Comprehensive simulations of stimuli-responsive soft porous materials

嵌入在软多孔材料中的分子开关单元，如金属有机框架（MOFs）和共价有机框架（COFs），为开发刺激响应材料提供了一个通用的平台。使用框架结构作为支架，响应分子构建单元的排列和方向原则上可以被精确调节，从而适合于各种应用，如分子存储或催化。然而，尽管这些刺激响应软多孔材料的发展取得了进展，但对其结构和动态特性的基本方面的理解仍然有限。通过开发和应用一个力场库来准确有效地描述分子开关单元，本研究的目标是揭示基于嵌入式响应分子单元的耦合合作现象。将研究不同类别的分子开关，包括机械互锁的物种，在系统修饰的软多孔材料中固定化（例如，网络拓扑结构，孔隙尺寸）。在这种情况下，将开发参数化算法，以便详细参数化响应分子物种的切换途径。在此基础上，通过原子模拟不仅研究了功能化框架的结构特性，还研究了响应分子单元之间的动态相互作用以及它们与客体分子的相互作用。为了解释软多孔材料诱导的纳米限制的影响，将进行嵌入溶剂化环境中的分子开关的模拟，并对结果进行比较和定量评估。这些综合研究有望对刺激响应多孔材料中分子现象的时空控制提供基本的理解。

Molecular switching units embedded in soft porous materials such as Metal-Organic Frameworks (MOFs) and Covalent Organic Frameworks (COFs) offer a versatile platform for the development of stimuli-responsive materials. Using the framework structure as a scaffold, the arrangement and orientation of the responsive molecular building units can, in principle, be precisely modulated and thus tailored for various applications such as molecular storage or catalysis. However, despite the advances in the development of these stimuli-responsive soft porous materials, the understanding of fundamental aspects with respect to the structural and dynamic properties is still limited. By developing and applying a force field library to accurately and efficiently describe the molecular switching units, the goal of this research project is to reveal coupled and cooperative phenomena based on the embedded responsive molecular units. Different classes of molecular switches, including mechanically interlocked species, immobilized in systematically modified soft porous materials (e.g., network topology, pore dimension) will be studied. In this context, parametrization algorithms will be developed enabling to parametrize in detail the switching pathway of the responsive molecular species. Based on this, not only the structural properties of the functionalized frameworks but rather the dynamic interplay of the responsive molecular units with each other and their interactions with guest molecules will be investigated by atomistic simulations. To decipher the impact of nano-confinement induced by the soft porous materials, simulations of molecular switches embedded in a solvation environment will be performed, and the results will be compared and quantitatively evaluated. These comprehensive studies are expected to provide a fundamental understanding of the spatial and temporal control of molecular phenomena in stimuli-responsive porous materials.