H3PO4, protonation with

After reaction, evaporation of the solvent from the RU3(CO)i2/NMe3 solution, followed by protonation with H3PO4 yields principally H4Ru4(CO) 2> with some Ru3(CO) 2 and H2Ru (CO) 3. Isolation of the active anionic species has not been successful. 

Despite this enormous viscosity, fused H3PO4 (and D3PO4) conduct electricity extremely well and this has been shown to arise from extensive self-ionization (autoprotolysis) coupled with a proton-switch conduction mechanism for the... 

This value is compared with those for other acids and protonic liquids in Table 15.21 " the extent of autoprotolysis in H2SO4 is greater than that in water by a factor of more than lO " and is exceeded only by anhydrous H3PO4 and [HBp3(OH)] (p. 198). In addition to autoprotolysis, H2SO4 undergoes ionic selfdehydration ... 

NMR spectra at r.t. were recorded on a Bruker AV300 spectrometer, with residual protons of deuterated solvents ( H, relative to external SiMe4) P data are reported relative to 85% aq. H3PO4. 

In this reaction, the stronger base, OH-, displaces the weaker base, NH3, from the proton by removing H+ from NH4+. Reactions involving these principles are not always simple as a result of differences in volatility of the compounds and the effects of solvation. For example, it is possible to produce HC1 by heating a chloride with phosphoric acid even though H3PO4 is a weaker acid than HC1. The reaction occurs as a result of the volatility of HCl(g) ... 

PBI (see chemical structure above) is a hydrocarbon membrane that has been commercially available for decades. Free PBI has a very low proton conductivity ( 10 S/cm) and is not suitable for PEM fuel cell applications. However, the proton conductivity can be greatly improved by doping PBI with acids such as phosphoric, sulfuric, nitric, hydrochloric, and perchloric acids. The PA-doped PBI membrane is the most popular one in PEM fuel cell applications because H3PO4 is a nonoxidative acid with very low vapor pressure at elevated temperature. Savinell et al. and Wainright et al. first demonstrated the use of PBI-PA for HT fuel cells in 1994.270 272 since then, there has been a significant amount of research on the PBI-based membrane because of its low cost and good thermal and chemical stabil-... 

Addition of electrophiles is a reaction typical of aliphatic tt bonds (see Example 4.3). Such additions involve two major steps (1) addition of the electrophile to the nucleophilic tt bond to give an intermediate carbocation, and (2) reaction of the carbocation with a nucleophile. Typical electrophiles are bromine, chlorine, a proton supplied by HCl, HBr, HI, H2SO4, or H3PO4, Lewis acids, and carbocations. The nucleophile in step 2 is often the anion associated with the electrophile, e.g., bromide, chloride, iodide, etc., or a nucleophilic solvent like water or acetic acid. 

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