Reductive Deamination of a Diaminogermylene Promoted by an Aluminyl Anion: Isolation of Ge(I), Ge(0) and Ge(-I) Products

The reaction of the potassium aluminyl K[Al(NON)] ([NON]2− = [O(SiMe2NDipp)2]2−, Dipp = 2,6-iPr2C6H3) with the diaminogermylene Ge[N(SiMe3)2]2 afforded [K(C6H6)][Al(NON){(Me3Si)2NGeGeN(SiMe3)2}] containing an AlGe2 ring. Structural and computational analysis confirm an aluminacyclodigermene complex that can be considered as an η2-coordinated digermyne at aluminium with Ge(I) centres. This compound is an intermediate on the reduction pathway to K3[(Ge4){Al(NON)}2{N(SiMe3)2}], which contains a distorted tetrahedral cluster of Ge(-I) centres. Characterisation of the dialumane (NON)Al─Al(NON) from this reaction is indicative of sequential one electron redox processes initiated by the aluminyl anion. Repeating the reaction in methylcyclohexane afforded K2[{Al(NON)}2(Ge2)], containing a formally digermanium(0) unit with an exceptionally long Ge═Ge double bond.