Fluoride derivatives

Fluorinated ether-containing dicarboxyhc acids have been prepared by direct fluorination of the corresponding hydrocarbon (17), photooxidation of tetrafluoroethylene, or by fluoride ion-cataly2ed reaction of a diacid fluoride such as oxalyl or tetrafluorosuccinyl fluorides with hexafluoropropylene oxide (46,47). Equation 8 shows the reaction of oxalyl fluoride with HEPO. A difunctional ether-containing acid fluoride derived from HEPO contains regular repeat units of perfluoroisopropoxy group and is terminated by two alpha-branched carboxylates. 

Liquid oxygen/dichloromethane, 1,1,1-trichloroethane, trichloroethylene mixtures detonate violently. Under the same conditions, carbon tetrachloride detonates with less intensity and some fluoridated derivatives do not detonate. 

T. Shioiri, A. Bohsako, A. Ando, Importance of the Hydroxymethyl-quinudidine Fragment in the Catalytic Asymmetric Adol Readions Utilizing Quaternary Ammonium Fluorides derived from Cinchona Akaloids , Heterocycles 1996, 42, 93-97. 

SnCI2-AgX The L-fucosyl fluoride derivative 18 reacts with glycosyl acceptor 19 in the presence of SnCl2-AgC104 to give the corresponding disaccharide 20 as a-anomer only (Scheme 2.7) [84],... 

BF3-OEt2 Unnatural P-sialoside derivatives are produced preferentially by using O-acetylated glycosyl fluoride donor and BF3-OEt2 as the promoter. When P-sialyl fluoride derivative 28 was reacted with acceptor 22 in the presence of BF3-OEt2 in dichloromethane, the P-sialoside 28 was obtained in a mixture of anomers (a/p 17/83) (Scheme 2.11) [44],... 

Another stratagem to avoid nonideality of the gas state is to compare heats of formation of fluorides derived from fluorine combustion on the element, with heats of hydrolysis determined directly or indirectly, as in... 

The 2,5-anhydrides of 2-ketoses constitute a special case, in which the hemiacetalic carbon atom is involved in the anhydride bridge. Such anhydrides more closely resemble the 1,6-anhydroaldoses (glycosans) than the 2,5-anhydroaldoses. An example of a 2,5-anhydride of a 2-hexulose is obtained by the action of base on a D-fructosyl fluoride derivative treatment of l-0-methyl-/3-D-fructopyranosyl fluoride at 90° with concentrated, aqueous sodium hydroxide leads,80 in poor yield, to 2,5-anhydro-l-0-methyl-/3-D-fructopyranose. 

Finally, the chemistry of zirconium fluorides should be mentioned. This is a rather special case but does have some relevance to industrial usage, as discussed later. Zirconium fluorides exhibit a marked reluctance to hydrolyse at acid pHs. These zirconium fluoride derivatives tend to be less polymeric, although some polymeric nature is believed to exist [3]. 

Higher silicon halides Si X +2 with n > 2 but of limited molecular weight have been known for a long time, above all from chlorine, but a few from bromine, and none from iodine. In the case of fluorine, some higher silicon fluorides derived from difluorosilylene have been recently discovered (see p. 60). 

Calcium fluoride has also been used in metathetical reactions. Usually, heat is required to promote reactions of this type. Booth and Dutton4 passed vapors of a volatile halide [phosphorus(V) oxychloride] over a bed of heated calcium fluoride to produce the chlorofluoride and fluoride derivatives. Sodium fluoride, potassium fluoride, titanium (IV) fluoride, and zinc fluoride have been used in similar metathetical fluorination reactions. 

A number of complex niobium(V) oxide fluoride derivatives, such as... 

Ferromagnetic Fluorides Derived from the K2NiF4 Type. 108... 

The only other route to scandium fluoride derivatives has been via C—F bond activation of fluoro-alkenes with [ScR(Cp )2] (R = H, Me) to give [ScF(Cp )2] [1], Very recent work has produced the first report of an organometallic yttrium fluoride. The reaction between [(CsH5)3Y] and Me3NHF results in the isolation of [ (C5H5)2YF(THF) 2] which has been fully characterised by elemental analysis, infra-red, mass and NMR spectroscopies and X-ray diffraction [8]. 

Recent Group IV chemistry has seen an upsurge in the number of amide derived species, and this has included fluoride derivatives. None of these compounds are of oxidation state -(-III or less, which are the subject of this review, but refer to titanium, zirconium or hafnium where the metal is the +IV state [1,9-12] and, consequently, not covered here. 

The study of Group 9 carbonyl fluoride derivatives in the +1 oxidation state has revolved solely around fluoro derivatives of Vaska s complex, [MF(CO)(PR.3)2] (M = Ir, Rh). The preparation of [MF(CO)(PPh3)2] was originally the outcome... 

Fluoride derivatives of palladium(II) and platinum(II), all of which are phosphine derivatives, can be most simply grouped into one of two subsections, namely neutral or cationic species. The neutral species are all of the form [MXF(PPh3)2] (M = Pd, Pt) where X can be Cl, Br, I, H, methyl, phenyl and C6F5. The synthetic route into these compunds involves either addition of HF to a metal phosphine dihalide or... 

Another zinc fluoride has been prepared incorporating a pyrazolyl borate ligand. Reaction of [KHB(3-R-5-methylpyrazol-l-yl)] (R=/ -tol) with [Zn(OAc)2.2H2OJ leads to the production of [TpR MeZnOAc], which is transformed to the fluoride derivative upon addition of KF [99], This compound has been structurally characterised. Use of [Zn(C104)2] as the starting material in combination with [KHB(3- Bu-5-methylpyrazol-l-yl)], followed by addition of KF leads to [TptBu,MeZnF], Further reaction of this compound at the fluoride anion leads to a variety of species. Abstraction of F by BF3.solv. (solv. = py, Et20) leads to [TpZn(solv.)][BF4], whilst use of [HSiEt3] leads to formation of the hydride species,... 

Fig. 12. Water drop on solid type fluoride, derived thin film and PTFE (A) on solid type fluoride (B) on thin film derived from solid type fluoride (C) on PTFE. (Quoted from H. Fujimoto, A. Mabuchi, T. Maeda, Y. Matsumura, N. Watanabe, H. Touhara, Carbon, 30 (1992) 851, with permission).

In similar way pcrfluoroclhanecan be produced from perfluoropropanoyl fluoride. This process has also been applied " to high molecular weight molecules and to acyl fluorides derived from polymcrizalion of tetralluoroethylenc oxide. 

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