Ion-pairing ability, chemical stability, and selectivity behavior of halogenated dodecacarborane cation exchangers in neutral carrier-based ion-selective electrodes.
Ion-pairing ability, chemical stability, and selectivity behavior of halogenated dodecacarborane cation exchangers in neutral carrier-based ion-selective electrodes.
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DOI：
10.1021/ac026056o
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发表时间：
2003-04
影响因子：
7.4
通讯作者：
S. Peper;Yu Qin;P. Almond;M. Mckee;M. Telting-Diaz;T. Albrecht‐Schmitt;E. Bakker
中科院分区：
文献类型：
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作者：
S. Peper;Yu Qin;P. Almond;M. Mckee;M. Telting-Diaz;T. Albrecht‐Schmitt;E. Bakker
最近，人们发现，碳-闭-十二硼酸酯可用作中性载体基离子选择性化学传感器中的阳离子交换剂。由于其固有的化学稳定性和多功能的功能化化学，它们提供了许多优点，这些优点可能被用于需要非传统样品条件（包括强酸性介质）的离子分析。在这项工作中，三甲基铵盐的十一氯（UCC），十一溴（UBC），六溴（HBC），和十一碘（UIC）碳硼烷阴离子的制备和评价其潜在的使用在溶剂聚合物膜为基础的传感器。计算方法包括自然布居分析和静电作图被用来预测每个亲脂性阴离子的离子交换能力。此外，使用夹层膜技术来原位评估每种碳硼烷阴离子的离子配对能力（即，在双（2-乙基己基）癸二酸酯（DOS）-和2-硝基苯基辛基醚（o-NPOE）-增塑的伊势膜内）。计算和电位研究结果发现，阴离子的结合亲和力遵循HBC > UCC > UBC > UIC的总体趋势。使用含有色离子载体ETH 5315和相应阴离子的PVC-DOS本体光电二极管薄膜来确定碳硼烷和四[3，5-双（三氟甲基）苯基]硼酸酯（TFPB）在酸性介质（0.2M HOAc）中在流动条件下的化学稳定性/亲脂性。研究发现，在稳定性/亲脂性方面，UIC > UBC > TFPB约为UCC >> HBC。电极含有铅（2+）-选择性离子载体，叔丁基杯[4]芳烃-四（N，N-二甲基硫代乙酰胺）（铅IV），用于评估每个阳离子交换剂的功能。响应特性，如斜率和选择性的评价发现，UIC和UBC是相当的TFPB的行为。有趣的是，UIC和UBC都显示出对镉的显著选择性改善，log K（pot）（pb）、（Cd）值分别为-7.19和-7.29，TFPB给出的值为-5.89。碳硼烷，特别是UIC，表现出优异的稳定性和合适的静电性能，是四苯基硼酸酯的非常有前途的替代物，并且应该在化学传感器领域中找到广泛的应用。
Recently, it has been discovered that carba-closo-dodecaborates can be used as cation exchangers in neutral carrier-based ion-selective chemical sensors. Because of their inherent chemical stability and versatile functionalization chemistries, they offer many advantages that may potentially be exploited for ion analyses that require nontraditional sample conditions, including strongly acidic media. In this work, trimethylammonium salts of undecachlorinated (UCC), undecabrominated (UBC), hexabrominated (HBC), and undecaiodinated (UIC) carborane anions were prepared and evaluated for their potential use in solvent polymeric membrane-based sensors. Computational methods including Natural population analysis and electrostatic mapping were used to predict the ion-exchanging ability of each lipophilic anion. In addition, the sandwich membrane technique was used to evaluate the ion-pairing ability of each carborane anion in situ (i.e., within bis(2-ethylhexyl) sebacate (DOS)- and 2-nitrophenyl octyl ether (o-NPOE)-plasticized ISE membranes). The results of the computational and potentiometric studies found that binding affinity of the anions followed the generalized trend HBC > UCC > UBC > UIC. PVC-DOS bulk optode thin films containing the chromoionophore ETH 5315 and a respective anion were used to determine the chemical stability/lipophilicity of the carboranes and tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (TFPB) in acidic media (0.2 M HOAc) under flowing conditions. The studies found that in terms of stability/lipophilicity UIC > UBC > TFPB approximately UCC >> HBC. Electrodes containing a Pb(2+)-selective ionophore, tert-butylcalix[4]arene-tetrakis(N,N-dimethylthioacetamide)(lead IV), were used to evaluate the functionality of each cation exchanger. An evaluation of response characteristics such as slope and selectivity found that UIC and UBC were quite comparable to the behavior of TFPB. Interestingly, both UIC and UBC showed a marked selectivity improvement over cadmium, with log K(pot)(pb),(Cd) values of -7.19 and -7.29, respectively, with TFPB giving a value of -5.89. Demonstrating excellent stability and suitable electrostatic properties, the carboranes, UIC in particular, are a very promising alternative to the tetraphenylborates and should find widespread application in the field of chemical sensors.