Accurate measurements of internuclear distances in solid-state NMR - REDOR (Rotational Echo DOble Resonance) -

REDOR is a solid-state NMR technique for retrieving heteronuclear dipolar interactions decoupled by magic-angle spinning and determining internuclear distances from thus recoupled dipolar interactions.
REDOR is widely used for structural analysis of proteins in solids since the distances can be determined with 0.1Å accuracy without single crystals, although samples should usually be enriched.

JNM-ECA series support REDOR measurements, and the result using JNM-ECA and 4mm HXY probe is shown below.

For 2-¹³C, ¹⁵N-labeled glycine (H₂¹⁵N-¹³CH₂-COOH), the distance between ¹³C and ¹⁵N nuclei was determined using JNM-ECA930.
The resultant dipolar coupling was 793 Hz, and the distance was evaluated to be 1.58Å. This result agrees with 1.48Å deduced in X-ray analysis, demonstrating the effectiveness of the solid-state NMR measurement.