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101.
Saliha Bouhroum Jong Seung Kim Soon W. Lee Pierre Thuéry Glenn Yap Françoise Arnaud-Neu Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(3-4):239-250
The synthesis and crystal structure of p-tert-butylthia- and p-tert-butylcalix[4]arene derivatives 1–7 substituted at the narrow rim by diethylthiophosphate ester groups, -PS(OEt)2 are reported. In these compounds the phosphorus atoms are directly attached to the phenolic O atoms of the calix units and the S atoms of the thiophosphate may serve as a two-electron donor to a metal ion. Their crystal structures were solved, which revealed their cone conformation. Their cation-binding properties have been established by liquid-liquid extraction of metal picrates from water into dichloromethane and stability constant determination in acetonitrile using UV-absorption spectrophotometry. Quantitative extraction was achieved for Ag+ (%E = 99) with the tetra-substituted thiacalix[4]arene derivative. The complexes were found to be of 1:1 stoichiometry and the location of the metal cations was shown to be nearby the sulphur atoms by 1H NMR. 相似文献
102.
Amel Ben Othman Young Hoon Lee Keisuke Ohto Rym Abidi Yang Kim Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(1-2):187-191
Hyperbranched molecules, 4–8, based on calixarenes attached to newly synthesised cores 2 and 3 have been prepared. Preliminary complexation studies of the complexation of Zn(Pic)2 by 8 showed that the ligand prefers to bind the picrate anions. 相似文献
103.
L. Baklouti R. Abidi P. Thuery M. Nierlich Z. Asfari J. Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(4):323-325
The direct preparation of the sodium complex of 5,11,17,23-tetra(tert-butyl)-25,27-di(ethoxymethoxy)-26,28-(diethylacetamido) calix[4]arene 1.NaI is reported. The crystal structure of 1.NaI shows the calix unit to be in a cone conformation with the sodium located in the cavity delineated by the oxygen atoms. 相似文献
104.
Crystal structure of a complex between the aminoglycoside tobramycin and an oligonucleotide containing the ribosomal decoding a site 总被引:4,自引:0,他引:4
Aminoglycoside antibiotics target the decoding aminoacyl site (A site) on the 16S ribosomal RNA and induce miscoding during translation. Here, we present the crystal structure, at 2.54 A resolution, of an RNA oligonucleotide containing the A site sequence complexed to the 4,6-disubstituted 2-deoxystreptamine aminoglycoside tobramycin. The three aminosugar rings making up tobramycin interact with the deep-groove atoms directly or via water molecules and stabilize a fully bulged-out conformation of adenines A(1492) and A(1493). The comparison between this structure and the one previously solved in the presence of paromomycin confirms the importance of the functional groups on the common neamine part of these two antibiotics for binding to RNA. Furthermore, the analysis of the present structure provides a molecular explanation to some of the resistance mechanisms that have spread among bacteria and rendered aminoglycoside antibiotics inefficient. 相似文献
105.
Amel Ben Othman Najah Cheriaa Rym Abidi Jacques Vicens Pierre Thury 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o859-o861
The title compound, C47H60O6·3CHCl3, is the first example of a lower‐rim mono‐ester calixarene derivative to be crystallographically characterized. The cone conformation adopted by the macrocycle is stabilized by three intramolecular hydrogen bonds. Self‐inclusion of the methyl ester chain in the cavity of an adjacent molecule gives rise to infinite chains parallel to the c axis. C—H⋯π interactions involving the methyl group most imbedded in the cavity contribute to the stabilization of the system. 相似文献
106.
Abdelwaheb Hamdi Rachid Souane Lidia Kim Rym Abidi Lucia Mutihac Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2009,64(1-2):95-100
Calixarenes 2–4, 6 and 7 in the cone conformation variously substituted by acid or amido functions, glycolic chains and hydroxyl groups were synthesised. They have been used in extraction of native amino acid and amino acid esters. 相似文献
107.
New fluorescent chemosensor 1 with two amidoanthraquinone groups (1-AAQs) at the lower rim of p-tert-butylcalix[4]arene has been synthesized. The significant changes of absorption and fluorescence bands show that chemosensor 1 is selective toward fluoride ion (F−) over other anions such as Cl−, Br−, I−, CH3COO−, , , and OH−. The ESIPT process of 1 is inhibited by the fluoride-induced H-bonding followed by deprotonation of NH of the 1-AAQ. 相似文献
108.
The present critical review reports on recent developments of optical nanoparticles based on the association of gold, silver, silica and quantum dots and calixarenes. These hybrid organic-inorganic compounds characterized by a thick organic layer self-assembled on the surface of a core of mineral surface atoms take advantage of the supramolecular recognition of luminescent calixarenes to fabricate nanodevices of nanoparticle size, capable of detecting metal cations, polyaromatic hydrocarbons and pesticides. Also presented is an explanation of the involvement of such nanoparticles in biochemical systems. This critical review provides an overview of their preparation, the manner in which they are characterized, and their use (108 references). 相似文献
109.
Lidia Kim Abdelwaheb Hamdi Ana Delia Stancu Rachid Souane Lucia Mutihac Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2010,66(1-2):55-59
The selective active transport through liquid membrane assisted by the pH gradient of amino acid methylesters by using a series of calix[4]arenes substituted by acid and amido functions, glycolic chains, and hydroxyl groups as carriers has been performed. All these receptors have been found to act as carriers for transport of aromatic amino acid methylesters from the aqueous source phase to the aqueous receiving phase aiming at their separation. The receptors bearing diacid and tetraamido functions have the better ability to transport of amino acids than the other receptors studied. The influence of calixarene and amino acid structures upon transport through liquid membrane is discussed. The obtained results are correlated with those acquired by solvent extraction. 相似文献
110.
Hicham Maskrot Nathalie Herlin-Boime Yann Leconte Krystina Jursikova Cécile Reynaud Jean Vicens 《Journal of nanoparticle research》2006,8(3-4):351-360
Composite TiSiOC nanoparticles with Ti/Si ratio varying in a very large range were prepared by laser pyrolysis of a gas–spray mixture of silane and titanium tetra-isopropoxide. The as-formed nanoparticle batches exhibit intense blue colours, varying from dark to light blue while the Ti/Si ratio increases. This blue colour is attributed to the formation of sub-stoichiometric TiOcompounds induced by the presence of reducing agents such as silicon-based radicals and carbon atoms in the reaction medium. The blue colour of the powders is stable for several months at room temperature in normal atmospheric conditions. Elemental analysis, specific surface area and pycnometry measurements, as well as Photon Correlation Spectroscopy allow determining the chemical composition and size of the as-synthesized nanoparticles as a function of the Ti/Si ratio. X-ray diffraction, transmission electron microscopy and IR spectroscopy have been used to analyse their chemical organisation, nanostructure and morphology. Mean grain size is found around 20 nm. The nanoparticles exhibit a core-shell structure TiO/SiO2, with a core made of titania, surrounded by an amorphous shell, mainly of silica. Crystallites of anatase are present in the core with size increasing with the Ti/Si ratio. Annealing under air at 800°C induces the removal of carbon and the crystallisation of the powders with light beige to white colours. 相似文献