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1.
A new C-linked peptidocalix[4]arene functionalized with four l-alanine and dansyl units at the upper rim has been prepared, which exhibited highly selective recognition towards F along with weaker complexation to AcO and H2PO4 and no complexation to Cl, Br, I, and HSO4 by fluorescence spectroscopy and 1H NMR method.  相似文献   

2.
Calix[4]arene 3, which contains two distal triazole groups on the lower rim and two distal o-methoxyphenylazo groups on the upper rim, was synthesized and found to be a specific and ratiometric sensor for Hg2+ in a polar protic solvent. A series of o-methoxyphenylazo derivatives (3, 4, 5, 7, and 9) were synthesized, which proved that the lower-rim triazoles and the hydroxyl azophenol(s) were the major ligands for metal ion binding. Though analogues 4 and 10 showed some sensitivity for Hg2+, compound 3 was the only ratiometric chemosensor for Hg2+ among the series of azocalix[4]arenes synthesized in this work. The formation of 3·Hg2+ complex was supported by UV/vis and NMR titration studies and Mass spectrometry. Based on the symmetrical features of NMR spectra of 3·Hg2+, the complex is believed to be symmetrical with respect to the calix[4]arene cavity. Furthermore, the complex was determined to be 1:1 binding stoichiometry by Job’s plot, and the association constant was determined to be 4.02×103 M−1 using Benesi-Hildebrand plot.  相似文献   

3.
A novel calix[4]arene derivative with pyrene fluorophores at the upper rim and tetraester ionophores at the lower rim was synthesized in six steps,and its structure was proved by NMR and ESI-MS spectro-scopies. Furthermore,the chemosensing behavior of the host compound for alkali and alkaline earth metal ions was investigated by fluorescence spectroscopy. The obtained results show that the calix-arene host can selectively bind sodium ion with the complexation stability constant of 2190 mol-1.L. The complexa...  相似文献   

4.
A new fluorogenic calix[4]arene containing one pendent N-dansylcarboxamide group has been synthesized. The ligand demonstrates selective optical recognition of Tl+ and Hg2+ in solvent extraction from aqueous solutions with high content of Na+. Complexation of Tl+ and Hg2+ produces contrasting changes in the fluorescence spectrum of this sensor. Partial cone is the dominant calixarene conformation in the complex with Tl+.  相似文献   

5.
A new thiacalix[4]arene based fluorescent sensor 1 bearing two naphthyl groups has been synthesized in 1,3-alternate conformation. In the absence of fluoride ion, the receptor 1 is in ‘off-state’ showing no fluorescence emission. The presence of fluoride ion triggered the fluorescence emission to ‘on-state’. The receptor shows pronounced selectivity for fluoride ions. In THF, the presence of F ions induces the formation of a 1:1 (G:H) complex.  相似文献   

6.
A novel calix[4]arene derivative with pyrene fluorophores at the upper rim and tetraester ionophores at the lower rim was synthesized in six steps, and its structure was proved by NMR and ESI-MS spectroscopies. Furthermore, the chemosensing behavior of the host compound for alkali and alkaline earth metal ions was investigated by fluorescence spectroscopy. The obtained results show that the calixarene host can selectively bind sodium ion with the complexation stability constant of 2190 mol−1·L. The complexation with sodium ion can pronouncedly induce the excimer emission to decrease and the monomer emission to increase, whereas the addition of the other alkali and alkaline earth metal ions does not cause appreciable changes in the fluorescence spectrum of the host compound. The present calix[4]arene derivative displays potential application as fluorescent chemosensor for sodium ion. Supported by the National Natural Science Foundation of China (Grant Nos. 20421202, 20673061 & 20703025) and the 111 Project (Grant No. B06005)  相似文献   

7.
An 2-aminopyridyl-bridged calix[6]arene on the upper rim fixed in cone conformation (3) was successfully synthesized and its highly selective recognition towards fluoride ion was proved by fluorescent and 1H NMR titration experiments.  相似文献   

8.
《Tetrahedron letters》2014,55(51):7094-7098
A new thiacalix[4]arene based fluorescent chemosensor thiacalix[4]arene-N-(quinolin-8-yl)acetamide (TCAN8QA) has been synthesized. TCAN8QA has been found to exhibit highly selective behavior for F ions among all other anions, that is, Cl, Br, I, PO4−3, OH, H2PO4, and CH3COO in the absorption spectra as well as in the emission spectra. Red shift and quenching in emission spectra constituting the signature for fluoride detection are due to photoinduced charge transfer (PCT) which can be attributed to deprotonation of acidic NH proton in the presence of fluoride ions.  相似文献   

9.
A novel bridged fluorescent calix[4]arene with 1,8-diaminoanthracene and glycine at the upper rim has been prepared, which exhibited selective recognition towards AcO over other anions such as F, Cl, Br, , , I and by fluorescence spectroscopy and 1H NMR method.  相似文献   

10.
Novel anthraquinone-modified calix[4]arene was synthesized by click chemistry and exhibited selective fluorescent enhancement in the presence of Ca2+, which is attributed to photo-induced electron-transfer effect from the 1,2,3-triazole ring. The enhanced fluorescence was further quenched by F ion. Thus, the potential Ca2+ and F ion switched INHIBIT logic gate has been constructed.  相似文献   

11.
The present study describes the Pb2+ sorption potential of newly synthesized tetraester calix[4]arene (TC4) based resin from aqueous media. The TC4 resin was synthesized through diazotization reaction of TC4 with Amberlite XAD-4 in the presence of sodium nitrite in acidic medium. The TC4 resin was characterized by using different analytical techniques such as FT-IR, elemental analysis and scanning electron microscopy (SEM). The Pb2+ removal ability of the resin from the aqueous environment has been evaluated by both batch adsorption as well as column studies. The experiments have been conducted involving the determination of effect of pH, adsorbate concentration, adsorbent dosage, contact time and temperature. Moreover, on the basis of kinetic studies, the pseudo-first-order and pseudo-second-order adsorption kinetics were calculated. The thermodynamic parameters of lead adsorption were also calculated. Equation isotherms such as Langmuir (L), Freundlich (F), and Dubinin-Radushkevich (D-R) were successfully used to model the experimental data. From the D-R isotherm parameters, it was considered that the uptake of Pb2+ by TC4 resin is ion exchange mechanism. From the results it has been found that the TC4 resin is a versatile adsorbent for the removal of Pb2+ from the aqueous environment. The study also confers its impact on human health, reinstate of polluted sites and other fields of material science.  相似文献   

12.
Arisa Jaiyu 《Tetrahedron letters》2007,48(10):1817-1821
A series of stilbene-bridged calix[4]arenes was synthesized through an intramolecular reductive McMurry coupling of bisbenzaldehyde calix[4]arene in high yields. Tetra- and pentaethylene glycol chains were tethered to the phenolic groups of calix[4]arene to form stilbene-bridged calix[4]arene crown-5 and crown-6, respectively. The presence of stilbene bridge over the calix[4]arene rim effectively prevented the connection of the polyether chains in the cone conformation resulting in the exclusive formation of 1,3-alternate stilbene-bridged calix[4]arene crown product. Compared to the cone analogues, the 1,3-alternate calix[4]arene crown ethers showed a greater extraction ability and selectivity toward Cs+.  相似文献   

13.
A new phenanthrene-based fluorescent calix[4]arene (4) has been synthesized in cone conformation. This compound was examined for its fluorescent properties towards different metal ions (Na+, Li+, Mg2+, Ni2+, Ba2+, Ca2+, Cu2+, Pb2+) and anions (F, Cl, Br, H24PO,H2PO4,3NO,NO3,4HSO,HSO4, CH3COO) by fluorescence spectroscopy. The properties of the compound were evaluated and show that it is a fluorescence sensor for Cu2+ and F. With the addition of Cu2+ and F, the fluorescence was severely quenched.  相似文献   

14.
A PVC membrane electrode for Hg(II) ions, based on a new cone shaped calix[4]arene (L) as a suitable ionophore was constructed. The sensor exhibits a linear dynamic in the range of 1.0 × 10?6–1.0 × 10?1 M, with a Nernstian slope of 29.4 ± 0.4 mV decade?1, and a detection limit of 4.0 × 10?7 M. The response time is quick (less than 10 s), it can be used in the pH range of 1.5–4, and the electrode response and selectivity remained almost unchanged for about 2 months. The sensor revealed comparatively good selectivity with respect to most alkali, alkaline earth, and some transition and heavy metal ions. It was successfully employed as an indicator electrode in the potentiometric titration of Hg2+ ions with potassium iodide, and the direct determination of mercury content of amalgam alloy and water samples.  相似文献   

15.
New fluorescent chemosensors 1,3-alternate-1 and 2 with pyrenyl-appended triazole-based on thiacalix[4]arene were synthesized. The fluorescence spectra changes suggested that chemosensors 1 and 2 are highly selective for Ag+ over other metal ions by enhancing the monomer emission of pyrene in neutral solution. However, other heavy metal ions, such as Cu2+, and Hg2+ quench both the monomer and excimer emission of pyrene acutely. The 1H NMR results indicated that Ag+ can be selectively recognized by the triazole moieties on the receptors 1 and 2 together with the ionophoricity cavity formed by the two inverted benzene rings and sulfur atoms of the thiacalix[4]arene.  相似文献   

16.
A novel tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu2Pc4) (5) has been synthesized by the reaction of dimeric lutetium(III) phthalocyanine (4) with two equiv. of dilithium octakis hexylthiophthalocyanine in amyl alcohol. The phthalonitrile derivative 1 was obtained through the displacement reaction of 4-nitrophthalonitrile with 1,3-dimethoxy-4-tert-butylcalix[4]arene and was converted to the isoindoline derivative 2 by bubbling ammonia gas in dry MeOH. Compound 4 was prepared from 2, 4,5-bis(hexylthio)-1,2-diiminoisoindoline (3), and lutetium acetate in dry DMF. The new compounds and phthalocyanines were characterized by elemental analysis, IR, UV–Vis, 1H NMR, ESR and MALDI-TOF MS spectra. The electrochemical properties of 4 and 5 have been examined by cyclic voltammetry, and compared. Distinctive differences between the voltammetric behaviour of 4 and 5 were detected. These differences were compatible with the structures of the compounds. A detailed study of the effect of temperature on the d.c. conductivity and impedance spectra (40–105 Hz) of spin coated films of 4 and 5 at temperatures between 290 K and 420 K was carried out. By analyzing the d.c. electrical behaviour of the 5 film, it was found that the experimental data are described by a thermally activated conductivity dependence on temperature with an activation energy of 0.77 eV. The a.c. results give a power law behaviour, σa.c. = A(T)ωs, in which the frequency exponent s decreases with temperature. The sensing behaviour of the film for the online detection of volatile organic solvent vapors was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the target molecules on the coating surface cause a reversible negative frequency shift of the resonator. Thus, a variety of solvent vapors can be detected by using the 5 film as sensitive coating, with sensitivity in the ppm and response times in the order of several seconds depending on the dipole moment of the organic solvent.  相似文献   

17.
Abstract

A new series of water-compatible proline catalysts (4–6) derived from calixarene bearing a hydrophobic nature have been synthesised. It was found that the compound 4 was a highly efficient organocatalyst for aldol reactions occurred in the water. Under optimised reaction conditions, high yields (up to 82%), good enantioselectivities (ee up to 81%) and high diastereoselectivities (dr up to 91:9) were obtained.  相似文献   

18.
We report a new direct route for the selective preparation of novel partial cone O-aryl ether calix[4]arenes to be used as new platforms for the preparation of non-aggregated dyes. These partial cone conformers have the aromatic substituents lying within the calix[4]arene annulus via the upper rim.  相似文献   

19.
Lu J  He X  Zeng X  Wan Q  Zhang Z 《Talanta》2003,59(3):553-560
A novel calix[4]arene derivative containing benzothiazole group was coated on glassy carbon electrode (GCE) and then applied to the recognition of mercury ion. Cyclic and square wave voltammetric results showed that the modified electrode selectively recognizes Hg2+ ion in aqueous media. A new anodic stripping peak at −0.3 V (vs. Ag/Ag+) can be obtained by scanning the potential from −0.6 to 0.6 V, and the peak currents are proportional to the Hg2+ concentration. The modified electrode in a 0.1 M H2SO4+0.01 M NaCl solution shows linear voltammetric response in the range of 25-300 μg l−1 and detection limit of 5 μg l−1 (ca. 2.5×10−8 M). This modified GCE does not present any significant interference from alkali, alkaline and transition metal ions except for Pb2+, Ag+ and Cu2+ ions. Only 500, 50 and 100-fold molar excess of Pb2+, Ag+ and Cu2+ ions, respectively, can lead to voltammetric response comparable with that of Hg2+. The proposed method was successfully applied to determine mercury in natural water.  相似文献   

20.
Yang X  Wang K  Xiao D  Guo C  Xu Y 《Talanta》2000,52(6):23-1039
A fluorescent optode membrane for sodium ion that works on the basis of a cation-exchange mechanism has been developed. The plasticized poly(vinyl chloride) (PVC) membrane incorporating sodium-selective ionophore (4-tert-butylcalix[4]arene tetraacetic acid tetraethyl ester), acidic fluorescent pH indicator (5,10,15,20-tetraphenylporphine, TPP) and a lipophilic anionic site (potassium tetrakis(4-chlorophenyl)borate) was used as the sensing device, which exhibits the theoretically expected fluorescent response to sodium ion. The selectivity, response time, reproducibility and lifetime of the optode membrane were discussed.  相似文献   

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