Time displacement rotational echo double resonance: Heteronuclear dipolar recoupling with suppression of homonuclear interaction under fast magic-angle spinning

Abstract: We have developed a novel variant of REDOR which is applicable to multiple-spin systems without proton decoupling. The pulse sequence is constructed based on a systematic time displacement of the pi pulses of the conventional REDOR sequence. This so-called time displacement REDOR (td-REDOR) is insensitive to the effect of homonuclear dipole–dipole interaction when the higher order effects are negligible. The validity of td-REDOR has been verified experimentally by the P-31{C-13} measurements on glyphosate at a spinning frequency of 25kHz. The experimental dephasing curve is in favorable agreement with the simulation data without considering the homonuclear dipole–dipole interactions. [Copyright &y& Elsevier]