Structural and Dynamic Properties of Gallium Alkoxides

[Image: see text] A comparison of chlorido-gallium functionalized alkoxides as precursors for aerosol-assisted chemical vapor deposition (AACVD) was carried out. Variable-temperature (VT)-NMR studies were used to probe the fluxional behavior of these alkoxides in solution, and hence their utility as precursors. The synthesis involved the initial isolation of the dimer [GaCl(NMe(2))(2)](2) via a salt metathesis route from GaCl(3) and 2 equiv of LiNMe(2). This dimer was then reacted with 4 equiv of HOCH(2)CH(2)CH(2)NEt(2), resulting in the formation of Ga[μ-(OCH(2)CH(2)CH(2)NEt(2))(2)GaCl(2)](3) (1). Mass spectrometry and VT-NMR confirmed the oligomeric structure of 1. Tuning of the ligand properties, namely, the chain length and substituents on N, resulted in formation of the monomers [GaCl(OR)(2)] (R = CH(2)CH(2)NEt(2), (2); CH(2)CH(2)CH(2)NMe(2), (3)). VT-NMR studies, supported by density functional theory calculations, confirmed that the ligands in both 2 and 3 possess a hemilabile coordination to the gallium center, owing to either a shorter carbon backbone (2) or less steric hindrance (3). Both 2 and 3 were selected for use as precursors for AACVD: deposition at 450 °C gave thin films of amorphous Ga(2)O(3), which were subsequently annealed at 1000 °C to afford crystalline Ga(2)O(3) material. The films were fully characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and energy dispersive X-ray analysis.