异质单重态光化学诱导动态核极化
Photochemically induced dynamic nuclear polarization of heteronuclear singlet order
摘要：
光化学诱导动态核极化（photo-CIDNP）是一种利用光来超极化核自旋的方法。在大多数情况下，CIDNP实验在高磁场下进行，样品由核磁共振（NMR）光谱仪内的光照射。在这里，我们展示了光CIDNP超极化产生的地球磁场和零至超低场（ZULF）的条件下。用便宜的发光二极管照射样品几秒钟，产生1H和13 C核自旋的强超极化，使NMR信号增强几百倍。在地球场和ZULF中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1H-13 C核自旋之间的单线态。这种状态比在地球场超极化的状态具有更长的寿命。该方法是简单和成本效益，并应适用于许多分子系统已知的表现出光CIDNP，包括氨基酸和核苷酸。
英文摘要：
Photochemically induced dynamic nuclear polarization (photo-CIDNP) is a method to hyperpolarize nuclear spins using light. In most cases, CIDNP experiments are performed at a high magnetic field and the sample is irradiated by the light inside a nuclear magnetic resonance (NMR) spectrometer. Here we demonstrate photo-CIDNP hyperpolarization generated in the Earth magnetic field and under zero- to ultralow field (ZULF) conditions. Irradiating a sample for several seconds with inexpensive light-emitting diodes produces a strong hyperpolarization of 1H and 13C nuclear spins enhancing the NMR signals several hundred times. The hyperpolarized spin states at the Earth field and in ZULF are different. In the latter case, the state corresponds to the singlet order between scalar-coupled 1H-13C nuclear spins. This state has a longer lifetime than the state hyperpolarized at Earth 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.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
