Lin Yulan, Yan Ming, Su Jianwei, Huang Yuqing, Feng Jianghua, Chen Zhong
Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
J Chem Phys. 2020 Nov 7;153(17):174114. doi: 10.1063/5.0025962.
The H coupling networks, including H-H correlation and J coupling values, provide the important information for structure elucidation and conformation analysis. However, the presence of a large number of couplings and the phase-twist lineshapes often prevents revealing H coupling networks. Here, we provide a clean absorption-mode 2D NMR method, SIMAJ (SImple Methods for 2D Absorption mode J-resolved spectrum), for a straightforward assignment and measurement of the coupling network involving the chosen proton. Relying on the pure shift element, H-H couplings and chemical shift evolution are totally separately demonstrating along the F and F dimensions, respectively. Processing with a single experiment dataset and free of 45° spectral shearing, an absorption-mode 2D J-resolved spectrum can be reconstructed. Two pulse sequences were proposed as examples. The SIMAJ signal processing method will be a general procedure for obtaining absorption-mode lineshapes when analyzing the experiment datasets with chemical shifts and J coupling multiplets in the orthogonal dimensions. With excellent sensitivity, high spectral purity, and ability of easily identifying H-H correlations, significant improvements are beneficial for structural, conformational, or complex composition analyses.
H耦合网络，包括H-H相关性和J耦合值，为结构解析和构象分析提供了重要信息。然而，大量耦合的存在以及相位扭曲线形常常阻碍H耦合网络的揭示。在此，我们提供一种清晰的吸收模式二维核磁共振方法，即SIMAJ（二维吸收模式J分辨谱的简单方法），用于直接确定和测量涉及所选质子的耦合网络。依靠纯移元素，H-H耦合和化学位移演化分别沿F1和F2维度完全独立地呈现。通过处理单个实验数据集且无需45°谱剪切，可重建吸收模式二维J分辨谱。提出了两个脉冲序列作为示例。当在正交维度分析具有化学位移和J耦合多重峰的实验数据集时，SIMAJ信号处理方法将是获得吸收模式线形的通用程序。凭借出色的灵敏度、高光谱纯度以及易于识别H-H相关性的能力，显著的改进有利于结构、构象或复杂组成分析。
