Hypoelectronic isomeric diiridaboranes [(Cp∗Ir)<inf>2</inf>B<inf>6</inf>H<inf>6</inf>]: The "rule-Breakers"(Cp∗ = η⁵-C<inf>5</inf>Me<inf>5</inf>)

In an effort to synthesize supraicosahedral iridaboranes, pyrolysis of [Cp∗IrCl2]2 with excess [BH3·THF] was carried out, and this synthesis afforded the isomeric iridaborane [(Cp∗Ir)2B6H6] clusters 1 and 2. The geometry of 1 was determined to be dodecahedral, i.e., similar to that of [B8H8]2-, whereas 2 was found to exhibit a cluster shape that can be derived from a nine-vertex tricapped trigonal prism by removing one of the capped vertices. The calculation of a large HOMO-LUMO gap further rationalized the isocloso structures for these isomers.