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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"Rotaxanes"”.
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Molecular necklaces: polyester rotaxanes
Polyrotaxanes consisting of 30-60 membered aliphatic crown ether macrocycles whose cavities are pierced by polysebacate chains were synthesized by several polymerization approaches including transesterification polymerization, the acid chloride method, and interfacial polymerization. The …
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New Liquid Crystalline [2]Rotaxanes
… of dumbbells (without macrocycle) and [2]rotaxanes (with macrocycle) substituted with purely aliphatic extended 3,5-disubstituted stoppers with increasing alkyl chain length. Chapter continues with phase characterization and structure-property relationships between dumbbells and rotaxanes. …
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Cyclodextrin-based rotaxanes for material science applications
In the work described in this thesis, CD-based rotaxanes were prepared and their solid-state structures/packing, morphology and crystal growth behaviour were explored. Encapsulation of profluorescent nitroxides through rotaxane formation demonstrated the use of CD-based rotaxanes to change the …
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Cyclodextrin-based rotaxanes for material science applications
In the work described in this thesis, CD-based rotaxanes were prepared and their solid-state structures/packing, morphology and crystal growth behaviour were explored. Encapsulation of profluorescent nitroxides through rotaxane formation demonstrated the use of CD-based rotaxanes to change the …
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Thermodynamically Driven (Reversible) End-Capping of Pseudorotaxanes to Produce Rotaxanes
Rotaxanes can be synthesized using a thermodynamically driven approach of self-assembly. The thermodynamically driven approach is an efficient method to provide a better controlled synthesis of specific structures. This synthetic approach takes advantage of a labile bond between the guest molecule …
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Design, Preparation and Characterization of Novel Pseudorotaxanes, Semirotaxanes, Rotaxanes, Non-Covalent Supramolecular Polymers and Polycatenanes
… of novel host/guest systems, such as pseudorotaxanes, semirotaxanes, rotaxanes and catenanes, with high association constants, enhanced yields and the abilities to respond to external stimuli are of great importance and significance due to their topological novelty and potential application. …
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Molecular composites of a conducting polymer: syntheses and characterization of poly(1,4-phenylenevinylene)-crown ether rotaxanes
Polyrotaxanes, a new class of polymer architectures, so called molecular composites, are comprised of macrocycles threaded by linear backbones with no covalent bond between them. By using poly(1,4-phenylenevinylene) (PPV), one of the most promising conductive polymers, as the linear backbone and …
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Dibenzo-30-crown-10: Synthetic optimization and studies of the binding conformation
… supramolecular architectures such as catenanes, rotaxanes, and supramolecular polymers. They have been used as selective hosts in diverse applications such as wastewater treatment, switchable catalysis, therapeutic agents, sensors, molecular machines, and stimuli responsive materials "smart …
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The synthesis and investigation of the electronic properties of crown ether, [2]-catenane, and [2]-rotaxane architectures
… ether for the formation of [2]-catenanes and [2]-rotaxanes. The electronic properties of these complexes are then probed by electrochemical, spectroelectrochemical, and conductivity measurements. The potential of a poly([2]-catenane) as a photoconductive polymer is also investigated. The obstacles …
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Synthetic studies towards an organometallic rotaxane
The synthesis of interlocking molecules such as rotaxanes and catenanes is a branch of supramolecular chemistry of particular current interest. The aim of this work was to assess the viability of the synthesis of an organometallic rotaxane in which the transition metal is covalently bonded to a …
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Hydroxy and amidinium containing acyclic and interlocked anion receptors
… synthesis of two cationic hydroxy containing [2]rotaxanes and compares their anion binding abilities to a previously reported analogous [2]rotaxane without hydroxy groups. Along with 1H NMR solution anion binding studies, the binding modes of these three [2]rotaxanes to various anions was …
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Linear, Branched and Crosslinked Polymers, Polyesters, Polyurethanes and Polymethacrylates Derived From Rotaxane Formation: Syntheses and Properties
As new family of composite materials, polyrotaxanes, polymers containing rotaxane units, have interested scientists world wide in last few decades because of their new properties. Crown ethers have been widely used as the cyclic component in various polyrotaxanes. However, due to significant loss …
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Towards interlocked structures based on H-bonded barbiturate complexes
… in generating interlocked structures, such as rotaxanes or catenanes. This thesis demonstrates the feasibility of such structures. A series of Hamilton-like receptors has been synthesised. Their conversion from “open” to “closed” forms by metathesis and their binding with barbital was studied, …
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Self-Assembly: Synthesis and Complexation of Crown Ethers and Cryptands with R2-NH2 Ions
… was to use the self-assembly process to create rotaxanes between several large bisphenylene crown ethers (> 22 atoms) with secondary ammonium salts. Also of great interest was to understand the complexation behavior of the crown ethers with the salts, with emphasis on determining the …
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New polymer architectures: synthesis and characterization of polyurethane-crown ether based polyrotaxanes
… architectures. Unlike conventional polymers, polyrotaxanes are molecular composites comprised of macrocycles threaded by linear polymer backbones with no covalent bonds between the two components. This novel class of materials displays unusual chemical and physical properties due to their unique …
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Synthesis and characterization of liquid crystalline polyrotaxanes based on poly(azomethine)s
Polyrotaxanes are new polymers. Macrocyclic molecules, such as crown ethers, are threaded by linear or branched polymer chains. There is no covalent bond between the crown ethers and the polymer backbone. After the crown ethers are threaded onto the polymer backbone, both ends of the polymer can be …
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Uncovering and Exploiting Cucurbit[8]uril Host-Guest Dynamics in Bulk Mechanical Behaviour
… guests created branched polymers with CB[8] rotaxanes, which formed gels upon mixing with hydroxyethyl cellulose (HEC) bearing pendant second guests. Lastly, the effect of different binding modes between guest molecules and CB[8] on gel behaviour was studied for systems based on two different …
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