Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, China.
Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, China.
Anal Chim Acta. 2021 Nov 15;1185:339055. doi: 10.1016/j.aca.2021.339055. Epub 2021 Sep 15.
J coupling constitutes an important NMR parameter for molecular-level composition analysis and conformation elucidation. Dozens of J-based approaches have been exploited for J coupling measurement and coupling network determination, however, they are generally imposed to insufficient spectral resolution to resolve crowded NMR resonances and low measurement efficiency that a single experiment records one J coupling network. Herein, we propose a general NMR method to collect high-resolution 2D J-edited NMR spectra, which are characterized with advantages of pure absorptive lineshapes, decoupled chemical shift dimension, as well as eliminated axial peaks, thus facilitating J coupling partner assignments and J coupling constant measurements. More meaningfully, this protocol allows simultaneous determination of multiple coupling networks for highly efficient multiplet analyses via addressing multiple protons within one single experiment. Additionally, another variant is proposed for high-resolution applications under adverse magnetic field conditions. Therefore, this study provides a useful NMR protocol for configurational and structural studies with extensive applications in chemistry, biology, and material science.
J 耦合是分子水平组成分析和构象阐明的一个重要 NMR 参数。已经开发了数十种基于 J 的方法来测量 J 耦合和确定耦合网络，然而，它们通常受到光谱分辨率不足的限制，无法分辨拥挤的 NMR 共振和低测量效率，即单个实验仅记录一个 J 耦合网络。在此，我们提出了一种通用的 NMR 方法来采集高分辨率的 2D J 编辑 NMR 光谱，其具有纯吸收线形状、去耦的化学位移维度以及消除轴向峰的优点，从而有助于 J 耦合伙伴的分配和 J 耦合常数的测量。更有意义的是，该方案允许通过在单个实验中寻址多个质子，同时确定多个耦合网络，从而实现高效的多峰分析。此外，还提出了另一种变体，用于在不利的磁场条件下进行高分辨率应用。因此，这项研究提供了一种有用的 NMR 方案，用于构象和结构研究，在化学、生物学和材料科学中有广泛的应用。
