Multiple-Quantum MAS NMR of Quadrupolar Nuclei. Do Five-, Seven- and Nine-Quantum Experiments yield Higher Resolution than the Three-Quantum Experiment

Kevin J Pike, Reena P Malde, Sharon Elizabeth Ashbrook, Jamie McManus, Stephen Wimperis

Research output: Contribution to journalArticlepeer-review

99 Citations (Scopus)

Abstract

The question of whether or not higher-order (five-, seven- and nine-quantum) multiple-quantum magic angle spinning (MQMAS) experiments yield isotropic NMR spectra of half-integer quadrupolar nuclei with higher resolution than the basic three-quantum MAS experiment is examined. The frequency dispersion is shown theoretically to be greatly increased in higher-order MQMAS spectra, but it is argued that whether or not this translates into an increase in resolution depends upon the ratio of the homogeneous to inhomogeneous contributions to the isotropic linewidth. Experimentally, it is demonstrated using three-, five- and seven-quantum Sc-45 MAS NMR and three- and five-quantum Al-27 MAS NMR of crystalline samples that higher-order MQMAS experiments can yield a real and useful increase in resolution but that, owing to the presence of inhomogeneous broadening in the isotropic spectra, this increase is less than the theoretically predicted value. A number of practical issues relating to resolution in MQMAS NMR are also pointed out. (C) 2000 Elsevier Science B.V. All rights reserved.

Original languageEnglish
Pages (from-to)203-215
Number of pages13
JournalSolid State Nuclear Magnetic Resonance
Volume16
DOIs
Publication statusPublished - Jun 2000

Keywords

  • multiple-quantum MAS NMR
  • quadrupolar nuclei
  • high resolution
  • ANGLE-SPINNING NMR
  • SOLID-STATE NMR
  • MQMAS NMR
  • ALMEPO-BETA
  • AL-27
  • TRIPLE
  • SPECTROSCOPY
  • ORDER

Fingerprint

Dive into the research topics of 'Multiple-Quantum MAS NMR of Quadrupolar Nuclei. Do Five-, Seven- and Nine-Quantum Experiments yield Higher Resolution than the Three-Quantum Experiment'. Together they form a unique fingerprint.

Cite this