共查询到20条相似文献,搜索用时 15 毫秒
1.
采用紫外分光光度法和荧光分光光度法研究了主体分子对二甲氨基苯甲酸与HPO42-、SO42-、H2PO4-、ClO4-、HSO4-、NO3-、BF4-、PF6-、F-、Cl-和Br-等11种阴离子客体的识别作用.发现在乙腈溶液中,该主体分子对二价阴离子HPO42-和SO42-表现了强亲和力和高选择性;并对一价阴离子F-和H2PO4- 具有一定的响应能力;而与一价阴离子ClO4-、HSO4-、NO3-、BF4-、PF6-、Cl-和Br-几乎没有作用.结果表明主客体分子本身的酸碱性和阴离子的负电荷数目是影响主体分子对阴离子识别性能的主要因素. 相似文献
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A novel cyclic dimer based on oleanolic acid was synthesized using click chemistry and it showed remarkable selectivity and affinity to bind fluoride ion through C-H?F hydrogen bond interactions which involved the delocalization of proton in methylene. 相似文献
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[structure: see text] Novel deoxycholic acid-based cyclic receptors, 3 and 4, containing two imidazolium groups and m-xylene and p-xylene as spacers have been synthesized. These receptors bind anions through hydrogen bonds utilizing two imidazolium (C-H)(+) and inwardly directed methylene hydrogens of both acetyl groups. Receptor 3 shows a moderate selectivity for fluoride ion whereas receptor 4 shows high affinity and selectivity for chloride ion in CDCl(3). 相似文献
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Evgeny A. Kataev Patricia Pantos Elizabeth Karnas Grigory V. Kolesnikov Ivan G. Tananaev Vincent M. Lynch 《Supramolecular chemistry》2015,27(5-6):346-356
Cyclo[8]pyrrole, an octapyrrolic expanded porphyrin with no meso-linking atoms, was found to interact with a series of anions in the solid state and in a chloroform solution. The anion selectivities have been determined relative to a structurally characterised salt, H2cyclo[8]pyrrole2+·I? ·I3 ? , via counter anion exchange. Although cyclo[8]pyrrole demonstrates a general selectivity for sulfate, it interacts well with both the pertechnetate and perrhenate anions. Moreover, it has been shown to act as a phase-transfer catalyst facilitating the extraction of pertechnetate from an aqueous to an organic phase in the presence of sulfate. 相似文献
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The synthesis and anion recognition properties of four novel [2]rotaxane host architectures containing additional alkyl functionality integrated within macrocyclic and axle components to shield the binding cavity from the solvent are described. The rotaxane species containing a tetra(methyl)-functionalised macrocycle component is found to be a weaker anion complexant than the equivalent unfunctionalised receptor, which is likely due to steric hindrance restricting the anion's access to the interlocked cavity. Rotaxane molecules containing tetra(methyl)-functionalised axle components are also investigated, and the additional alkyl functionality serves to enhance anion binding affinity and selectivity when incorporated within the axle's flexible ethylene linkages. Moreover, the equivalent unfunctionalised rotaxane displays a rare preference for oxoanions over chloride guest species. 相似文献
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设计合成了一种含双腙类阴离子受体1(5-甲基双水杨醛-2,4-二硝基苯腙)。用紫外-可见吸收光谱、荧光光谱考察了其与AcO-,H2PO4-,F-,Cl-,Br-和I-阴离子的作用。当加入AcO-、F-和H2PO4-时,受体分子1的吸收光谱发生明显的红移,与此同时溶液颜色由浅粉色变为紫色,而加入其他阴离子则无变化。通过在DMSO-d6核磁滴定实验进一步研究受体1和F-相互作用的本质。 相似文献
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Esteban-Gómez D Platas-Iglesias C de Blas A Fabbrizzi L Rodríguez-Blas T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(19):5829-5838
In this paper, we report two macrobicyclic receptors containing pyridine head units derived from 1,10-diaza-15-crown[5] (L1) or 4,13-diaza-18-crown[6] (L2) that can be protonated in MeCN and used for anion recognition. The interaction of these protonated lateral macrobicycles with different anions has been investigated by means of spectrophotometric titrations in MeCN. The association constants for the complexes of halide anions with the protonated macrobicycles follow the sequences Cl(-)>Br(-)>I(-)>F(-) (L1) and Cl(-)>F(-)>I(-)>Br(-) (L2), whereby an increase of more than two logarithmic units is observed from F(-) to Cl(-) for the binding constants of the receptor derived from L1. The association constants also indicate an important degree of selectivity of these macrobicyclic receptors for Cl(-) over Br(-) or I(-). The X-ray crystal structure analyses of the chloride and bromide complexes confirms the formation of the envisaged supramolecular complexes. Moreover, the binding constants indicate that these receptors present a high sulfate-to-nitrate binding selectivity. The stability trend observed for the recognition of halide anions by the macrobicycles presented herein as well as the sulfate-to-nitrate binding selectivity have been rationalised by means of DFT calculations at the B3LYP/LanL2DZ level. These studies indicate that the especially high binding selectivity for Cl(-) is the result of the optimum fit between the protonated macrobicyclic cavity and the size of the anion, whereas the sulfate-to-nitrate selectivity results from shape complementarity between the hydrogen-binding acceptor sites on sulfate and the hydrogen-bond donors of the macrobicycle. 相似文献
9.
Tomasz Zieliński 《Tetrahedron》2005,61(16):4081-4089
Amide and thioamide derivatives of the 1H-pyrrole-2,5-dicarboxylic acid have been synthesised. Properties of these simple anion receptors and their behaviour in the presence of anions have been studied both in solution and in the solid state. The results allowed to compare anion complexation properties of thioamides versus their amide analogues. 相似文献
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Calix[4]arene-based receptors linked to amide and pyridine moieties have been synthesised in four steps from calix[4]arene, and characterised by 1H and 13C NMR spectroscopy. The recognition properties of these receptors towards different anions were evaluated using 1H NMR and computational studies. The receptors show modest selectivities towards dihydrogen phosphate versus carboxylates. 相似文献
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采用含原位聚合阴离子交换整体柱的微芯片分离氨基酸 总被引:1,自引:0,他引:1
采用原位聚合法,制备了以2-甲基丙烯酰氧乙基三甲基氯化铵(META)为功能单体的强碱性季铵盐离子交换型微整体柱,构建了带微整体柱的复合式微流控芯片;以氨基酸-H2O2-Lum inol化学发光体系为样品对象,根据氨基酸等电点的差异,在原位聚合微整体柱上进行分离实验。进行了苯丙氨酸-白氨酸、苯丙氨酸-组氨酸、苯丙氨酸-精氨酸3组氨基酸混合体系的分离,获得了很好的分离结果。优化并讨论了影响氨基酸分离效果的多种因素,如缓冲液pH值、洗脱液pH值和洗脱液流速等。在优化条件下,苯丙氨酸-精氨酸的分离度达到1.6,结果显示出整体柱与微流控体系相结合的可行性。 相似文献
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Giacomo Picci Israel Carreira-Barral Daniel Alonso-Carrillo David Sanz-González Pablo Fernández-López María García-Valverde 《Supramolecular chemistry》2020,32(2):112-118
ABSTRACTEight N,N´-diarylisophthalamide/dipicolineamide derivatives have been synthesised and fully characterised, both in solution and in the solid state. The transmembrane anion transport properties of these compounds have been studied by chloride-selective electrode and fluorescence experiments. The substitution pattern of the aromatic moieties determines the transport properties of these systems, with those containing electron-withdrawing groups in their structures being the most active ones of the series. 相似文献
16.
Micha? Chmielewski 《Tetrahedron letters》2004,45(31):6007-6010
Comparison of the anion binding properties of a series of uncharged macrocyclic tetraamides reveal significant effects of the receptor's size on the strength of its anion complexes. This study allowed for estimation of the optimal size of a macroring for complexation of common anions. 相似文献
17.
《Journal of separation science》2018,41(6):1355-1364
In the enantiomeric separation of highly polar compounds, a traditionally challenging task for high‐performance liquid chromatography, ion‐exchange chiral stationary phases have found the main field of application. In this contribution, we present a series of novel anion‐exchange‐type chiral stationary phases for enantiomer separation of protected amino phosphonates and N‐protected amino acids. Two of the prepared selectors possessed a double and triple bond within a single molecule. Thus, they were immobilized onto silica support employing either a thiol‐ene (radical) or an azide‐yne (copper(I)‐catalyzed) click reaction. We evaluated the selectivity and the effect of immobilization proceeding either by the double bond of the Cinchona alkaloid or a triple bond of the carbamoyl moiety on the chromatographic performance of the chiral stationary phases using analytes with protecting groups of different size, flexibility, and π‐acidity. The previously observed preference toward protecting groups possessing π‐acidic units, which is a typical feature of Cinchona‐based chiral stationary phases, was preserved. In addition, increasing the bulkiness of the selectors’ carbamoyl units leads to significantly reduced retention times, while very high selectivity toward the tested analytes is retained. 相似文献
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阴离子交换树脂提取谷氨酸 总被引:4,自引:0,他引:4
谷氨酸是蛋白质的主要构成成分,具有重要的生理生化功能,其主要应用于食品、医药等工业。目前国内从发酵液中提取谷氨酸普遍采用的步骤是:先用等电法结晶大部分谷氨酸,等电母液采用离子交换法浓缩其中的谷氨酸,此时谷氨酸为阳离子,洗脱高浓度馏分再回入等电罐进行结晶回收[1]。上述工艺的最大缺点是:在结晶和离子交换过程中要使用大量的硫酸调节发酵液和母液的pH,造成环境污染;且提取谷氨酸后产生的废液中其COD和SO2 4和氨态氮含量很高,用常规的方法较难处理[2]。由于谷氨酸发酵液的pH为6 8~7 2,此时,谷氨酸主要以阴离子状态形式存… 相似文献
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The anion binding properties of bile acid-based cyclic bisbenzimidazolium receptors 6-8 bridged with m-xylene, p-xylene, and 2,6-dimethylpyridine have been studied. Receptors 6 and 7 exhibit much higher binding affinity for fluoride and chloride ions, respectively, as compared to the imidazolium receptors 1 and 2. Receptor 8, however, shows high selectivity but very low binding affinity for anions due to the presence of pyridyl nitrogen. The single-crystal X-ray structure of imidazolium receptor 10-(Br)2 containing pyridyl spacer reveals the binding pattern. 相似文献