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 homonuclear spins. In this method, a weak radio-frequency field is applied during the mixing time of the exchange NMR, and its frequency and intensity are chosen to realize rotational resonance for a particular pair of spins in the tilted rotating frame. The selective recoupling is demonstrated for the dipolar interaction between the CH and CH3 carbons in triply 13C-enriched l-alanine, whose chemical shift difference is too small to apply the conventional rotational resonance method.