共查询到20条相似文献,搜索用时 15 毫秒
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A new polymer-supported calix[6]arene hydroxamic acid has been synthesised by reacting the acid chloride 37,38,39,40,41,42 hexahydroxy 1,8,13,19,25,31 hexacarboxy calix[6]arene with poly(styrene β-hydroxylamine). The synthesised resin was characterised by elemental analysis, FT-IR and mass spectra. Physicochemical properties viz. swelling, wet-density, void-volume, exchange capacity etc. were determined. The resin has 4.46 mmol/g exchange capacity for rare elements. The resin was used for the chromatographic separation of U(VI), Th(IV) and Ce(IV) by the judicious adjustment of pH 4.0, 6.0 and 7.5, respectively. The thorium and cerium were eluted with 0.1 M HCl while uranium was eluted with 2 M HCl. These rare elements were preconcentrated and determined in the presence of each other, monazite sand and environmental samples. 相似文献
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Hydrogen-bonded dimers of tetra-urea calix[4]arenes are able to include ferrocenium ions as a guest. Heterodimeric capsules are exclusively formed in 1:1 mixtures of tetra-arylurea calix[4]arene 1 with tetra-tosylurea calix[4]arene 2. Sulfide groups attached via spacers on the urea rim of 1 allow their binding to metal surfaces rendering simultaneously their dissociation more difficult. Thus, the electrochemical response of encapsulated ferrocenium could be studied in a self-assembled monolayer (SAM) in addition to the solution electrochemistry with cyclic voltammetry. The stability of the electrochemically active monolayers was tested after a heat treatment (225 °C for 30 min in N2 atmosphere) and multiple cycling (up to 1200 cycles), which could be required for a possible application as molecular based information storage. 相似文献
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In this study, a new type of flexible polyurethane foam containing p-tert-butyl thiacalix[4]arene (TC4A) macrocycle was synthesized. TC4A macrocycle was incorporated into polyurethane foam as a part of crosslinking agent as well as glycerol. Structural, morphological, thermal and mechanical properties of this prepared foam were studied and compared with a polyurethane foam based on only glycerol as crosslinking agent, by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), Thermal gravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The effect of introduction of TC4A crosslinker on cream time, rise time, apparent density, and water absorbency of the PU foams was evaluated. Moreover, it was shown that new TC4A-based polyurethane foam (TC-PUF) can be a high performance adsorbent for removal of malachite green from aqueous media using batch adsorption technique. The adsorption results indicated that TC-PUF has a high adsorption capacity of 58.82 mg/g for malachite green due to the presence of TC4A macrocycles in the structure of polyurethane foam. The kinetics of adsorption of malachite green was also investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results of kinetic studies showed that the adsorption of malachite green onto TC-PUF followed pseudo-second-order kinetic model. 相似文献
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Dongping Zhan Yi Yuan Yanjing Xiao Bingliang Wu Yuanhua Shao 《Electrochimica acta》2002,47(28):4477-4483
In this paper, a novel monoaza-B15C5 derivative, N-(2-tosylamino)-isopentyl-monoaza-15-crown-5 (L), is used as an ionophore to facilitate alkali metal cations transfer across a water/1,2-dichloroethane (W/DCE) interface. Well-defined voltammetric behaviors are observed at the polarized W/DCE interfaces supported at micro- and nano-pipets except Cs+. The diffusion coefficient of this ionophore in the DCE phase is calculated to be equal to (3.3±0.2)×10−6 cm2 s−1. The experimental results indicate that a 1:1 (metal:ionophore) complex is formed at the interface with a TIC/TID mechanism. The selectivity of this ionophore towards alkali ions follows the sequence Na+>Li+>K+>Rb+>Cs+. The logarithm of the association constants (log β1o) of the LiL+, NaL+, KL+ and RbL+ complexes in the DCE phase are calculated to be 10.6, 11.6, 9.0 and 7.1, respectively. The kinetic parameters are determined by steady-state voltammograms using nanopipets. The standard rate constants (k0) for Li+, Na+, K+ and Rb+ transfers facilitated by L are 0.54±0.05, 0.63±0.09, 0.51±0.04 and 0.46±0.06 cm s−1, respectively. The pH values of aqueous solution have little effect on the electrochemical behaviors of these facilitated processes. The results predicate that this new type of ionophore might be useful to fabricate electrochemical sensor of sodium ion. 相似文献
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Serkan Elçin Gülbanu Koyundereli Çılgı Hasalettin Deligöz 《Polycyclic Aromatic Compounds》2017,37(1):46-51
In this article, calix[4]arene (4) was prepared by debutylation and hydrolyses reacting from 25,27-dibenzoyl-26,28-dihydroxy-5,11,17,23-tetra(tert-butyl)calix[4]arene (2). Azocalix[4]arenes (6a-c) were coupled by linking 4-methoxy, 4-ethyl, and 4-nitroaniline to calix[4]arene (4) through a diazo-coupling reaction. Thermal behavior characteristics and decomposition routes of 25,26,27,28-tetrahydroxy-11,23-di(tert-butyl)-5,17-(p-substitue phenyl)azocalix[4]arene (6a-c) were investigated in air atmosphere by means of thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) analyses. It was found that the decomposition of all compounds complete with two exothermic stages which corresponded to removal of substitute groups (methoxy-, ethyl-, nitro-) and second stage rest of structure decomposition. 相似文献
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以对叔丁基苯酚为起始原料,通过缩合得到对叔丁基杯[4]芳烃,再对其下沿酚羟基进行化学修饰,得到具有化学活性的杯[4]衍生物,该化合物与具有活泼氢的4巯基吡啶反应制得新的含N、S杯芳烃衍生物,总收率15.3%。 相似文献
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In this study, a novel azocalix[4]arene derivative, 5,11,17-tris[(1-naphtyl)azo]-25,26,27,28-tetrahydroxy-calix[4]arene (NAC4) bearing napthyl groups on the upper rim was synthesized. Its complexation behavior for alkali, alkaline-earth and various heavy metal ions (Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+, Pb2+, Hg2+, Ni2+, Cd2+, Cu2+, Zn2+, Co2+, Fe2+, Cr3+, Ag+) was investigated by spectroscopic and voltammetric methods. This chemosensor exhibits decreased absorbance in the presence of Hg2+ and a unique absorbance quenching effect only for Cr3+. In addition, a new absorption band centered at 565 nm with the formation of the 1:1 host–guest complex (Cr3+-NAC4) was observed in the case of Cr3+, leading to an obvious color change from light orange to dark lilac. In voltammetric experiments, Cr3+ ions decreased voltammetric peaks of NAC4, whereas no significant changes occurred in the presence of the other metal ions. The Benesi–Hildebrand method was used to determine a logarithmic value of 3.76 for the association constant of the complex between Cr3+ and NAC4. 相似文献
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A macrocyclic 1,3-di(1-dodecyloxy)-2,4-crown-6-calix[4]arene (DodCalix[4]C6) was synthesized and characterized. The extraction of Cs(I) and more than 10 typical metals with DodCalix[4]C6/octanol in HNO3 medium was investigated. DodCalix[4]C6 exhibited strong extraction ability and high selectivity for Cs(I) over others except for Rb(I). The optimum acidity in Cs(I) extraction was 3.0 M HNO3. The Cs(I) separation from a simulated highly active liquid waste by five-stage countercurrent extraction was performed. The extraction efficiency of Cs(I) for five-stage extraction was greater than 99%. The effective partitioning of Cs(I) by DodCalix[4]C6/octanol through multistage countercurrent extraction was achieved. 相似文献
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Calix[4]arenes bearing tetrathiafulvalene (TTF) moieties appended to the upper rim via the amidic functions were synthesized and used for 1H NMR and UV/Vis complexation studies towards selected anions. It was found that the complexation affinity towards H2PO4− dramatically depends on the substitution pattern of the calixarene moiety. As a result, the proximally disubstituted derivative has a complexation constant by two orders of magnitude higher than the distally disubstituted analogue. The differences between proximal and distal receptors were also documented by their behaviour during the oxidation of the attached TTF units. 相似文献
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杯[4]芳烃醚类衍生物的合成(Ⅱ) 总被引:4,自引:1,他引:4
以对叔丁基苯酚和甲醛为起始原料,通过选用不同的催化剂,合成了一系列新的杯[4]芳烃的四醚化衍生物,并对其结构用IR、^1HNMR、^13CNMR、MR进行了表征。 相似文献
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Ramachandra Rao Sathuluri Yehezkiel Steven Kurniawan Jee Young Kim Masatoshi Maeki Wataru Iwasaki Shintaro Morisada 《分离科学与技术》2018,53(8):1261-1272
ABSTRACTStepwise recovery of silver(I), palladium(II) and platinum(IV) with suitable calix[4]arene extractants was carried out by investigating the extraction and stripping process using a droplet-based microreactor system. The highest percentages of silver, palladium (100%) and platinum ion (37.2%) were extracted from a real waste only within 4.00s using a microreactor system compared with 24 and 72 h to reach extraction equilibrium in a batch method. Fourier transform infrared spectroscopy studies revealed a very good relation in peak shifts on the metal complexation with calix[4]arene derivatives after extraction and stripping. The droplet-based microreactor system emerges as an effective tool to be applied in metal recovery. 相似文献
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以对叔丁基杯[4]芳烃为原料,经碱催化两步合成了26,28-双(2-亚甲基蒽醌)-5,11,17,23-四叔丁基杯[4]-25,27-冠-6。产物经IR、1HNMR表征和元素分析表征,该衍生物为锥形结构并与设计思想一致。 相似文献
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Cd2+-selective sensors have been fabricated from poly(vinyl chloride) (PVC) matrix membranes containing t-butyl thiacalix[4]arene (I) and thiacalix[4]arene (II) as electroactive materials. The addition of sodium tetraphenylborate and the plasticizer 2-nitrophenyl octyl ether has been found to improve the performance of the sensors substantially. The membranes of various compositions of the two thiacalixarenes have been investigated and it was found that the best performance was obtained for the membrane of composition II:PVC:NaTPB:NPOE in the ratio 5:120:3:150. The sensor shows a linear potential response for Cd2+ over a wide activity range 3.2 × 10−6 to 1.0 × 10−1 M with Nernstian compliance (29.5 mV decade−1 of activity) in pH range 4.5-6.5 and a fast response time of ∼8 s. The potentiometric selectivity coefficient values determined by matched potential method indicate excellent selectivity for Cd2+ ions over mono-, di- and trivalent interfering cations. The sensor exhibits adequate shelf life (∼3 months) with good reproducibility (S.D. ±0.2 mV) and can also be used in partially non-aqueous media having up to 20% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working activity range. The sensor has been used in the potentiometric titration of Cd2+ with EDTA. The sensor could be successfully used for the quantification of cadmium in river water samples. 相似文献