RESOLUTION ENHANCEMENT BY HOMONUCLEAR J DECOUPLING IN SOLID-STATE MASNMR

It is shown that in C-13 MAS NMR experiments on fully labelled compoun ds a significant line narrowing can be achieved by homonuclear C-13-C- 13 J decoupling. The linewidth for proteins can be reduced by up to 10 0 Hz, making assignments for larger molecules possible. The practical usefulness of decoupling in indirectly observed frequency dimensions o f multidimensional spectra is demonstrated by spin-diffusion experimen ts on fully labelled L-threonine and L-arginine hydrochloride. A 3D sp in-diffusion experiment is demonstrated for obtaining a 2D spin-diffus ion spectrum which correlates well resolved chemical shifts.