Phosphorus-substituted azulenes accessed via direct hafner reaction of a phosphino cyclopentadienide

The Hafner azulene synthesis may be applied to the direct synthesis of phosphorus-substituted azulenes, when a phosphinocyclopentadienide is used as one of the reactants. The azulenyl phosphines produced in this fashion are preferentially isolated as the corresponding phosphine oxides or phosphine borane adducts.</p

Synthesis, Structure and CVD Studies of the Group 13 Complexes [Me₂M{tfacnac}] [M = Al, Ga, In; Htfacnac = F₃CC(OH)CHC(CH₃)NCH₂CH₂OCH₃]

A family of group 13 metal dimethyl complexes of the general form [Me2M{ MeC(O)CHC(NCH2CH2OMe)CF3}] (M = Al (2), Ga (3) or In (4)) have been synthesised by reaction of the isolated free ligand (1) with the corresponding trimethyl-metal reagents. The isolated complexes (2-4) were characterised by elemental analysis, NMR spectroscopy, and the molecular structures of the complexes were determined by single crystal X-ray diffraction which reveals the compounds to be monomeric 5 coordinate complexes with coordination of the pendent ether bearing lariat in the solid state. Thermogravimetric analysis showed complexes 2-4 all to have residual masses, at 200 °C, of 2.4% or less well below the value for the respective metal oxides, and vapour pressure measurements show the indium complex (4) to be an order of magnitude less volatile (0.09 Torr at 80 oC) than the Al (2) or Ga (3) derivatives despite being isoleptic systems. Complexes 2-4 have all been investigated for their utility in the LP-MOCVD growth of the respective metal oxides in the absence of additional oxidant at 400 °C on silicon substrates

Synthesis and characterization of fluorinated β-ketoiminate zinc precursors and their utility in the AP-MOCVD growth of ZnO:F

A novel family of zinc bis beta-ketoiminate complexes 2b-2h have been synthesized by reaction of the isolated free ligands (1a-h) with dimethylzinc. The isolated zinc complexes were characterized by elemental analysis, NMR spectroscopy, and in the case of 2b-d and 2f-h, the molecular structures of the complexes were determined by single crystal X-ray diffraction which reveals the compounds to be pseudo-octahedral 6-coordinate, monomeric homoleptic complexes in the solid state. TG analysis showed complexes 2b-f all to have residual masses at 400 °C of 10% or less, well below the value for ZnO and thus indicative of volatility. Of these systems 2b [Zn{MeC(O)CHC(NCH2CH2OMe)CF3}2] has been investigated for its utility in the AP-MOCVD growth of F –doped ZnO (ZnO:F) in the absence of additional oxidant at 400 °C on glass and silicon substrates

Precursors for p-Type Nickel Oxide: Atmospheric-Pressure Metal-Organic Chemical-Vapour Deposition (MOCVD) of Nickel Oxide Thin Films with High Work Functions

A series of unsymmetrical nickel beta-diketonate derivatives have been synthesised and structurally characterised for application as atmospheric-pressure metal-organic chemical vapour deposition (AP-MOCVD) precursors for nickel oxide.TMEDA)Ni[MeC(O) CHC(O) OEt](2) (TMEDA = tetramethylethylenediamine) was selected and used to deposit NiO films of varying thickness onto commercial indium tin oxide (ITO)-coated glass; the work function of the ITO was raised as a consequence

Cobalt(III) Diazabutadiene Precursors for Metal Deposition: Nanoparticle and Thin Film Growth

We report the synthesis and characterization of a family of cobalt­(III) metal precursors, based around cyclopentadienyl and diazabutadiene ligands. The molecular structure of the complexes cyclopentadienyl-Cobalt­(III)­(<i>N,N</i>′-dicyclohexyl-diazabutadiene) (<b>2c</b>) and cyclopentadienyl-Cobalt­(III)­(<i>N,N</i>′-dimesityl-diazabutadiene) (<b>2d</b>) are described, as determined by single crystal X-ray diffraction analysis. Thermogravimetric analysis of the complexes highlighted the isopropyl derivative CpCo­(^<i>i</i>Pr₂-dab) (<b>2a</b>) as a possible cobalt metal chemical vapor deposition (CVD) precursor. Atmospheric pressure CVD (AP-CVD) was employed using precursor <b>2a</b> to synthesize thin films of metallic cobalt on silicon substrates under an atmosphere of hydrogen (H₂). Analysis of the thin films deposited at substrate temperatures of 250 °C, 275 °C, 300 °C, 325 °C, and 350 °C, respectively, by scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveal temperature dependent growth features: films grown at 325 and 350 °C are continuous and pinhole free, whereas those films grown at substrate temperatures of 250 °C, 275 °C, and 300 °C consist of crystalline nanoparticles. Powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS) all show the films to be high purity metallic cobalt. Raman spectroscopy has also been used to prove the absence of cobalt silicides at the substrate/thin film interface

Cobalt(III) Diazabutadiene Precursors for Metal Deposition: Nanoparticle and Thin Film Growth

We report the synthesis and characterization of a family of cobalt­(III) metal precursors, based around cyclopentadienyl and diazabutadiene ligands. The molecular structure of the complexes cyclopentadienyl-Cobalt­(III)­(<i>N,N</i>′-dicyclohexyl-diazabutadiene) (<b>2c</b>) and cyclopentadienyl-Cobalt­(III)­(<i>N,N</i>′-dimesityl-diazabutadiene) (<b>2d</b>) are described, as determined by single crystal X-ray diffraction analysis. Thermogravimetric analysis of the complexes highlighted the isopropyl derivative CpCo­(^<i>i</i>Pr₂-dab) (<b>2a</b>) as a possible cobalt metal chemical vapor deposition (CVD) precursor. Atmospheric pressure CVD (AP-CVD) was employed using precursor <b>2a</b> to synthesize thin films of metallic cobalt on silicon substrates under an atmosphere of hydrogen (H₂). Analysis of the thin films deposited at substrate temperatures of 250 °C, 275 °C, 300 °C, 325 °C, and 350 °C, respectively, by scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveal temperature dependent growth features: films grown at 325 and 350 °C are continuous and pinhole free, whereas those films grown at substrate temperatures of 250 °C, 275 °C, and 300 °C consist of crystalline nanoparticles. Powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS) all show the films to be high purity metallic cobalt. Raman spectroscopy has also been used to prove the absence of cobalt silicides at the substrate/thin film interface