Improving resolution in proton solid-state NMR by removing nitrogen-14 residual dipolar broadening
Residual dipolar coupling between quadrupolar and other nuclei under MAS has not usually been thought to be important in high field NMR spectroscopy. We show that coupling to (14)N broadens (1)H lineshapes significantly even at 11.7 T, and that we can decouple (14)N from (1)H during (1)H homonuclear decoupling to successfully improve (1)H resolution. The method used for decoupling is the application of evenly spaced pulses to the quadrupolar nucleus. (c) 2008 Elsevier B.V. All rights reserved.