51V magic angle spinning solid state NMR studies of Bi4V2O11 in oxidized and reduced states

The environment of vanadium in α-Bi4V2O11 was investigated by 51V solid state NMR studies.The NMR parameters used for the best-fit simulations show the presence of at least three different sites of vanadium, two tetrahedral and one bipyramidal trigonal (or distorted octahedral). 51V magic angle spinning NMR spectra obtained at different stages in the reduction of Bi4V2O11 confirm the progressive V(V)–V(IV) reduction. The original upfield shifted signal is attributed to V(V) interacting with paramagnetic V(IV) in Bi4V2O10.66.