Details

Autor(en) / Beteiligte

• Kobayashi, Takeshi
• Perras, Frédéric A.
• Nishiyama, Yusuke

Titel

Determination of the chemical shift tensor anisotropy and asymmetry of strongly dipolar coupled protons under fast MAS

Ist Teil von

• Solid state nuclear magnetic resonance, 2021-08, Vol.114, p.101743-101743, Article 101743

Ort / Verlag

Netherlands: Elsevier Inc

Erscheinungsjahr

2021

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Orientationally-dependent interactions such as dipolar coupling, quadrupolar coupling, and chemical shift anisotropy (CSA) contain a wealth of spatial information that can be used to elucidate molecular conformations and dynamics. To determine the sign of the chemical shift tensor anisotropy parameter (δaniso), both the |m| ​= ​1 and |m| ​= ​2 components of the CSA need to be symmetry allowed, while the recoupling of the |m| ​= ​1 term is accompanied with the reintroduction of homonuclear dipolar coupling components. Therefore, previously suggested sequences which solely recouple the |m| ​= ​2 term cannot determine the sign a 1H's δaniso in a densely-coupled network. In this study, we demonstrate the CSA recoupling of strongly dipolar coupled 1H spins using the Cnn1(9003601805400360180900) sequence. This pulse scheme recouples both the |m| ​= ​1 and |m| ​= ​2 CSA terms but the scaling factors for the homonuclear dipolar coupling terms are zeroed. Consequently, the sequence is sensitive to the sign of δaniso but is not influenced by homonuclear dipolar interactions. [Display omitted] •A CSA recoupling sequence is presented that is sensitive to the sign of the anisotropy as well as the asymmetry.•Scaling factors for homonuclear dipolar terms are zeroed.•The sequence can be applied to strongly dipolar coupled protons.