Synthesis and characterization of an air-stable gallium hydride, [t-Bu(H)Ga(mu-NEt(2))](2), and related chloride derivatives

The synthesis of [t-Bu(H)Ga(mu-NEt(2))](2) (1) was accomplished by the addition of 4 t-BuLi to [Cl(2)Ga(mu-NEt(2))](2). Evidence suggests that two tert-butyl groups are lost as isobutylene and result in Ga-H bond formation. The gallium hydride 1 is remarkably stable toward ambient air, oxygen, photolysis, and moderate heating; however, in CHCl(3) the hydride is replaced by chloride, producing [t-Bu(Cl)Ga(mu-NEt(2))](2) (2). Compound 1 may also be synthesized by sequential tert-butyl additions to [Cl(2)Ga(mu-NEt(2))](2). A singly substituted tert-butyl dimer, t-Bu(Cl)Ga(mu-NEt(2))(2)GaCl(2) (3), was also isolated, and interconversions between 1, 2, and 3 are described. Compound 1 was tested for utility in the chemical vapor deposition of GaN and produced gallium-rich films at low temperatures (<250 degrees C) with limited nitrogen incorporation due to facile Et(2)NH elimination.