Microwave-free optical hyperpolarization enhances 1H, 19F and two-dimensional 19F NMR in liquids

Experimental datasets. Federico De Biasi, Lorenzo Franco, Marco Ruzzi, and Gabriele Stevanato* Department of Chemical Sciences, University of Padova, via Marzolo 1 35131 Padova, Italy ABSTRACT: Optical dynamic nuclear polarization (oDNP) in liquids offers a microwave‑free route to NMR signal enhancement but has so far relied on a single dye–radical pair with modest performance and poor photostability. Here, we show that porphyrin–BDPA pairs overcome these limitations, yielding bulk solution 1H enhancement factors of –7.5 at 0.35 T and −25 at 0.16 T. X‑band enhancements are twice that of previously reported liquid‑state oDNP platforms and are achieved under static conditions using a low‑power incoherent light source (<0.9 W). Beyond 1H hyperpolarization, we demonstrate the first 19F oDNP enhancement in solution (+5 at 0.37 T) and the first oDNP-enhanced 2D NMR experiment in liquids exemplified by a 19F COSY spectrum. Positive 19F enhancements indicate a significant scalar contribution to the electron–nuclear interaction. Our results establish a robust platform for multidimensional homonuclear and heteronuclear hyperpolarized NMR experiments in solution under microwave-free conditions. ACKNOWLEDGMENT This research has been funded/co-funded by the European Union (ERC StG, HYPMET, 101117082). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. The authors thank Sabrina Mattiolo for the assistance with sample preparation.实验数据集。 费德里科·德·比亚西、洛伦佐·佛朗哥、马尔科·鲁齐与加布里埃莱·斯特瓦纳托* 意大利帕多瓦大学化学科学系，马尔佐洛路1号，35131帕多瓦，意大利 摘要：液态体系中的光学动态核极化（optical dynamic nuclear polarization, oDNP）为核磁共振（NMR）信号增强提供了无需微波的可行路径，但迄今为止相关研究仅依托单一染料-自由基对体系，存在性能平庸、光稳定性欠佳的短板。本研究证实，卟啉-BDPA对（porphyrin–BDPA pairs）可克服上述局限，在0.35 T场强下实现体相溶液质子（¹H）增强因子达-7.5，在0.16 T场强下可达-25。其X波段（X-band）增强效果为此前报道的液态oDNP平台的两倍，且可在静态条件下借助功率低于0.9 W的低功率非相干光源实现。除质子超极化外，本研究还首次实现了溶液体系中氟-19（¹⁹F）的oDNP增强（0.37 T场强下为+5），并首次将oDNP增强技术应用于液态二维核磁共振（2D NMR）实验，以氟-19相关谱（COSY spectrum）为例进行了演示。氟-19的正增强结果表明，电子-核相互作用中存在显著的标量耦合贡献。本研究成果为无需微波的液态多维同核及异核超极化核磁共振实验构建了稳健的技术平台。 致谢 本研究由欧盟（欧洲研究委员会启动基金，ERC StG，HYPMET，项目编号101117082）资助或共同资助。文中所表达的观点与见解仅代表作者本人，未必反映欧盟或欧洲研究委员会的立场。欧盟及资助机构不对本文内容承担任何责任。作者感谢萨布丽娜·马蒂奥洛在样品制备工作中提供的协助。