Antiaromaticity in Bare Deltahedral Silicon Clusters Satisfying Wade's and Hirsch's Rules: An Apparent Correlation of Antiaromaticity with High Symmetry

Entirely unlike the arom. closo B6H62- and B12H122- borane dianions, isoelectronic Si62- and Si122- are antiarom. Their Oh and Ih symmetries are responsible, as the other deltahedral silicon dianion clusters do not exhibit this behavior. These high symmetries prevent mixing among the degenerate lone pair and skeletal orbitals, leading to paratropic behavior. [on SciFinder (R)]