Broadband MAS NMR spectroscopy in the low-power limit

Kevin J Sanders (1) , Andrew Pell (2) , Sebastian Wegner (3) , Clare Grey (4) , Guido Pintacuda (1)

1 Biological Solid-State NMR Methods - Méthodes de RMN à l'état solide en biologie
2 Department of Materials and Environmental Chemistry - Arrhenius Laboratory
3 Bruker BioSpin GmbH, D-76287 Rheinstetten, Germany
4 CAM - University of Cambridge [UK]

We investigate the performance of broadband adiabatic inversion pulses in the high-power (short high-powered adi-abatic pulse, SHAP) and low-power (single-sideband-selective adiabatic pulse, S 3 AP) RF regimes on a spin system subjected to large anisotropic interactions. We show by combined experimental results and spin dynamics simulations that when the magic-angle spinning rate exceeds 100 kHz S 3 APs begin outperforming SHAPs. This is especially true for low-gamma nuclei, such as 6 Li in paramagnetic Li-ion battery materials. Finally, we show how S 3 APs can be improved by combining multiple waveforms sweeping over multiple sidebands simultaneously, in order to produce inverted sideband profiles free from intensity biasing.

Mots clés: Adiabatic pulses; Ultrafast MAS; Paramagnetic NMR; Broadband NMR; Li-ion battery; ultrafast MAS; paramagnetic NMR; broadband NMR; Li-ion battery

Domaines: Chimie analytique

Kevin J Sanders, Andrew Pell, Sebastian Wegner, Clare Grey, Guido Pintacuda. Broadband MAS NMR spectroscopy in the low-power limit. Chemical Physics Letters, 2018, 697, pp.29-37. ⟨10.1016/j.cplett.2018.01.028⟩. ⟨hal-01744691⟩