Dialkyl phosphorous acids

The base-catalyzed condeasation of 2-thiophenealdehyde with dialkyl phosphorous acid leads to a-(2-thienyl )phosphinic acid. ... 

Examples of liquid cation exchangers are alkyl and dialkyl phosphoric acids, alkyl sulphonic acids and carboxylic acids, although only two appear to have been used to any extent, viz. di-(2-ethylhexyl)phosphoric(V) acid and dinonylnaphthalene sulphonic acid. 

This kind of ester acts as a nonionic surfactant if the alkanol groups contain hydrophilic moieties. If only two molecules of alkanoles are added to the phosphoric acid molecule an acid or secondary dialkyl phosphoric acid ester is formed that are an amphiphilic molecule by itself see Eq. (5). 

Table 4.17 Comparison of the Extraction Constants Aei for the Ilh-Suhgroup Divalent Ions, and inh Lanthanide Ions, with Sulfur or Oxygen Dialkyl Phosphoric Acids ...

It is concluded from these results, which show the ratio of free phosphoric acid to dialkyl phosphoric acid to be close to 1 1, that the ester taken orig-... 

The degradation of several trialkylphosphates has been investigated, because lengthening the alkyl chain can enhance the actinide loading capacity in normal long-chain diluents. The main degradation products were the related dialkyl phosphoric acid HO(RO)2P = O and monoalkyl phosphoric acid (HO)2(RO)P = O (18, 84, 152). The yield of formation of the main compound HO(RO)2P = O varied from 2.83 for R = CH3 to 1.47 for R = C5Hn (18). 

Several dialkyl phosphoric acids have been studied under different experimental conditions (32, 71, 166). The main trends are the following ... 

The effect of the presence of dialkyl phosphoric acid was moderate, with an increase of the malonamide degradation probably by hydrolysis, as has been observed in specific hydrolysis experiments (71). 

In the DIAMEX-SANEX process, the presence of malonamide protected HDEHP (5, 10, 32) but it should be noted that the presence of dialkyl phosphoric acid in the organic phase had a slightly negative effect on the malonamide s stability (5, 48, 71) ... 

As expected, the reaction of the lithium salts of phosphonates with oxygen results in the formation of dialkyl phosphoric acids-8 and carbonyl products i.e. the cleavage of the C-P bond takes place (, 5). However, when the halomagnesiurn salts of phosphonates Z were oxidized, a-hydroxyphosphonates 2 were formed. 

D. H. Liem On the Solvent Extraction of Metal Ions by Dialkyl Phosphoric Acid and Some Non-Acidic Complexing Agents, Stockholm 1971... 

Stable esters coming formally from alkynols and carboxylic, sulphonic or dialkyl phosphoric acids were prepared for the first time via alkynyliodonium salts with the corresponding anion. Several alkynyl carboxylates were obtained by anion exchange of alkynyl iodonium tosylates the initially formed salts, PhI+C=CR RCO2, were converted spontaneously into the esters on elution through a chromatographic column packed with an anion-exchange resin (Pol+ArCOj) ... 

Pudovik, A.N., and Plakatina, N.L, Addition of dialkyl phosphorous acids to unsaturated compounds. Part 10. Addition of dialkylphosphorous acids to unsaturated nitriles, Sb. Statei Obshch. Khim., 2, 831, 1953 Chem. Abstr, 49, 6821b, 1955. 

Compared with formic acid (pX = 3.77 in water, 5.75 in 95% aqueous ethanol), acetic acid (pKa = 4.76 in water), and benzoic acid (pK = 4.17 in water, 7.07 in 95% aqueous ethanol), simple symmetrical dialkylphosphinic acids (1) are moderately strong acids. Thus, for dimethylphosphinic acid (R = Me), pK = 3.08 (in water) and 6.64 in 95% aqueous ethanol, figures which rise to 3.56 for R = Pr and 4.24 for R = Bu for solutions in water for R = Ph, pK = 5.80 in 95% aqueous ethanol. These values can also be compared with those for the dialkyl phosphoric acids for dimethyl hydrogenphosphate, pK = 0.47 in water and 1.88 in 80% aqueous ethanol. Obviously the phosphorus-oxygen bonded acids are rather stronger, with the simple phosphinic acids closer to the carboxylic acids in their acidity. 

Determination of the acidity of water-immiscible HA encounters difficulties similar to those in the determination of water-immiscible amine basicity and can be approached similarly. By analogy to pHhn measurements, we have equilibrated HA-containing organic phases with aqueous NaOH solutions and determined aqueous phase pH. The acidity sequence followed that of the water-soluble analogs carboxylic acids < ot-halo carboxylic acids < dialkyl phosphoric acid esters < sulfonic acids [44]. 

During Purex process thermal degradation and hydrolysis of TBP also takes place. The thermal degradation yields a large number of products including butane, butene, N2, NO2, CO2, NO, and butanol. The specific concern is the dealkylation of the phosphate ester since the dialkyl phosphoric acid ester, formed in the reaction, is capable of nonspecific interactions with metal ions (Katsumura 2004 Shkrob et al. 2007). 

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