J-CROSS-POLARIZATION IN MAGIC-ANGLE-SPINNING NMR

J cross polarization in magic-angle-spinning (MAS) solid-state NMR spe ctroscopy is demonstrated. In the fast spinning limit, pure J cross po larization can be obtained at the centerband of the Hartmann-Hahn matc hing profile while dipolar cross polarization takes place at the sideb and conditions. Transient oscillations with the phase- and intensity p atterns characteristic for the J-cross-polarization process are observ ed.