Zangger Klaus
Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
Prog Nucl Magn Reson Spectrosc. 2015 Apr;86-87:1-20. doi: 10.1016/j.pnmrs.2015.02.002. Epub 2015 Feb 12.
Although scalar-coupling provides important structural information, the resulting signal splittings significantly reduce the resolution of NMR spectra. Limited resolution is a particular problem in proton NMR experiments, resulting in part from the limited proton chemical shift range (∼10 ppm) but even more from the splittings due to scalar coupling to nearby protons. "Pure shift" NMR spectroscopy (also known as broadband homonuclear decoupling) has been developed for disentangling overlapped proton NMR spectra. The resulting spectra are considerably simplified as they consist of single lines, reminiscent of proton-decoupled C-13 spectra at natural abundance, with no multiplet structure. The different approaches to obtaining pure shift spectra are reviewed here and several applications presented. Pure shift spectra are especially useful for highly overlapped proton spectra, as found for example in reaction mixtures, natural products and biomacromolecules.
尽管标量耦合提供了重要的结构信息，但由此产生的信号分裂显著降低了核磁共振谱的分辨率。分辨率有限在质子核磁共振实验中是一个特别的问题，部分原因是质子化学位移范围有限（约10 ppm），但更多是由于与附近质子的标量耦合导致的分裂。“纯位移”核磁共振光谱法（也称为宽带同核去耦）已被开发用于解开重叠的质子核磁共振谱。所得光谱大大简化，因为它们由单线组成，让人联想到天然丰度下的质子去耦碳-13光谱，没有多重峰结构。本文综述了获得纯位移光谱的不同方法，并介绍了一些应用。纯位移光谱对于高度重叠的质子光谱特别有用，例如在反应混合物、天然产物和生物大分子中发现的光谱。
