A comparison between REDOR and θ-REDOR for measuring 13C-2D dipolar interactions in solids

C-y13-observe REDOR and theta-REDOR experiments for recovering the C-13-D-2 dipolar interaction during MAS NMR are compared. It is found that limited D-2 RF power may severely compromise the performance of the REDOR experiment whereas the theta-REDOR experiment can be designed to work well. Results are presented for an isolated C-13-D-2 Spin pair with a large deuterium quadrupolar coupling constant and for a C-13 coupled to three methyl deuterons undergoing fast methyl group rotation. (C) 1999 Academic Press.