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.