磺化杯[4]芳烃与双正电荷季铵盐的键合作用

Binding Thermodynamics of p-Sulfonatocalix[4]arene with Quaternary Ammonium Dications

采用核磁波谱和等温微量热滴定等手段研究了磺化杯[4]芳烃与3个双正电荷季铵盐相互作用的键合比、键合模式以及热力学参数.结果表明,磺化杯[4]芳烃与3个双正电荷季铵盐以不同的键合模式形成1:1络合物,其键合常数均超过105L/mol,键合作用主要由焓变驱动,同时伴随着微弱的正负熵变.

The stoichiometric ratio, binding modes, complex stability constants and thermodynamic parame- ters of p-sulfonatocalix[ 4 ] arene with three quaternary ammonium dication salts were studied in aqueous buffer solution （ pH = 7.20） by means of 1H NMR spectroscopy and microcalorimetrical titration. The results obtained from NMR experiments suggest the 1 ： 1 stoichiometric ratio with different binding modes between host and guest. The results of the microcalorimetrical titration show that the complex stability constants of p-sulfonato- calix[4 ] arene with three quaternary ammonium dication salts are more than 105 L/mol. Thermodynamically, the host-guest binding behavior are mainly driven by the favorable enthalpic changes, accompanied by the unfavorable entropic changes.