The preparation and reactions of stable monomeric and tetrameric organoaluminum(I) compounds are described. Especially, their conversion to the more stable oxidation state (III) is discussed. The synthesis of unusual and unique molecules such as LAl(OH)(2), LAl(SH)(2), LAl(SeH)(2), and LAl(NH2)(2) is reported. A new synthetic approach to organometallic hydroxides and amides was discovered, when N-heterocyclic carbenes are used as hydrogen chloride acceptors. The synthesis of LGeOH demonstrates that this method can also be applied for other elements in the periodic system. The successful preparation of carbaalanes and aluminum nitride clusters resulted in the generation of several model compounds for the fixation of organometal substituents on carbide and nitride surfaces. It is shown that AlH3.NMe3 is a powerful hydroalumination reagent for acetylenes, nitriles, and isonitriles.