Glanzer Simon, Zangger Klaus
Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
J Am Chem Soc. 2015 Apr 22;137(15):5163-9. doi: 10.1021/jacs.5b01687. Epub 2015 Apr 13.
Scalar coupling patterns contain a wealth of structural information. The determination, especially of small scalar coupling constants, is often prevented by merging the splittings with the signal line width. Here we show that real-time J-upscaling enables the visualization of unresolved coupling constants in the acquisition dimension of one-dimensional (1D) or multidimensional NMR spectra. This technique, which works by introducing additional scalar coupling evolution delays within the recording of the FID (free induction decay), not only stretches the recorded coupling patterns but also actually enhances the resolution of multiplets, by reducing signal broadening by magnetic field inhomogeneities during the interrupted data acquisition. Enlarging scalar couplings also enables their determination in situations where the spectral resolution is limited, such as in the acquisition dimension of heteronuclear broadband decoupled HSQC (heteronuclear single quantum correlation) spectra.
标量耦合模式包含丰富的结构信息。尤其是小标量耦合常数的测定，常常因分裂与信号线宽合并而受阻。在此我们表明，实时J值放大能够在一维（1D）或多维核磁共振谱的采集维度中可视化未解析的耦合常数。该技术通过在自由感应衰减（FID）记录过程中引入额外的标量耦合演化延迟来起作用，不仅拉伸了记录的耦合模式，还通过在中断数据采集期间减少磁场不均匀性导致的信号展宽，实际上提高了多重峰的分辨率。放大标量耦合还能在光谱分辨率受限的情况下，如在异核宽带去耦的异核单量子相关（HSQC）谱的采集维度中，对其进行测定。
