title: Multiple-quantum cross polarization in quadrupolar spin systems during magic-angle spinning.
abstract: We describe the concept of multiple-quantum cross polarization (CP) between an I = 32 and an I = 12 spin during magic-angle spinning. Experimental and theoretical results for (23)Na-(1)H pairs are presented that elucidate the transfer mechanism and the beneficial effect of adiabatic amplitude modulations of the CP field. The multiple-quantum CP approach is shown to be beneficial for improving the sensitivity of CP-MQMAS experiments and for detecting dipolar correlations.
authors.affiliation: Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: D
authors.initials: D
authors.lastname: Rovnyak
authors.forename: M
authors.initials: M
authors.lastname: Baldus
authors.forename: R G
authors.initials: RG
authors.lastname: Griffin
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*