Chemistry, Centre for Chemical Biology, The University of Newcastle, Callaghan, NSW 2308, Australia.
Org Biomol Chem. 2014 Feb 7;12(5):844-53. doi: 10.1039/c3ob42399a. Epub 2013 Dec 16.
The interactions between each component of the pre-polymerisation mixtures used in the synthesis of molecularly imprinted polymers (MIP) specific for 1,2,3,4,5-pentachlorobenzene (1) and 1,2,3-trichlorobenzene (2) were examined in four molecular dynamics simulations. These simulations revealed that the relative frequency of functional monomer-template (FM-T) interactions was consistent with results obtained by the synthesis and evaluation of the actual MIPs. The higher frequency of 1 interaction with trimethylstyrene (TMS; 54.7%) than 1 interaction with pentafluorostyrene (PFS; 44.7%) correlated with a higher imprinting factor (IF) of 2.1 vs. 1.7 for each functional monomer respectively. The higher frequency of PFS interactions with 2 (29.6%) than TMS interactions with 2 (1.9%) also correlated well with the observed differences in IF (3.7) of 2 MIPs imprinted using PFS as the FM than the IF (2.8) of 2 MIPs imprinted using TMS as the FM. The TMS-1 interaction dominated the molecular simulation due to high interaction energies, but the weaker TMS-2 resulted in low interaction maintenance, and thus lower IF values. Examination of the other pre-polymerisation mixture components revealed that the low levels of TMS-2 interaction was, in part, due to interference caused by the cross linker (CL) ethyleneglycol dimethylacrylate (EGDMA) interactions with TMS. The main reason was, however, attributed to MeOH interactions with TMS in both a hydrogen bond and perpendicular configuration. This positioned a MeOH directly above the π-orbital of all TMS for an average of 63.8% of MD2 creating significant interference to π-π stacking interactions between 2 and TMS. These findings are consistent with the deviation from the 'normal' molecularly imprinted polymer synthesis ratio of 1 : 4 : 20 (T : FM : CL) of 20 : 1 : 29 and 15 : 6 : 29 observed with 2 and TMS and PFS respectively. Our molecular dynamics simulations correctly predicted the high level of interference from other MIP synthesis components. The effect on PFS-1 interaction by MeOH was significantly lower and thus this system was not adversely affected.
在四个分子动力学模拟中，研究了用于合成对 1,2,3,4,5-五氯苯（1）和 1,2,3-三氯苯（2）的分子印迹聚合物（MIP）的预聚合混合物的各个成分之间的相互作用。这些模拟表明，功能单体-模板（FM-T）相互作用的相对频率与实际 MIP 的合成和评估结果一致。与 1 与五氟苯乙烯（PFS；44.7%）的相互作用相比，1 与三甲基苯乙烯（TMS；54.7%）的相互作用频率更高，这与每个功能单体的印迹因子（IF）分别为 2.1 和 1.7 相关。PFS 与 2（29.6%）的相互作用频率高于 TMS 与 2（1.9%）的相互作用频率，这也与观察到的 IF（3.7）的差异很好地相关，即使用 PFS 作为 FM 印迹的 2 MIP 的 IF（3.7）高于使用 TMS 作为 FM 印迹的 2 MIP 的 IF（2.8）。TMS-1 相互作用由于高相互作用能而主导分子模拟，但较弱的 TMS-2 导致相互作用维持能力较低，因此 IF 值较低。检查其他预聚合混合物成分表明，TMS-2 相互作用水平低，部分原因是交联剂（CL）乙二醇二甲基丙烯酸酯（EGDMA）与 TMS 的相互作用造成的干扰。然而，主要原因是甲醇在氢键和垂直构型中与 TMS 相互作用。这将甲醇直接置于所有 TMS 的π-轨道上方，在 MD2 的平均时间为 63.8%，从而对 2 和 TMS 之间的π-π堆积相互作用产生显著干扰。这些发现与从 2 和 TMS 以及 PFS 分别观察到的“正常”分子印迹聚合物合成比 1：4：20（T：FM：CL）的偏差一致，即 20：1：29 和 15：6：29。我们的分子动力学模拟正确预测了其他 MIP 合成成分的高度干扰。甲醇对 PFS-1 相互作用的影响要低得多，因此该系统没有受到不利影响。
