Tuning the Thermodynamics and Kinetics of H+ and e- Transfer in Nanoconfined Environments

在化学系大分子、超分子和纳米化学项目的支持下，罗格斯大学的Mark Lipke博士将设计和研究中空分子笼的化学性质。该项目旨在提供详细的见解，如何酸度和电子转移性质的化学物质是如何改变时，限制在纳米尺寸的腔。这一基础知识对于化学工艺和催化材料在先进制造业中的应用的发展是重要的。除了这些努力，PI和他的学生将在当地的高中进行讲座，说明高中水平的化学概念如何在前沿研究中有用。Lipke博士还将为高中生提供研究实习机会，并将为本科课程开发新的教材。本研究将使用模块化卟啉纳米笼进行，这种纳米笼可以控制纳米限制环境中的溶剂化和非共价相互作用，以探索这些变量如何影响H+和e -转移过程的热力学和动力学，包括对许多电化学转化至关重要的质子耦合电子转移（PCET）过程。这项工作有三个目的。目标1将开发不同尺寸、形状和氢键能力的坚固的、具有氧化活性的纳米笼，这些纳米笼非常适合系统的化学和电化学研究。Aim II将系统地测量被封装客体的pKa值和还原电位如何受到低相对介电常数纳米空腔的影响。目的III将研究如何控制氢离子和电子向纳米笼中结合的客体分子的传输动力学。在这些研究中使用的纳米笼可以在溶液和固体状态下进行表征，从而可以在纳米孔结构上进行详细的溶液相机制实验，这些纳米孔结构可以在固体状态下用原子分辨率进行表征。这项研究将对纳米空间中H+和e−转移过程的机理理解做出重大贡献，反过来，这将有助于为这些重要化学过程提供具有可调性质的多孔结构的合理设计。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Dr. Mark Lipke of Rutgers, The State University of New Jersey will design and study the chemical properties of hollow molecular cages. This project aims to provide detailed insights into how the acidity and electron-transfer properties of chemical species are altered when confined in nanometer-sized cavities. This fundamental knowledge is important for the development of chemical processes and catalytic materials for applications in advanced manufacturing. Alongside these efforts, the PI and his students will give talks at local high schools to illustrate how high school level chemical concepts are useful in cutting edge research. Dr. Lipke will also provide research internships for high school students and will develop new teaching materials for undergraduate courses.This research will be carried out using modular porphyrin nanocages that provide control over solvation and noncovalent interactions in nanoconfined environments to probe how these variables influence the thermodynamics and kinetics of H+ and e− transfer processes, including proton-coupled electron transfer (PCET) processes that are essential to many electrochemical transformations. This work has three aims. Aim I will develop robust, redox-active nanocages of different sizes, shapes, and H-bonding abilities that are well-suited to systematic chemical and electrochemical studies. Aim II will systematically measure how the pKa values and reduction potentials of encapsulated guests are affected by low relative permittivity nanocavities. Aim III will examine how the kinetics of H+ and e– transport to guest molecules bound in the nanocages can be controlled. The nanocages that will be employed in these studies can be characterized in both solution and the solid state, enabling detailed solution-phase mechanistic experiments to be performed on nanoporous structures that can be characterized with atomic resolution in the solid state. This research will make significant contributions to the mechanistic understanding of H+ and e− transfer processes in nanoconfined spaces, which in turn, will be useful for informing the rational design of porous structures with tunable properties for these important chemical processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.