A Nuclear Singlet Lifetime of More than One Hour in Room-Temperature Solution
A Nuclear Singlet Lifetime of More than One Hour in Room-Temperature Solution
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DOI：
10.1002/anie.201411978
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发表时间：
2015-03-16
影响因子：
16.6
通讯作者：
Levitt, Malcolm H.
中科院分区：
文献类型：
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作者：
Stevanato, Gabriele;Hill-Cousins, Joseph T.;Levitt, Malcolm H.
核磁共振（NMR）和磁共振成像（MRI）是极其重要的技术，几乎在所有科学分支中都有许多应用。然而，直到最近，NMR方法受到时间常数T-1的限制，用于通过与热分子环境接触而衰减核自旋磁化。长寿命态是多个原子核的相关量子态，其衰变时间常数可能超过T-1很大的系数。在这里，我们展示了一个由两个C-13原子核组成的长寿命态，其在室温溶液中的寿命超过1小时，比T-1长约50倍。量子理论、分子动力学和量子化学的结合很好地预测了这种行为。这种超长寿命的状态预计将有助于核超极化的传输和应用，这将导致NMR和MRI信号增强高达五个数量级。
Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are supremely important techniques with numerous applications in almost all branches of science. However, until recently, NMR methodology was limited by the time constant T-1 for the decay of nuclear spin magnetization through contact with the thermal molecular environment. Long-lived states, which are correlated quantum states of multiple nuclei, have decay time constants that may exceed T-1 by large factors. Here we demonstrate a nuclear long-lived state comprising two C-13 nuclei with a lifetime exceeding one hour in room-temperature solution, which is around 50 times longer than T-1. This behavior is well-predicted by a combination of quantum theory, molecular dynamics, and quantum chemistry. Such ultra-long-lived states are expected to be useful for the transport and application of nuclear hyperpolarization, which leads to NMR and MRI signals enhanced by up to five orders of magnitude.