Tetrathiafulvalene-calix[4]pyrroles: Synthesis, anion binding, and electrochemical properties
Tetrathiafulvalene-calix[4]pyrroles: Synthesis, anion binding, and electrochemical properties
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DOI：
10.1021/ja057367u
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发表时间：
2006-02-22
影响因子：
15
通讯作者：
Jeppesen, JO
中科院分区：
文献类型：
--
作者：
Nielsen, KA;Cho, WS;Jeppesen, JO
本文报道了在三吡咯烷8和二吡咯甲烷9存在下，四硫代吡咯并[3，4-d]四硫代富瓦烯（MPTTF，7）与丙酮酸催化缩合，合成了单四硫代富瓦烯-杯[4]吡咯5和双四硫代富瓦烯-杯[4]吡咯6。化合物5和先前报道的四硫富瓦烯-杯[4]吡咯4在固态下都采用1，3-替代构象，如由X-射线晶体学分析确定的。在丙酮中，用H-1 NMR光谱和等温滴定量热法（ITC）研究了四硫富瓦烯-杯[4]吡咯5和6以及母体meso-八甲基杯[4]吡咯（1）的阴离子结合性质，在误差范围内，结果基本一致。基于在1，2-二氯乙烷中进行的ITC研究的结果，增加与杯[4]吡咯系统成环的四硫富瓦烯单元的数目用于显著提高阴离子结合亲和力，但以降低的选择性为代价。在1，2-二氯乙烷中进行的循环伏安法（CV）研究提供了Cl-和Br-离子的阴离子依赖性电化学响应的证据。该响应在单四硫富瓦烯-杯[4]吡咯5的情况下特别显著，在加入约1当量的Cl-离子后观察到-145 mV的Δ E-max。
The syntheses of monotetrathiafulvalene-calix[4]pyrrole 5 and bistetrathiafulvalene-calix[4]pyrrole 6, prepared from the acid-catalyzed condensation of monopyrrolo[3,4-d]tetrathiafulvalene (MPTTF, 7) with acetone in the presence of tripyrrane 8 and dipyrromethane 9, respectively, are described. Compound 5 and the previously reported tetrathiafulvalene-calix[4]pyrrole 4 both adopt a 1,3-alternative conformation in the solid state, as determined from X-ray crystallographic analysis. The anion binding properties of the tetrathiafulvalene-calix[4]pyrroles 5 and 6, as well as those of the parent meso-octamethylcalix[4]pyrrole (1), were investigated in acetone using H-1 NMR spectroscopic and isothermal titration calorimetry (ITC) techniques and, within the error limits of the methods, were generally found to give concordant results. On the basis of the results of the ITC studies carried out in 1,2-dichloroethane, increasing the number of tetrathiafulvalene units annulated to the calix[4]pyrrole system serves to enhance the anion binding affinities substantially but at the price of lowered selectivity. Cyclic voltammetry (CV) studies, carried out in 1,2-dichloroethane, provided evidence of an anion-dependent electrochemical response with Cl- and Br- ions. This response was particularly dramatic in the case of the monotetrathiafulvalene-calix[4]pyrrole 5, with a Delta E-max of -145 mV being seen after the addition of approximately 1 equiv of Cl- ion.