Anionic aluminium turns textbook knowledge on its head

The first stable anionic aluminium compound demonstrates that received wisdom isn’t always right: unlike all other electrophilic aluminium compounds, this unusual molecule is a nucleophile.

Researchers from the UK and Finland made the nucleophile by reducing an aluminium(iii) complex with potassium graphite. Although aluminium vastly prefers to be in a +3 oxidation state – like in aluminium chloride or the polymerisation co-catalyst triethyl aluminium – this reaction creates a bright yellow, dimeric aluminium(i) molecule.