title: TRAPDOR double-resonance and high-resolution MAS NMR for structural and template studies in zeolite ZSM-5.
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.
authors.affiliation: Institute for Chemical and Bioengineering, Swiss Federal ETH Zurich, Zurich 8093, Switzerland.
authors.forename: Anuji
authors.initials: A
authors.lastname: Abraham
authors.forename: Roel
authors.initials: R
authors.lastname: Prins
authors.forename: Jeroen A
authors.initials: JA
authors.lastname: van Bokhoven
authors.forename: Ernst R H
authors.initials: ER
authors.lastname: van Eck
authors.forename: Arno P M
authors.initials: AP
authors.lastname: Kentgens
mesh_terms: D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites