Chemical Physics Letters, Vol.502, No.4-6, 259-265, 2011
Probing the quenching of rotary resonance by PISSARRO decoupling
Solid-state NMR experiments may suffer from rotary resonance recoupling (R-3) due to the interference between sample spinning at a frequency v(rot) and rf irradiation with an amplitude m(1)(H) in the vicinity of harmonic relationships v(1)(H) = nv(rot) where n = 1 or 2. Until recently, only the use of very high rf amplitudes (e.g., v(1)(H) >> 2v(rot)) made it possible to avoid such interference effects. With the advent of PISSARRO decoupling, the deleterious effects of rotary resonance recoupling can be quenched, notably for v(1)(H) = 2v(rot), so that demands on the rf amplitude v(1)(H) are relaxed. Here, we discuss how PISSARRO decoupling benefits from mirror symmetry and phase-shifting. We also show that PISSARRO can cope with the chemical shift anisotropy of protons and with proton-proton dipolar interactions. PISSARRO is most effective for very fast spinning at very high static fields. (C) 2010 Elsevier B.V. All rights reserved.