title: The CLIP/CLAP-HSQC: pure absorptive spectra for the measurement of one-bond couplings.
abstract: 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 alpha and beta 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.
authors.affiliation: Munich Center for Integrated Protein Science, Department Chemie, Organische Chemie II, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Enthart
authors.forename: J Christoph
authors.initials: JC
authors.lastname: Freudenberger
authors.forename: Julien
authors.initials: J
authors.lastname: Furrer
authors.forename: Horst
authors.initials: H
authors.lastname: Kessler
authors.forename: Burkhard
authors.initials: B
authors.lastname: Luy
mesh_terms: D002244:Carbon / Q000737:chemistry; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D013331:Strychnine / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D013395:Sucrose; D002244:Carbon; D013331:Strychnine