Synthesis, Structure, and Complexation Properties of Monoazacryptands

Nakatsuji, Yohji; Sunagawa, Takuya; Masuyama, Araki; Kida, Toshiyuki; Ikeda, Isao

doi:10.1246/cl.1995.445

Cited by 6 publications

(3 citation statements)

References 6 publications

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“…Synthesis. Syntheses of N -alkyl aza crown ethers have been previously investigated. − The typical synthesis in the literature started with the alkylamine followed by several steps to reach the desired monoaza crown ethers. The reaction used for synthesizing recyclable monoaza crown ethers in this study is illustrated in Scheme .…”

Section: Resultsmentioning

confidence: 99%

Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

2004

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A series of N-alkyl aza-18-crown-6 ethers were synthesized and characterized by NMR spectroscopy and mass spectrometry. These monoaza-substituted crown ethers in ionic liquids were investigated as recyclable extractants for separation of Sr(2+) and Cs(+) from aqueous solutions. The pH-sensitive complexation capability of these ligands allows for a facile stripping process to be developed so that both macrocyclic ligands and ionic liquids can be reused. The extraction efficiencies and selectivities of these monoaza-substituted crown ethers for Na(+), K(+), Cs(+), and Sr(2+) were studied in comparison to those of dicyclohexano-18-crown-6 under the same conditions. The extraction selectivity order for dicyclohexano-18-crown-6 in the ionic liquids investigated here was K(+) >> Sr(2+) > Cs(+) > Na(+). The extraction selectivity order for N-alkyl aza-18-crown-6, in which the alkyl group is varied systematically from ethyl to n-dodecyl, was Sr(2+) >> K(+) > Cs(+) > Na(+) in 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide and K(+) > Sr(2+) > Cs(+) > Na(+) in 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] amide and 1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide. The strong dependence of selectivity on the type of ionic liquid indicates an important role played by solvation in solvent extraction processes based on ionic liquids. The optimization of macrocyclic ligands and ionic liquids led to an extraction system that is highly selective toward Sr(2+).

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Section: Resultsmentioning

confidence: 99%

Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

2004

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“…The ammonium chloride of the ionophore is soluble in the organic membrane and moves to the neutral source phase across the membrane. At the neutral interface, the ionophore can exchange the proton with the metal cation without the assistance of neutralization by OH -in this case, because monoazacryptand 20.18.18 possesses very high complexation ability toward K + in comparison with monoaza-18-crown-6 23 . The exchange process of metal ion and proton at the source interface demands high complexing ability to the ionophore.…”

Section: Chart 1 Structure Of Ionophoresmentioning

confidence: 99%

Supported Liquid Membrane Transport of Alkali Metal Cations by Monoazacryptand with a Partially Fluorinated Sidearm and the Corresponding Monoazacrown Ethers

et al. 2010

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Monoazacryptand [20.18.18] (1), monoaza-15-crown-5 (2a), and monoaza-18-crown-6 (2b) with a partially fl uorinated sidearm were newly prepared and their transport abilities were estimated in a supported liquid membrane containing a mixture of 2-(perfl uorohexyl) ethyl alcohol and 2-(perfl uorooctyl) ethyl alcohol. In competitive passive transport of K + , Na + , and Li + under neutral conditions, the K + selectivity increased in the order: ionophore 2a

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“…In this study, symmetry-adapted cluster (SAC)-configuration interaction (CI) [22][23][24] was applied. The SAC-CI method has been established as an accurate electron-correlation method for investigating ground, excited, ionized, and electron-attached states.…”

Section: Introductionmentioning

confidence: 99%

Investigation of excited‐state properties of fluorene–thiophene oligomers by the SAC‐CI theoretical approach

Poolmee

Hannongbua

2010

J Comput Chem

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Excited states of fluorene-ethylenedioxythiophene (FEDOT) and fluorene-S,S-dioxide-thiophene (FTSO2) monomers and dimers were studied by the symmetry-adapted cluster (SAC)-configuration interaction (CI) method. The absorption and emission peaks observed in the experimental spectra were theoretically assigned. The first three excited states of the optimized conformers, and the conformers of several torsional angles, were computed by SAC-CI/D95(d). Accurate absorption spectra were simulated by taking the thermal average for the conformers of torsional angles from 0 degrees to 90 degrees. The conformers of torsional angles 0 degrees, 15 degrees, and 30 degrees mainly contributed to the absorption spectra. The full width at half-maximum of the FEDOT absorption band is 0.60 eV (4839 cm(-1)), which agrees very well with the experimental value of 0.61 eV (4900 cm(-1)). The maximum absorption wavelength is located at 303 nm, which is close to those of the experimental band (327 nm). The calculated absorption spectrum of FTSO2 showed two bands in the range of 225-450 nm. This agrees very well with the available experimental spectrum of a polymer of FTSO2, where two bands are detected. The excited-state geometries were investigated by CIS/6-31G(d). These showed a quinoid-type structure which exhibited a shortening of the inter-ring distance (0.06 A for FEDOT and 0.04 A for FTSO2). The calculated emission energy of FEDOT is 3.43 eV, which agrees very well with the available experimental data (3.46 eV). The fwhm(E) is about 0.49 eV (3952 cm(-1)), while the experimental fwhm is 0.43 eV (3500 cm(-1)). For FTSO2, two bands were also found in the emission spectrum.

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Synthesis, Structure, and Complexation Properties of Monoazacryptands

Cited by 6 publications

References 6 publications

Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

Supported Liquid Membrane Transport of Alkali Metal Cations by Monoazacryptand with a Partially Fluorinated Sidearm and the Corresponding Monoazacrown Ethers

Investigation of excited‐state properties of fluorene–thiophene oligomers by the SAC‐CI theoretical approach

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Synthesis, Structure, and Complexation Properties of Monoazacryptands

Cited by 6 publications

References 6 publications

Solvent Extraction of Sr2+ and Cs+ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

Solvent Extraction of Sr2+ and Cs+ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

Supported Liquid Membrane Transport of Alkali Metal Cations by Monoazacryptand with a Partially Fluorinated Sidearm and the Corresponding Monoazacrown Ethers

Investigation of excited‐state properties of fluorene–thiophene oligomers by the SAC‐CI theoretical approach

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Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers

Solvent Extraction of Sr²⁺ and Cs⁺ Based on Room-Temperature Ionic Liquids Containing Monoaza-Substituted Crown Ethers