Aerosol-assisted chemical vapour deposition of substituted polyoxometalates H₄[PMo₁₁VO₄₀], H₇[PMo₈V₄O₄₀], [nBu₄N]₄[PVW₁₁O₄₀] and [nBu₄N]₅[PV₂W₁₀O₄₀] resulted in the formation of vanadium-doped metal oxide thin films. Depositions were carried out at 550 °C in methanol or acetonitrile for the POMs that contained molybdenum or tungsten, respectively. The as-deposited films were X-ray amorphous and relatively non-adherent. However, on annealing in air at 600 °C, decolourised translucent films that were more mechanically robust were obtained. Films deposited from H₄[PMo₁₁VO₄₀] and H₇[PMo₈V₄O₄₀] consisted of V-doped MoO₃ in the orthorhombic phase and films from [nBu₄N]₄[PVW₁₁O₄₀] and [nBu₄N]₅[PV₂W₁₀O₄₀] comprised of monoclinic V-doped WO₃. All films were fully characterised by using X-ray photoelectron spectroscopy, energy-dispersive X-ray diffraction, scanning electron microscopy and UV/Vis spectroscopy.

A conventional solution-based route to a cyclic trimeric organozinc compound [{Zn(Et)(β-diketonate)}₃] (β-diketonate=OC(OMe)CHC(Me)O, 1) is described, with 1 structurally characterized for the first time. The ligand selection of bidentate β-diketonates is shown to be key to isolating a cyclic trimer. Additional reaction of β-diketonates with diethyl zinc were spectroscopically characterized as compounds of the type [{Zn(Et)(β-diketonate)}_n] (β-diketonate=OC(Me)CHC(Me)O, 2, OC(OtBu)CHC(Me)O, 3). Further studies have shown that selective oxidation of these species produces cubanes of the general formula [{Zn(OC(R)CHC(Me)O)₂Zn(Et)OEt}₂] (R=OMe, 4; Me, 5; OtBu, 6), allowing a high oxygen content whilst remaining structurally suitable for use as precursors. The successful deposition of thin films of zinc oxide through aerosol-assisted chemical vapor deposition (AACVD), using a novel precursor, is described and fully characterized.

Titanium(IV) chloride and the triester glycerol tribenzoate (gtb) were reacted under moisture-free conditions in order to investigate the use of triester-containing oils in the purification of TiCl₄ in industrial processes. This resulted in the isolation of a chloro-bridged dimeric complex containing four titanium centres [{(TiCl₄)₂(gtb)}₂] (1). Further novel coordination compounds of TiCl₄ and the diesters; diisopropyl malonate, dibenzyl malonate and diethyl succinate were synthesised by direct reaction under moisture-free conditions, yielding [TiCl₄{CH₂(COOiPr)₂}] (2), [TiCl₄{CH₂(COOCH₂Ph)₂}] (3) and [TiCl₄{C₂H₄(COOEt)₂}] (4) respectively. The structures of compounds 1–4 were determined by single-crystal X-ray diffraction. All structures assumed an octahedral geometry consisting of the titanium bound to four chloride ligands and the diester molecule acting as a bidentate ligand, through its two carbonyl oxygen atoms. Exposure of the isopropyl malonate reaction to trace amounts of water during synthesis resulted in the formation of an oxo-bridged dimeric structure [Ti₂(μ-O)Cl₃{CH₂(COOiPr)₂}₂] (2b), the structure of which was also obtained via single-crystal X-ray diffraction.

Single-source zinc β-iminoesterate precursors have been used for the first time in the aerosol-assisted chemical-vapour deposition (AACVD) of ZnO thin films. Depositions at 450 °C on silica-coated glass substrates produced strongly adherent films with excellent coverage of the substrate. The zinc β-iminoesterates [Zn(L₁)₂] (1) and [Zn(L₂)₂] (2) were synthesised by the reaction between ZnEt₂ and 2 equiv. of a synthesised β-iminoester ligand CH₃C[NHCH(CH₃)₂]CHC(O)OCH₂CH₃ (L₁) and CH₃C(NHCH₃)CHC(O)OCH₂CH₃ (L₂). The synthesised complexes were isolated and characterised by ¹H and ¹³C NMR spectroscopy, mass spectrometry and thermal gravitational analysis (TGA). The structures of the compounds were determined by single-crystal X-ray diffraction. The ZnO films deposited from 1 and 2 were analyzed by glancing-angle X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and their optical properties determined by UV/Vis/NIR transmission spectroscopy. These results reveal that the organic ligand attached to the N moiety of the zinc complex has a significant effect on the level of carbon incorporated into the deposited thin film. Upon annealing, highly transparent hexagonal wurtzite ZnO thin films were produced.

Bis-β-ketoimine ligands of the form [(CH₂)_n{N(H)C(Me)CHC(Me)O}₂] (LⁿH₂, n=2, 3 and 4) were employed in the formation of a range of gallium complexes [Ga(Lⁿ)X] (X=Cl, Me, H), which were characterised by NMR spectroscopy, mass spectrometry and single-crystal X-ray diffraction analysis. The β-ketoimine ligands have also been used for the stabilisation of rare gallium hydride species [Ga(Lⁿ)H] (n=2 (7); n=3 (8)), which have been structurally characterised for the first time, confirming the formation of five-coordinate, monomeric species. The stability of these hydrides has been probed through thermal analysis, revealing stability at temperatures in excess of 200 °C. The efficacy of all the gallium β-ketoiminate complexes as molecular precursors for the deposition of gallium oxide thin films by chemical vapour deposition (CVD) has been investigated through thermogravimetric analysis and deposition studies, with the best results being found for a bimetallic gallium methyl complex [L³{GaMe₂}₂] (5) and the hydride [Ga(L³)H] (8). The resulting films (F5 and F8, respectively) were amorphous as-deposited and thus were characterised primarily by XPS, EDXA and SEM techniques, which showed the formation of stoichiometric (F5) and oxygen-deficient (F8) Ga₂O₃ thin films.

Copper-based spinel oxide CuGa₂O₄ films have been deposited by means of a simple one-pot solution-based chemical vapour deposition (CVD) method. Aerosol-assisted (AA) CVD of copper(II) 2,2,6,6,-tetramethylheptan-3,5-dionate (thd), Cu(thd)₂ and gallium(III) acetylacetonate, Ga(acac)₃, in toluene resulted in the formation of transparent films with a slight yellow tinge at 300–500 °C. Scanning electron microscopy (SEM) indicated that the films had grown by means of an island growth mechanism. Energy-dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS) showed that CuGa₂O₄ had formed along with copper(I) oxide and gallium(III) oxide was observed at the surface of the film. Annealing the films under a range of conditions (air, N₂, vacuum) resulted in oxidation and the formation of CuGa₂O₄ and copper(II) oxide, as shown by powder X-ray diffraction (XRD). The films were further analysed by UV/Vis spectroscopy and atomic force microscopy. Similar AACVD depositions using copper(II) acetylacetonate, Cu(acac)₂, and Ga(acac)₃ in a range of solvents only resulted in the formation of gallium oxide owing to the lower solubility of the copper precursor than the gallium complex. AACVD is dependent on the precursor solubility hence Cu(thd)₂ is a superior precursor to Cu(acac)₂ owing to its increased solubility.

Aerosol-assisted chemical vapour deposition (AACVD) reactions of GaMe₃, ZnEt₂ and the donor-functionalised alcohol HOCH₂CH₂OMe (6 equiv.) in toluene resulted in the deposition of amorphous transparent zinc gallate (ZnGa₂O₄) films at a range of temperatures (350–550 °C). The zinc–gallium oxide films were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis, glancing-angle X-ray powder diffraction (XRD) and optical studies. The optimum growth temperature was found to be 450 °C, which produced transparent films with excellent coverage of the substrate. XPS confirmed the presence of zinc, gallium and oxygen in the films. Annealing these films at 1000 °C resulted in crystalline films and glancing-angle powder XRD showed that a zinc gallate spinel framework with a lattice parameter of a=8.336(5) Å was adopted.

The donor-functionalised alkoxides {Me_3−xN(CH₂CH₂O)_x} (L^x; x=1, 2) have been used to form gallium hydride complexes [{GaH₂(L¹)}₂] and [{GaH(L²)}₂] that are stable and isolable at room temperature. Along with a heteroleptic gallium tris(alkoxide) complex [Ga(L¹)₃] and the dimeric complex [{GaMe(L²)}₂], these compounds have been used as single-source precursors for the deposition of Ga₂O₃ by aerosol-assisted chemical vapour deposition (AACVD) with toluene as solvent. The resulting films were mostly transparent, indicating low levels of carbon contamination, and they were also mainly amorphous. However, [Ga(L¹)₃] did contain visibly crystalline material deposited at a substrate temperature of 450 °C, by far the lowest ever observed for the CVD of gallium oxide.

Titanium arsenide thin films were deposited by the atmospheric-pressure chemical vapour deposition (APCVD) of TiCl₄ and tBuAsH₂ at substrate temperatures between 450 and 550 °C. The deposited films are typically silver in appearance, demonstrate good adherence and were identified by X-ray powder diffraction as crystalline TiAs. X-ray photoelectron spectroscopy (XPS) and Raman microscopy support the formation of TiAs. The TiAs films have an approximate 1:1 ratio of Ti:As, as identified by wavelength dispersive analysis of X-rays (WDX), and the films grow by an island growth mechanism with deposition rates of ca. 0.1 μm min^–1. The films display borderline metallic/semiconductor conductivity and those deposited at 550 °C possess high hardness.