Novel two-dimensional NMR methods that combine single-quantum cross-polarization and multiple-quantum MAS of quadrupolar nuclei

Ashbrook, S.E. and Wimperis, S. (2001) Novel two-dimensional NMR methods that combine single-quantum cross-polarization and multiple-quantum MAS of quadrupolar nuclei. Chemical Physics Letters, 340(5-6), pp. 500-508. (doi: 10.1016/S0009-2614(01)00453-5)

Abstract

A new approach to combining cross-polarization with multiple-quantum MAS in a two-dimensional NMR experiment is demonstrated, involving cross-polarization from 1H to the single-quantum coherences of a quadrupolar nucleus. These coherences are then converted directly to multiple-quantum coherences rather than via a population state. In two separate methods, pure-absorption lineshapes are obtained using a z-filter and a shifted echo, respectively, with the latter, a ‘reversed split-t1' method, demonstrated to be particularly effective. The efficiency of both sequences may be improved by incorporating ‘fast-amplitude-modulation' (FAM) pulses for both the conversion and excitation of triple-quantum coherences.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wimperis, Professor Stephen
• Authors: Ashbrook, S.E., and Wimperis, S.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Chemical Physics Letters
• ISSN: 0009-2614