title: Recoupled polarization transfer heteronuclear 1H-13C multiple-quantum correlation in solids under ultra-fast MAS.
abstract: A new approach for high-resolution solid-state heteronuclear multiple-quantum MAS NMR spectroscopy of dipolar-coupled spin-12 nuclei is introduced. The method is a heteronuclear chemical shift correlation technique of abundant spins, like 1H with rare spins, like 13C in natural abundance. High resolution is provided by ultra-fast MAS and high magnetic fields, high sensitivity being ensured by a direct polarization transfer from the abundant protons to 13C. In a rotor-synchronized variant, the method can be used to probe heteronuclear through-space proximities, while the heteronuclear dipolar coupling constant can quantitatively be determined by measuring multiple-quantum spinning-sideband patterns. By means of recoupling, even weak heteronuclear dipolar interactions are accessible. The capabilities of the technique are demonstrated by measurements on crystalline L-tyrosine hydrochloride salt.
authors.affiliation: Max-Planck-Institute for Polymer Research, Mainz, D-55021, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Saalwächter
authors.forename: R
authors.initials: R
authors.lastname: Graf
authors.forename: H W
authors.initials: HW
authors.lastname: Spiess
mesh_terms: D009682:Magnetic Resonance Spectroscopy