NMR Diffraction Revisited with a Modified CRAZED Double Quantum Imaging Sequence

Distant dipolar fields allow observation of intermolecular multiple quantum coherences. Recently, this phenomenon has been exploited to obtain structural information since these signals result from pairs of spins separated by the correlation distance (Dc). Here we show experimentally in a model system consisting of a 7×6 array of water-filled capillaries that capillary diameter and spacing can be retrieved by a CRAZED-type double quantum sequence. Using phase cycling, signal attributed to different coherence transfer pathways (M=0, 2, ±1) at various Dc could be isolated. For M=0, ±1, diffraction peaks occurring at Dc=(2-M)×λ/2 could be observed, with λ being the inter-capillary spacing.