Alkali metal reduction of 1,3,2-diazagallol-2-ylidene radical derived from acenaphthene-1,2-diimine

Reduction of the open-shell gallylene [(Ar^BIG-bian)Ga:] {Ar^BIG-bian = 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene} with one equivalent of lithium or sodium metal in THF followed by recrystallization from DME or diethyl ether affords the lithium and sodium salts of the anionic 1,3,2-diazagallol, [(Ar^BIG-bian)GaLi(DME)₃] and [(Ar^BIG-bian)GaNa(Et₂O)₂(THF)₂]. In contrast, reaction of [(Ar^BIG-bian)Ga:] with potassium gives the solvent-free derivative [(Ar^BIG-bian)K] and gallium metal.