TRAPDOR double-resonance and high-resolution MAS NMR for structural and template studies in zeolite ZSM-5

Solid State Nucl Magn Reson. 2009 Apr;35(2):61-6. doi: 10.1016/j.ssnmr.2009.01.004. Epub 2009 Feb 10.

Abstract

A combination of (27)Al magic-angle spinning (MAS)/multiple-quantum (MQ) MAS, and (27)Al-{(14)N} TRAnsfer of Population in DOuble-Resonance (TRAPDOR) nuclear magnetic resonance (NMR) was used to study aluminium environments in zeolite ZSM-5. (27)Al-{(14)N} TRAPDOR experiments, in combination with (14)N NMR were employed to show that the two tetrahedral peaks observed in the (27)Al MAS/3Q-MAS spectra of as-synthesized ZSM-5 are due to aluminium atoms occupying crystallographically inequivalent T-sites. A (13)C-{(27)Al} TRAPDOR experiment was used to study the template, tetrapropyl ammonium bromide (TPABr), in the three-dimensional pore system of ZSM-5. The inequivalency of the methyl groups of TPA was observed in the (13)C-{(27)Al} TRAPDOR spectra of as-synthesized ZSM-5 and the motion of the methyl end of the propyl chain appeared to be more restricted in the sinusoidal channel than in the straight channel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Magnetic Resonance Spectroscopy / methods*
  • Models, Chemical*
  • Models, Molecular*
  • Molecular Conformation
  • Zeolites / chemistry*

Substances

  • Zeolites