Para-hydrogen enrichment and hyperpolarization
Para-hydrogen enrichment and hyperpolarization
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DOI：
10.1002/cmr.a.20065
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发表时间：
2006-09-01
影响因子：
0.6
通讯作者：
Reineri, Francesca
中科院分区：
文献类型：
--
作者：
Canet, Daniel;Aroulanda, Christie;Reineri, Francesca
本文从氢气富集成对异构体（对应于单线态的核自旋）的一般考虑开始；这是相关人口过剩转移获得超极化的必要条件。这种转移通常由氢化反应介导，使两个质子变得不相等。这种新自旋系统的能级居群可以用密度矩阵的形式明确地计算出来。对这种形式进行了回顾，并提出了一种简单的方法，可以在氢化反应和样品插入核磁共振磁体后得到自旋态。还考虑了射频脉冲的影响。(C) 2006 Wiley期刊有限公司
This article begins with general considerations about enrichment of hydrogen gas into its para isomer (corresponding to nuclear spins in the singlet state); this is a necessary condition to obtain hyperpolarization from transfer of the relevant population excess. This transfer is generally mediated by a hydrogenation reaction such that the two protons become nonequivalent. The energy level populations of this new spin system can be calculated unambiguously using a density matrix formalism. This formalism is reviewed, and the authors propose a simple method that leads to the spin state after the hydrogenation reaction and the insertion of the sample in the NMR magnet. The effect of radiofrequency pulses is also considered. (C) 2006 Wiley Periodicals, Inc.