Calix[4]pyrrole as a chloride anion receptor: Solvent and countercation effects
Calix[4]pyrrole as a chloride anion receptor: Solvent and countercation effects
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DOI：
10.1021/ja064012h
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发表时间：
2006-09-20
影响因子：
15
通讯作者：
Gale, Philip A.
中科院分区：
文献类型：
--
作者：
Sessler, Jonathan L.;Gross, Dustin E.;Gale, Philip A.
本文用X射线晶体学方法研究了杯吡咯与几种氯化物盐的相互作用，并用等温滴定量热法（ITC）和H-1 NMR光谱滴定法研究了杯吡咯与氯化物盐的相互作用。在二甲亚砜、乙腈、硝基甲烷、1，2-二氯乙烷和二氯甲烷中，使用各种氯化物盐，特别是四乙基铵（TEA）、四丙基铵（TPA）、四丁基铵（TBA）、四乙基鏻（TEP）、四丁基鏻（TBP）和四苯基鏻（TPhP）进行滴定，结果显示不依赖于测量方法。另一方面，发现所得亲和常数（K-a）高度依赖于溶剂的选择，在本研究所用的试验溶剂中记录的K-a范围为10（2）-10（5）M-1。在二氯甲烷中，还观察到对抗衡阳离子的强烈依赖性，与氯化物相互作用的Ka为10（2）-10（4）M-1。在TPA、TBA和TBP的情况下，ITC数据不能拟合1：1结合谱。
The interaction of calixpyrrole with several chloride salts has been studied in the solid state by X-ray crystallography as well as in solution by isothermal titration calorimetry (ITC) and H-1 NMR spectroscopic titrations. The titration results in dimethylsulfoxide, acetonitrile, nitromethane, 1,2-dichloroethane, and dichloromethane, carried out using various chloride salts, specifically tetraethylammonium (TEA), tetrapropylammonium (TPA), tetrabutylammonium (TBA), tetraethylphosphonium (TEP), tetrabutylphosphonium (TBP), and tetraphenylphosphonium (TPhP), showed no dependence on method of measurement. The resulting affinity constants (K-a), on the other hand, were found to be highly dependent on the choice of solvent with K-a's ranging from 10(2)-10(5) M-1 being recorded in the test solvents used for this study. In dichloromethane, a strong dependence on the countercation was also seen, with the Ka's for the interaction with chloride ranging from 10(2)-10(4) M-1. In the case of TPA, TBA, and TBP, the ITC data could not be fit to a 1:1 binding profile.