Recent Advances in Small Molecule NMR: Improved HSQC and HSQMBC Experiments

A general description of the latest developments in heteronuclear single-quantum correlation and heteronuclear single-quantum multiple bond correlation experiments designed for small molecules at the natural isotopic abundance is reported. A discussion is made on the details introduced into novel NMR pulse sequences with special emphasis on modern concepts such as fast NMR or pure shift NMR and also on robust techniques affording pure in-phase multiplet patterns, which are amenable for a simpler and a more accurate analysis. The suitability of some of these methods for the quantitative measurement of one-bond and long-range proton-carbon coupling values in molecules in isotropic and weakly aligned anisotropic conditions is also reviewed.