The article describes the synthesis and evaluation of the dichromate anion (Cr2O72−/HCr2O7−) extraction properties of p-tert-butylcalix[4]arene diamide derivatives (5-7) containing different binding sites. Among these compounds, 6 and 7 have been synthesized via aminolysis in a toluene-methanol solvent system with 3-aminomethylpyridine and 3,6-dioxa-1,8-diamino octane, respectively. On the other hand, compound 5 has been synthesized via an acid chloride method due to its inefficiency under aminolysis. The extraction properties of these diamides toward dichromate anions are studied by liquid-liquid extraction. The results show that p-tert-butylcalix[4]arene diamide derivative 7 exhibited a much higher affinity toward dichromate anions than that of 6 due to its special structure, while 5 was an ineffective ligand for these anions. 相似文献
A series of novel bisthiacalix[4]arenes with diimine linkages of different aromatic or heteroaromatic dialdehydes have been synthesized. The structure of one of the bisthiacalixarene has been analyzed by X-ray crystallography. These molecules quantitatively extract silver ion from aqueous into organic phase under neutral conditions. 相似文献
Five novel azo calix[4]arenes were reported. The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution. Mono-, bis-, tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene(1) under pH=7.5--8.5 at 0-5℃. All (p-formylphenyl)azo calix[4]arenes were characterized by ^1H NMR, ^13C NMR, IR, MS (ESIMS) spectroscopies and elemental analysis. 相似文献
A novel series of N-alkylphthalimidylaminocarbonylmethoxylcalix[4]arenes with the reaction between 4-(N-bromoacetyla- mino)-phthalimide derivatives and calix[4]arene has been synthesized and structurally characterized by IR,~1HNMR and MS.From their analysis data,it was found that compounds 7a-7d adopted a cone conformation. 相似文献
Two novel carboxylphenyl-modified calix[4]arenes, tetrakis-carboxylphenylcalix[4]arene (TCPC) and 1,3-bis-carboxylphenylcalix[4]arene (BCPC), as well as a corresponding analogue for comparison, tetrakis-phenylcalix[4]arene (TPC), have been synthesized by palladium-catalyzed Suzuki cross-coupling of arylboronic acid and tetrabromocalix[4]arene as a key step. The binding properties of these calix[4]arene derivatives with bovine heart cytochrome c (cyt c) in dimethylformamide (DMF) was investigated by fluorescence spectroscopy. The binding affinity in the order of TCPC > BCPC ? TPC reflects a clear dependence on the number of carboxyl ligating groups attached onto a receptor and suggests the electrostatic force may be the predominant factor driving the complexing process. The stable 1:1 complexes of TCPC and BCPC with cyt c were evidenced with the binding constants of 3.15 × 106 and 5.85 × 105 L mol−1, respectively. Due to a large overlap between the emission spectrum of TCPC and the absorption spectrum of cyt c, and a short interaction distance (estimated to be 5.6 nm) between them, the fluorescence quenching of TCPC upon complexation with cyt c is attributed to an efficient energy transfer. 相似文献
Bromocalix[4]arene methyl ether serves as a precursor in the synthesis of the title thiocalixarene via the reagent CuSEt. Ethylthiocalix[4]arene methyl ether crystallizes in the monoclinic space groupP21/c witha = 20.577(9),b, = 10.722(5),c = 20.315(9) Å, = 120.46(4)°, andDc = 1.24 g cm–3 forZ = 4. Refinement based on 1441 observed reflections led toR = 0.080. The configuration of the calixarene lies between the partial cone and the 1,3-altemate conformations. Bromocalix[4]arene methyl ether crystallizes in the triclinic space groupPI witha = 12.283(7),b = 17.658(9),c = 18.118(6) Å, = 90.25(6), = 105.95(4), = 105.11(6)°, andDc = 1.68 g cm–3 forZ = 4. Refinement based on 3028 observed reflections led toR = 0.083. The unit cell also contains four CHCl3 molecules which exist pairwise enclathrated by six calixarenes. The partial cone conformation of the bromocalixarene is identical to that of ethylthiocalix[4]arene methyl ether. 相似文献
A doubly-crowned calix and a double-calixcrown derived from 4,6,10,12,16,18,22,24,25,26,27, 28-dodecamethyl-5,11,17, 23-tetrahydroxycalix[4]arene (1) have been prepared by reaction of appropriate oligoethylene glycol ditosylates with (1) in acetonitrile in the presence of potassium carbonate. A potassium template effect is observed during one of the double cyclizations. 相似文献
New boronoalkoxycalix[4]arenes were synthesized by allylation, alkylation, hydroboration and hydrolysis of 25,26,27,28-tetrahydroxycalix[4]arene, and identified by elemental analysis, IR, 1H NMR, 13C NMR, 11B NMR, MS and UV spectra. The data of UV and fluorescence spectra showed that tctrapropoxycalix-[4]arene triboronic acid could coordinate significantly with monosaccharides. 相似文献
p-tert-Butylcalix[4]arene-based dipodal receptor has been synthesized in cone conformation. The binding affinity of this receptor was evaluated with some aliphatic diacetates such as malonate, succinate, glutarate, adipate, pimelate, and suberate in CH3CN. The receptor has the highest binding affinity for pimelate by making a 1:1 complex. This receptor was used to estimate pimelate in the presence of other dicarboxylates. 相似文献
p-tert-Butylcalix[8]arene bonded capillaries for open-tubular capillary electrochromatography were prepared with γ-glycidoxypropyltrimethoxysilane as a bridge. The bonded capillary displayed low and steady electroosmotic flow (EOF) values over the pH range from 4 to 9. Detection limits for direct spectrophotometric detection at 277 nm for benzenediols (at a signal to noise ratio of 2) were 0.96 mg l−1 for the unbonded capillary and 1.48 mg l−1 for the bonded capillary, showing that the bonded layer did not show significant absorbance and hence decreased sensitivity. The bonded capillaries showed good separation selectivity for o-, m- and p-benzenediols, α- and β-naphthols, and α- and β-naphthylamines. This selectivity was attributed to significant interactions between the analytes and the bonded p-tert-butylcalix[8]arene, which contributed to the electrochromatographic separation mechanism. The bonded capillaries gave high stability and reproducibility. 相似文献
The first single crystal X-ray analysis of the heterodimer of tetraaryl- and tetratosylurea calix[4]arenes was reported, which revealed the real pattern of the hydrogen bonds. Moreover, the heterodimer showed good encapsulation abilities for some organic molecules in CDCl3. 相似文献
A series of new calix[4]phenols, calix[4]resorcinols and calix[4]pyrogallols with acetylhydrazide substitutes has been␣synthesized
with high yields by hydrazinolysis of ester group containing calix[4]arenes. The synthesized calix[4]phenols adopt the cone
conformation while the calix[4]resorcinol and calix[4]pyrogallol derivatives prefer the boat conformation. The amide fragment
of the hydrazide groups predominantly exists in the trans-conformation. The binding ability of synthesized calix[4]arenes toward transition and alkali metals by solvent extraction
has been investigated. 相似文献
The versatility of cationic cyclopentadienyliron complexes is demonstrated for the generation of calix[4]arene‐based dendrimers and polymers. Dendrimers were prepared from a branched organoiron calix[4]arene through subsequent reactions of azo dyes and organoiron complexes. The resulting azo dye‐containing metallocalix[4]arenes were soluble in polar organic solvents and displayed λmax ranging between 430 and 456 nm. Upon addition of various acids, the λmax shifted to higher wavelengths (513–535 nm). In the solid state and in solution, the azo dye‐containing metallocalix[4]arenes reversibly changed colour in the presence of acid and base, indicating their potential use as acid sensors. Cyclic voltammetric studies showed that the iron centres of the metallocalix[4]arenes were reversibly reduced at E1/2 = −1.49 V. When non‐branching organoiron‐based calix[4]arene were reacted with dithiols, polymers containing calix[4]arenes either in their side chains or main chains were obtained. The polymers possessed weight average molecular weights between 35 000 and 53 000. The polymers were determined to be thermally stable with backbone decomposition occurring above 500 °C.
The inhibitory effect of 1,3-substituted p-tert-butylcalix[4]arenes on butyrylcholinesterase from horse serum has been discovered and kinetically investigated with photometric microassay techniques. The interaction of calix[4]arene with the enzyme is described in accordance with the formal kinetics of competitive reversible inhibition. The inhibition constants calculated depend on the substituent in the lower rim of the calix[4]arene and vary in the range of (5–110) × 10-6 M. The proposed mechanism of inhibition involves the cooperative interaction of indophenyl acetate used as a substrate, calix[4]arene and the enzyme without any covalent or electrostatic binding of the functional groups in the active site of cholinesterase. This results in the coordination of the calixarene on the enzyme surface in the proximity of the enzyme active site. Such interaction prevents the substrate from entering the enzyme active site. 相似文献
We describe the condensation of an appropriate tetraaldehyde derivative of mesitol calix[4]arene with 1,n-diaminoalkanes to afford double Schiff-base calix[4]arene receptors in the 1,3-alternate conformation. 相似文献
Calixarenes are a versatile class of macrocyclic compounds which have attracted extensive interest due to their ability to form host-guest complexes and act as enzyme mimic, especially when appropriately functionalized1. Introduction of azo group to calixarenes can make the later to be easily detected in the process of molecular recognition, azo groups have been introduced into calixarenes by the diazo-coupling reaction of calix[4]arene with BF4- or chloride salt of substituted benzene diazon… 相似文献
New p-tert-butylthiacalix[4]arenes with several different substituents at the lower rim have been synthesised. A method for the selective introduction of one or two guanidinium fragments into the structure of p-tert-butylthiacalix[4]arenes has been developed. The 1,3-alternate thiacalix[4]arenes containing guanidinium groups interact with silver nitrate and oxalic acid in methanol with a logKassoc of about 3.5 and 1:1 stoichiometry, while the macrocycle in the cone conformation interacts with oxalic acid with logKassoc of 7.4 and 2:1 stoichiometry. The new p-tert-butylthiacalix[4]arenes form nanoscale aggregates with hydrodynamic radii of about 70 nm by self-association and by mediation with silver cations and oxalic acid. 相似文献
The π-A isotherms and UV-vis spectra of the transferred films suggested that the monolayer of p-tert-butylthiacalix[4]arene can coordinate with Hg2+ at the air-water surface. From these observations, a glassy carbon electrode coated with Langmuir-Blodgett film of p-tert-butylthiacalix[4] arene as a new voltammetric sensor is designed for the determination of trace amounts of Hg2+. Compared with bare glassy carbon electrode and modified glassy carbon electrode using direct coating method, the Langmuir-Blodgett film-modified electrode can greatly improve the measuring sensitivity of Hg2+. Under the selected conditions, the Langmuir-Blodgett film-modified electrode in 0.1 mol L−1 H2SO4 + 0.01 mol L−1 KCl solution shows a linear voltammetric response for Hg2+ in the range of 5.0 × 10−10 to 1.5 × 10−7 mol L−1, with a detection limit of 2.0 × 10−10 mol L−1. The proposed method was also applied to determine Hg2+ in water samples (tap, lake and river water). In addition, the fabricated electrode exhibited a distinct advantage of simple preparation, non-toxicity, good reproducibility and good stability. 相似文献