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Synthesis of two new p-tert-butylcalix[4]arene β-ketoimin derivatives for extraction of dichromate anion 总被引:1,自引:0,他引:1
Mevlut Bayrakci Seref Ertul Ozlem Sahin Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2009,63(3-4):241-247
In this study the selective derivatization of p-tert-butylcalix[4]arene was carried out and two new p-tert-butylcalix[4]arene β-ketoimin, 5,11,17,23-tetra-tert-butyl-25,27-bis-3-methyl-[(β-ketoimine)-ethoxy]-26,28-dihydroxycalix[4]arene (4), and 5,11,17,23-tetra-tert-butyl-25,27-bis-3-chloro-[(β-ketoimine)-ethoxy]-26,28-dihydroxycalix[4]arene (5) have been synthesized. In the synthesis, the lower rim of p-tert-butylcalix[4]arene was modified in order to acquire binding site for the recognition of dichromate anion. It was observed that these ionophores 4 and 5 showed high affinity towards dichromate anion. The protonated Schiff-base forms of the receptors were effective for transferring the HCr2O7 ? anion from aqueous phase to a dichloromethane phase. 相似文献
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Mevlüt Bayrakci ?eref Ertul Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2012,74(1-4):293-303
This study presents the selective chloromethylation of calix[4](aza)crown ethers 2a–c, using chloromethyl n-octyl ether and SnCl4 in chloroform at room temperature in good yield for the first time. Chloromethylated products 2a–c are used as key intermediates to synthesize new water-soluble p-phosphonato calix[4](aza)crown ethers 5a–c. Liquid–liquid phase extraction and phase solubility studies with poor water soluble drug molecules such as nifedipine, niclosamide and furosemide are performed to evaluate their binding properties. Among the studied drugs, furosemide was the most effectively dissolved drug by p-phosphonato calix[4](aza)crown ethers 5a–c in water. 相似文献
3.
The classical square functions play important role in Harmonic Analysis and have a very direct connection with L
2-estimates and Littlewood-Paley theory. In this paper we introduce a new variant of square-like functions generated by some
composite wavelet transform. We establish Calderón-type reproducing formula and then prove L
2-boundedness of newly defined square-like functions. 相似文献
4.
The synthesis of upper rim-functionalized calix[4]arene-based l-proline was described, and its catalytic efficiency as organocatalyst for the enantioselective aldol reaction in water was investigated. The results showed that the nature of the hydrophobic cavity of calixarene is critical for catalytic activity in water. The products of the reaction between various ketones and aldehydes with anti-configuration were obtained in high yields (up to 94%) with high diastereo- (up to 95:5 dr) and enantioselectivities (up to 80% ee). 相似文献
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New macrocyclic polyethers, 2,3,5,6-bis-[5′(5′)-chlorobenzo]-1,7,10-trioxacyclododeca-2,5-diene (I), 2,3,5,6-bis-[5′(5′)-chlorobenzo]-1,7,10,13-tetra oxacyclo pentadeca-2,5-diene (II), and 2,3,5,6-bis-[5′(5′)-chlorobenzo]-1,7,10,13,16-penta oxa cyclo octadeca-2,5-dien (III), and macrocylic lactones 2,3,5,6-bis-[5′(5′)-chlorobenzo]-1,7,10,13-tetraoxacyclopentadeca-2,5-diene-8,15-dione (IV) and 2,3,5,6-bis[5′(5′)-chlorobenzo]-1,7,10,13,16-pentaoxacyclooctadeca-2,5-diene-8,18-dione (V) were synthesized. Complexes of ligands III and V with metal cations were prepared. Furthermore, their metal-picrate extraction with some metal salts was attempted. Structures
of the ligands and complexes were confirmed using spectroscopic techniques. 相似文献
6.
Bayrakci SP Mirebeau I Bourges P Sidis Y Enderle M Mesot J Chen DP Lin CT Keimer B 《Physical review letters》2005,94(15):157205
NaxCoO2, the parent compound of the recently synthesized superconductor Na(x)CoO(2):yH(2)O, exhibits bulk antiferromagnetic order below approximately 20 K for 0.75=x=0.9. We have performed neutron scattering experiments in which we observed Bragg reflections corresponding to A-type antiferromagnetic order in a Na0.82CoO2 single crystal and characterized the corresponding spin-wave dispersions. The spin waves exhibit a strongly energy-dependent linewidth. The in-plane and out-of-plane exchange constants resulting from a fit to a nearest-neighbor Heisenberg model are similar in magnitude, which is unexpected in view of the layered crystal structure of NaxCoO2. Possible implications of these observations are discussed. 相似文献
7.
We have studied structural, elastic, thermodynamic (Debye temperature and melting temperature), and lattice dynamical (phonon dispersion curves, heat capacity, and entropy) properties of CaX via ab initio calculations within the local density approximations. The results are compared with the available experimental and other theoretical data, and the agreement is, generally, quite good. We also predict the temperature and/or pressure-dependent behaviors of some mechanical, lattice dynamical, and thermodynamic properties for the same compounds. 相似文献
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Mevlut Bayrakci Bahar Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2018,90(3-4):341-349
In this work, the interactions between ethidium bromide (ET) and water-soluble sulfonate calix[n]arenes (n: 4, 6, and 8) were investigated by NMR, FT-IR, and fluorescence spectroscopic methods. The aim was to evaluate both the stoichiometry and the mechanism of the possible complex structure between sulfonate calix[n]arenes and ET. The spectroscopic data revealed that a 1:1 binding mode between calixarene and ET was occurred. Furthermore, thermodynamic parameters and fluorescence titration experiments were studied at different temperatures to determine both the quenching mechanism and the type of intermolecular forces in complex formation. Host–guest complexation of sulfonate calix[n]arenes and ET could be used to overcome some adverse effects related to the using of ethidium bromide during biological applications as a DNA marker treatment. 相似文献
10.
A useful methodology is represented to functionalize polyacrylonitrile nanofibers by using humic acid as a makeup agent in electrospinning process. Both morphology and surface chemistry of polyacrylonitrile nanofiber mats were understood to be influenced by incorporation of humic acid into the structure. Physicochemical changes were evidenced by Fourier transform infrared spectroscopy, scanning electron microscope, and surface charge measurements. Unlike some anionic dyes (i.e., methyl orange, methyl red, and Congo red), there was an enhancement in crystal violet (a cationic dye) adsorption after incorporation of humic acid. The Langmuir model fitted well to crystal violet data, and monolayer adsorption capacity was calculated as 81.6 mg/g (r2 = 0.998). 相似文献
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