Cooperative dynamics in ligand binding reactions at the solution/solid interface

许多大分子有几个化学反应部位。通常，这些位置的行为是独立的，发生在一个位置的化学反应对其他位置没有影响。然而，情况并不总是如此。在某些情况下，一个位点的结合可以改变另一个位点的化学反应活性。活性中心之间的合作在从生物学到分子电子学的各种问题中都扮演着重要的角色。然而，研究协作性是具有挑战性的，因为许多实验方法很难区分反应位点。在大分子、超分子和纳米化学以及化学、结构、动力学和机制计划的支持下，华盛顿州立大学的Ursula Mazur教授、Bhaskar Chilukuri教授和K.W.Hipps教授正在使用高分辨率成像方法探索小分子与大型化学复合体附近位置结合的合作效应。这些发现可能有助于新材料的设计，并对推进与传感、催化和光电子学相关的技术具有广泛的影响。该项目的发现被纳入了华盛顿州立大学的本科课程，提供了现代研究范例，以突出化学、材料科学和工程学的概念。参与该项目的研究实验室还为研究生和本科生提供培训机会，其中包括一些女性和少数族裔学生。Mazur、Chilukuri和Hipps教授正在与他们的学生合作，合成由多个融合的卟啉环组成的富含电子的大分子，然后将它们沉积在Au、石墨和MoS2等导电基板上。然后，该团队将卟啉多聚体暴露在与金属中心发生反应的小分子(例如O2、CO和NO)中。通过扫描隧道显微镜(STM)对产物进行成像，可以直接观察到协同结合。实验观察与分子动力学和密度泛函理论计算相比较，以确定是否通过金属载体或分子内pi结构发生通信，以及分子间耦合发生的程度。Mazur教授、Chilukuri教授和Hipps教授参与了本科教育和指导来自代表性不足群体的学生。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Many large molecules have several chemically reactive sites. Oftentimes these sites behave independently, with the chemical reactions occurring at one site having no effect on the others. This is not always the case, however. In some instances, the binding at one site can change the chemical reactivity of another. Cooperation between reactive sites plays an important role in problems ranging from biology to molecular electronics. However, investigating cooperativity is challenging, since many experimental methods have trouble distinguishing the reactive sites. With support from the Macromolecular, Supramolecular, and Nanochemistry and the Chemical, Structure, Dynamics and Mechanisms A programs in the Division of Chemistry, Professors Ursula Mazur, Bhaskar Chilukuri, and K. W. Hipps at Washington State University are exploring cooperative effects in the binding of small molecules on nearby sites in large chemical complexes using a high resolution imaging method. The discoveries could aid in the design of new materials, as well as have broad implications for advancing technologies related to sensing, catalysis, and optoelectronics. The project's findings are incorporated into undergraduate courses at Washington State University, providing modern research examples to highlight concepts in chemistry, materials science, and engineering. The research labs involved in the project also provide training opportunities for graduate and undergraduate students, including a number of female and minority students.Working with their students, Professors Mazur, Chilukuri, and Hipps are synthesizing large, electron-rich molecules that consist of multiple fused porphyrin rings, and then depositing them on conducting substrates such as Au, graphite, and MoS2. The team then exposes the porphyrin multimers to small molecules (e.g. O2, CO, and NO) that react with the metal centers. By imaging the products with scanning tunneling microscopy (STM), they can directly observe of cooperative binding. Experimental observations are compared with molecular dynamics and density functional theory calculations to determine if communication occurs through the metal support or the intramolecular pi structure, as well as the extent to which intermolecular coupling occurs. Professors Mazur, Chilukuri, and Hipps are involved in undergraduate education and mentoring students from underrepresented groups.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.