Fast remote correlation experiments for 1H homonuclear decoupling in solids

Pinelopi Moutzouri; Bruno Simões de Almeida; Lyndon Emsley

doi:10.1016/j.jmr.2020.106856

Fast remote correlation experiments for ¹H homonuclear decoupling in solids

J Magn Reson. 2020 Dec:321:106856. doi: 10.1016/j.jmr.2020.106856. Epub 2020 Oct 22.

Authors

Pinelopi Moutzouri¹, Bruno Simões de Almeida¹, Lyndon Emsley²

Affiliations

¹ Institut des Sciences et Ingéniere Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
² Institut des Sciences et Ingéniere Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland. Electronic address: lyndon.emsley@epfl.ch.

PMID: 33157355
DOI: 10.1016/j.jmr.2020.106856

Abstract

In ¹H MAS spectra, the residual homogeneous broadening under MAS is due to a combination of higher-order shifts and splittings. We have recently shown how the two-dimensional anti-z-COSY experiment can be used for the removal of the splittings. However, this requires spectra with high resolution in the indirect dimension (t₁), leading to experiment times of hours. Here, we show how anti-z-COSY can be adapted to be combined with the two-dimensional one pulse (TOP) transformation which leads to significantly reduced experimental time while retaining the line narrowing effect. The experiment is demonstrated on a powdered sample of L-histidine monohydrochloride monohydrate, where the new TAZ-COSY sequence at 100 kHz MAS, yields between a factor 1.6 and 2.3 increase in resolution compared with the equivalent one-pulse experiment, in just 20 min. The same methodology is also adapted for the acquisition of liquid state ¹H homodecoupled data, and an example is given for testosterone.

Keywords: (1)H resolution; Anti-z-COSY; Magic angle spinning; Solid-state NMR; TOP.