ROTATIONAL RESONANCE IN THE TILTED ROTATING-FRAME

We propose a new solid-state NMR technique under magic-angle spinning to recouple the dipolar interaction for a particular pair of homonucle ar spins. In this method, a weak radio-frequency field is applied duri ng the mixing time of the exchange NMR, and its frequency and intensit y are chosen to realize rotational resonance for a particular pair of spins in the tilted rotating frame. The selective recoupling is demons trated for the dipolar interaction between the CH and CH3 carbons in t riply C-13-enriched l-alanine, whose chemical shift difference is too small to apply the conventional rotational resonance method.