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Showing 1 to 20 of 23 for “"Cryptand"”.
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Spectroscopic studies of lithium and sodium complexes with the dilactam of C222 cryptand
Thesis (M.S.)--Michigan State University. Dept. of Chemistry, 1975
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Host-Guest Systems Based on Crown Ether, Cryptand, and Pseudocryptand Hosts with Paraquat, Diquat, Secondary Ammonium, and Monopyridinium Salt Guests
… 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 …
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Efficient Syntheses of Strong Binding Cryptands and their Derivatives for Supramolecular Polymer Synthesis
… strongly associating crown ether-based cryptands is desired for pseudorotaxane complexation of bipyridinium guests to produce suprapolymers and supramolecularly-linked block copolymers. Cryptands based on bis(meta-phenylene)-32-crown-10 (BMP32C10) were synthesized. The functionality of …
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Synthesis and investigation of hexacarboxamide cryptands as anionic binucleating ligands by Glen E. Alliger.
We have investigated the use of hexacarboxamide cryptands as sextuply anionic binucleating ligands. Two homobimetallic complexes of a t-butyl-substituted cryptand, featuring manganese(II) ion and cobalt(II) ions, have been synthesized. The manganese species features a bridging hydroxide ligand; …
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Synthesis and properties of novel cage-functionalized crown ethers and cryptands.
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 …
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Synthesis and reactivity studies of mono-, bi-, and trimetallic complexes supported by oxidatively-resistant polyanionic ligands
… of the oxidatively-resistant hexacarboxamide cryptand, mBDCA-5t-H₆, to support mono-, bi-, and trimetallic complexes are presented. Selective single metal ion insertion into the cryptand was achieved to generate the mono-Co(II) and Zn(II) complexes that contain proximal hydrogen-bonding …
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Design, Preparation and Characterization of Novel Pseudorotaxanes, Semirotaxanes, Rotaxanes, Non-Covalent Supramolecular Polymers and Polycatenanes
… the first [2]pseudorotaxane and the first pseudocryptand-type poly[2]pseudorotaxane based on BMP32C10 were isolated as crystalline solids as shown by X-ray analyses. The first dual component pseudocryptand-type [2]pseudorotaxanes were designed and prepared via the self-assembly of synthetically …
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Synthesis and Characterization of Polyamine Bicycles for Anion Binding
… and a group of familiar Schiff base derived azacryptands. Often these systems are synthesized by tosylating i.e., protecting, the bridging amine sites to prevent them from undesirable interactions. Only after detosylation to retrieve the secondary amines are the anion binding properties …
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Aspects of the chemistry of lead in multiphase soil model systems and the environment
… soluble structurally-distinct complexing agents cryptand 2.2.2 (a macrobicyclic ligand) and nitrilotriacetic acid (NT A). The addition of each ligand generally improved the percentages of Pb recovered from the multi-phase model soils, with Pb originally spiked on calcite. However, the …
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INTERMOLECULAR COMPLEXES OF GERMANIUM(II
… and examined computationally. The structure of (cryptand[2.2.2]Ge) , as the inflate salt, was reported and is the first example of a non-metal cation situated within a cryptand. A number cationic germanium crown ether complexes were are also synthesized including [[12]crown-4)2*Ge]2+, …
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Estrogen Depletion Effects on Myelination and Lipid Regulation within the Central Nervous System
… strategies using ether-based macrocycles, 2.2.2 cryptand and 18-crown-6, to trap metal cations in order to delay precipitation of phytate salts and define the influence of nearby counterions on phytate’s ring flip. Nuclear magnetic resonance (NMR) spectroscopy spectra showed that the 2.2.2 …
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Trigonal Based Copper Sites - A Natural Situation?
… fall into two main classes; iminopodands and azacryptands. The iminopodands are derived from the condensation of tris(2- aminoethy1)amine (tren) or tris(3-aminoisopropy1)amine (trpn) and a range of aromatic aldehydes. The compounds invariably co-ordinated Cu(1) and the structural consequences of …
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Explorations with Polycarbocyclic Cage Compounds
… A highly preorganized, cage-functionalized cryptand also has been designed and has been synthesized for use as a selective Li+ complexant. The alkali metal picrate extraction profiles of these cage-functionalized crown ethers also have been studied. Novel cage-functionalized diazacrown …
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Ligand participation in energy storage electrocatalysis and photocatalysis
… dianion stabilized by a hydrogen-bonding cryptand ligand. Ultrafast oxidation of the peroxide using photosensitizers of varying oxidizing power allows for measurement of the inner-sphere reorganization energy, which is dominated by the contraction of the O-O bond.
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Design, Synthesis and Self-Assembly of Polymeric Building Blocks and Novel Ionic Liquids, Ionic Liquid-Based Polymers and Their Properties
… 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 …
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Quantification of Supramolecular Complexes Involving Charged Species in Non-Aqueous Solvents: Theory and Application
… supramolecular bicyclic macrocycles (pseudocryptands) and stabilizing the complex in a cooperative manner. Significantly, Ka,exp of one of the pseudocryptands was shown to equal that determined in the corresponding cryptand complex.
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Generation and observation of reactive intermediates in the gas phase and condensed media
… the molecule was explored. The hexacarboxamide cryptand mBDCA-5t-H₆ was used as a ligand to prepare mono- and bimetallic iron complexes of the formula [Fe₂(mBDCA-5t)]²- and [Fe(mBDCA-5t-H³)]-. Both complexes were observed to react reversibly or irreversibly with CO or NO respectively to afford …
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Fluorescence Off-On Sensors for F-, K+, Fe3+, and Ca2+ Ions
… fluorophore and a 1,10-diaza-18-crown-6 based cryptand acting as the Fe3+ recognition moiety. FeS displays good selectivity, high sensitivity, reversibility, and pH insensitivity toward Fe3+ sensing. Based on its excellent performance in determining Fe3+ and very low cytotoxicity, FeS was …
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1,2–Dithiolate Complexes of the Lanthanides and Actinides and High– Pressure Studies of f–Element Complexes
… samarium(II) complexes with a crown ether and a cryptand ligand. In both complexes, samarium is observed spectroscopically to oxidize from the +2–oxidation state to the +3–oxidation state. In chapter 10 a cerium mellitate coordination polymer is structurally characterized under pressure using …
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