Gołowicz Dariusz, Kazimierczuk Krzysztof, Urbańczyk Mateusz, Ratajczyk Tomasz
Faculty of Chemistry, Biological and Chemical Research Centre University of Warsaw Żwirki i Wigury 101 02-089 Warsaw Poland.
Centre of New Technologies University of Warsaw Banacha 2 C 02-097 Warsaw Poland.
ChemistryOpen. 2019 Feb 14;8(2):196-200. doi: 10.1002/open.201800294. eCollection 2019 Feb.
Low-field benchtop nuclear magnetic resonance (BT-NMR) spectrometers with Halbach magnets are being increasingly used in science and industry as cost-efficient tools for the monitoring of chemical reactions, including hydrogenation. However, their use of low-field magnets limits both resolution and sensitivity. In this paper, we show that it is possible to alleviate these two problems through the combination of parahydrogen-induced polarization (PHIP) and fast correlation spectroscopy with time-resolved non-uniform sampling (TR-NUS). PHIP can enhance NMR signals so that substrates are easily detectable on BT-NMR spectrometers. The interleaved acquisition of one- and two-dimensional spectra with TR-NUS provides unique insight into the consecutive moments of hydrogenation reactions, with a spectral resolution unachievable in a standard approach. We illustrate the potential of the technique with two examples: the hydrogenation of ethylphenyl propiolate and the hydrogenation of a mixture of two substrates - ethylphenyl propiolate and ethyl 2-butynoate.
配备哈尔巴赫磁体的低场台式核磁共振（BT-NMR）光谱仪作为一种经济高效的工具，正越来越多地应用于科学和工业领域，用于监测包括氢化反应在内的化学反应。然而，其低场磁体的使用限制了分辨率和灵敏度。在本文中，我们表明，通过将仲氢诱导极化（PHIP）与具有时间分辨非均匀采样（TR-NUS）的快速相关光谱相结合，可以缓解这两个问题。PHIP可以增强NMR信号，从而使底物在BT-NMR光谱仪上易于检测。使用TR-NUS对一维和二维光谱进行交错采集，能够对氢化反应的连续瞬间提供独特的见解，这是标准方法无法实现的光谱分辨率。我们通过两个例子说明了该技术的潜力：苯乙炔酸乙酯的氢化反应以及两种底物——苯乙炔酸乙酯和2-丁炔酸乙酯混合物的氢化反应。
