三唑酮分子印迹预组装体系的分子模拟与吸附性能

以三唑酮为模板分子, 以丙烯酰胺(AM)、 丙烯酸(AA)、 甲基丙烯酸(MAA)和三氟甲基丙烯酸(TFMAA)为功能单体预组装了分子印迹聚合物体系, 采用半经验法和从头算法, 利用Hyperchem软件模拟了三唑酮与4种功能单体所组成的分子印迹预组装体系的构型、 能量、 反应配比及复合反应的结合能, 选择复合物结合能最高的功能单体用于分子印迹聚合物的合成. 采用密度泛函方法计算了模板与单体在不同致孔剂中的溶剂化能. 结果表明, 三唑酮与三氟甲基丙烯酸所形成复合物的作用力最强, 在非极性溶剂中溶剂化能最弱. 由预组装体系的差示紫外光谱法研究发现, 一分子三唑酮可与两分子三氟甲基丙烯酸在氯仿中形成氢键复合物, 与分子模拟的结果一致. 在最佳模拟条件下, 合成了三唑酮的印迹聚合物, 利用吸附等温线Langmuir和Freundlich模型研究了印迹聚合物的吸附行为及识别机理. 上述方法对于分子印迹体系的筛选及分子印迹聚合物性能的预测有重要的意义.

Molecular Simulation and Adsorption Property of Molecularly Imprinted Polymerization System Using Triadimefon as Template

A molecular simulation method for molecularly imprinted polymerization system using triadimefon as template and acrylic amide(AM), acrylic acid(AA), methacrylic acid(MAA) and trifluoromethyl acrylic acid(TFMAA) as functional monomers was presented. The geometry conformation, energy, reaction ratio and binding energy of the pre-organization system were simulated by a semi-empirical method(PM3) and ab inito algorithm methods with Hyperchem 8.0 software. The monomer that provided the largest binding energy was then chosen for the synthesis of molecularly imprinted polymers(MIPs). The solvation energy, an intensity index of the molecular interaction between different porogens with template molecule and monomer, was calculated using density functional theory(DFT). The results show that TFMAA gives stronger hydrogen-bonding interaction with triadimefon than other monomer molecules studied, and the salvation energy for template and monomer in polar solvents is greater than that in non-polar solvents. The pre-assembled system of triadimefon and TFMAA was studied using differential UV spectra and the results indicate that one molecule triadimefon and two molecules TFMAA can form stable hydrogen-bonded complexes in chloroform. This is consistent with the predictions based on the molecular simulation. The adsorption and recognition properties for MIPs were investigated using Langmuir and Freundlich adsorption isotherm. The results can give useful information for screening molecular imprinting system and predicting the performance of MIPs.