Internuclear 31P−51V Distance Measurements in Polyoxoanionic Solids Using Rotational Echo Adiabatic Passage Double Resonance NMR Spectroscopy
journal contributionposted on 31.10.2007, 00:00 by Wenlin Huang, Alexander J. Vega, Terry Gullion, Tatyana Polenova
We report the first results establishing rotational echo adiabatic passage double resonance (REAPDOR) experiments for distance measurements between a spin-1/2 (31P) and spin-7/2 (51V) pair in a series of vanadium-substituted polyoxoanionic solids from the Keggin and Wells−Dawson families. We have quantitatively measured 31P−51V distances in monovanadium substituted K4PVW11O40, 1-K7P2VW17O62, and 4-K7P2VW17O62. Numerical simulations of the experimental data yield very good agreement with the averaged P−W/P−V distances determined from the X-ray diffraction measurements in the same or related compounds. REAPDOR is therefore a very sensitive P−V distance probe anticipated to be especially useful in the absence of long-range order. Our results suggest that REAPDOR spectroscopy could be broadly applicable for interatomic distance measurements in other spin-7/2−spin-1/2 nuclear pairs.