Sinnaeve Davy
Department of Organic and Macromolecular Chemistry, Ghent University, Campus Sterre, S4, Krijgslaan 281, B-9000, Ghent, Belgium.
Magn Reson Chem. 2018 Oct;56(10):947-953. doi: 10.1002/mrc.4671. Epub 2017 Oct 27.
2D J-resolved spectroscopy is one of the oldest and conceptually most elegant ways to separate homonuclear scalar couplings from chemical shift information. In practice, the classical experiment suffers from a number of complications that limits accuracy and resolution, including phasetwist lineshapes, strong coupling artifacts, and the need for shearing the spectrum by 45° to obtain a (J,δ)-representation. Here, a novel pure shift 2DJ experiment based on the TSE-PSYCHE experiment is reported that deals with all these issues. Previous experiments proposed z-filtration to avoid excessive artifacts caused by chunked pure shift acquisition. It will be shown that these artifacts can also easily be avoided by means of the Pell-Keeler method. As opposed to its z-filtered counterparts, the new experiment provides pure shift 2DJ spectra that are free of artifacts from pulse imperfections and minimize responses related to strong coupling. In this way, multiplet analysis becomes possible at maximal resolution and a minimum of spectral complications.
二维J分辨光谱是从化学位移信息中分离同核标量耦合的最古老且概念上最简洁的方法之一。在实际应用中，经典实验存在诸多限制精度和分辨率的复杂问题，包括相位扭曲线形、强耦合伪影，以及需要将光谱剪切45°以获得(J,δ)表示。在此，报道了一种基于TSE - PSYCHE实验的新型纯位移二维J实验，该实验解决了所有这些问题。先前的实验提出了z滤波以避免由分块纯位移采集引起的过多伪影。将表明，通过佩尔 - 基勒方法也可轻松避免这些伪影。与z滤波的同类实验不同，新实验提供的纯位移二维J光谱没有脉冲缺陷产生的伪影，并将与强耦合相关的响应降至最低。通过这种方式，在最大分辨率和最小光谱复杂性的情况下进行多重峰分析成为可能。
