Sheberstov Kirill F, Chuchkova Liubov, Hu Yinan, Zhukov Ivan V, Kiryutin Alexey S, Eshtukov Artur V, Cheshkov Dmitry A, Barskiy Danila A, Blanchard John W, Budker Dmitry, Ivanov Konstantin L, Yurkovskaya Alexandra V
Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany.
GSI Helmholtzzentrum für Schwerionenforschung, Helmholtz-Institut Mainz, 55128 Mainz, Germany.
J Phys Chem Lett. 2021 May 20;12(19):4686-4691. doi: 10.1021/acs.jpclett.1c00503. Epub 2021 May 12.
Photochemically induced dynamic nuclear polarization (photo-CIDNP) is a method to hyperpolarize nuclear spins using light. In most cases, CIDNP experiments are performed in high magnetic fields and the sample is irradiated by light inside a nuclear magnetic resonance (NMR) spectrometer. Here we demonstrate photo-CIDNP hyperpolarization generated in the Earth's magnetic field and under zero- to ultralow-field (ZULF) conditions. Irradiating a sample containing tetraphenylporphyrin and para-benzoquinone for several seconds with light-emitting diodes produces strong hyperpolarization of H and C nuclear spins, enhancing the NMR signals more than 200 times. The hyperpolarized spin states at the Earth's field and in ZULF are different. In the latter case, the state corresponds to the singlet order between scalar-coupled H-C nuclear spins. This state has a longer lifetime than the state hyperpolarized at Earth's field. The method is simple and cost-efficient and should be applicable to many molecular systems known to exhibit photo-CIDNP, including amino acids and nucleotides.
光化学诱导动态核极化（光化学诱导动态核极化，photo-CIDNP）是一种利用光使核自旋超极化的方法。在大多数情况下，CIDNP实验是在高磁场中进行的，样品在核磁共振（NMR）光谱仪内受到光照射。在此，我们展示了在地球磁场和零至超低场（ZULF）条件下产生的光化学诱导动态核极化超极化。用发光二极管照射含有四苯基卟啉和对苯醌的样品几秒钟，会使氢和碳核自旋产生强烈的超极化，将NMR信号增强200倍以上。在地球磁场和ZULF条件下的超极化自旋态是不同的。在后一种情况下，该状态对应于标量耦合的氢 - 碳核自旋之间的单重态序。这种状态的寿命比在地球磁场中超极化的状态更长。该方法简单且成本效益高，应适用于许多已知会表现出光化学诱导动态核极化的分子系统，包括氨基酸和核苷酸。
