Si-29 NMR in solid state with CPMG acquisition under MAS

TitleSi-29 NMR in solid state with CPMG acquisition under MAS
Publication TypeJournal Article
Year of Publication2008
AuthorsWiench JW, Lin VSY, Pruski M
Journal TitleJournal of Magnetic Resonance
Volume193
Pages233-242
Date PublishedAug
Type of ArticleArticle
ISBN Number1090-7807
Accession NumberISI:000258357600010
Keywordsangle-spinning nmr, CHEMICAL-SHIFT CORRELATIONS, CORRELATION SPECTROSC, CPMG acquisition, functionalized mesoporous silicas, hetcor, INTEGER QUADRUPOLAR NUCLEI, j-coupling, MAS, PURCELL-MEIBOOM-GILL, si-29 nmr, solid-state nmr, STRUCTURAL-CHARACTERIZATION
Abstract

A remarkable enhancement of sensitivity can be often achieved in Si-29 solid-state NMR by applying the well-known Carr-Purcell-Meiboom-Gill (CPMG) train of rotor-synchronized pi pulses during the detection of silicon magnetization. Here, several one- and two-dimensional (1D and 2D) techniques are used to demonstrate the capabilities of this approach. Examples include 1D Si-29{X} CPMAS spectra and 2D Si-29{X} HETCOR spectra of mesoporous silicas, zeolites and minerals, where X = H-1 or Al-27. Data processing methods, experimental strategies and sensitivity limits are discussed and illustrated by experiments. The mechanisms of transverse dephasing i nuclei in solids are analyzed. Fast magic angle spinning, at rates between 25 and 40 kHz, is instrumental in achieving the highest sensitivity gain in some of these experiments. In the case of Si-29-Si-29 double-quantum techniques, CPMG detection can be exploited to measure homonuclear J-couplings. (c) 2008 Elsevier Inc. All rights reserved.

DOI10.1016/j.jmr.2008.05.007
Alternate JournalJ. Magn. Reson.