NITROGEN-15 MAGNETIC RESONANCE SPECTROSCOPY. I. CHEMICAL SHIFTS.
NITROGEN-15 MAGNETIC RESONANCE SPECTROSCOPY. I. CHEMICAL SHIFTS.
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氮 15 磁共振波谱。
DOI：
10.1073/pnas.51.5.735
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发表时间：
1964
影响因子：
11.1
通讯作者：
J. Roberts
中科院分区：
文献类型：
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作者：
J. B. Lambert;G. Binsch;J. Roberts
除了最初的核矩测定（1）外，氮磁共振波谱仅限于质量数为14的同位素。虽然N14是一种丰富的同位素，但它具有电四极矩，除了最对称的环境外，它严重地加宽了氮的共振。(2)因此，氮n.m.r.光谱学在确定有机结构中的应用有限。N15的自旋为1/2，没有四极矩，这可能是非常有用的，但天然丰度低（0.36%）和固有的低信号强度（1.04 x 10^（-3）H1在恒定磁场下的信号强度）迄今为止排除了N15在n.m.r.中的应用。谱（三）
Except for the original determination(1) of nuclear moments, nitrogen magnetic resonance spectroscopy has been limited to the isotope of mass number 14. Although N14 is an abundant isotope, it possesses an electric quadrupole moment, which seriously broadens the resonances of nitrogen in all but the most symmetrical of environments.(2) Consequently, nitrogen n.m.r. spectroscopy has seen only limited use in the determination of organic structure. It might be expected that N15, which has a spin of ½ and no quadrupole moment, would be very useful, but the low natural abundance (0.36%) and the inherently low signal intensity (1.04 x 10^(-3) that of H1 at constant field) have thus far precluded utilization of N15 in n.m.r. spectroscopy.(3)