Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
Chemistry Department, Texas A&M University, College Station, TX, USA.
Nat Commun. 2022 Feb 11;13(1):833. doi: 10.1038/s41467-022-28304-w.
Nuclear magnetic resonance (NMR) spectroscopy provides detailed information about dynamic processes through line-shape changes, which are traditionally limited to equilibrium conditions. However, a wealth of information is available by studying chemical reactions under off-equilibrium conditions-e.g., in states that arise upon mixing reactants that subsequently undergo chemical changes-and in monitoring the reactants and products in real time. Herein, we propose and demonstrate a time-resolved kinetic NMR experiment that combines rapid mixing techniques, continuous flow, and single-scan spectroscopic imaging methods, leading in unison to a 2D spectrotemporal NMR correlation that provides high-quality kinetic information of off-equilibrium chemical reactions. These kinetic 2D NMR spectra possess a high-resolution spectral dimension revealing the individual chemical sites, correlated with a time-independent, steady-state spatial axis that delivers information concerning temporal changes along the reaction coordinate. A comprehensive description of the kinetic, spectroscopic, and experimental features associated with these spectrotemporal NMR analyses is presented. Experimental demonstrations are carried out using an enzymatically catalyzed reaction leading to site- and time-resolved kinetic NMR data, that are in excellent agreement with control experiments and literature values.
核磁共振（NMR）光谱学通过谱线形状变化提供有关动态过程的详细信息，这些变化传统上仅限于平衡条件。然而，通过研究非平衡条件下的化学反应，可以获得大量信息，例如在混合反应物后发生化学变化的状态下，以及实时监测反应物和产物。在此，我们提出并证明了一种时间分辨的动力学 NMR 实验，该实验结合了快速混合技术、连续流动和单扫描光谱成像方法，共同导致二维光谱时间相关 NMR 相关，提供了非平衡化学反应的高质量动力学信息。这些动力学二维 NMR 光谱具有揭示单个化学位点的高分辨率光谱维度，与提供有关沿反应坐标的时间变化的时间独立的稳态空间轴相关联。本文全面介绍了与这些光谱时间 NMR 分析相关的动力学、光谱和实验特征。实验演示使用酶催化反应进行，得到了位分辨和时间分辨的动力学 NMR 数据，这些数据与对照实验和文献值非常吻合。
