Deuteron 2D exchange sample-turning NMR: determination of interbond angles

Deuteron 2D exchange NMR based on spin diffusion in powder samples has been developed to determine the angle between the unique axes of the quadrupole coupling tensors for two deuterons, providing bond angles, dihedral angles, and the like. To overcome the long deuteron T1 in rigid solids, adiabatic cross polarization is proposed, which allows us to obtain the whole of a broad deuteron powder spectrum. Cross relaxation between two deuterons is caused by sample turning around an axis perpendicular to the static field direction during the mixing time. The DCD bond angle in α-glycine-[2,2-d2] is precisely determined to demonstrate the effectiveness of the proposed method.