Hyperpolarization of Frozen Hydrocarbon Gases by Dynamic Nuclear Polarization at 1.2 K
Hyperpolarization of Frozen Hydrocarbon Gases by Dynamic Nuclear Polarization at 1.2 K
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DOI：
10.1021/acs.jpclett.6b01345
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发表时间：
2016-08-18
影响因子：
5.7
通讯作者：
Jannin, Sami
中科院分区：
文献类型：
--
作者：
Vuichoud, Basile;Canet, Estel;Jannin, Sami
本文报道了一种用动态核极化（DNP）研究凝聚态气体超极化的简单而通用的方法。气体被吸附在被称为HYPSO（HYper Polarizing Solids）的结构化中孔二氧化硅基质的孔中，HYPSO具有共价结合到中孔表面的顺磁性极化剂。DNP在低温和中等磁场（T = 1.2 K和B-0 = 6.7 T）下进行。在接近电子自旋共振频率（f = 188.3 GHz）处施加调频微波辐射，HYPSO极化剂的电子自旋极化被转移到冷冻气体的核自旋。可以获得高达P（H-1）= 70%的质子极化，其随后可以通过交叉极化转移到天然丰度的C-13，对于乙烯产生高达P（C-13）= 27%。
We report a simple and general method for the hyperpolarization of condensed gases by dynamic nuclear polarization (DNP). The gases are adsorbed in the pores of structured mesoporous silica matrices known as HYPSOs (HYper Polarizing SOlids) that have paramagnetic polarizing agents covalently bound to the surface of the mesopores. DNP is performed at low temperatures and moderate magnetic fields (T = 1.2 K and B-0 = 6.7 T). Frequency-modulated microwave irradiation is applied close to the electron spin resonance frequency (f = 188.3 GHz), and the electron spin polarization of the polarizing agents of HYPSO is transferred to the nuclear spins of the frozen gas. A proton polarization as high as P(H-1) = 70% can be obtained, which can be subsequently transferred to C-13 in natural abundance by cross-polarization, yielding up to P(C-13) = 27% for ethylene.