Chemical Triggers for Spin-State Switching: Discovery and Control of Switching Mechanisms

在这个由化学部化学结构、动态和机制B项目资助的项目中，科罗拉多州立大学化学系的Matthew Shores教授正在探索可以作为分子开关的新型过渡金属配合物。这项研究的目的是了解主客体相互作用如何改变配位配合物的结构和改变它们的磁性。这些结果将为化学传感器、可切换分子磁体和磁共振造影剂的开发提供设计原则。该项目结合了几种综合、测量和计算技术，为参与研究的学生提供多样化的训练。与科罗拉多州立大学本科生化学研究经验项目的互动以及与科罗拉多州立大学普韦布洛分校的研究人员的合作旨在扩大代表性不足群体的参与。该小组在磁测量和数据解释方面的专业知识将通过与全国各地的无机和材料化学研究小组进行的几个正在进行的和新的磁合作来促进发现。可以在两种明确定义的磁性状态中存在并可靠地在两者之间切换的复合物为纳米和分子长度尺度上的功能材料的开发提供了可能性。提出的研究旨在通过与客体分子的外球非共价相互作用来控制局部几何形状和配体场效应，从而增强过渡金属配合物的磁性转换。本项目的具体研究目标是：(1)通过计算理解磁态开关中的热力学和畸变途径，建立预测模型；(2)探索新的自旋态开关配合物的化学触发器和新离子；(3) Co（II）单分子磁性配合物轴向磁各向异性的外部控制。最终目的是在设计磁性开关新机制方面获得新的认识，并为化学传感和分子成像应用提供新的传感体系结构。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。

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Matthew Shores of the Department of Chemistry at Colorado State University (CSU) is exploring new classes of transition metal complexes that can serve as molecular switches. The goal of the research is to understand how host-guest interactions alter the structure of coordination complexes and change their magnetic properties. These results will inform design principles for the development of chemical sensors, switchable molecular magnets, and magnetic resonance contrast agents. The project combines several synthetic, measurement and computational techniques to provide diverse training for the research students involved. Interactions with the CSU Chemistry Research Experiences for Undergraduates program and collaborations with researchers at CSU-Pueblo aim to broaden participation from underrepresented groups. The group's expertise in magnetic measurements and data interpretation will promote discovery via several ongoing and new magnetic collaborations with inorganic and materials chemistry research groups around the country.Complexes that can exist in and reliably switch between two well-defined magnetic states offer the possibility for functional materials development at the nano- and molecular length scales. The proposed research aims to enhance magnetic property switching in transition metal complexes by controlling local geometry and ligand field effects via outer sphere, non-covalent interactions with guest molecules. Specific research goals for this project are: (1) computational understanding of thermodynamics and distortion pathways in magnetic-state switching, toward predictive models; (2) exploration of new chemical triggers and new ions for guest-dependent spin-state switching complexes; and (3) external control of axial magnetic anisotropy in Co(II) single-molecule magnet complexes. The ultimate aim is to gain new understanding in the design of novel mechanisms for magnetic property switching, and contribute new sensing architectures relevant to chemical sensing and molecular imaging applications.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.