Hydrazone-Based Feedback Loops

在化学系大分子、超分子和纳米化学项目的支持下，达特茅斯学院的伊万·阿普拉哈米安教授将研究如何使分子开关相互通信。这些研究旨在加深对如何使用分子开关控制分子集合的基本理解，这反过来将有助于理解设计反应级联和系综所需的基础科学，在这些过程中，催化、非平衡自组装、振荡系统等过程可以自主调节。该项目的多学科性质将使培训和留住从高中到本科生到研究生的不同教育水平的学生成为可能。该小组的公众宣传和参与与科学、技术、工程和数学(STEM)相关的活动，如一年一度的达特茅斯科学日，将有助于向更广泛的受众传播该小组的工作。此外，这些活动将加强和扩大该小组与当地学校和科学博物馆的非正式和正式科学教育伙伴关系和网络。在这项研究中，我们将使用基于肼的开关和锌(II)引发的负反馈环(NFL)来研究如何利用开关间的通信来控制级联反应并产生功能产品。Hydrazone开关和NFL组件的直接合成和模块化将允许进行结构-性能分析，以确定控制NFL阈值的动力学和热力学因素。有了这些知识，NFL将以一种可以相互竞争或相互补充的方式结合在一起，从而创造出相互依存的关系。然后，NFL将用于合成精确数量的配位笼和聚合物。还将开发光可逆配体，以便光可以用来控制溶液中锌(II)的浓度，而光酸/碱将用来调节溶液的pH值。预计这些系统将允许使用光对整个级联过程进行清洁监管，从而使方法更接近自动化。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。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Ivan Aprahamian of Dartmouth College will study how molecular switches can be made to communicate with each other. These studies aim to result in a deeper fundamental understanding of how to control an ensemble of molecules using molecular switches, which in turn will facilitate the understanding of the basic science required to engineer reactions cascades and ensembles, where catalysis, out-of-equilibrium self-assemblies, oscillating systems, among other processes, can be autonomously regulated. The multidisciplinary nature of the project will enable the training and retention of students at different levels of education from high school to undergraduate to graduate students. The group’s public outreach and participation in science, technology, engineering and mathematics (STEM)-related events, such as the annual Science Day at Dartmouth, will help disseminate the group’s work to broader audiences. Moreover, these activities will strengthen and extend the group’s informal and formal science education partnerships and networks with local schools and science museums. In this research, hydrazone-based switches and Zn(II)-initiated negative feedback loops (NFLs) will be used to study how inter-switch communication can be employed for controlling cascade reactions and result in functional products. The straightforward synthesis and modularity of the hydrazone switches and NFL components will allow structure-property analyses for determining the kinetic and thermodynamic factors that control the NFL threshold. With this knowledge at hand, the NFLs will be coupled together in such a way that they can either compete or feed into each other, thus creating interdependency. The NFL will then be used in the synthesis of precise amounts of coordination cages and polymers. Photoreversible ligands will also be developed so light can be used in controlling the concentration of Zn(II) in the solution, while photoacids/bases will be used to tune the solution’s pH. These systems are expected to allow for the clean regulation, using light, of an entire cascade process, thus bringing the approach a step closer to automation.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.