Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

6-2021

Journal or Book Title

Journal of Magnetic Resonance

Volume

327

First Page

106983

DOI

10.1016/j.jmr.2021.106983

Abstract

Constant-time (CT) dipolar heteronuclear multiple quantum coherence (D-HMQC) has previously been demonstrated as a method for proton detection of high-resolution wideline NMR spectra of spin-1/2 nuclei with large chemical shift anisotropy (CSA). However, 1H transverse relaxation and t1-noise often reduce the sensitivity of D-HMQC experiments, preventing the theoretical gains in sensitivity provided by 1H detection from being realized. Here we demonstrate a series of improved pulse sequences for 1H detection of spin-1/2 nuclei under fast MAS, with 195Pt SSNMR experiments on cisplatin as an example. First, a t1-incrementation protocol for D-HMQC dubbed Arbitrary Indirect Dwell (AID) is demonstrated. AID allows the use of arbitrary, rotor asynchronous t1-increments, but removes the constant time period from CT D-HMQC, resulting in improved sensitivity by reducing transverse relaxation losses. Next, we show that short high-power adiabatic pulses (SHAPs), which efficiently invert broad MAS sideband manifolds, can be effectively incorporated into 1H detected symmetry-based resonance echo double resonance (S-REDOR) and t1-noise eliminated (TONE) D-HMQC experiments. The S-REDOR experiments with SHAPs provide approximately double the dipolar dephasing, as compared to experiments with rectangular inversion pulses. We lastly show that sensitivity and resolution can be further enhanced with the use of swept excitation pulses as well as adiabatic magic angle turning (aMAT).

Comments

This is a manuscript of an article published as Venkatesh, Amrit, Frédéric A. Perras, and Aaron J. Rossini. "Proton-detected solid-state NMR spectroscopy of spin-1/2 nuclei with large chemical shift anisotropy." Journal of Magnetic Resonance 327 (2021): 106983. DOI: 10.1016/j.jmr.2021.106983. Posted with permission.

Copyright Owner

Elsevier Inc.

Language

en

File Format

application/pdf

Available for download on Thursday, April 20, 2023

Published Version

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