Fluorine/fluoride complex

In contrast to pyridine-hydrogen fluoride, which is acidic and acts as a protonating agent, in alkylamine-hydrogen fluoride complexes, fluorine is a nucleophile. The difference of the nature of these two types of reagents has been... 

S)-[ F]fluoroethylcarazolol 8, 111 subtypes of, 100 Adriamycine (doxorubicine), 589 Agrochemical agents, 215 AIF. See Aluminium monofluoride Aliphatic nucleophilic substitution, 28 Alkenes, as amide bond substitutes, 702-703 Alkenes fluorination, 18 Allyl hydrazines as SSAO inhibitors, 674 Aluminium monofluoride, 534 Alumino-fluoride complexes, 364 Alzheimer s disease (AD)... 

Phenylmercury(II) fluoride-hydrogen fluoride complex fluorinates phenyl(tribromo-methyl)mereury in 60-65% yield when the reaction is carried out in the presence of 48% hydrogen fluoride. Phenyl(trichloromethyl)mercury can be fluorinated to the trifluoromethyl derivative in this manner, but a reaction temperature of 90 C is required. Partial fluorination of (bromodichloromethyl)phcnylmcrcury to (dichlorofluoromethyl)phenylmercury in 60% yield can be achieved at room temperature, but attempted partial fluorination of phenyl(tri-bromomethyl)mercury, (dibromochloromethyl)phenylmercury, and (dibromofluoromethyl)-phenylmereury was unsuccessful phenyl(trifluoromethyl)mercury is the major product obtained.61... 

Finally, the metal-perfluoroalkyl linkage also appears to be less susceptible to facile decomposition by the a- or -elimination pathways that dominate much of the chemistry of hydrocarbon alkyls and lead to metal hydrides. The absence of these reaction pathways, at least for the later transition metals, may reflect the relative strength of the C—F bond versus the M—F bond compared to C—H/M—H analogues (32). However, a-fluoride abstraction reactions can be accomplished with exogenous fluoride acceptors to give fluorinated carbene complexes (see Section III,B,1). One example of an apparent -fluorine elimination reaction is shown in Eq. (2) (33) and presumably is driven by the stronger bond to fluorine formed by early transition... 

Stable dialkyl ether poly(hydrogen fluoride) complexes (R20-[HF]n, R = Me, Et, n-Pr) have recently been developed by Prakash, Olah, and colleagues.33 DFT calculations suggest a cyclic poly(hydrogen fluoride) bridged structure. Dimethyl ether-5 HF (DMEPHF) was shown to be a convenient and effective fluorinating agent (see Section 5.10.1). 

Stable dialkyl ether poly(hydrogen fluoride) complexes have been shown to be convenient and effective fluorinating agents.553 Various open-chain and cyclic alkenes undergo hydrofluorination with dimethyl ether-5 HF (DMEPHF) atroom temperature to furnish the corresponding fluoro derivatives in high yields (73-94%) with excellent selectivities. The fluorination of secondary and tertiary alcohols exhibit similar features. Bromofluorination of alkenes can also carried out with DMEPHF in combination with /V-bromosuccinimide. The homologous diethyl ether and dipropyl ether complexes are also suitable for fluorinations. 

There are, in fact, very few reports of nickel(II) fluoride complexes in the literature over the past thirteen years. The formation of a nickel fluorine bond has been implied in two separate reports of organic couplings. However, there has been no characterising spectroscopic data and the suggested mechanisms which may give rise to the Ni—F bonds have been based only upon the products obtained [80,81]. 

The reaction of the porphyrin ligand, TTP (tetra-p-tolylporphyrin) with BF3-OEt2 leads to the oxide fluoride complex, B2OF2(TTP) and the structure has been established using H, 13C, nB and 19F NMR spectroscopy and FAB mass spectrometry [9], The structure contains a B—O—B bridge in which each boron is bonded to fluorine and to a nitrogen of TTP. The structure of the diboron complex was confirmed by an X-ray crystal structure determination of the tetrakis-(p-chlorophenyl)porphyrin (TpCiPP) derivative. 

S. BAIRD (Texas Instruments) I would like to suggest an experiment. You believe that the iron fluoride complex sets down at a kink and stops its motion. Further insight to this mechanism could be gained by substituting other transition elements that form stable complexes with fluorine perhaps one or more of them will be too big to fit into the kink. Another way would be to use other complexing agents than fluorine for the iron in order to vary the size of the ion setting down at the kink. 

The fluorination of uracil (56) and cytosine (57) in a F AcOF/aq. AcOH system has been performed via a radical cation fluoride complex (58). This radical cation intermediate (58) is probably formed by an electron transfer due to the action of hypofluorite (AcOF) as shown in Scheme 5. ... 

A recent study of the alkali metal/uranium fluoride complex systems has shown that KriUFo, K3UF7, and K UFs are isomorphous (99), the crystal symmetry being unaffected by the fluoride ion absences. The structure of K PaFy has been determined only recently (39), and it has been shown that each protactinium atom is surrounded by nine fluorine atoms in what is effectively a trigonal prism with three added equatorial fluorine atoms the PaFo groups are linked in infinite chains by two fluorine bridges. 

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