Electron paramagnetic resonance spectrometer for rapid scan, freeze quench and kinetic measurements

用于快速扫描、冷冻淬灭和动力学测量的电子顺磁共振波谱仪

• 批准号: 500203554
• 金额: --
• 依托单位: Ludwig-Maximilians-Universität München (LMU)
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2022
• 资助国家: 德国
• 起止时间: 2021-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/500203554?language=en
• 关键词: Electron; paramagnetic; resonance; spectrometer; rapid

In our interdisciplinary mechanistic-synthetic research that paves the path for the control of redox (electron transfer) processes in living systems, biomimetic catalysis and chemical energy conversion, almost all investigated compounds and their catalytic or stoichiometric reactions are paramagnetic or implicate the formation/decay of paramagnetic species, respectively. Thus, the application of electron paramagnetic resonance (EPR) as a direct and non-invasive technique is an essential tool to characterise compounds of interest (complexes with redox-active metal centres and/or ligands and free radical species such as superoxide, nitric oxide, hydroxyl radical etc.) and clarify the mechanism of their transformation. In particular, it will be crucial for kinetic studies, trapping/characterizing of reactive intermediates and real-time monitoring of fast (catalytic) processes when UV/Vis and NMR methods exhibit their limitations, which is often the case in processes investigated by us that involve multicomponent paramagnetic reaction mixtures (e.g. when reactants, intermediates and products are all paramagnetic) and two or more parallel-running (catalytic) reactions. Thus, the nature or our research requires a rather unconventional EPR device capable of rapid scan (RS), freeze quench (FQ) and stopped-flow (SF) measurements (RS/FQ/SF-EPR). Such a multifunctional, high-performance EPR instrument with unique rapid-mixing and rapid-scan measurement capability does not exist at LMU and to best of our knowledge not even in Germany. For the objectives of our kinetic/mechanistic approaches, the required EPR device, apart from standard EPR measurements (CW, X-band mode), should be able to meet the following requirements: (i) to operate at Q-band microwaves, (ii) to utilise two cooling systems using liquid helium and liquid nitrogen, (iii) to easily handle freeze-quench experiments to catch and characterize short-lived radical intermediates, (iv) to be compatible with the home-built, dielectric ring resonator that is essential to construct the EPR stopped-flow equipment, (v) to operate in rapid-scan mode using the RS-resonator to carry out time-resolved measurements of very short-lived radical/paramagnetic species and (vi) to operate with a mixing (flow) resonator to study short-lived radicals generated in biological medium. Such instrumentation will allow broad application (within our collaborations or service measurements) of the EPR technique for interested groups in different fields and will be indispensable for further scientific achievements of our ongoing and planned projects, contributing to the development of efficient catalysts, redox-modulators, therapeutics or diagnostic tools. It will also allow us to push the boundaries of possible EPR methodology by constructing a rather unique rapid-scan EPR stopped-flow device of improved resolution that would currently be operative in the field of bioinorganic chemistry and chemical energy conversion.

在我们的跨学科机理合成研究中，该研究铺平了控制氧化还原（电子转移）过程的路径，几乎所有研究的化合物及其催化或催化反应几乎是磁磁性的，或暗示了sagionagnotic种类的形成/衰减。因此，将电子顺磁共振（EPR）应用于直接和非侵入性技术是表征感兴趣的化合物的必不可少的工具（具有氧化还原活性金属中心和/或配体的复合物以及自由基物种，例如上氧化物，硝酸氧化物，硝酸氧化物，羟基激进等），并阐明了其转换的机制。特别是，对于动力学研究，反应性中间体的捕获/表征和对快速（催化）过程的实时监测至关重要（催化）反应。因此，性质或我们的研究需要一个非常规的EPR设备，能够快速扫描（RS），冻结（FQ）和停止流量（SF）测量（RS/FQ/SF-EPR）。 LMU的这种多功能高性能EPR仪器具有独特的快速混合和快速扫描的测量能力，甚至在我们的德国也不存在。 For the objectives of our kinetic/mechanistic approaches, the required EPR device, apart from standard EPR measurements (CW, X-band mode), should be able to meet the following requirements: (i) to operate at Q-band microwaves, (ii) to utilise two cooling systems using liquid helium and liquid nitrogen, (iii) to easily handle freeze-quench experiments to catch and characterize short-lived radical intermediates, （iv）要与构造EPR停止流量设备至关重要的自制介电环谐振器兼容，（v）使用RS谐振器在快速扫描模式下运行，以进行非常短的自由基/paramagnetic物种和（vi）进行介绍（VI）进行介绍（介质）进行介绍（介质）进行介绍（介质），以进行简短的（VI）进行研究。这种仪器将允许对不同领域的感兴趣小组的EPR技术进行广泛的应用（在我们的协作或服务测量中），并且对于我们正在进行的和计划的项目的进一步科学成就是必不可少的，这有助于开发有效的催化剂，氧化还原调节剂，治疗疗法或诊断工具。它还将使我们能够通过构建一种相当独特的快速扫描EPR停止流量设备的改进分辨率的设备来突破可能的EPR方法，该设备目前将在生物无机化学和化学能转化率领域中起作用。