Collaborative Research: Exploiting Spin Networks and Efficient Catalyst/Substrate Separations for NMR "SABRE" Enhancement of Complex Systems

在化学系化学测量和成像计划的支持下，南伊利诺伊大学(SIU)的Boyd Goodson教授和韦恩州立大学(WSU)的Eduard Chekmenev教授正在努力提高核磁共振(NMR)的灵敏度，这是一种重要的化学分析方法，是众所周知的临床成像方式-磁共振成像(MRI)的基础。古德森/切克梅耶夫团队正在开发新的、廉价且易于制造的增强核磁化的方法--核磁化是许多核磁共振和核磁共振应用中的灵敏度限制因素，包括对一系列疾病的诊断测试。预期的成本节约也可以使这些方法更适用于其他实验室环境，特别是那些研究基础设施更有限和/或以本科生研究为特色的实验室。几名学生参与其中，获得了高度跨学科的培训机会。该团队还致力于招收本科生，并将他们与两个校区的各种导师研究机会相匹配，目标是增加寻求STEM职业的本科生的数量和多样性。正在使用的核磁共振/核磁共振方法是基于可逆交换信号放大，或SABRE。在SABRE中，有机金属催化剂被用来共同定位对氢和目标分子(底物)在瞬时络合物中；在适当匹配的外部磁场下，核自旋有序可以自发地、有效地从对氢转移到底物，从而产生核磁共振和核磁共振信号，这些信号被增加了几个数量级。Goodson/Chekmenev团队的工作旨在：(1)在同核和异核情况下，通过模型系统中的自旋中继网络，提高对远程SABRE极化转移的理解和使用；(2)开发和表征用于SABRE的新型多相催化剂(HET-SABRE)，以及催化剂回收的方法；以及(3)通过改进对模型扩展网络中复杂自旋行为的基本量子力学的理解，拓宽适合SABRE的物质范围。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professors Boyd Goodson at Southern Illinois University (SIU) and Eduard Chekmenev at Wayne State University (WSU) are working to improve the sensitivity of nuclear magnetic resonance (NMR), an important method of chemical analysis which underlies the well-known clinical imaging modality, magnetic resonance imaging (MRI). The Goodson/Chekmenev team is developing new, inexpensive, and easy-to-make means of enhancing nuclear magnetization - a sensitivity-limiting factor in many NMR and MRI applications, including diagnostic tests for a host of diseases. Anticipated cost savings can also make these methods more available for other lab settings, particularly those that have more limited research infrastructure and/or that feature undergraduate research. Several students are involved, gaining exposure to highly interdisciplinary training. The team is also engaged in efforts to recruit undergraduate students and match them with a variety of mentored research opportunities on both campuses, with a goal of increasing the numbers and diversity of undergraduate students seeking STEM careers. The NMR/MRI approaches being used are based on Signal Amplification by Reversible Exchange, or SABRE. In SABRE, an organometallic catalyst is used to co-locate parahydrogen and a target molecule (substrate) within a transient complex; with properly matched external magnetic fields, nuclear spin order can transfer spontaneously and efficiently from parahydrogen to the substrate, giving rise to NMR and MRI signals that are increased by several orders of magnitude. Work by the Goodson/Chekmenev team seeks to: (1) improve the understanding and utility of long-range SABRE polarization transfer via spin-relay networks in model systems, for both homonuclear and heteronuclear cases; (2) develop and characterize new heterogeneous catalysts for SABRE ("HET-SABRE"), as well as approaches for catalyst recovery; and (3) broaden the range of substances amenable to SABRE through improved understanding of the fundamental quantum mechanics of complex spin behavior in model extended networks.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.