title: High resolution heteronuclear correlation NMR spectroscopy between quadrupolar nuclei and protons in the solid state.
abstract: A high resolution two-dimensional solid state NMR experiment is presented that correlates half-integer quadrupolar spins with protons. In this experiment the quadrupolar nuclei evolve during t1 under a split-t1, FAM-enhanced MQMAS pulse scheme. After each t1 period ending at the MQMAS echo position, single quantum magnetization is transferred, via a cross polarization process in the mixing time, from the quadrupolar nuclei to the protons. High-resolution proton signals are then detected in the t2 time domain during wPMLG5* homonuclear decoupling. The experiment has been demonstrated on a powder sample of sodium citrate and 23Na-1H 2D correlation spectra have been obtained. From the HETCOR spectra and the regular MQMAS spectrum, the three crystallographically inequivalent Na+ sites in the asymmetric unit were assigned. This MQMAS-wPMLG HETCOR pulse sequence can be used for spectral editing of half-integer quadrupolar nuclei coupled to protons.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot, 76100, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Goldbourt
authors.forename: E
authors.initials: E
authors.lastname: Vinogradov
authors.forename: G
authors.initials: G
authors.lastname: Goobes
authors.forename: S
authors.initials: S
authors.lastname: Vega