Premium
Doubly compensated multiplicity‐edited HSQC experiments utilizing broadband inversion pulses
Author(s) -
Hu Haitao,
Krishnamurthy Krish
Publication year - 2008
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2221
Subject(s) - heteronuclear single quantum coherence spectroscopy , heteronuclear molecule , chemistry , multiplicity (mathematics) , inversion (geology) , adiabatic process , anharmonicity , nuclear magnetic resonance , two dimensional nuclear magnetic resonance spectroscopy , physics , quantum mechanics , stereochemistry , nuclear magnetic resonance spectroscopy , mathematics , mathematical analysis , paleontology , structural basin , biology
We propose a family of doubly compensated multiplicity‐edited heteronuclear single quantum coherence (HSQC) pulse sequences. The key difference between our proposed sequences and the compensation of refocusing inefficiency with synchronized inversion sweeps (CRISIS)‐HSQC experiments they are based on is that the conventional rectangular 180° pulses on the proton channel in the latter have been replaced by the computer‐optimized broadband inversion pulses (BIPs) with superior inversion performance as well as much improved tolerance to B 1 field inhomogeneity. Moreover, all adiabatic carbon 180° pulses during the INEPT and reverse‐INEPT periods in the CRISIS‐HSQC sequences have also been replaced with the much shorter BIPs, while the adiabatic sweeps during the heteronuclear spin echo for multiplicity editing are kept in place in order to maintain the advantage of the CRISIS feature of the original sequences, namely J ‐independent refocusing of the one‐bond 1 H 13 C coupling constants. These modifications have also been implemented to the preservation of equivalent pathways (PEP)‐HSQC experiments. We demonstrate through a detailed comparison that replacing the proton 180° pulses with the BIPs provide additional sensitivity gain that can be mainly attributed to the improved tolerance to B 1 field inhomogeneity of the BIPs. The proposed sequences can be easily adapted for 19 F 13 C correlations. Copyright © 2008 John Wiley & Sons, Ltd.