Phosphine-Stabilized Digermavinylidene

An intramolecular germylene-phosphine Lewis pair (1) was reacted with germanium dichloride to give in 92% yield a phosphine adduct of a chloro substituted germyl-germylene (2). After reduction of this dichloride with strong reductants like the Mg(I) reagent {((Mes)Nacnac)Mg}(2) (72% yield) or Na (52% yield) a phosphine stabilized digermavinylidene (3) was isolated as crystalline material [(Mes)Nacnac = {[(Mes)NC-(Me)](2)CH}(-), Mes = 2,4,6-Me3C6H2]. The electronic structure of the digermavinylidene was investigated by density functional theory calculations. In reaction with adamantylphosphaalkyne the product of a [2+2] cyclo-addition was characterized (4). Adamantylazide abstracts at room temperature a germanium atom from the digermavinylidene and a tetrameric organogermanium nitride (5) was isolated as colorless crystals.