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1.
以对叔丁基苯酚为起始原料,经过3步反应,在母体杯芳烃的下沿引入3种不同的含氮基团,得到5种含氮杯[4]芳烃,并通过1HNMR和熔点测定确定了产物结构.实验中发现,当母体杯芳烃下沿引入的溴代烷基变长时,进一步引入含氮基团,只能得到1,3位环化的含氮杯[4]芳烃.  相似文献   

2.
For all microhelices on aromatic rings of inherently chiral calix[4]arene, an expression was derived from one approximation and one hypothesis on the basis of the electron-on-a-helix model of Tinoco and Woody as follows: , where µ = 1 for the right-handed microhelix and µ = −1 for the left-handed microhelix; and H and K are constant and greater than zero. The expression correlates microhelical electronic energy (E) with the atom polarizability difference (Δα) on both microhelix ends, which intuitively and clearly shows the impact of helical substituent polarizability on helical electronic energy. The case analysis almost entirely proves that the qualitative analysis of the helical electronic energy of inherently chiral Calix[4]arenes with the expression is scientific and can be used to effectively assign their absolute configuration.  相似文献   

3.
Two different oligomeric calix[4]arene-crowns ( 2b and 3b ) were synthesized ( via ) the condensation reaction of p- tert -butylcalix[4]arene-oxacrown-4 ( 2a ) and p- tert -butylcalix[4]arene-thiacrown-4 ( 3a )(calix[4]arene-crown monomers) with 1,5-dibromopentane. In these oligomerization reactions, it has been found that only three or four calix[4]arene-crowns-4 units have been linked together through alkyl bridges. Their comparative complexing properties with selected alkali and transition metals are reported here. It has been deduced that the selectivity of monomer 2a toward alkali metals has not been reserved, but a pronounced increase in its complexing ability was observed after the oligomerization. However, the selectivity of the monomer 3a toward Cu 2+ , Hg 2+ , and Pb 2+ has also been lost after oligomerization, and it has been found that oligomer 3b is an efficient extractant for the transition metal cations employed in the two-phase extraction systems.  相似文献   

4.
The development of novel potassium-ion selective microelectrodes using microfabrication technologies and electrochemical polymerization is described. The microelectrode is based on electropolymerized polypyrrole films, doped with cobaltabis(dicarbollide) ions ([3,3′-Co(1,2-C2B9H11)2]), as an internal solid contact layer between the platinum surface and the polymeric sensing membrane. The ion selective membranes, which are based on a plasticized PVC membrane, contain 1,3-(di-4-oxabutanol)-calix[4]arene-crown-5 as a novel potassium ionophore, and are deposited on top of a layer of the conducting PPy[3,3′-Co(1,2-C2B9H11)2]. The response of the microelectrode was linear with a Nernstian slope of 51 ± 2 mV decade−1 over a K+ ion concentration range of 6 × 10−6 to 1 × 10−1 M, with a detection limit of 1.8 × 10−6 M. The microelectrode is suitable for use within the pH range of 3-11. The electrode could be used for at least one month without a considerable alteration in its potential.  相似文献   

5.
《分离科学与技术》2012,47(5):664-672
In the present article a comparative extraction efficiency of dichromate by a calix[4]arene derivative (d) and a newly synthesized calix[4]arene appended Amberlite XAD-4 resin (5) are reported. The liquid and solid phase extraction methods have been applied to ascertain the extraction efficiency of both the calix[4]arene derivative and the resin. Different parameters have been optimized such as pH, dosage, concentration, and temperature. Analysis of experimental data has been carried out by log-log plot analyses and the determination of characteristic parameters of each isotherm model such as Freundlich, Langmuir, and Dubinin-Radushkevich (D-R). The kinetic adsorption experiments show that the adsorption process follows pseudo second order kinetics. The adsorption mechanism has been investigated by Reichenberg (R-B) and Morris-Webster equations. From the thermodynamic parameters it is concluded that the adsorption process is endothermic and spontaneous in nature at higher temperature. The results show that the resin-5 has good capability to efficiently remove dichromate from aqueous media.  相似文献   

6.
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   

7.
Dyes are a potential menace and are considered major contributors to environmental pollution. However, the cleanliness of the environment from colored toxicants is a challenging task of the contemporary era. In this regard, this approach is based on the confiscation of hazardous dyes. The main features of this work are the synthesis and the application of newly synthesized calix[4]arene grafted Amberlite XAD-4 (resin 5) for the selected methyl orange (MO) and methyl red (MR) azo dyes removal from aqueous environment. The adsorption ability of resin 5 for the selected azo dyes was evaluated through optimizing various parameters. Moreover, treatment with real water samples reveal that newly synthesized resin is an extremely effective adsorbent for the removal of the selected azo dyes from aqueous media.  相似文献   

8.
This work reports a new method to covalently attach calix[4]arene derivatives onto MCM-41, using a diisocyanate as a linker. The modified mesoporous silicates were characterized by fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by X-ray diffraction and nitrogen adsorption analysis.  相似文献   

9.
以对叔丁基苯酚和甲醛为原料,分别对对叔丁基杯[4]及杯[6]芳烃的合成和萃取性质进行了研究.结果表明,在本研究范围内,以KOH为催化剂,对叔丁基杯[6]芳烃的最高产率为77.8%;以NaOH为催化剂,对叔丁基杯[4]芳烃的最高产率为47.3%。对于对叔丁基杯[4]和杯[6]芳烃,最佳的反应回流温度都为140℃。对叔丁基杯[6]芳烃对模拟废水中的铜离子具有一定的萃取效果,最高萃取率为70.3%。  相似文献   

10.
以杯[4]芳烃为起始原料,首先制得中间体杯[4]芳烃双溴代烷基衍生物,然后经微波辐射和阴离子交换,共得9种杯[4]芳烃咪唑盐衍生物,化合物的结构与构象经元素分析、IR、1HNMR、19FNMR、31PNMR表征.研究了它们在对氯硝基苯氟化反应中的催化性能以及对K+的萃取性能.结果表明,这9种化合物在氟化反应中的催化效果良好,对氟硝基苯的收率为80.89%~92.67%;同时化合物对K+具有较好的萃取效果,其中以化合物25,27-二[4-(3-甲基咪唑)乙氧基]-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃六氟磷酸盐的萃取效果最好,萃取率可达75.45%.  相似文献   

11.
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   

12.
《分离科学与技术》2012,47(7):1113-1120
The present study describes the sorption of fluoride on a potential and newly synthesized p-tetraaminocalix[4]arene based resin (p-TAC4 resin). The p-TAC4 resin was synthesized via immobilization of p-tetranitrocalix[4]arene (p-TNC4) onto the Merrifield resin followed by catalytic reduction with SnCl2/EtOH/HCl. The p-TNC4 and p-TAC4 resins were characterized using FT-IR, elemental analysis, and scanning electron microscopy (SEM). Fluoride removal capability from the aqueous media of the p-TAC4 resin has been evaluated through batch sorption study. The effect of pH, sorbate concentration, sorbent dosage, and contact time on fluoride removal was evaluated. The Langmuir (L), Freundlich (F), and Dubinin–Radushkevich (D-R) isotherms revealed that the fluoride on p-TAC4 resin follows physiosorption mechanism. All the results support and emphasize that the p-TAC4 resin is an effective sorbent for the removal of fluoride from the aqueous environment at a wide range of pH. The study may confer its impact on human health, reinstate polluted sites and other fields such as analytical, clinical, as well as material sciences.  相似文献   

13.
本论文主要以自制氮杂杯[6]芳烃和迭氮化钠为原料,合成氮杂杯[6]芳烃迭氮化衍生物。通过红外光谱分析法和核磁共振氢谱法对产物进行了表征,证实其为目标产物,从而验证了合成路线的可行性。  相似文献   

14.
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   

15.
相转移催化合成四乙酰氧基对叔丁基杯[4]芳烃   总被引:1,自引:0,他引:1  
史春越  范平  姜薇 《辽宁化工》2005,34(3):106-107
以聚乙二醇(PEG)600为相转移催化剂合成四乙酰氧基对叔丁基杯[4]芳烃。实验结果表明:当对叔丁基杯[4]芳烃1.0g,乙酸酐9mL,0.0224g浓98%H2SO4(质量分数)和0.4gPEG600,回流反应20min,产率达到75.1%。  相似文献   

16.
Self-assembly by H-bonding and by metal-coordination of functionalized calix[4]arenes and cavitands to large supramolecular capsules is described. In addition, a new method of analyzing supramolecular recognition processes at the single molecule level is discussed. By measuring interaction forces in a hydrogen-bonded assembly using single-molecule force spectroscopy (SMFS), the dynamics of the self-assembly process can be evaluated. In the future, consequent application of this new technique will influence supramolecular design principles and the use of non-covalent interactions as construction elements in the field of nanotechnology.  相似文献   

17.
Poorly water-soluble calix[4]resorcinarenes modified with amino acid (Ala, Val) at the upper rim formed a water-soluble mixed system with micelles of monocationic surfactants cetyltrimethylammonium bromide, cetyldimethyl(2-hydroxyethyl)ammonium bromide, and dicationic (gemini) surfactants, alkanediyl-α,ω-bis(dimethyltetradecylammonium bromides (14-s-14, where s = 2, 4, or 6). UV–Vis and DLS methods demonstrated that the micellar systems of surfactant/functionalized calix[4]resorcinarene underwent structural changes within a relatively narrow concentration range followed by changes in solubilization capacity and polydispersity. Gemini surfactants and monocationic/gemini mixed surfactant systems were provided selectivity in their interaction with calix[4]resorcinarene depending on the bulkiness of the substituent at the upper rim of calix[4]resorcinarene, gemini surfactant spacer length, and mixed micelles. These systems represent a direction to create biocompatible water-soluble functionalized calix[4]resorcinarene composition and may open perspectives in designing organized systems with controllable properties.  相似文献   

18.
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   

19.
以4-(N,N-二乙氧酰甲基)氨基苯甲醛和邻苯二胺为原料,首先得到了2-[4-N,N-二(乙氧酰甲基)氨基苯基]-1H-苯并咪唑。再将得到的苯并咪唑与5,11,17,23-四叔丁基-26,28-二羟基-25,27-二丁氧基杯[4]芳烃反应,合成了含氨基乙酸酯苯并咪唑杯[4]芳烃荧光分子探针L,并采用红外和核磁对所合成的化合物进行了结构表征和确认。通过紫外和荧光光谱实验研究表明,探针L在甲醇溶液中对Al3+具有选择性识别性能,且不受其他金属离子的干扰;当Al3+物质的量浓度增加到探针浓度的5倍时,探针L的荧光强度降低到最低值。Job's曲线确定了探针与Al3+之间形成物质的量比为1∶1的金属配合物。  相似文献   

20.
《分离科学与技术》2012,47(12):1655-1667
Abstract

The rate of complex formation between calix[6]arene-p-hexasulfonate and uranyl ion is studied over a wide range of carbonate ion concentrations. The presence of carbonate ion decreases the complexation rate. The distribution of various uranyl species is calculated from a set of mass balances of participating ions with their stability constants. UO2(CO3)3 4? has the highest concentration, followed by UO2(OH)3 ? and UO2(CO3)2 2?. Other uranyl species are negligible. The complexation rate is proportional to the 0.27–1.0 power of the total concentration of uranyl species other than UO2(CO3)3 4?. This implies that the rate-determining step of the complexation is the reaction between calix[6]arene-p-hexasulfonate and UO2(OH)3 ? or UO2(CO3)2 2?.  相似文献   

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