“IPAP–HSQMBC: Measurement of long-range heteronuclear coupling constants from spin-state selective multiplets”, by Sergi Gil, Juan Félix Espinosa and Teodor Parella; Journal of Magnetic Resonance, 207, 312-321 (2010). DOI: 10.1016/j.jmr.2010.09.017
A new NMR approach is proposed for the measurement of long-range heteronuclear coupling constants (nJXH,n > 1) in natural abundance molecules. Two complementary in-phase (IP) and anti-phase (AP) data are separately recorded from a modified HSQMBC experiment and then added/subtracted to provide spin-state-selective α/β–HSQMBC spectra. The magnitude of nJXH can be directly determined by simple analysis of the relative displacement between α– and β-cross-peaks. The robustness of this IPAP–HSQMBC experiment is evaluated experimentally and by simulation using a variety of different conditions. Important aspects such as signal intensity dependence and presence of unwanted cross-talk effects are discussed and examples on the measurement of small proton–carbon (nJCH) and proton–nitrogen (nJNH) coupling constants are provided.
Bruker Pulse Program: ipap_hsqmbc
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