A general strategy towards efficient hyperpolarization in high-field magnetic resonance using mixed-valence compounds

使用混合价化合物实现高场磁共振有效超极化的一般策略

• 批准号: 468786575
• 负责人: Dr. Svetlana Pylaeva
• 金额: --
• 依托单位: Bijvoet Center for Biomolecular Research
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/468786575?language=en
• 关键词: general; strategy; towards; efficient; hyperpolarization

Dynamic nuclear polarization (DNP) is a powerful method that greatly enhances signal intensities in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) enabling unprecedented applications in life and material science. The ultimate scientific goal is to expand the use of DNP to ultra-high magnetic fields where optimal spectral resolution and sensitivity are integrated. While considerable progress has been made in constructing DNP-NMR instruments operating at ultra-high magnetic fields, designing polarizing agents that optimally perform under such conditions has thus far been challenging. The investigation of new radicals that allow for significant DNP enhancements in high fields is therefore urgently needed. Recently, the so called Overhauser effect has become an interesting focus to overcome these challenges. Firstly, in contrast to previous expectations, the effect was demonstrated to occur in glassy insulating matrices which would be required for practical applications in NMR/MRI. Secondly, the effect was shown to scale favorably with static magnetic field strength.Here I propose to systematically and broadly investigate the Overhauser effect in insulating solids by combination of experimental and theoretical techniques. Previously, I have examined the BDPA radical by ab initio methods. My findings put this radical into a larger group of mixed-valence compounds, also known as Jahn-Teller systems. In preliminary calculations, I have identified several new molecules that have properties similar to the studied radical. Some of the molecules were synthesized, and have experimentally demonstrated Overhauser effect DNP in insulating matrix . These results set the stage for optimization of their molecular properties including the electron transfer rate, charge, and the surrounding solvent with the goal to develop a novel class of powerful DNP agents that optimally perform at ultra-high magnetic fields.

动态核极化 (DNP) 是一种强大的方法，可大大增强核磁共振 (NMR) 和磁共振成像 (MRI) 中的信号强度，从而在生命和材料科学中实现前所未有的应用。最终的科学目标是将 DNP 的使用扩展到超高磁场，其中集成了最佳光谱分辨率和灵敏度。虽然在构建在超高磁场下运行的 DNP-NMR 仪器方面已经取得了相当大的进展，但设计在这种条件下发挥最佳性能的偏振剂迄今为止仍然具有挑战性。因此，迫切需要研究能够在高场中显着增强 DNP 的新自由基。最近，所谓的奥弗豪瑟效应已成为克服这些挑战的一个有趣的焦点。首先，与之前的预期相反，该效应被证明发生在玻璃绝缘基体中，这对于 NMR/MRI 的实际应用是必需的。其次，该效应被证明与静磁场强度成正比。在这里，我建议通过实验和理论技术的结合，系统而广泛地研究绝缘固体中的奥沃豪瑟效应。之前，我已经通过从头开始的方法检查了 BDPA 自由基。我的发现将这个基团归入一大组混合价化合物中，也称为 Jahn-Teller 系统。在初步计算中，我已经确定了几种新分子，其特性与所研究的自由基相似。合成了一些分子，并通过实验证明了 DNP 在绝缘基质中的奥豪瑟效应。这些结果为优化其分子特性（包括电子转移速率、电荷和周围溶剂）奠定了基础，目标是开发一类新型强大的 DNP 试剂，使其在超高磁场下具有最佳性能。