Next generation adduct purification techniques for low oxygen content metal alkyls

A new synthesis and adduct purification route has been developed for Group III metal alkyls which avoids the use of ether solvents. The R₃M compound is synthesized in a trialkylamine solvent such as NEt₃ which leads to adducts of the type R₃Ga(NEt₃). The NEt₃ ligand can be displaced by the addition of involatile tertiary amines (L) containing 2, 4, or 6 nitrogen donor sites to give adducts of the type (R₃Ga)_xL (x = 2, 4, 6), from which base free R₃Ga compounds are obtained by mild thermal dissociation. The synthesis, characterization and thermal dissociation of these adducts is described and brief growth data are given for AlGaAs films grown by CBE using triisopropyl gallium prepared by this new route.