化学学报 ›› 2005, Vol. 63 ›› Issue (3): 189-195. 上一篇    下一篇

研究论文

分子印迹手性分离过程的热力学研究

孙瑞丰,于慧敏*,罗晖,沈忠耀   

  1. (清华大学化工系 北京 100084)
  • 投稿日期:2004-06-07 修回日期:2004-10-08 发布日期:2010-12-10
  • 通讯作者: 于慧敏

Thermodynamic Study on Chiral Separation Process Using Molecular Imprinting

SUN Rui-Feng,YU Hui-Min*,LUO Hui,SHEN Zhong-Yao   

  1. (Department of Chemical Engineering, Tsinghua University, Beijing 100084)
  • Received:2004-06-07 Revised:2004-10-08 Published:2010-12-10
  • Contact: YU Hui-Min

以丙烯酰胺为功能单体, 以二甲基丙烯酸乙二醇酯为交联剂, 在模板分子N-叔丁氧羰酰-L-色氨酸(N-Boc-L-Trp)和N-叔丁氧羰酰-L-酪氨酸(N-Boc-L-Tyr)的存在下, 分别采用光引发聚合和热引发聚合制备了N-Boc-L-Trp和N-Boc-L-Tyr的分子印迹聚合物(MIPs), 进行分子印迹手性分离过程的热力学研究. 测定了分离过程的熵变、焓变和自由能变化. 结果显示, 在流动相中添加异丙醇或甲醇等强氢键竞争性溶剂时, 熵变对分离起到了主要作用, 而且分离过程中的溶剂化对分离的影响也非常大. 分子印迹聚合物对印迹分子和非印迹分子进行分子识别的主要作用是印迹聚合物与印迹分子匹配的三维空间结构.

关键词: 分子印迹聚合物, 热力学, 溶剂化, 分子识别

Two kinds of enantio-selective molecularly imprinted polymers (MIP) of N-tert-butoxycarbonyl-L-tryptophan (N-Boc-L-Trp) and N-tert-butoxycarbonyl-L-tyramine (N-Boc-L-Tyr), were synthesized by photo-induced and thermal-induced polymerization, respectively, in which acrylamide (functional monomer) and ethylene glycol dimethacrylate were co-polymerized in the presence of N-Boc-L-Trp and N-Boc-L-Tyr. Thermodynamic studies on chiral separa-tion process using molecular imprinting were then carried out when the above two MIPs were employed as the stationary phase in liquid chromatography. Changes of entropy, enthalpy and Gibbs free energy in the process of imprinted-separation were analyzed. The results showed that not only the change of entropy played an important role in the separation, but also the solvation effect of the solutes and stationary phase, when a strong hydrogen-bond competitive solvent, such as isopropyl alcohol, alcohol or methanol, was sup-plemented into the mobile phase. Further studies showed that the molecular recognition of imprinted mole-cules and their enantiomorphs mainly depended on how well the geometric cavity structures of MIP suited the structure of the imprinted molecules.

Key words: molecular imprinting polymer, thermodynamics, solvation, molecular recognition