heteronuclear single quantum coherence 1H–15N heteronuclear single quantum coherence 1H-15N HSQC 2009-03-11T05:05:26Z CHMO:0001147 https://orcid.org/0000-0001-5985-7429 A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and the 15N nuclei to which they are covalently bound. Only the magnetisation of the 15N nucleus is allowed to evolve.