Collaborative Research: Cooperative Processes at Surfaces: Ligand Binding at the Single Molecule Level

在化学系化学结构、动力学和机制-A（CSDM-A）项目的支持下，华盛顿州立大学的Ursula Mazur和Kerry Hipps以及伊利诺伊州州立大学的Bhaskar Chilukuri正在利用高灵敏度的成像和计算方法探索合作结合事件。化学反应性和检测灵敏度等化学过程依赖于协同效应。研究这些合作的相互作用需要两个表面技术，能够单分子检测和计算工具，用于量化的相互作用的程度。Chilukuri，Hipps和Mazur博士及其学生将研究单个分子如何与一个反应位点相互作用，以及该系统如何使用实验和计算方法影响其他附近的域。将研究和分析分子间、分子内和基底诱导的表面化学反应协同效应之间的相互作用。高中生、研究生和本科生将接受研究指导，本科生将开设纳米物理化学课程。扫描隧道显微镜（STM）测量揭示了分子间和分子内通信对亚分子水平协同性的贡献，而密度泛函理论（DFT）和分子动力学提供了一种量化基底作用的机制，分子间和分子内相互作用、空间效应和自旋-自旋相互作用在轴向复合中产生协同性。实时STM成像将用于监测溶液和/或气相中的分子与含有两个或更多个反应位点的表面支撑金属络合物上的反应位点之间的反应。反应性将作为温度、反应物浓度、溶剂化环境和金属络合物载体性质的函数进行监测。几种方法将被用来模拟STM实验，包括巨正则系综参数化的能量结合的每个分布在反应位点和定期DFT计算提供洞察电子分布如何影响结合协同反应位点。将采用分子动力学计算来模拟溶剂效应。通过开发表面反应协同性的综合模型，可以提高表面化学、催化和传感器开发中反应性的可预测性。该奖项反映了NSF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 support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Ursula Mazur and Kerry Hipps of Washington State University and Bhaskar Chilukuri of Illinois State University are exploring cooperative binding events using highly sensitive imaging and computational methods. Chemical processes such as chemical reactivity and detection sensitivity depend on cooperativity. Studying these cooperative interactions requires both surface techniques that are capable of single molecule detection and computational tools for quantifying the degree of interactions. Drs. Chilukuri, Hipps, and Mazur and their students will investigate how single molecules interact with one reactive site and how that system impacts beyond other nearby domains using both experimental and computational methods. The interplay among intermolecular, intramolecular, and substrate-induced effects on chemical reaction cooperativity at surfaces will be studied and analyzed. High school, graduate, and undergraduate students will be mentored in research, and an undergraduate course in nanoscale physical chemistry will be developed.Scanning tunneling microscopy (STM) measurements reveal contributions of both inter- and intramolecular communications to cooperativity on the submolecular level while density functional theory (DFT) and molecular dynamics provide a mechanism for quantifying the role of the substrate, inter and intramolecular interactions, spatial effects, and spin-spin interactions in producing cooperativity in axial complexation. Real-time STM imaging will be used to monitor the reaction between molecules in solution and/or the gas phase and reactive sites on surface supported metal complexes containing two or more reactive sites. Reactivity will be monitored as a function of temperature, reactant concentration, solvation environment, and nature of the support for the metal complexes. Several approaches will be used to model the STM experiments, including the grand canonical ensemble to parameterize the energetics of binding for each distribution over the reactive sites and periodic DFT calculations to provide insight into how electronic distributions affect binding cooperativity at reactive sites. Molecular dynamics calculations will be employed to model solvent effects. By developing a comprehensive model of reaction cooperativity at surfaces, improved predictability of reactivity in surface chemistry, catalysis, and sensor development is envisioned.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.