Fluorophosphates, hexa

Reaction of dibenzofuran, ferrocene, and aluminum powder in the presence of aluminum chloride with subsequent hydrolysis and precipitation of the hexa-fluorophosphate salt gives 34 [80JOM(186)265]. When ferrocene and aluminum chloride are in excess, dicationic complexes 35 result. The reaction leading to 36 was also reported [84JOM(260)105]. 

The photolysis of crystalline diazonium tetrafluoroborates and hexa-fluorophosphates affords a convenient route to aromatic fluorides<53) ... 

In a closely related approach, Yen and Chu have reported the preparation of tetra-hydro-/3-carbolinediketopiperazines employing a three-step Pictet-Spengler, Schot-ten-Baumann, and intramolecular ester amidation sequence (Scheme 6.233) [415]. Throughout the synthesis, the ionic liquid l-butyl-2,3-dimethylimidazolium hexa-fluorophosphate (bdmimPF6) was employed. In a typical experiment, (S)-tryptophan methyl ester was dissolved in a 1 1 mixture of the ionic liquid and tetrahydrofuran... 

Recently, there has been considerable interest in developing molten salts that are less air and moisture sensitive. Melts such as l-methyl-3-butylimidazolium hexa-fluorophosphate [211], l-ethyl-3-methylimidazolium trifluoromethanesulfonate [212], and l-ethyl-3-methylimidazolium tetrafluoroborate [213] are reported to be hydro-phobic and stable under environmental conditions. In some cases, metal deposition from these electrolytes has been explored [214]. They possess a wide potential window and sufficient ionic conductivity to be considered for many electrochemical applications. Of course if one wishes to take advantage of their potential air stability, one loses the opportunity to work with the alkali and reactive metals. Further, since these ionic liquids are neutral and lack the adjustable Lewis acidity common to the chloroaluminates, the solubility of transition metal salts into these electrolytes may be limited. On a positive note, these electrolytes are significantly different from the chloroaluminates in that the supporting electrolyte is not intended to be electroactive. 

The nature of coordination of anions such as nitrate, perchlorate, and thiocyanate has been studied by both infrared and Raman techniques. In the case of anions, such as nitrate and perchlorate, the vibrational spectra indicate whether they are ionic or coordinated and if coordinated, whether they are unidentate, bidentate or bridging. In the case of thiocyanate, the vibrational spectra are useful in deciding the site of coordination. The change in the site symmetry of the anion upon coordination leads to changes in vibrational spectra of anions like perchlorate, nitrate, perrhenate and hexa-fluorophosphate. These changes in the vibrational spectra have been used to indicate the nature of coordination. 

In the reversed-phase mode, mixtures of aqueous buffer and acetonitrile are commonly used as mobile phase. Other modifiers are possible, but as shown in Figure 6, acetonitrile often produces the best separations and peak shapes. Several studies have shown the fundamental importance of keeping the chiral analytes neutral when working with polysaccharide stationary phases in the reversed-phase mode. ° ° Therefore, acidic compounds are preferably analyzed at low pFI while basic compounds will be analyzed either in basic media or at low pH in the presence of a chaotropic salt such as sodium perchlorate (NaC104) or potassium hexa-fluorophosphate Some illustrations of the effect of the addi-... 

Pure ILs have a dual nature since they are actually molten salts or a mixture of cations and anions. They were found to have a relatively high solvent polarity, comparable to that of short-chain alcohols [4-5]. Since CCC needs to work with a Diphasic liquid system, water-insoluble ILs should be selected if an aqueous phase is desired, l-butyl-3-methylimidazolium hexa-fluorophosphate ([C4CiIm][PFg]) has limited water solubility (18 g/L or 1.3% or 63 mM [5]) and is easy to synthesize. It was the first IL used in CCC [6]. 

Baker, S.N., Baker, G.A., Bright, F.V., Temperature-dependent microscopic solvent properties of dry and wet l-butyl-3-methylimidazolium hexa-fluorophosphate corelation with ET(30) and kamlet-taft polarity scales. Green Chem., 4, 165-169, 2002. 

Several catalysts and initiator systems have been tested for the polymerization of GlcAnBzl3, including the following Lewis acids boron trifluoride and its etherate, phosphorus pentafluoride, titanium tetrachloride, and antimony pentachloride and pentafluoride. Several cationic initiators have also been used, including (triphenylmethyl) antimony hexachloride, 2,3,4,6-tetra-O-acetyl-D-glucopyranosyl hexa-fluorophosphate, acetyl hexafluorophosphate, pentamethylbenzyl hexa-fluorophosphate (most of which were generated in situ), and triethyl-... 

These preparations of bis(2,4,6-trimethylpyridine)iodine(l) and bromine(l) hexa-fluorophosphate are adaptations of methods previously reported for obtaining the corresponding perchlorates.2... 

Meerwein did not study PFjT but by analogous arguments the hexa-fluorophosphate ion might be expected to be the most stable of the three. 

Cyclooctadiene) (pyridine) (tri-cyclohexylphosphine)iridium(I) hexa-fluorophosphate, 88 Palladium catalysts, 230 Potassium-Graphite, 252 Sodium borohydride-Molybdenum(VI) oxide, 279... 

TT-cycl opentad i eny 1 d i ca rbony 1 -nitrosylmanganese(I ) hexa-fluorophosphate, AJO ... 

These methylene-bridged complexes III are extremely robust, air-stable substances. We have sought without success to effect insertions into the Pd-C bonds. The complexes are unreactive toward carbon monoxide (at 5 atm at 30°C) or sulfur dioxide. Reaction with methyl isocyanide or pyridine results in displacement of the terminal halide ions and produces cations that have been isolated as hexa-fluorophosphate salts [Pd2(dpm)2( -CH2)(CNCH3)2][PF6]2( (CN) = 2217 cm-1) and [Pd2(dpm)2(/Lt-CH2)(py)2][PF6]2. Treatment of III with fluoroboric or trifluoroacetic acid slowly results in the protonation of the methylene group which is converted into a terminal methyl group. The resulting brown complex, which has been isolated as its tetra-fluoroborate salt has been shown by H-l and P-31 NMR spectroscopy and X-ray crystallography to have Structure IV. 

Methyl-2-diphenylphosphino-3-(l -isoquinolyl)indole with pallada-cycle derived from dimethyl-1-naphthyl ethylamine and potassium hexa-fluorophosphate yields chelate 310 (97T4035). With [(r)3-PhCH = CH = CHPh)Pd( j.-Cl)]2, allyl 311 follows in the presence of silver tetrafluor-oborate. Addition of ligands 312 (R = R1 = H, Me) to [(r 3-PhCHCHCHPh)Pd (Cl) ]2 under conditions of allylic alkylation of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate leads to the formation of P,N-chelates 313 (R = R1 = H, Me), the active species of the catalytic reaction (00T(A)4753). 

Substituted imidazole 1-oxides 263 upon treatment with dimethyl or diethyl sulfate furnish l-alkoxy-3-subtituted imidazolium salts 283 that were converted to the tetrafluoroborate 283 (A- = BF4 ) or hexafluorophos-phates 283 (A = PF6-) by treatment with sodium tetrafluoroborate or hexa-fluorophosphate (2007ZN(A)295). The tetrafluoroborates 283 (A = BF4 ) reacted with cyanide ion to give 2-cyanoimidazoles 285 (1975JCS(P1)275). The reaction probably follows a mechanism similar to that suggested to be operative in the pyrazole series encompassing O-alkylation succeeded by nucleophilic addition and elimination of methanol (Scheme 85). 

Porphyrin-containing [2]catenanes have been synthesized by Gunter et al.,1311 following the template-directed synthetic strategy outlined in Figure 15. The bis(hexa-fluorophosphate) salt 15-2PF6 was treated with the dibromide 16 in the presence of the previously formed macrocyclic polyether 22 or 23. After counterion exchange,... 

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