The CLIP/CLAP-HSQC: Pure absorptive spectra for the measurement of one-bond couplings

Journal of Magnetic Resonance, 2008, 192, 314-322 published on 21.03.2008
Journal of Magnetic Resonance, online article
Heteronuclear residual dipolar one-bond couplings of organic molecules at natural abundance are most easily measured using t2 coupled HSQC spectra. However, inevitably mismatched transfer delays result in phase distortions due to residual dispersive antiphase coherences in such experiments. In this article, slightly modified t2 coupled HSQC experiments with clean inphase (CLIP) multiplets are introduced which also reduce the intensities of undesired long-range cross peaks. With the corresponding antiphase (CLAP) experiment, situations where a and b components overlap can be resolved for all multiplicities in an IPAP manner. A comparison of the experiments using hard pulses and shaped broadband excitation and inversion pulses on the heteronucleus is given and potential spectral artefacts are discussed in detail.  

TU München
Helmholtz München
MPI of Neurobiology
MPI of Biochemistry