Organometallic Precursors for the Formation of GaN by MOCVD: Structural Characterization of (CH3)3GaNH(CH2CH3)2 by Gas-Phase Electron Diffraction and ab Initio Molecular Orbital Calculations

The reaction of (CH 3 ) 3 Ga with NH(CH 2 CH 3 ) 2 led to the formation of trimethylgallium diethylamine, (CH 3 ) 3 Ga·NH(CH 2 CH 3 ) 2 . The structure of (CH 3 ) 3 Ga·NH(CH 2 CH 3 ) 2 was determined from gas-phase electron-diffraction data combined with results from ab initio molecular orbital and density functional theory calculations. A gauche-anti conformer was found where the two Ga−N−C−C torsional angles are φ 1 = 151(4)° and φ 2 = −100(4)°. The average experimental bond distances ( r g ) and bond angles (∠ α ), with estimated 2σ uncertainties (σ include estimates of systematic errors and correlation in the experimental data) are r (C−H) = 1.116(3) Å, r (Ga−C) = 1.996(3) Å, r (Ga−N) = 2.204(12) Å, r (C−N) = 1.474(4) Å, r (C−C) = 1.544(4) Å, ∠N−Ga−C = 99.5(13)°, ∠Ga−N−C = 112.5(9)°, ∠N−C−C = 114.8(8)°, ∠C−N−C = 113.3(11)°, and ∠C−Ga−C = 117.3(7)°. Thermolysis of (CH 3 ) 3 Ga·NH(CH 2 CH 3 ) 2 was studied, from which it was concluded that the compound is not a suitable precursor for the production of GaN in MOCVD.