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Cornering the 13th vertex: The first 13-vertex carborane (see picture, B: brown, C: gray, H: white) has been prepared by a methodology that can in principle be applied repeatedly, leading to 14-, 15-, 16-, …︁ vertex carboranes in the future. The 13-vertex species has a henicosahedral geometry, not the docosahedral one expected, but the two forms are found to be very close in energy by DFT calculations.
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Burke et al. (2003) studied this question.
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