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Showing 1 to 20 of 53 for “"Crown Ether"”.
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Synthesis of Crown Ether/Ammonium Salt for Electron Transfer Study
… organic complexes in this study are a series of crown ether/ammonium salt, which incorporate a redox partner on each component of the complex. The dimethoxynaphthalene redox donor was attached to the crown ether and a series of ammonium salts was synthesized which bear substituted quinone and …
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Synthesis and characterisation of amides based on crown ether supramolecular gels
… We have synthesised supramolecular gels based on crown ether amides because amide moieties have been extensively used as supramolecular synthons to generate LMWGs with tuneable properties and crown ethers represent a group of compounds with an exceptional ability to selectively coordinate to ions …
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New polymer architectures: synthesis and characterization of polyurethane-crown ether based polyrotaxanes
… their unique architectures. The studies include crown ether and blocking group syntheses, synthetic methodologies leading to rotaxanes and polyrotaxanes and structure-property relationships of polyrotaxanes. Crown ethers (30-crown-10, 36-crown-12, 42-crown-14, 48-crown-16 and 60-crown-20) were …
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Modeling Ionophore Selectivity in the Gas Phase: IR Spectroscopy of Solvated Metal Ion-Crown Ether Complexes
Crown ethers are a family of compounds that are closely related to a variety of biological and naturally-occurring ionophores. Thus, crown ethers have become the prototypical ionophore-model systems in chemistry and biology. Insight gained by studying the interaction of crown ethers with metal ions …
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Molecular composites of a conducting polymer: syntheses and characterization of poly(1,4-phenylenevinylene)-crown ether rotaxanes
… as the linear backbone and different sizes of crown ethers (42C14, 60C20) as macrocycles, molecular composites of the conducting polymer were generated To compare with the PPV rotaxanes, PPV was synthesized and characterized by NMR, IR, UV-vis, photoluminescence spectroscopy, and TGA. The …
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The synthesis and investigation of the electronic properties of crown ether, [2]-catenane, and [2]-rotaxane architectures
… of thiophene and phenylene-ethynylene based crown ethers are determined via fluorescence quenching titrations, in an attempt to correlate structure with binding affinities. The insight obtained from the binding constant determinations allows for the proper choice of crown ether for the …
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Host-Guest Systems Based on Crown Ether, Cryptand, and Pseudocryptand Hosts with Paraquat, Diquat, Secondary Ammonium, and Monopyridinium Salt Guests
… 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 …
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New Rotaxane Ligands with Donors on Both the Axle and Wheel
… This was followed by the synthesis of a new thioether crown ether ligand and the resulting coordination of this ligand with the same metal centers studied with the model ligand. Where possible, the single crystal X-ray data for these coordination complexes was collected and has been presented. In …
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Electrochemical facilitated transport: a study in synthesis, simulation and experimentation
… through use of an electrochemically modifiable crown ether will be examined in this work. This process will be referred to as electrochemical facilitated transport. The design and synthesis of a new ferrocenophane crown ether for use in this work will be presented. Experiments using this model …
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Noncovalent Interactions Between Alkali Metal Cation And Aza/thia-Crown Macrocycles: Mass Spectrometric Techniques And Theoretical Studies
… and theoretical description of cation-aza-crown and thia-crown ether interactions with alkali metal cations. Infrared multiple photon dissociation (IRMPD) action spectroscopy and energy-resolved collision-induced dissociation (CID) techniques were used in conjunction with theoretical …
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INTERMOLECULAR COMPLEXES OF GERMANIUM(II
… within a cryptand. A number cationic germanium crown ether complexes were are also synthesized including [[12]crown-4)2*Ge]2+, [[15]crown-5*GeOTf]+ and [benzo[15]crown-5•GeC1]+ and [benzo[15]crown-5•GeOTf. The geometries of the crown ether-germanium complexes were found to be highly dependent on …
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Enhanced Architectural and Structural Regulation Using Controlled Free Radical Polymerization Techniques; Supramolecular Assemblies: Pseudorotaxanes and Polypseudorotaxanes
… several functionalized bis-(meta-phenylene)-32-crown-10 macrocycles with various paraquat guest moieties was. As expected, studies indicated that electron-donating substituents on the crown ether drive association, a likely result of increased p -p interactions among host and guest species. The …
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Chemical Studies of Coulombic Complexations in Polymers
… For the polymer-monoion complexation, a poly(crown ether) (PCE), is studied in the form of an ion-doped polymer. The experimental work was aimed at understanding the significant changes brough about by ion-doping including not only the molecular conformations of polymer chains but also the …
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Linear, Branched and Crosslinked Polymers, Polyesters, Polyurethanes and Polymethacrylates Derived From Rotaxane Formation: Syntheses and Properties
… 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 of threaded cyclic during polymerization, the driving force for threading remains unidentified. To prevent threaded cyclics from …
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Nano chemistry : large molecular capsules and coordination networks based on self-assembly
… been used to identify p-sulfonatocalix[4]arene/crown ether complexation in the solution phase. Notably, remarkable control can be achieved over the formation and geometries of nano-metre scale spheroids or tubules containing p-sulfonatocalix[4]arene via guest selection. Chapter 1 gives a short …
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Separation of alkali metal cations and alkaline earth cations using ionizable crown ethers
Proton-ionizable crown ethers are novel agents for the separation of metal ions by extraction and membrane transport processes. A series of novel crown ether carboxylic acids , crown ether phosphonic acid monoesters, and crown ether phosphonic acids which possess lipophilic pendant groups were …
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Molecular necklaces: polyester rotaxanes
… 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 polyrotaxanes …
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Explorations with Polycarbocyclic Cage Compounds
… of novel cage-functionalized pyridyl containing crown ethers have been prepared for use in selective alkali metal complexation studies. A highly preorganized, cage-functionalized cryptand also has been designed and has been synthesized for use as a selective Li+ complexant. The alkali metal …
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Self-Assembly: Synthesis and Complexation of Crown Ethers and Cryptands with R2-NH2 Ions
… 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 stoichiometries and association constants of the …
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