Microwave-gated dynamic nuclear polarization
Microwave-gated dynamic nuclear polarization
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DOI：
10.1039/c6cp05587g
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发表时间：
2016-01-01
影响因子：
3.3
通讯作者：
Jannin, Sami
中科院分区：
文献类型：
--
作者：
Bornet, Aurelien;Pinon, Arthur;Jannin, Sami
溶解动态核极化(D-DNP)已成为增强核磁共振信号的一种选择方法。最近，我们提出将交叉极化(CP)与D-DNP相结合，在较短的建立时间内提供高极化P(C-13)。在这篇文章中，我们证明了在CP之前关闭微波辐射几百毫秒可以显著提高效率。通过实施微波选通，[1-C-13]乙酸钠的C-13极化可达%，极化建立时间常数为160S，对[C-13]尿素甚至可达到P(C-13)=78%的极化。
Dissolution dynamic nuclear polarization (D-DNP) has become a method of choice to enhance signals in nuclear magnetic resonance (NMR). Recently, we have proposed to combine cross-polarization (CP) with D-DNP to provide high polarization P(C-13) in short build-up times. In this paper, we show that switching microwave irradiation off for a few hundreds of milliseconds prior to CP can significantly boost the efficiency. By implementing microwave gating, C-13 polarizations on sodium [1-C-13]acetate as high as 64% could be achieved with a polarization build-up time constant as short as 160 s. A polarization of P(C-13) = 78% could even be reached for [C-13]urea.