Scalar Magnetics, LLC, 3 Harolwood Ct., Apt C, Windsor Mill, MD 21244, USA.
Athinoula A. Martinos Center for Biomedical Engineering, Massachusetts General Hospital, 149(th) Thirteenth St., Charlestown, MA 02129, USA; Department of Physics, Harvard University, 17 Oxford St., Cambridge, MA 02138, USA.
J Magn Reson. 2022 Aug;341:107244. doi: 10.1016/j.jmr.2022.107244. Epub 2022 May 23.
In the strong coupling regime with J-coupling much larger than chemical shift differences, J-coupling spectroscopy enables spectral identification of molecules even when conventional NMR fails. While this classically required the presence of a heteronucleus, we recently showed that J-coupling spectra can be acquired in many homonuclear systems using spin-lock induced crossing (SLIC). Here, we present an alternative method using a spin echo train in lieu of a spin-locking SLIC pulse, which has a number of advantages. In particular, spin echo acquisition within the pulse train enables simultaneous collection of time and frequency data. The resulting 2D spectrum can be used to study dynamic spin evolution, and the time domain data can be averaged to create a 1D J-coupling spectrum with increased signal-to-noise ratio.
在 J 耦合远大于化学位移差的强耦合情况下，即使常规 NMR 失效，J 耦合光谱也能实现分子的光谱鉴定。虽然这在经典情况下需要存在杂核，但我们最近表明，使用自旋锁定诱导交叉（SLIC）可以在许多同核系统中获得 J 耦合光谱。在这里，我们提出了一种替代方法，使用自旋回波序列代替自旋锁定 SLIC 脉冲，该方法具有许多优点。特别是，在脉冲序列内进行自旋回波采集可以同时采集时间和频率数据。由此产生的 2D 光谱可用于研究动态自旋演化，并且可以对时域数据进行平均以创建具有更高信噪比的一维 J 耦合光谱。
