Synthesis and Characterization of Fluorinated Aminoalkoxide and Iminoalkoxide Gallium Complexes:  Application in Chemical Vapor Deposition of Ga₂O₃ Thin Films

Abstract

Gallium trichloride, GaCl 3 , reacts with the in situ prepared sodium salt of an aminoalkoxide or iminoalkoxide, denoted as NaL, to give the disubstituted compounds GaL 2 Cl, where L ) OC(CF 3 ) 2 CH 2 NMe 2 (1), OC(CF 3 ) 2 CH 2 C(Me)dNMe (2). Single-crystal X-ray diffraction studies on 1 and 2 indicated the formation of a trigonal-bipyramidal structure with chloride and alkoxy groups occupying the equatorial sites and the nitrogen donors located at the axial positions. For the related trimethylgallium reagent GaMe 3 , addition of an equal amount of amino alcohol LH induced the elimination of methane to afford the complexes GaMe 2 L, where L ) OC(CF 3 ) 2 CH 2 NHMe (3), OC(CF 3 ) 2 CH 2 NHBu t (4), OC(CF 3 ) 2 CH 2 NMe 2 (5), in high yields. The crystal structure of 5 was determined by X-ray diffraction, showing a distortedtetrahedral framework which differs greatly from that observed in the trigonal-bipyramidal Ga complexes 1 and 2. Variable-temperature 1 H NMR studies on 3 and 4 indicated the occurrence of rapid NfGa bond scission, followed by recoordination with a change of the absolute configuration. A lower activation barrier was observed for the Bu t complex 4 upon changing solvents from CDCl 3 to more polar media such as deuterated toluene and THF. Complexes 1 and 4 were then evaluated as potential precursor molecules for the chemical vapor deposition of Ga 2 O 3 , and the as-deposited films were analyzed using scanning electron micrographs (SEM), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering (RBS).

Metal–Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials

“…100 39 They also used the metathesis reaction of the sodium salt of fluorinated aminoalcohol [HOC(CF 3 ) 2 CH 2 NMe 2 (Hamak F )] and iminoalcohol [HOC(CF 3 ) 2 CH(Me)NMe (Himak F )] with GaCl 3 in diethyl ether to prepare the bis complexes [Ga(amak F ) 2 Cl] and [Ga(imak F ) 2 Cl]. 42 In contrast, the reactions of same ligands with trimethylgallium afforded only the monosubstituted complexes [GaMe 2 (amak F )] and [GaMe 2 (imak F )]. 42 On the other hand, complete halide removal was possible in the reactions of MX 4 [M = Ti (X = F), Zr (X = Cl)] with Li/Na salts of hexafluorophenyltertiarybutanol or a tetradentate β-diketoimine, 101 However, the reactions proceeds with the formation of water as a byproduct to give sometimes hydrated metal complexes.…”

“…42 In contrast, the reactions of same ligands with trimethylgallium afforded only the monosubstituted complexes [GaMe 2 (amak F )] and [GaMe 2 (imak F )]. 42 On the other hand, complete halide removal was possible in the reactions of MX 4 [M = Ti (X = F), Zr (X = Cl)] with Li/Na salts of hexafluorophenyltertiarybutanol or a tetradentate β-diketoimine, 101 However, the reactions proceeds with the formation of water as a byproduct to give sometimes hydrated metal complexes. These hydrated complexes are, however, unattractive for the materials processing due to the uncontrolled reactivity, which water molecules may introduce in the precursor solution.…”

Multidentate fluorinated alkoxide ligand platforms for oxophilic metal centers: from MOCVD source reagents to polymerizationcatalysts

“…17 Gallium derivatives Ga{OL} 2 Cl, where LO = OC(CF 3 ) 2 -CH 2 NMe 2 , OC(CF 3 ) 2 CH 2 C(Me)=NMe, were similarly prepared from GaCl 3 and the corresponding ligand sodium salt (Scheme 10). 20 Single-crystal X-ray diffraction studies revealed mononuclear compounds in a trigonal-bipyramidal (tbp) geometry with chloride and alkoxy groups occupying the equatorial sites and the nitrogen donors located at the axial positions. Methane elimination reactions from GaMe 3 and one equivalent of fluorinated amino-alcohol LOH (LO = OC(CF 3 ) 2 CH 2 NRR¢ with R = H, R¢ = Me, tBu, R = R¢ = Me) proceeded in high yields to afford the GaMe 2 {OL} complexes (Scheme 10).…”

Diorgano-gallium and -indium complexes with salen ligands: Synthesis, characterization, crystal structure and C–C coupling reactions

“…Interest in these compounds, particularly with internally functionalized ligands, appears to be due to their wide structural diversity [1], potential applications as catalyst [4,5] as well as molecular precursors for the preparation of metal oxide thin films [6][7][8] and photophysical properties [9][10][11][12].…”