Assignment of Multiline Tungsten-183 NMR Spectra of Diamagnetic Polyoxotungstates from Intensity Patterns

Measurement of relative integrated intensities and peak heights of multiline one-dimensional 183W NMR spectra of diamagnetic polyoxotungstates can result in complete or partial assignment of chemical shifts, even when 183W-183W spin-coupled satellites are not detectable or well-resolved. The intensity of the center peak of each signal is diminished according to the number and type (corner- vs edge-sharing of WO6 octahedra) of potential spin-couplings. Application of the method is exemplified by analysis of spectra of alpha-[XW11O39]n- and derivatives, alpha2-[P2W17O61]10-, and [As4W40O140]28-. Intensity patterns of the six-line spectra of the beta1 and beta3 isomers of [XW11O39]n- are sufficiently different to allow identification.