Multiple Quantum Magic-Angle Spinning (MQ-MAS)

Multiple Quantum Magic-Angle Spinning (MQ-MAS) is a solid-state NMR method for obtaining a high resolution spectrum of half-integer spin quadrupolar nuclei. It was invented by Professor Lucio Frydman and coworkers. It is performed as a two-dimensional NMR experiment, and correlates a high resolution (isotropic) spectrum to the anisotropic central transition MAS spectrum. Below are the two most basic MQ-MAS sequences.

To determine when the MQ-MAS echo occurs in t₂ consult the table below:

For additional implementation details (phase cycling and data processing), please see the references below, particularly, Massiot et al. Solid-State NMR, 6, 73 (1996).

FASTER (FAst Spinning gives Transfer Enhancement at Rotary resonance) MQ-MAS exploits rotary resonance conditions for exciting multiple quantum coherences of quadrupolar nuclei under fast sample rotation.

RAPT-enhanced RIACT MQ-MAS Experiment

References and Related Resources from our Lab

• 027 - Solid-State NMR, 6, 73 (1996),
  Two-dimensional Magic-Angle Spinning Isotropic Reconstruction Sequences for Quadrupolar Nuclei,
  D. Massiot, B. Touzo, D. Trumeau, J. P. Coutures, J. Virlet, P. Florian and P. J. Grandinetti
• Our Shifted Echo MQ-MAS Sequence for Bruker
• 038 - J. Chem. Phys. , 114, 4618-4624 (2001) Multiple Quantum Magic-Angle Spinning using Rotary Resonance Excitation,
  
T. Vosegaard, P. Florian, D. Massiot, and P. J. Grandinetti
• 041 - Chem.Phys.Lett., 352, 252-261 (2002) Rotary Resonance in Multiple-Quantum Magic-Angle Spinning,
  
Z. Gan and P. J. Grandinetti
• 039 - J. Magn. Reson., 150, 1-80 (2001), Enhanced Sensitivity in RIACT/MQ-MAS NMR Experiments Using RAPT
  
H.-T. Kwak, S. Prasad, Z. Yao, P. J. Grandinetti, J. R. Sachleben, and L. Emsley
• RAPT-RIACT Bruker Sequence