Experimental and theoretical studies of electrochemical switching processes in crown ether/ammonium rotaxanes

冠醚/轮烷铵电化学转换过程的实验与理论研究

• 批准号: 434455294
• 负责人: Professorin Dr. Beate Paulus
• 金额: --
• 依托单位: Abteilung Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/434455294?language=en
• 关键词: Experimental; theoretical; studies; electrochemical; switching

Mechanically interlocked molecules like rotaxanes are an important class of molecular switches and machines. For example, motion and transport can be controlled on the molecular scale when using switchable rotaxanes that change their co-conformations when external stimuli are applied. Influences of the environment, e.g. solvent and counterion effects, may strongly affect the co-conformational equilibria and thus the function of these switchable interlocked molecules. As these effects, however, operate in a complex interplay with intramolecular non-covalent interactions as well as the mechanical bond, it is challenging to single out and quantify these environmental effects. The project aims at a more profound understanding of these effects in a combination of experiment and theory. Also, a model will be developed that allows a better prediction of co-conformational changes in interlocked molecules. At first, a library of electrochemically switchable crown ether/ammonium pseudorotaxanes is synthesized which allows to quantify the dependence of intramolecular interactions on environment effects by a network analysis. Based on this data set, DFT-based theoretical models in combination with molecular dynamics simulations allow to predict the energy profiles of co-conformational changes. This enables us to fine-tune conformations and thus functions of switchable rotaxanes with the help of environment effect. In the last part of the project, these models will be used to design, prepare and study novel molecular machines, which allow for directional transport phenomena.

像轮烷这样的机械联锁分子是一类重要的分子开关和机器。例如，当使用可切换轮烷时，可以在分子尺度上控制运动和运输，当施加外部刺激时，可切换轮烷改变它们的共构象。环境的影响，例如溶剂和反溶剂效应，可以强烈地影响共构象平衡，从而影响这些可切换的互锁分子的功能。然而，由于这些影响与分子内非共价相互作用以及机械键的复杂相互作用，因此挑选和量化这些环境影响具有挑战性。该项目旨在通过实验和理论相结合的方式更深入地了解这些影响。此外，将开发一个模型，可以更好地预测互锁分子的共构象变化。首先，电化学可切换冠醚/铵伪轮烷的库的合成，其允许通过网络分析来量化分子内相互作用对环境影响的依赖性。基于此数据集，DFT为基础的理论模型与分子动力学模拟相结合，可以预测的能量分布的共构象变化。这使得我们能够在环境效应的帮助下微调可转换轮烷的构象和功能。在该项目的最后一部分，这些模型将用于设计，制备和研究新的分子机器，允许定向传输现象。