Hexafluoro-acetylacetonates

Also increasingly common, as CVD precursors, are many halogen-acetylacetonate complexes, such as trifluoro-acetylacetonate thorium, Th(C5H4F302)4, used in the deposition of thoriated tungsten for thermionic emitters, the trifluoro-acetylacetonates of hafnium and zirconium and the hexafluoro-acetylacetonates of calcium, copper, magnesium, palladium, strontium, and yttrium. 

Me2SO solution b Hibbert (1974) Protonated amine salt with magnesium tris(hexafluoro-acetylacetonate) (Truter and Vickery, 1972) 4 CF3COOH solution (Alder et al., 1968) Altman et al. (1978) 1 Protonated amine salt with copper(n) tris(hexafluoroacetylacetonate) (Truter and Vickery, 1972) 9 Hydrobromide salt (Pyzalka et al., 1983) Staab el al. (1983) Staab et al. (1988a) JSaupe et al. (1986) Staab and Saupe (1988) Staab et al. (1988b) Zirnstein and Staab (1987). 

Consequently, Fhb is the difference between the OH barrier calculated in the chelate conformation and the same barrier calculated in a molecule structurally close to the examined compound but hydrogen bond free. In most of our calculations, the reference molecule was attained by substituting the hydrogen bond acceptor fragment with a H atom. When tested on malonaldehyde and acetylacetone the approach worked very well [185]. The method was then applied with discrete success to many other molecules as formazan [186], carbonylamine [187], hexafluoro-acetylacetone [184], glyoxaloxime [188], 2-nitroresorcinol, 4,6-dinitroresorcinol and 2-nitrophenol in vacuum and in solution [189], malonamide and nitromalonamide [158] and ort/zo-halophenols [190]. 

Buemi, G., Ab initio DFT study of hydrogen bridges in hexafluoro-acetylacetone, trifluor-oacetyl-acetone and some 3-substituted derivatives, J. Mol Struct. Theochem, 499, 21-34 (2000). 

Five-membered nitrogen-containing heterocycles may be synthesized from tV,VV-diethylaminomethylene-l,l,l,5,5,5-hexafluoro-acetylacetone (93TL7737) (Scheme 112). 

The major breakthrough that transformed metal chelate GC into a useful analytical technique was the introduction of fluorinated beta-diketone ligands, which formed complexes of greater volatility and thermal stability. Trifluoroacetylacetone (l,l,l-trifluoro-2,4-pentanedione—HTFA) and hexafluoro-acetylacetone (l,l,l,5,5,5-hexafluoro-2,4,-pentanedione—HHFA) are the fluorinated ligands most frequently employed. HTFA extended the range of metals that may be gas chromatographed with little or no evidence of decomposition to include Ga3+, In3+, Sc3+, Rh3+ and V4+. An example of a recent application is the analysis for beryllium in ambient air particulates. After filter sampling and extraction/chelation, packed column GC with electron capture detection allowed ppm level beryllium quantitation in collected particulates which corresponded to levels of 2-20 x 10 5 pg/m3 in the sampled air. 

B4 THE PREPARATION AND PROPERTIES OF RARE EARTH HEXAFLUORO-ACETYLACETONATES, M. Steinberg, J. Masha 11 and A. Glasner... 

The complexes Eu(hfa)3(L), where Hhfa = l,Ll,5,5,5-hexafluoro-acetylacetone, L = mono- or diglyme, give vEu-O bands in the IR spectra near 250 cm. IR bands due to EuFeOs were assigned from the IR spectrum of the Eu203 Fe203 system. "... 

Replacement of the terminal methyl groups of acacH by an electron-withdrawing or aromatic group such as CF3, C4H3S (2-thienyl), and CfiHs shifts the equilibrium in favor of the enol tautomer. Hexafluoro-acetylacetone (hfacH), thenoyltrifluoroacetone (in carbon disulfide), and dibenzoylmethane (dbmH) (in carbon tetrachloride), for example, exist entirely in the enol form. °" ... 

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