共查询到20条相似文献,搜索用时 15 毫秒
1.
Demet Kuruo?lu Esin Canel Shahabuddin Memon Mustafa Yilmaz Esma Kili? 《Analytical sciences》2003,19(2):217-221
A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.0 +/- 0.2 mV/pH at 20 +/- degrees C. This electrode showed a rapid response of the emf to changes in the pH, high ion selectivity with respect to lithium, sodium and potassium, and characteristics similar to those reported for the conventional pH glass membrane electrode. It can be used as a potentiometric indicator electrode in hydrofluoric acid solutions. The effects of iodide, thiocyanate, perchlorate and bromide on the characteristics of the electrode were also considered. 相似文献
2.
A new ligand capable of producing calcium-selective electrodes with excellent characteristics is presented. The ligand (1) is a calix[4]arene bearing phosphine oxide ligating groups on the lower rim and this is the first report that such ligands can discriminate in favour of calcium ions against magnesium ions and the alkali metal ions. This calcium selectivity is in complete contrast to the behaviour of the well-known calix[4]arene tetraester derivatives (such as 2) which are selective for sodium against other alkali metal ions and group II ions. Electrodes based on PVC membranes incorporating ligand 1 display almost nernstian slopes and excellent selectivity against common interferants, including magnesium (log K(Ca,Mg)(pot)). The electrodes have demonstrated effective lifetimes of at least 7 weeks (duration of the study) and very fast response times. 相似文献
3.
Mohammad Mazloum Ardakani Ali Asghar Ensafi Mohammad Salavati Niasari Hossain Mirhoseini 《Analytical sciences》2003,19(8):1187-1190
The performance of octahydroxycalix[4]arene derivative used as a neutral carrier for silver polymeric membrane electrode was studied. The sensor gave a good Nernstian response of 58 +/- 1 mV per decade for silver ion in the activity range 3.3 x 10(-6) to 3.3 x 10(-2) M Ag+. The limit of detection reached 2.1 x 10(-6) M Ag+ and exhibited high selectivity for silver ion against the alkali, alkaline earth and transition metal ions. The sensor can be used in wide pH range from 1.5 to 6.5. The response time of the sensor is less than 20 s. The potentiometric sensor was used as the indicator electrode in the titration of Ag+ ions by sodium chloride solution. 相似文献
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5.
Rakesh Kumar Mahajan Ravneet Kaur Inderpreet Kaur Vandana Sharma Manoj Kumar 《Analytical sciences》2004,20(5):811-814
A PVC membrane incorporating p-tert-butyl calix[4]crown with imine units as an ionophore was prepared and used in an ion-selective electrode for the determination of mercury(II) ions. An electrode based on this ionophore showed a good potentiometric response for mercury(II) ions over a wide concentration range of 5.0 x 10(-5) - 1.0 x 10(-1) M with a near-Nernstian slope of 27.3 mV per decade. The detection limit of the electrode was 2.24 x 10(-5) M and the electrode worked well in the pH range of 1.3 - 4.0. The electrode showed a short response time of less than 20 s. The electrode also showed better selectivity for mercury(II) ions over many of the alkali (Na+, -1.69; K+, -1.54), alkaline-earth (Ca2+, -3.30; Ba2+, -3.32), and heavy metal ions (Co2+, -3.67; Ni2+, -3.43; Pb2+, -3.31; Fe3+, -1.82). Ag+ ion was found to be the strongest interfering ion. Also, sharp end points were obtained when the sensor was used as an indicator electrode for the potentiometric titration of mercury(II) ions with iodide and dichromate ions. 相似文献
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7.
Morteza Hosseini Mohammad Rahimi Hayedeh Bagheri Sadeghi Saeed Taghvaei-Ganjali Shiva Dehghan Abkenar Mohammad Reza Ganjali 《International journal of environmental analytical chemistry》2013,93(6):407-422
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
8.
A PVC membrane electrode for silver(I) ion based on Schiff base-p-tert-butylcalix[4]arene is reported. The electrode works well over a wide range of concentration (1.0 x 10(-5)-1.0 x 10(-1) mol dm-3) with a Nernstian slope of 59.7 mV per decade. The electrode shows a fast response time of 20 s and operates in the pH range 1.0-5.6. The sensor can be used for more than 6 months without any divergence in the potential. The selectivity of the electrode was studied and it was found that the electrode exhibits good selectivity for silver ion over some alkali, alkaline earth and transition metal ions. The silver ion-selective electrode was used as an indicator electrode for the potentiometric titration of silver ion in solution using a standard solution of sodium chloride; a sharp potential change occurs at the end-point. The applicability of the sensor to silver(I) ion measurement in water samples spiked with silver nitrate is illustrated. 相似文献
9.
5,11,17,23,29,35-Hexakis(1,1,3,3-tetramethylbutyl)-37,38,39,40,41,42-hexakis(carboxy methoxy)calix[6]arene (I) has been evaluated as an ionophore for the analysis of Sr2+. The influences of the nature of the plasticizers (DBA, CN, DOP, NPOE) and of the anion excluder (NaTPB) on the characteristics of the electrode were discussed. The best electrode was fabricated with a membrane having composition 6:150:170:3 (I:PVC:DBA:NaTPB). The response to Sr2+ was Nernstian in the range 1.9 x 10(-5) to 1.0 x 10(-1) M of Sr2+. The influence of pH has also been studied. The electrode exhibited better potential stability and had an operational lifetime of 4 months. The K(A,B)(Pot) values showed that other alkaline earth metal ions are well discriminated. The sensor has also been used as an indicator electrode in the potentiometric titration of sodium carbonate with strontium(II) ions. 相似文献
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11.
Ozcan Kocyigit Serkan Erdemir Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2012,72(1-2):137-147
This study contains the synthesis of silica gel-immobilized calix[4]arene derivative (TR-CL[4]P) as a new sorbent and its sorption studies towards Cu (II) ion in aqueous solution. The aldehyde pointed calix[4]arene derivative 5 was synthesized and then it was immobilized onto 3-aminopropilsilica gel (APS). In batch sorption experiments, the experimental results showed that TR-CL[4]P is effective sorbent towards Cu (II) ion. Therefore, the effect of solution pH, sorption time, temperature and initial metal ion concentration onto Cu (II) sorption was investigated. Maximum Cu(II) removal was obtained at 30?°C, 30?min and pH 6.0 for TR-CL[4]P and the batch sorption capacity was found as 17.8?mg/g. The characteristics of the sorption process for Cu (II) ion were evaluated by using the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) adsorption isotherms. Also, thermodynamic parameters, i.e., ΔG, ΔS, and ΔH were calculated for the system. 相似文献
12.
Anion complexation. A ditriphenylphosphonium calix[4]arene derivative as a novel receptor for anions
A novel anionic receptor 2 consisting of a calix[4]arene bearing two alkytriphenylphosphonium has been prepared by two different procedures. The complexation occurred at the phosphonium sites probably due to electrostatic and/or π-anion forces. 相似文献
13.
A novel calix[4]arene derivative locked in the 1,3-alternate conformation (2) bearing two pyrene and rhodamine fluorophores was synthesized as a selective sensor for the Hg(2+) ion. The sensoring is based on FRET from pyrene excimer emissions to ring-opened rhodamine absorption upon complexation of the Hg(2+) ion. Addition of Hg(2+) to a mixed solution of 2 gave significantly enhanced fluorescence at ~576 nm via FRET with excitation at 343 nm. We also found that the pyrene excimer emissions formed by the intramolecular π-π interactions are more effective in obtaining strong FRET bands than those by intermolecular π-π interactions. 相似文献
14.
Mercedes Vázquez Johan Bobacka Minna Luostarinen Kari Rissanen Andrzej Lewenstam Ari Ivaska 《Journal of Solid State Electrochemistry》2005,9(5):312-319
Potentiometric ion sensors have been prepared by galvanostatic electrosynthesis of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with p-sulfonated calix[4]arene (C[4]S) and p-methylsulfonated calix[4]resorcarenes (Rn[4]S) with alkyl substituents of different chain length (R1=CH3; R2=C2H5; R3=C6H13). The bowl-shape of these doping ions makes them suitable as ionic recognition sites, and their bulky character is expected to prevent them from leaching out of the conducting polymer membrane. For comparison, sensors based on PEDOT doped with poly(styrene sulfonate) (PSS) and poly(vinyl sulfonate) (PVS) were also constructed. The resulting GC/PEDOT electrodes were conditioned in 0.01 mol L–1 AgNO3 and their performance as Ag+ ion-selective electrodes (ISEs) studied. Results reveal that selectivity and lifetime of the electrodes is affected by the doping anion structure, although all electrodes show selectivity towards Ag+ ions. Interaction of Ag+ with sulfur atoms present in the conducting polymer backbone is considered to be the main reason for this behavior. A second set of electrodes was constructed and conditioned in 0.1 mol L–1 KCl. These electrodes were tested in chloride solutions of quaternary ammonium cations, showing that C[4]S and R2[4]S exhibit significant sensitivity towards pyridinium.Dedicated to Professor György Horányi on the occasion of his 70th birthday in recognition of his outstanding contributions to electrochemistry 相似文献
15.
Cacciapaglia R Casnati A Di Stefano S Mandolini L Paolemili D Reinhoudt DN Sartori A Ungaro R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(18):4436-4442
Two novel regioisomeric calix[4]arene derivatives (2 and 3), decorated with two aza[18]crown-6 units at vicinal (1,2) or diagonal (1,3) positions of the upper rim, were synthesized. The catalytic activities of their dinuclear Ba2+ complexes were investigated in the ethanolysis of esters 8-11, endowed with a carboxylate anchoring group. Major results are as follows: 1) the two metal ions in the dinuclear catalysts work together in a cooperative fashion; 2) the vicinal calix[4]arene catalyst 2 is far superior to its diagonal regioisomer 3 in the reactions of all of the investigated esters; and 3) the distance between the carboxylate and ester carbonyl, which increases regularly from 8 to 11, influences reactivity of catalytic ester cleavage in a way that is decidedly suggestive of the importance of a good match between ester size and metal-to-metal distance. However, the superiority of the vicinal catalyst 2 relative to 3 cannot be explained on the basis of the putative match of ester size to intermetal distance, thus providing an indication that additional, still poorly understood effects may contribute significantly to catalytic efficiency. 相似文献
16.
M. R. Yaftian M. R. Razipour D. Matt 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(2):357-361
Summary The extractive properties of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(diphenylphosphinoylmethoxy)calix[4]arene towards thorium(IV) and europium(III) ions are studied.
The conventional log-log analysis of the extraction data reveals that the stoichiometry of the extracted species is 1 : 1
metal ion to ligand ratio for the two metals. The effects of ligand concentration, types of diluent and concentration of the
salting-out agents are investigated and discussed. The selectivity of the ligand for thorium and europium ions versus Mn2+, Pb2+, Cd2+, Fe2+, Ni2+ and Co2+ is examined. 相似文献
17.
New lipophilic tetraesters of calix[6]arene and calix[6]diquinone are investigated as cesium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion-selective electrode based on calix[6]arene tetraester I, the linear response is 1x10(-6)-1x10(-1) M of Cs(+) concentrations. The selectivity coefficients for cesium ion over alkali, alkaline earth and ammonium ions are determined. The detection limit (log a (Cs (+))=-6.31) and the selectivity coefficient (log k (Cs (+),Rb (+))(pot )=-1.88) are obtained for polymeric membrane electrode containing calix[6]arene tetraester I. 相似文献
18.
WANG KeRang GUO DongSheng JIANG BangPing & LIU Yu State Key Laboratory of Elemento-Organic Chemistry 《中国科学B辑(英文版)》2009,(4)
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
19.
Ki Cheol Song 《Tetrahedron letters》2007,48(31):5397-5400
A new chemosensor with a phenanthroimidazole subunit based upon calix[4]arene-diamide has been synthesized, and its Mg2+-selective fluoroionophoric properties were investigated in an aqueous DMSO solution. The compound exhibited a pronounced Mg2+-selective fluoroionophoric behavior over other physiologically relevant metal ions. A significant red shift in fluorescence emission (Δλ = 86 nm) provided the ratiometric determination as well as naked-eye detection of Mg2+ ions. 相似文献
20.
Ravindra V. Patel Jayesh G. Panchal V. A. Rana Shobhana K. Menon 《Journal of inclusion phenomena and macrocyclic chemistry》2010,66(3-4):285-295
New liquid crystals based on calix[4]arene Schiff base were prepared by the reaction of tetraamino-calix[4]arene with aldehydes (4-hydroxy benzaldehyde, 2-vanillin, 4-vanillin and 2-hydroxy naphthaldehyde). Dielectric investigations on a magnetically oriented sample forming N, SmA, and SmC phases were carried out. The dielectric constant (ε’ and ε”) and dielectric loss (tan δ) have been determined as a function of frequency (20 Hz–2 MHz). The synthesized derivatives were purified and characterized by FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF MS. All the synthesized compounds were investigated for liquid crystalline properties using DSC (Differential Scanning Calorimetry), DTA (Differential Thermal Analysis) and POM (Polarizing Optical Microscopy) attached with a hot stage. They generally exhibited nematic and typical fanlike or mosaic texture, which suggest the ordered smectic mesophases. Compounds were found to adopt a specific molecular structure due to the rigid bowl like calix[4]arene core, i.e., a cone-like structure with mesogenic units aligned within the molecule. 相似文献