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，可以大大增强核磁共振（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，其中集成了最佳的光谱分辨率和灵敏度。虽然在构建在超高磁场下操作的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最佳表现的极化剂迄今为止一直具有挑战性。因此，迫切需要研究新的自由基，使显着的DNP增强在高领域。最近，所谓的Overhauser效应已成为一个有趣的焦点，以克服这些挑战。首先，与先前的预期相反，该效应被证明发生在NMR/MRI实际应用所需的玻璃绝缘基质中。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相结合，系统和广泛地研究绝缘固体中的Overhauser效应。以前，我已经检查了BDPA自由基从头算方法。我的发现将这种自由基放入了一个更大的混合价化合物组中，也称为Jahn-Teller系统。在初步计算中，我已经确定了几个新的分子，它们具有与所研究的自由基相似的性质。合成了部分分子，并在实验上证明了绝缘基体中的Overhauser效应DNP。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，目标是开发一类在超高磁场下表现最佳的新型强大DNP试剂。