Broadband Polarization Transfer under Magic-Angle Spinning: Application to Total Through-Space-Correlation NMR Spectroscopy

摘要: Abstract A pulse sequence is described that leads to a broadband recoupling of the dipolar interaction in magic-angle-spinning solid-state NMR experiments 13 C spins. The based on combination rotating frame and laboratory transfer periods. recovered only weakly dependent spectral parameters but faithful measure for internuclear distances. Furthermore, pure zero-quantum term (of type found static “spin-diffusion” experiments). This makes particularly suited incorporation into two-dimensional total through-space correlation deliver simultaneous information about all couplings single 2D experiment. It necessary decoupling from abundant protons best performed two steps: first, strong homonuclear between high-γ spins are averaged by Lee–Goldburg irradiation and, second, heteronuclear combined application an RF field low-γ magic-angle sample spinning. Phase-inversion amplitude attenuation refocusing pulses part introduced achieve optimum chemical-shift offset-independence suppression unwanted double-quantum transitions. design principles explained detail. Finally, scheme applied total-correlation spectroscopy uniformly labeled amino acid. experimental cross-peak intensities qualitative agreement with known crystal structure model compound.