Patent ID: 7276903

Claim:
A method for obtaining a two-dimensional NMR (=nuclear magnetic resonance) spectrum of quadrupolar nuclei of 14 N having spin I=1 using magic angle spinning (=MAS) of a solid powder sample and transfer of coherence from a neighboring nucleus with spin S=½ to single- or double-quantum transitions of said quadrupolar nuclei of 14 N having spin I=1, wherein the detection of the spectrum occurs indirectly via the spin S=½ nuclei, wherein the transfer of coherence occurs through residual dipolar splittings, the method comprising the steps of: a) exciting the neighboring nucleus single quantum coherence; b) applying a delay of τ exc ≈1/(2D), wherein D is a splitting between the quadrupolar nuclei of 14 N and the nuclei with spin S=½ due to residual dipolar splittings, leading to antiphase coherence; c) applying a first 14 N RF-pulse of duration τ p the quadrupolar nuclei of 14 N having spin I=1 for transferring anti-phase coherence into heteronuclear coherence; d) applying a π-RF-pulse to the neighboring nucleus with spin S=½ in a middle of an evolution interval t 1 ; e) applying a second 14 N RF-pulse at t 1 of duration τ p to the quadrupolar nuclei of 14 N having spin I=1, wherein to is an interval between centers of the first and the second 14 N pulses; and f) recording the signal of the neighboring nucleus with spin S=½ after a duration τ rec ≈1/(2D) in t 2 , wherein t 2 is the detection time interval.