.
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Supramolecular Chemistry plays an important role in attaining levels of com-plexity in chemical systems that would not be available otherwise, this includes design of complex chemical signalling networks. Here a report is made on the discovery of a host-guest complex of a catalyst—OsO4—in an Fe4L6 tetrahedral imine coordination cage which enables the regu-lation of its activity without covalent transformations. The remarkable stability of the assembly hosting this powerful oxidizer is studied as to its stability and dy-namics by NMR. Due to the sensitivity of the work, improvements were done on the previously known the synthesis of the guanidinium salt of the cage.
The analogues with 2,5-dihydrofuran and benzene as guests were also charac-terized. Using these competing guests as signals, the principle of orthogonal regulation of dihydroxylation with OsO4 was demonstrated. However, no signifi-cant deviations from the normal dihydroxylation kinetics were detected in the conditions tested.<br>A Química Supramolecular desempenha um papel importante na obtenção de níveis de complexidade inatingíveis pela Química “clássica”, a sua função inclui a criação de redes de sinalização intricadas.
Neste trabalho é feito um relatório da descoberta e caracterização de um com-plexo supramolecular contendo um catalisador—OsO4—cuja encapsulação numa gaiola do tipo Fe4L6 de ligandos imina permite a regulação da sua catálise de forma não covalente. A surpreendente estabilidade da estrutura supramole-cular contendo um oxidante tão poderoso foi estudada e a sua dinâmica caracterizada por RMN. Devido à sensibilidade deste trabalho foram feitas me-lhorias à síntese do sal de guanidínio da gaiola.
Outros dois complexos hóspede-hospedeiro análogos foram caracterizados contendo 2,5-di-hidrofurano e benzeno como hóspedes. Embora não tenha sido conseguido, isto teve em vista o design de sistemas mais complexos que apre-sentassem uma variação significativa da cinética de di-hidroxilação normal e demonstrassem regulação ortogonal da catálise.<br>Mestrado em Química
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Chang, Yung-Yu, and 張永育. "(I) Studies on Diatropic Effects, pKa Values, and Kinetics of a Polycyclic System. (II) Studies on Kinetics, Host-Guest Chemistry, and Self Assembly of a Photo-responsive Triazoly Azobenzene Bridged Bispillar[5]arene." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/82038324959675231000.
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博士<br>國立交通大學<br>應用化學系碩博士班<br>103<br>In part I, a series of polycyclic compounds 38, 39, and 41b were synthesized. Diatropic effects of a flanking phenyl rings by adjacent C-H, C-F, and N-Me bonds were studied, respectively. Furthermore, compounds 40 and 41 were designed to probing the limit of the Menschutkin reaction and kinetic studies in highly congested polycyclic systems. Surprisingly, the strong deshielding effect of the 19F NMR of 39a and 39b were opposite to what we originally expected, the results are fully explainable by “steric effect” instead of “ring-current effect”on the fluorine NMR. On the other hand, the distances between N atoms and nearby flanking phenyl rings of 40 in X-ray single-crystal structure are significantly smaller than the sum of van der Waals radii of C and N atoms (3.2 Å), which implies that the molecular spaces between the phenanthroline and the phenyl group in 40 are very congested. Hence, the methylation rate constants (k’) of 49c and 40 with MeI were found to be 2.22 × 10-4 and 5.80 × 10-6 s-1mol-1L, respectively, and the pKa values of the conjugate acids of 49c and 40 in acetonitrile were determined to be 4.65 and 5.07, respectively, which are much smaller compared to that of pyridine (k’ = 3.18 × 10-4 s-1mol-1L and pKa = 12.33), implying that the basicity, nucleophilicity, and amine alkylation rates of 49c and 40 are remarkably decreased by the severe steric hindrance of the flanking phenyl rings in the polyheterocycles. Interestingly, the rotational barriers of the phenyl ring nearby the N-methyl group in rac-41b and rac-78 were estimated to be >>18.1 kcal/mol from VT-NMR experiments making them a new type of helical atropisomers. Compared to those without a nearby phenyl, the N-methyl protons in (P/M) 41b exhibit a significant upfield shift ( 1.0 ppm) in its 1H-NMR, indicating a strong CH- interaction is involved.
In part II, the triazole-azobenzene bridged bispillar[5]arene 97 was synthesized and used to study the photochemical transformation of trans to cis azo followed by thermally induced cis-trans isomerization. However, the energy barrier of the isomerization of cis-97 is smaller compared to that of azobenzene. The result implies that the electronic effect rather than the size of the substituent decreases the energy barrier of the thermally induced cis-trans isomerization of the azobenzene. On the other hand, trans-97 and dipyridinium 95d at different concentration exhibit different complexation ratios and models by NMR-titration, Mass, and DOSY-NMR experiments. In mixed solvent of CHCl3, compound trans-97 showed a self-assemble vesicular structure by SEM, TEM, and FIB. Furthermore, VT NMR was applied to explore the morphology.
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Noujeim, Nadim. "Propriétés supramoléculaires des cations diimidazolium disubstitués : des complexes d’inclusion en solution aux interactions à l’état cristallin et cristal liquide." Thèse, 2010. http://hdl.handle.net/1866/4751.
Full textAbstract:
Les sels d’imidazolium ont un rôle important dans certaines protéines et acides nucléiques et ont été utilisés à de nombreuses reprises dans des assemblages supramoléculaires en raison de leurs propriétés uniques. Les sels de diimidazolium dérivés sont toutefois moins connus. Ils ont pour l’instant uniquement été utilisés comme des précurseurs de carbènes N-hétérocycliques. Ils sont donc à la base de plusieurs catalyseurs utilisés pour des réactions de couplage croisés mais leurs propriétés sont toutefois méconnues dans le cadre de la chimie supramoléculaire. Cette classe de composés a nottament attiré notre attention en raison de la facilité de modification de leurs propriétés physico-chimiques par modification de leur structure chimique. L’objectif général des travaux présentés dans cette thèse est l’étude des propriétés supramoléculaires des sels de diimidazolium disubstitués en solution (aqueuse ou organique), ainsi qu’en phase solide ou cristal-liquide. L’influence de l’espaceur entre les deux noyaux imidazolium ainsi que l’influence des substituants latéraux et des contre-ions a été étudiée.
Dans un premier temps, les propriétés de complexation des sels de diimidazolium à des macrocycles sont étudiées. Les sels bromure sont étudiés en solution aqueuse avec plusieurs cyclodextrines et le cucurbit[7]uril, et les sels hexafluorophosphate sont étudiés en solution organique pour leur complexation avec l’éther couronne DB24C8 et un calix[4]arène. Cette nouvelle classe de composés a montré de très bonnes propriétés de complexation à ces différents macrocycles en solution et a également permis de contrôler différents assemblages supramoléculaires à l’interface air-eau.
Dans un deuxième temps, l’étude des sels de phénylènediimidazolium a permis de modifier les propriétés de complexation en solution pour obtenir la formation de complexes multiples avec le cucurbit[7]util en solution aqueuse. Cette même famille de composés a également permis la formation de cristaux liquides ioniques lorsque les substituants sont des chaînes alkyles plus longues.
La résolution de plusieurs structures cristallines de différents sels de diimidazolium a finalement permis de comprendre la nature des interactions intermoléculaires à l’état cristallin. La recherche présentée dans cette thèse a donc permis une étude détaillée des propriétés supramoléculaires des sels de diimidazolium dans tous les états de la matière qui leur sont accessibles.<br>Imidazolium salts play an important role in different proteins and nucleic acids and have been used many times in supramolecular assemblies due to their unique properties. Diimidazolium salts derived from imidazolium salts are less known. To date, they have only been used as precursors for N-heterocyclic carbenes, which are used to catalyze various cross-coupling reactions. Their properties are not well known in supramolecular chemistry. This class of compounds attracted our attention because of the ease of tuning their properties by modifying their chemical structure. The main goal of the research presented in this thesis was to study the supramolecular properties of disubstituted diimidazolium salts in solution (aqueous or organic solution), in the solid state and in the liquid-crystalline state. The role of the spacer between the two imidazolium moieties, of the sidechains and of the counterions was studied.
Firstly, the complexation between diimidazolium salts and various macrocycles was studied. Bromide salts were studied in aqueous solution with cyclodextrins and cucurbit[7]uril, while hexafluorophosphate salts were studied in organic solution with a DB24C8 crown ether and a calix[4]arene. This novel class of compounds showed very promising complexation properties with these macrocycles in solution and also allowed us to control the formation of various supramolecular assemblies at the air-water interface.
Secondly, phenylenediimidazolium salts were studied and allowed the modification of the complexation properties in aqueous solution. Multiple complexes can be formed simultaneously with cucurbit[7]uril in aqueous solution. The same class of compounds also has the ability to yield ionic liquid crystals when the alkyl sidechains are long.
The resolution of the crystalline structures of some synthesized diimidazolium salts allowed us to understand the nature of the intermolecular interactions in the solid state. The research presented in this thesis is a complete study of the supramolecular properties of diimidazolium salts in every accessible state of matter.