An article from the Wiegand group was selected to be one of the 2023 HOT PCCP articles

Our publication "The effect of methyl group rotation on ¹H–¹H solid-state NMR spin-diffusion spectra" was selceted to be one of the 2023 HOT PCCP articles. Topic of the publication is a deeper understanding of the origin of negative cross-peaks in proton-detected solid-state NMR spectra recorded at fast magic-angle spinning (MAS). This opens further avenues for simplified resonance assignment, for instance in proteins and organic systems. In this study, negative cross-peaks in 2D NMR spectra have been reported for a variety of small organic molecules involving methyl groups. By combining experimental observations with numerical simulations, we were able to disentangle coherent and incoherent effects contributing to such negative peaks. We will explore in the future, whether similar effects can be observed in ¹⁹F fast MAS experiments.