Hypophosphite anions

Quaternary ammonium salts aid the transfer of the hypophosphite anion in the palladium-catalysed reduction of, for example, alkynes to alkenes, nitroarenes to aminoarenes, and in the hydrogenolysis of tetrazolyl aryl ethers to phenols [12-14], It has been demonstrated that the hydrogenolysis is ineffective when preformed tetra-n-butylammonium hypophosphite is employed in a dry homogenous organic solvent [13, 14], For optimum hydrogen transfer, the concentration of hypophosphite relative to the substrate must be controlled at a low level and this is most effectively accomplished with a two-phase system. 

Thallium sulfophosphide TIPS was a latent crystalline substance of greenish-gray color, which was hydrolyzed slightly on its surface under the influence of the atmospheric moisture but was insoluble in water or in dilute acids and alkalies. Hot concentrated sulfuric acid decomposed this compound to give l drogen sulfide, producii hypophosphite anions. 

A potentially important application of white P for the extraction of SO2 and NO2 from power plant flue gases has recently been demonstrated. An aqueous emulsion of the phosphorus with NaOH is used to convert the waste gases to a mixture of sulphate, sulphite, nitrate, nitrite, phosphate, phosphite and hypophosphite anions (Section 4.4) [25]. 

Electroless (electrode-less) plating is used primarily to deposit nickel on the surface of other metals. In this process, nickel cations NH+ are reduced to metallic nickel, Ni , by hypophosphite anions, HjPO , which are themselves oxidised to phosphite HPO anions [38-41],... 

Note that the product we have obtained above, HP(OH)2, is a protonated form of what we need to get, namely, H2PO2". Like phosphorous acid (H3PO3), however, hypophosphorous acid (H3PO2) and the hypophosphite anion (H2PO2") both contain tetracoordinate phosphorus, so we still need to move a couple of protons around, which we do below with the help of OH- and H2O ... 

Sodium hypophosphite, NaHiPOi, has been suggested as a replacement of sodium nitrite, NaNO , as a meat preservative to prevent botulism. Draw the structure of each anion. 

Fig. 28. Determination of interfering nitrates in a nickel-plating bath. Leading (L) and terminating (T) anions chloride and glutamate, resp. Other components of the bath, namely hypophosphite (hypo P-ite), phosphite, (P-ite), phosphate (P-ate), and lactate (Lac) are also separated...

In the future, analytical isotachophoresis will find wide application in analytical control in industry. Particularly in the field of anions, this technique may bring about progress, due to its rapid application and easy interpretation of the record as demonstrated by Figs. 28 and 29. Figure 28 illustrates the determination of interfering nitrates in the presence of an active component (hypophosphite) in... 

It is common practice to write the acid anions in (5.2) as HPO and H2PO4, although POalOH) -and P02(0H)2- (or HO POf and (H0)2P02) are better representations. Unlike phosphite HPO3 and hypophosphite H2PO2 anions (5.209), acid orthophosphate anions contain no direct P-H hnkages. ... 

Hypophosphite complexes with the empirical formula MZr(H2P02)3, where M = Mg, Cu, Fe, Ni, Zn, probably have octahedral structures (5.230), not unlike those of the triphosphitochromate anion (5.220). 

MIH2PO2I, hypophosphites NaHjPOj H2O MH2PO2 NH4H2PO2 k. Mg(H2P02)2 6H2O Ba(H2P02)2 H20 Ca(H2P02)2, readily sol. in H2O, anion - dist. tetrah. 

Tin(IV) hypophosphite is remarkable in that it represents a class of compound containing tin(IV) and a strongly reducing anion. Considering the reduction potentials. 

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