Terry Gullion is a physical chemist whose work develops solid-state nuclear magnetic resonance. With Jacob Schaefer, he developed rotational-echo double resonance, or REDOR, which restores sensitivity to heteronuclear NMR dipolar coupling in a spinning solid. His first-person retrospective describes the method as a way to measure couplings and infer structural information.[ref]
Recollections of REDOR by Terry Gullion. Original author abstract and1989-paper commentary relationship
[ref]Development of REDOR rotational-echo double-resonance NMR by Jacob Schaefer (2011). 2011 first-person retrospective on the1989 Gullion–Schaefer report
Institutional profile: www.chemistry.wvu.edu/directory/professors/terry-gullion
The physical problem is that magic angle spinning suppresses interactions that broaden spectra but can also remove useful structural information. REDOR uses controlled pulse timing to reintroduce a selected interaction. A paired acquisition compares a reference signal with a dephased signal under matched conditions. Varying the evolution time supplies more information than a single intensity difference.[ref]
Development of REDOR rotational-echo double-resonance NMR by Jacob Schaefer (2011). Pulse-train development, magic-angle spinning and dipolar recoupling discussion
For an original arithmetic example, and give fractional dephasing . This does not directly mean that 28 percent of the atoms occupy a particular state. Structural inference requires an appropriate spin model, evolution times and controls on the acquisition. The example shows the inferential step that Gullion's method makes possible: a controlled change in a spectrum can encode an otherwise hidden interaction.
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