芳香族化合物在苯并系列冠醚聚硅氧烷固定液上的保留机理

Retention Mechanism of Aromatic Compounds on Benzo-Crown Ether Polysiloxane Stationary Phases

分离测得了不同结构芳香族化合物在单苯并（ＰＳＯ－Ｂ－３－１５Ｃ５或１８Ｃ６）、双苯并（ＰＳＯ－ＤＢ－３－１５Ｃ５）和双苯并双叔丁基（ＰＳＯ－ＤＴＢ－３－１５Ｃ５）取代的１５Ｃ５聚硅氧烷固定液上的保留指数、相对保留值以及１０组异构体的热力学参数──溶解焓△Ｈｓ，溶解摘△Ｓｓ和自由能△Ｇ；研究探讨了冠醚环上不同苯基取代的固定液结构对芳香族位置异构体保留行为的影响；通过热力学参数对不同冠醚柱子选择性的表征，证明了苯并系列冠醚固定液对芳烃位置异构体的良好选择分离，主要取决于冠醚环腔的高电子云密度所产生的定向力和强诱导力以及分子和冠醚环腔的适应程度，特别是空间位阻效应起了重要作用。

he retention mechanism is discussed by measuring the retention data and thermodynamic parameters ofsome aromatic compounds,including ten groups of positional isomers,on three new types of benzo-crownether polysiloxane stationary phases,i.e. benzopropyl-15-crown-5(PSO-B-3-15C5),dibenzopropyl-15-crown-5(PSO-DB-3-15C5)and di(tert-butylbenzo)-propyl-15-crown-5(PSO-DTB-3-15C5).It is shown thatthe retention of solutes on three stationary phases depends mainly on strong induction force formed by thehigh electron cloud density on the crown ether ring,the fitness of the solute molecules within the crown ethercavitv and the steric hindrance effect.