Year: 2024
Type: article
Abstract: . Heteronuclear low-power decoupling using the solution-state WALTZ sequences has become quite popular in solid-state protein NMR and seems to work well. However, there are no systematic studies that characterize these sequences under magic-angle spinning (MAS) and give recommendations which parameter should be used. We have studied in detail the use of WALTZ-16 and WALTZ-64 as low-power decoupling sequences under 100 kHz MAS by characterizing the resonance conditions analytically, using numerical simulations, and experiments on model substances. The recoupling at heteronuclear resonance conditions between the modulation frequency of the sequences and the MAS frequency is the most important feature. Pulse lengths corresponding to areas with vanishing first-order heteronuclear recoupling are good candidates for efficient decoupling. We have characterized two such conditions defined by ν1=νr/10 or τ90=τr/4 and ν1=2 νr/5 or τ90=τr which both lead to narrow lines and are stable against rf-field variations and chemical-shift offsets. More such conditions might exist but were not investigated here.
Source: Magnetic Resonance
Authors: Luzian Thomas, Matthias Ernst
Institution: ETH Zurich
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,107
OpenAlex ID: W4404528130