Perfluorocarboxylic salts

CF COONa and higher perfluorocarboxylated salts (116,117), CF2S02Na (118), and esters such as CF2CICOOCH2 (119) or FSO2CF2COOCH2 (120), represents a novel trifluoromethylation concept. 

Alkylation of thiolates with perfluoroalkyliodonium salts occurs under mild conditions [66, 67]. Perfluorocarboxylic peroxides can also be used for this transformation [68] (equations 59-61). 

Perfluorocarboxylic acids RFC02H (RF = CF3, C2F5) are reported153 to react with [Ir-(NO)(PPh3)3] in boiling acetone to give [Ir(NO)(OCORF)(PPh3)2](OCORF). The formation of this salt presumably involves successive protonations at the metal centre followed by elimination of... 

The 2,5-bisperfluoroalkyl-1,3,4-oxadiazoles, recently synthesized by Brown et al.,s6 show a particularly high sensitivity to nucleophilic attack, as could be expected because of the —I effect of the trifluoro-alkyl groups.38,120 This contrasts with their extraordinarily high thermal stability. No decomposition could be observed either after 15 hours heating at 350° or after 1 hour at 400°. Nevertheless they are hydrolyzed slowly by caustic soda to salts of perfluorocarboxylic acids and hydrolysis with concentrated sulfuric acid yields a mixture of the corresponding bisperfluoroacid hydrazides and the perfluorocarboxylic acids [Eq. (17)].36... 

In 1966, E. Fischer was granted a U.S. patent ( ) claiming a method for polymerizing cyclic ethers by means of diazonium salts of perchloric acid and perfluorocarboxylic acids decomposed by heat and/or ultraviolet radiation. The storage stability of mixtures of these salts with cyclic ethers was poor, and the handling of diazonium perchlorates would require special consideration before introduction into large-scale coating operations. 

This chapter summarizes the preparation and the fabrication of perfluorocarboxylate polymers and their fundamental properties including those of the ionized salt-type membranes. The application of Flemion in chlor-alkali electrolysis is also described. 

Scheme 11 indicates the usefulness of salts derived from Wittig ylide reagents and anhydrides of perfluorocarboxylic acids in the synthesis of fluorinated alkenylphosphonic diesters (127), often together with (epoxyalkyl)phosphonic diesters (128)(Rf = CF3 or... 

The ability to form stable salts of under the action of base is an important property of imides of perfluorocarboxylic acids. Henne and Zimmer used generated in situ silver salts of 46 and 47 for the preparation of the corresponding A -bromo deriva-... 

The molecular structure of a conventional polymer used for a PFSA membrane is shown in Fig. 1. Membranes registered as Nafion (DuPont), Flemion , (Asahi Glass), and Aciplex (Asahi Chemical) have been commercialized for brine electrolysis and they are used in the form of alkali metal salt. Figure 4 shows a schematic illustration of a membrane for chlor-alkali electrolysis. The PFSA layer is laminated with a thin perfluorocarboxylic acid layer, and both sides of the composite membrane are hydrophilized to avoid the sticking of evolved hydrogen and chlorine. The membrane is reinforced with PTFE cloth. The technology was applied to PEFC membranes with thickness of over 50 xm [14]. 

Perfluorocarboxylate polymers in the carboxylic methyl ester, potassium salt and carboxylic acid forms were analysed by FTIR transmission and ATR spectroscopies. Band assignments were made for most of the dominant peaks. An absorbance band ratio, comparing the 555/cm C-F band to the 982/cm C-O-C ether band, was found to be a direct measure of the equivalent weight of the polymers. In addition, the transition from the methyl ester form to the acid form was determined by examining the 2969/cm methyl ester band versus the broad 3200/cm band. Quantitative expressions were presented for use in the computation of equivalent weight and acid content based on the FTIR thin film absorbance measurements. The technique used provided a direct measure of the trade-off... 

Trudel D, Horowitz L, Wormuth M, Scheringer M, Cousins IT, Hungerbuhler K (2008) Estimating consumer exposure to PFOS and PFOA. Risk Analysis 28 251-269 US EPA (2004) Preliminary risk assessment of the developmental toxicity associated with exposure to PFOA and its salts. Office of Pollution Preventiona and toxics. Risk Assessment 39. Wania F (2007) A global mass balance analysis of the source of perfluorocarboxylic acids in the Arctic Ocean. Environ Sci Technol 41 4529-4535... 

A simple method for the generation of metal derivatives of perfluoroalkyl carbanions by the decarboxylation of alkali salts of perfluorocarboxylic acids, has also been used. For example, heating potassium perfluoroalkyl carboxylates in the presence of dipyridine disulfides in DMF or sulfolane leads to the formation of the corresponding pyridine perfluoroalkyl sulfides [61] (Scheme 28). 

Three types of lubricants which possess both the perfluoroalkyl group and hydrocarbon long chain, that is an ester, amide, and carboxylic acid amine salt, were synthesized by the following Scheme 1 in Fig.4. The ester and the amide were prep>ared by the addition of carboxylic add chloride to the hexane solution of the corresponding alcohol and amine in the presence of a base agent. The perfluorocarboxylic add and the carboxyhc add ammonium salts are prepared by warming the mixture of the perfluorocarboxylic add and the amine to 80°C imtil the complete dissolution was obtained (Scheme 2).(Kondo et al., 1989,1994)... 

Chem. Descrip. Sodium salt of perfluorocarboxylic acid ester Uses Surfactant for textile processing Properties Yel. liq. pH 6 (1% aq.) 30% act. 

The perfluorocarboxylic acid fluorides can be converted to perfluorocarboxylic acids, esters, amides, or other intermediates for surfactants (Fig. 2.2). Hydrolysis of the acid fluoride yields the carboxylic acid (I) or its salt (II). Alcohols form esters (HI), which can be hydrogenated to an alcohol (IV), an intermediate for nonionic surfactants. The reaction of the acid fluoride with an amine [e.g., NH2C3H6N(CH3)2] yields an intermediate (V) for an amine salt (VI), a cationic... 

Table 6.1) [5]. Alkali metal salts of perfluorocarboxylic acids having a chain length of four or more carbon atoms form micellar solutions. Their solubility in water can be characterized by their Krafft point (see Section 6.3) and critical micelle concentration (see Sections 6.2 and 6.6). 

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