Measurements of ¹H chemical shift anisotropy

Anisotropy of spin interactions gives fruitful information on molecular structure as  well as dynamics. Although ¹H is ubiquitous and abundant nuclei, there is only a few  reports on ¹H chemical shift anisotropy (CSA). This is because of small ¹H CSA and  strong ¹H-¹H dipolar interactions. Fortunately, thank to the hardware improvement,  the combination of high magnetic field and fast MAS solve this problem; the higher  B₀ field amplify the ¹H CSA and fast MAS kill ¹H-¹H dipolar interactions. Here we  introduce a new symmetry based sequence which recouples ¹H CSA in a g-encoded  manner keeping ¹H-¹H dipolar interactions decoupled. The use of 270⁰-90⁰ cmposite  pulse improves the robustness toward rf-field inhomogeneities.

Reference

M.K. Pandey, M. Malon, A. Ramamoorthy, Y. Nishiyama, J. Magn. Reson. 250 (2015) 45-54.