Perfluoroalkyl compounds water

Ahrens L, Barber JL, Xie ZY, Ebinghaus R (2009) Longitudinal and latitudinal distribution of perfluoroalkyl compounds in the surface water of the Atlantic Ocean. Environ Sci Technol 43(9) 3122-3127... 

Occurrence of perfluoroalkyl compounds in surface waters from the North Pacific to the Arctic Ocean. Environ. Sci. Technol. 46(2) 661-668. 

The cyanohydrin of methyl perfluoroheptyl ketone was synthesized by a two-step process addition of sodium bisulfite and subsequent treatment with sodium cyanide. When the ketone was reacted with sodium cyanide, cyclic addition products were obtained, instead of the product of cyanohydrin formation. This result was attributed to the solubility characteristic of a long perfluoroalkyl group, which makes the compound less soluble in water and polar organic solvents [54] (equation 40) (Table 14). 

Codeposition of silver vapor with perfluoroalkyl iodides at -196 °C provides an alternative route to nonsolvated primary perfluoroalkylsilvers [272] Phosphine complexes of trifluaromethylsilver are formed from the reaction of trimethyl-phosphme, silver acetate, and bis(trifluoromethyl)cadmium glyme [755] The per-fluoroalkylsilver compounds react with halogens [270], carbon dioxide [274], allyl halides [270, 274], mineral acids and water [275], and nitrosyl chloride [276] to give the expected products Oxidation with dioxygen gives ketones [270] or acyl halides [270] Sulfur reacts via insertion of sulfur into the carbon-silver bond [270] (equation 188)... 

Calibrants are required to calibrate the mass scale of any mass spectrometer, and it is important to find reference compounds that are compatible with a particular ion source. Calibrants commonly used in electron ionization (El) and chemical ionization (Cl), such as perfluorocarbons, are not applicable in the ESI mode. The right calibrants for LC-ESI-MS should (1) not give memory effects (2) not cause source contamination through the introduction of nonvolatile material (3) be applicable in both positive- and negative-ion mode. The main calibrants used or still in use to calibrate ESI-MS can be divided into the following categories polymers, perfluoroalkyl triazines, proteins, alkali metal salt clusters, polyethers, water clusters, and acetate salts. 

Water solubility and vapor pressures of PFOS and PFOA are given in Table 2. These data were obtained from products that were not refined and as a result may contain more than one PFA such that these data may not be representative of the pure compounds, especially in environmental media. Due to the lack of accurate information on the physico-chemical properties, accurate prediction of the environmental fate and transport of most perfluoroalkyl substances has not yet been possible. The prediction of the distribution and ultimate fates of perfluoroalkyl substances is further complicated by their hydrophobic and lipophobic properties, such that the fugacity approach that has been useful in describing the environmental fates of organochlorines is less useful for describing the environmental fate of PFAs and their precursors. The bulk of the available physical and chemical information is for PFOS... 

One of the major problems associated with the hydrolysis of fluorinatcd compounds is the activation of fluoride substitution by per- or polyfliioroalkyl, perfltioroaryl groups, or double bonds linked to the same or adjacent carbon. However, hydrolysis not involving the C-F bond is widely used for the synthesis of 2-(perfluoroalkyl)ethanols, precursors to useful materials such as oil and water repellents, surfactants, and fire-fighting foams. The alcohols... 

Tris(perfluoroalkyl)difluorophosphoranes (1) are very active compounds. They react readily with organic or inorganic fluorides [5-8] with formation of the corresponding salts with a FAP anion. The fluoride affinity of tris(perfluoro-alkyl)difluorophosphoranes is so high that by the reaction with HF in water the hydrolysis of phosphoranes practically completely suppressed and the corresponding tris(per luoroalkyl)tri luorophosphoric acid (2) is formed in nearly quantitative yield [Eq. (2)] [9],... 

A synthesis of p-perfluoroalkyl-P-alanine (34) (Scheme 29) has been described [65,66] and extended to the A-alkyl derivatives (35) (Scheme 30) [67]. The compounds 34 show a relatively poor solubility in water, but their sodium... 

A process is disclosed for preparing peihaloacyl chlorides such as trifluoroacetyl chloride by oxidizing lower perfluoroalkyl and monochloroperfluoroalkyl dichloromethanes with oxygen within the supercritical region of the compounds and in the absence of water. 

Matsumoto, K., Mazaki, H., Nishimura, R. et al. (2000) Perfluoroalkyl-philic character of poly(2-hydroxyethyl vinyl ether)-block-poly[2-(2,2, 2-trifluoroethoxy)ethyl vinyl ether] micelles in water Selective solubilization of per-fluorinated compounds. Macromolecules, 33, 8295-8300. 

MCM-41-supported metal (Yb, Zn) bis[(perfluoroalkyl)sulfonyl]imides were reported as effective catalysts for nitration of aromatic compounds with 1 eq. of 65 wt% nitric acid in the liquid phase Equation (8.68). The enhanced electron-drawing and steric effects from longer perfluori-nated alkyl chains were found to promote this action. Water exhibits also a positive effect. The catalysts were recycled without substantial loss of catalytic activity [103]. 

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