Sjolander Tobias F, Tayler Michael C D, Kentner Arne, Budker Dmitry, Pines Alexander
Department of Chemistry, University of California at Berkeley , Berkeley, California 94720-3220, United States.
Department of Physics, University of California at Berkeley , Berkeley, California 94720-7300, United States.
J Phys Chem Lett. 2017 Apr 6;8(7):1512-1516. doi: 10.1021/acs.jpclett.7b00349. Epub 2017 Mar 21.
We present a two-dimensional method for obtaining C-decoupled, H-coupled nuclear magnetic resonance (NMR) spectra in zero magnetic field using coherent spin-decoupling. The result is a spectrum determined only by the proton-proton J-coupling network. Detection of NMR signals in zero magnetic field requires at least two different nuclear spin species, but the proton J-spectrum is independent of isotopomer, thus potentially simplifying spectra and thereby improving the analytical capabilities of zero-field NMR. The protocol does not rely on a difference in Larmor frequency between the coupled nuclei, allowing for the direct determination of J-coupling constants between chemically equivalent spins. We obtain the C-decoupled zero-field spectrum of [1-C]-propionic acid and identify conserved quantum numbers governing the appearance of cross peaks in the two-dimensional spectrum.
我们提出了一种二维方法，用于在零磁场中使用相干自旋去耦获得碳去耦、氢耦合的核磁共振（NMR）谱。结果得到的谱仅由质子-质子J耦合网络决定。在零磁场中检测NMR信号至少需要两种不同的核自旋种类，但质子J谱与同位素异构体无关，因此有可能简化谱图，从而提高零场NMR的分析能力。该方法不依赖于耦合核之间拉莫尔频率的差异，能够直接测定化学等价自旋之间的J耦合常数。我们获得了[1-C]-丙酸的碳去耦零场谱，并确定了二维谱中控制交叉峰出现的守恒量子数。
