Ansell Richard J, Wang Dongyao, Kuah Janice K L
School of Chemistry, University of Leeds, Leeds, UK.
Analyst. 2008 Dec;133(12):1673-83. doi: 10.1039/b806376a. Epub 2008 Sep 3.
A sophisticated analysis of the pre-polymerisation association of monomer and template for the molecular imprinting of (-)-ephedrine (template) using methacrylic acid (monomer) has been performed using NMR titrations and data analysis with the computer program HypNMR. The fitted model takes account of the dimerisation of monomer, and 1 : 1, 2 : 1 and 3 : 1 monomer-template complexes. Values for the association constants and chemical shifts of the different nuclei in the various species are generated quickly and simply. The speciation has been compared in chloroform, toluene and acetonitrile, and in the absence and presence of cross-linking monomers. The 1 : 1 monomer-template interaction is very strong in all three solvents, such that 1 : 1 mixtures contain an almost stoichiometric amount of 1 : 1 complex. Imprinted polymers made with different monomer-template ratios have been used in the enantioseparation of (+/-)-ephedrine and confirm the utility of the 1 : 1 complex for the formation of effective recognition sites.
使用核磁共振滴定法，并通过计算机程序HypNMR进行数据分析，对以甲基丙烯酸（单体）对（-）-麻黄碱（模板）进行分子印迹时单体与模板的预聚合缔合进行了深入分析。拟合模型考虑了单体的二聚作用，以及1:1、2:1和3:1的单体-模板络合物。能够快速简便地得出各种物种中不同原子核的缔合常数和化学位移值。已对氯仿、甲苯和乙腈中以及存在和不存在交联单体的情况下的物种形成情况进行了比较。在所有三种溶剂中，1:1的单体-模板相互作用都非常强，以至于1:1的混合物中几乎含有化学计量的1:1络合物。用不同单体-模板比例制备的印迹聚合物已用于（±）-麻黄碱的对映体分离，并证实了1:1络合物对于形成有效识别位点的效用。
