In the attempt to synthesize compounds with aluminum in a low oxidation state and an AI-AI bond, by the reduction of alkylaluminum halides with alkali metals, analogous to a Wurtz coupling, in general the deposition of elemental aluminum and the formation of the corresponding trialkylaluminum compounds is observed. Thus, tetrasubstituted dialuminum compounds R,AI-AIR,, apart from a few poorly characterized examples, were for a long time considered part of an unverified class of substances. Only with the sterically very highly shielded tetrakis[bis(trimethylsilyl)methyl]dialuminum did we achieve the synthesis of the first completely characterized organoelement compound with unlimited stability, which shows aluminum in the oxidation state + II and has an AI-AI bond. In the meantime, corresponding compounds for the elements gallium and indium have been obtained. With the simple access to tetrasubstituted dimeta1 compounds, a fascinating new research area has opened for preparative chemistry, in which the particular interest will naturally lie in the reactive properties of the metal-metal bond