11B NMR Study of WB2
2017
Turner, Christopher L. | Zujovic, Zoran | Koumoulis, Dimitrios | Taylor, R. E. | Kaner, Richard B.
The structure of tungsten diboride, WB₂, differs from those of metal diborides with AlB₂- or ReB₂-type structures that have been previously studied by ¹¹B NMR spectroscopy. As opposed to the single ¹¹B resonance reported for the metal diborides having those AlB₂- or ReB₂-type structures, four groups of ¹¹B resonances are found for WB₂. There is also ¹¹B NMR spectral evidence to support the proposal by Kiesling in 1947 of an additional boron atom at the center of some of the six-membered boron rings. The ¹¹B quadrupolar frequencies of all four groups of resonances in WB₂ are all quite small (<20 kHz), in keeping with the trend observed for ¹¹B in metal diborides having the AlB₂-structure as the metal is taken from further down the groups (families) in the periodic table.
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