Exchange and pyrolysis in mixed trialkylgallanes

Abstract

Rapid alkyl exchange reactions in gas-phase mixtures of Me₃Ga and R₃Ga lead to statistical mixtures of trialkylgallanes when R = Et or Prⁱ, but not when R = Buⁱ. In the case of Me₃Ga and Et₃Ga, laser pyrolysis of mixtures at moderate temperatures brings about selective β-hydride elimination of Et groups, leading to a mixture of dialkyl- and monoalkyl-gallanes. These products have been identified by IR and ¹H NMR spectroscopies of both the parent products and of their adducts with NMe₃. These observations confirm earlier suggestions that the pyrolysis of mixed trialkylgallane precursors may result in non-uniform deposition of Ga.