Phosphates hexafluorophosphate anion

Anions other than the very water-sensitive and reactive haloaluminates have been added to the repertoire, including nitrate, phosphate, hexafluorophosphate, hexafluoroanti-monate, tetrafluoroborate, trifluoromethanesulfonate ( triflate ), and bis (trifluoro-methanesulfonyljimide, Examples of cations that are used include mraio- to... 

Other commonly used anions for ionic liquids, such as tetrafluoroborate and hexafluorophosphate, also imdergo hydrolysis at sufficiently rapid rates that would cause difficulties for their use with either aqueous solvents or hydroxylic cations. While the hexafluorophosphate anion imdergoes hydrolysis most rapidly only under acidic conditions (Freire et al. 2010), the preparation of the ionic liquids using hexafluorophosphoric add can lead to significant formation of the (hydrolyzed) phosphate salt (Lall et al. 2000). Similarly, the alternative approach for the prepwation of the phosphate salts (liquid ionic phosphates, LIPs) involving the use of 98% phosphoric acid (Lall et al. 2002) similarly experiences difficulty when cations are used that bear hydroxylic sites. Presumably the "anion exchange" method (Lall et al. 2002) would not experience this difficulty, but this process is extremely ineffident for the preparation of any sizable quantity of material. Similarly, the tetrafluoroborate anion imdergoes hydrolysis sufficient rapidly (Freire, et al. 2010) and can be anticipated to read with free hydroxyhc functions such that it would not be a useful anion for ionic hquids based on carbohydrate and carbohydrate-related materials. 

Fluorophosphates. As with many other oxo anions, fluorine can replace OH in phosphate to give mono- and di-fluorophosphate salts and esters. The dialkyl monofluorophosphate esters have been found to inhibit cholinesterase in the body and to be exceedingly toxic. The hexafluorophosphate ion, PFg, has been discussed (page 376). 

The effects of increasing the concentration of initiator (i.e. increased conversion, decreased and broader PDi) and reducing the reaction temperature (i.e. decreased conversion, increased M and narrower PDi) for the polymerizations in ambient-temperature ionic Uquids are the same as observed in conventional solvents. Mays et al. reported similar results and, in addition, used NMR to investigate the stereochemistry of the PMMA produced in (BMIMjlPFej. They found that the stereochemistry is almost identical to that for PMMA produced by free radical polymerization in conventional solvents [28]. The homopolymerization and copolymerization of several other monomers are also reported. Similar to vdiat was found by Noda and Watanabe, in many cases the polymer was not soluble in the ionic liquid and thus phase separated [28,29]. Free radical polymerization of n-butyl methacrylate in ionic liquids based on imidazolium, pyridinium, and alkylammonium salts as solvents was investigated with a systematic variation of the length of the alkyl substituents on the cations, and employing different anions such as tetrafluoroborate, hexafluorophosphate, tosylate, triflate, alkyl sulfates and dimethyl phosphate [31]. 

Figure 3.1 Chemical structures of some (modified phosphate anions fa hexafluorophosphate. Thl trifluorotris(pentafluoroethyl phosphate. FFAPI- and Tel...

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