Cationic dialanes with fluxional π-bridged cyclopentadienyl ligands.

Unique π-cyclopentadienyl bridged dialanes are synthesized as complex salts with aluminate anions by comproportionation of aluminocenium cations [Al III (Cp)(Cp*)] + /[Al III Cp 2 ] + with [(Al I Cp*) 4 ]. Very short Al-Al bond lengths occur in positively charged Al 2 4+ fragments. Intriguingly, the prepared asymmetric dialane shows a unique fluxional coordination of the cyclopentadienyl ligands.