Beyond the Icosahedron: The Quest for High-Nuclearity Supraicosahedral Metallaboranes.

The recent achievements and progress in the field of high-nuclearity supraicosahedral metallaborane chemistry are reviewed and compared to those made in borane, carborane and metallacarborane chemistry. In contrast to metallacarboranes, characterized large supraicosahedral metallaboranes only adopt isocloso deltahedral structural arrangements with n vertices and a non-Wadean n skeletal-electron-pair count. This anomaly can be rationalized by the preference of metal atoms for 6-connect vertices present in the cluster cages. [ABSTRACT FROM AUTHOR]