Vidal-Vidal Ángel, Cabaleiro-Lago Enrique M, Silva López Carlos, Faza Olalla Nieto
Departamento de Química Orgánica, Facultade de Química, Campus Lagoas-Marcosende, 36310 Vigo, Spain.
Departamento de Química Física, Facultade de Ciencias, Campus de Lugo, Avda. Alfonso X El Sabio s/n, 27002 Lugo, Spain.
ACS Omega. 2018 Dec 11;3(12):16976-16988. doi: 10.1021/acsomega.8b02673. eCollection 2018 Dec 31.
The viability of using []-cycloparaphenylenes (CPPs) of different sizes to encapsulate diquat (DQ) pesticide molecules has been tested analyzing the origin of the host-guest interactions stabilizing the complex. This analysis provides rational design capabilities to construct ad hoc capturing systems tailored to the desired pollutant. All CPPs considered ( = 7-12) are capable of forming remarkably stable complexes with DQ, though [9]-CPP is the best candidate, where a fine balance is established between the energy penalty due to the deformation + repulsion of the pesticide molecule inside the cavity (larger in smaller CPPs) and the maximization of the favorable dispersion, electrostatic and induction contributions (which also decrease in larger rings). These encouraging results prompted us to evaluate the potential of using Resonance Raman spectroscopy on nanohoop complexes as a tool for DQ sensing. The shifts observed in the vibrational frequencies of DQ upon complexation allow us to determine whether complexation has been achieved. Additionally, a large enhancement of the signals permits a selective identification of the vibrational modes.
通过分析稳定复合物的主客体相互作用的起源，测试了使用不同尺寸的[]-环对亚苯基（CPPs）包裹敌草快（DQ）农药分子的可行性。该分析提供了合理的设计能力，以构建针对所需污染物量身定制的特殊捕获系统。所有考虑的CPPs（ = 7-12）都能够与DQ形成非常稳定的复合物，不过[9]-CPP是最佳候选物，在该复合物中，由于腔内农药分子的变形+排斥（较小的CPPs中更大）导致的能量损失与有利的色散、静电和诱导贡献的最大化（在较大的环中也会降低）之间建立了良好的平衡。这些令人鼓舞的结果促使我们评估在纳米环复合物上使用共振拉曼光谱作为DQ传感工具的潜力。络合时DQ振动频率的变化使我们能够确定是否实现了络合。此外，信号的大幅增强允许对振动模式进行选择性识别。
