Cycloalkanes perfluorination

Fluonnation and skeletal transformation of fluorinated cycloalkanes occurs in the reaction with antimony pentafluoride at high temperature [777] In the case of perfluorinated benzocyclobutanes, an unexpected alicyclic ring cleavage has been observed Perfluorinated alkyl benzocyclobutanes, when treated with antimony pentafluoride, ean be converted to perfluorinated styrenes and then transformed to perfluorinated indans [77S, 779]... 

Perfluorinated alkanes and cycloalkanes are prepared from the corresponding hydrocarbons, either by electrochemical fluorination or by cobalt trifluoride fluo-rination [3], Many perfluorinated solvents are available commercially covering a wide selection of boiling points and densities. Some examples of perfluorinated solvents are listed in Table 3.1 together with their key physical properties. 

To the sodium cycloalkane- or -arenethiolate (20 mmol), preferably freshly prepared from the respective thiol with NaH in THF, in 1.3-dimethylimidazolidin-2-one (DMEU) (15 mL) flushed with N2 or argon was added perfluorinated Decalin (0.5 mmol). The mixture was stirred at ca. 65 C for the indicated time, then poured into toluene (50 mL) and washed with H20 (10x 300mL). The organic phase was dried (Na2S04) and the solvent evaporated. The crude residue was dissolved in CHC12 and purified by preparative TLC (silica gel, CHCl3/hexane 3 1). 

Approximately 180 vapor materials have been screened in the laboratory as candidate microencapsulated vapor taggants. In addition, several hundred other materials were rejected after a thorough analytical review. Five candidate perfluorinated cycloalkane compounds have been extensively tested, and have successfully completed barrier penetration, mutagen, toxicity, and atmospheric impact testing. The five candidate vapor taggants and their chemical properties are shown in table 16 ... 

As well as atmospheric sources, pyrolysis of fluorine-containing polymers, which may occur in engine oil additives, non-stick cookware or incinerated medical equipment (i.e. syringes) and household waste, may also produce TFA. This process may also produce perfluorinated alkanes and cycloalkanes, which have significant GWP, and have estimated tropospheric half-lives of more than 2000 years. Trifluoroacetate may also be produced by metabolism of trifluoromethyl-containing drugs such as Prozac, and anaesthetics including halothane and iso-fluorane [4],... 

This statement is not quite correct—in Reference 14, perfluorocyclohexane was used as a reference species for the thermochemical understanding of perfluorocyclopropane and perfluorocyclobutane. Enigmatically there are no enthalpy-of-formation data on perfluorinated (or even partially fluorinated) derivatives of any other cycloalkane. 

Perfluoro-w-alkanes Perfluoro-cycloalkanes Perfluoro-w-alkanes Perfluorinated cyclic ethers Perfluorotrialkylamines Perfluoro-w-alkanes Perfluorinated cyclic ethers Perfluorotrialkylamines Homopolymers of hexafluoropropene oxide Photooxidation products of hexafluoropropene or tetrafluoroethene Homopolymers of tetrafluorooxetane... 

Perfluorinated alkanes, alkenes or cycloalkanes show a high thermal stability, heating to temperatures over 1000 C results in radical cleavage to give short chains or alkenes.However, C C bonds which contain quaternary and tertiary carbons are cleaved at lower temperatures than those between secondary carbons. In the presence of bromine, chlorine or toluene, cleav age products are isolated, e.g.Rp—Rp - 2 RpBr Other examples involve pyrolyses. ... 

We have shown that perfluorination of the phthalocyanine ligand enhances the stability and catalytic activity of RuFiePc. Encapsulation of this complex in zeolite NaX by the synthesis method dramatically improves the activity and selectivity of RuFiePc. These results suggest that RuFi Pc-NaX is one of the best alkane oxidation catalysts of its kind. Although cycloalkanes are readily oxidized, the complete range of possible substrates is uncertain at this point. The oxidation of other alkanes and olefins will be the subject of continuing studies. 

These are described in literature as the new type of principal amorphous heterochain fluorine polymers containing the stable perfluorinated cycloalkane and aromatic fragments in the main chain of macromolecules [92]. The authors reported studies on the characterisation of various random polyfluorocyclobutene (PFCB) copolymers of new type of monomers F2C=CF-0-Ar-0-FC=CF2 (Ar, see Figure 8.16). These monomers were prepared from their corresponding phenolic precursors and have been described previously in paper [93]. 

The Co" complex [CoPcFig] have advantageous properties as electrocatalyst for the reduction of oxygen as compared to [CoPc] [39]. The Ru" complex [RuPcF, ] appeared to be an effective catalyst for the room tanperature oxidation of cycloalkanes [9]. Encapsulated in zeolite these species were used for catalytic oxidation of alkanes and alcohols [46]. In photoelectrochemical and (photo)conductivity studies it was shown that [ZnPcFig] behaves as n-type semiconductor in vacuo and photoconductor in the presence of oxygen [37, 47]. Due to its enhanced solubility in different solvents as compared to non-substituted [ZnPc] it has advantages for clinical application in photodynamic tumor therapy [11]. Perfluorinated In ", Ti and Zd phthalocyanines exhibit higher performance as optical limiters than non-fluorinated species [42]. 

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