286854-89-5Relevant articles and documents
Facile synthesis of a novel class of organometalloid-containing ligands, the sila-β-diketones: Preparation and physical and structural characterization of the copper(II) complexes, Cu[R′C(O)CHC(O)SiR3]2
Banger, Kulbinder K.,Ngo, Silvana C.,Higashiya, Seiichiro,Claessen, Rolf U.,Bousman, Kenneth S.,Lim, Poay N.,Toscano, Paul J.,Welch, John T.
, p. 15 - 32 (2003)
The substitution of a carbon atom by silicon provides an attractive, novel approach to modification of the thermal stability and volatility of metal-organic chemical vapor deposition precursors supported by β-diketonate ancillary ligands. The low temperature reaction of the lithium enolates of acetyltrialkylsilanes with acyl chlorides affords the sila-β-diketones, R′C(O)CH2C(O)SiR3 (R′=Me, Et, n-Pr, i-Pr, n-Bu, i-Bu, s-Bu, t-Bu; SiR3=SiMe3, SiEt3, SiMe2(t-Bu), SiMe2(t-hexyl), Si(i-Pr)3), in good yields. Multinuclear NMR studies suggest that the sila-β-diketones exist as the enolic tautomer with a vinylsilane isomeric structure. Homoleptic Cu(II) sila-β-diketonate complexes were prepared in a first pass study to evaluate how precursor performance is affected by modulation of the peripheral substituents in the ligands. Thermal analyses, (TGA, DSC) show that the silylated Cu(II) precursors (SiR3=SiMe3; R′=t-Bu or i-Bu) have greater volatility than the corresponding carbon analogues. Some of the new Cu(II) complexes exist as liquids or low melting solids, which are preferred states for industrial deposition processes. X-ray diffraction studies of selected copper complexes showed them to have typical, square planar geometry; calculations of molecular volumes suggest that packing in the solid-state is less efficient for the silicon-containing complexes than for the non-silylated analogues.
Investigations into the preparation of sila-β-diketones via 2-trimethylsilyl-1,3-dithianes: Structural characterization of a second polymorph of bis(2,2,6,6-tetramethyl-2-sila-3,5- heptanedionato)copper(II)
Claessen, Rolf U.,Kornilov, Andrei M.,Banger, Kulbinder K.,Ngo, Silvana C.,Higashiya, Seiichiro,Wells, Christopher C.,Dikarev, Evgeny V.,Toscano, Paul J.,Welch, John T.
, p. 71 - 81 (2004)
The sila-β-diketone, 2,2,6,6-tetramethyl-2-silaheptane-3,5-dione (tmshdH), was synthesized by the condensation of the anion of 2-trimethylsilyl-1,3-dithiane with 1-bromo-3,3-dimethylbutan-2-one, followed by unmasking of the latent carbonyl moiety with HgO/HgCl2. A monoclinic polymorph of the known copper(II) complex, Cu(tmshd)2, was crystallized and studied by X-ray diffraction methods and found to be disordered like the orthorhombic one. Attempts to synthesize the disilylated β-diketone, 2,2,6,6-tetramethyl-2,6-disilaheptane-3,5-dione and monosilylated 4,4-dimethyl-4-sila-3-oxo-pentanal using the dithiane method were not successful. However, the 1,3-dithianyl precursors, along with the impurity 2,2′-bis(trimethylsilyl)-2,2′- bi-1,3-dithiane, were studied crystallographically. Large stereoelectronic and steric effects on the solid-state bonding parameters were observed for these molecules.
MOCVD precursors based on organometalloid ligands
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Example 3, (2008/06/13)
Volatile metal complexes with α-sila-β-diketonate ligands containing haloalkyl, and particularly, perfluoroalkyl, substitutents are useful as metal precursors for chemical vapor deposition processes and as nanostructured materials containing fluorous domains.
