Hypoelectronic isomeric diiridaboranes [(Cp*Ir)2B6H6]: the “Rule-Breakers”(Cp* = η5-C5Me5)

Abstract

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.