Polyphosphinic acid

The yielded product can be converted to a surface-active compound if at least one ester group has been transformed to the free acid or an alkali metal salt thereof [160]. There are also many compounds from phosphinic acid derivatives claimed to be useful as sequestrants and builders to improve detergency, especially bisphosphonylmethylphosphinic acids and polyphosphinic acids [structures (9) and (10)], respectively ... 

Polyphosphinic acids are obtained by an Arbusov reaction from chloro-methylphosphonites in the presence of tertiary amines [161] see Eqs. (89)—(91) ... 

Substituting a hydroxide group of the phosphonic acid by an alkyl group or an aryl group, respectively, leads to the compound class of polyphosphinic acids ... 

Generally, these compounds form complexes with alkaline-earth metals that are less stable than the corresponding complexes of the polyphosphonic acids. WeiB and Hagele [96] investigated the chromatographic behavior of a variety of aliphatic and olefinic polyphosphonic and polyphosphinic acids, respectively, with 1 to 4 phosphorus atoms [87,88], that are applied in medicine and in pharmaceutical chemistry. 

Fig. 3-100. Separation of various aliphatic polyphosphinic acids. — Chromatographic conditions see Fig. 3-97 solute concentrations 20 ppm each of 2, 3, and 4.

In addition to structural isomers, stereoisomeric and, recently, rotational isomeric polyphosphonic and polyphosphinic acids can be separated. Most intriguing in this connection is the chromatogram in Fig. 3-103 of the sterically-crowded polyphosphonic acid 10,... 

The polyphosphinic acid was prepared by polymerization of CICH2P-(0C2H5)2, followed by oxidation and acid hydrolysis. This material exhibits a P NMR signal at —29.1 ppm relative to H3PO4 and a much smaller signal at —16.5 ppm. These signals correspond to the phosphinate and phosphonate phosphorus atoms, respectively. 

The authors wish to thank Dr. M. M. Crutchfield for many stimulating discussions and for providing us with the polyphosphonate sample. We are also grateful to Dr. L. Maier for supplying us with samples of PMPA, PMPO, and the polyphosphinic acid. 

Fig. 3-102. Separation of an aromatic polyphosphinic and polyphosphonic acid of equal carbon backbone. — Chromatographic conditions see Fig. 3-96 solute concentrations 200 ppm each of 7 and 6.

The metal phosphinates are prepared from metal salts and dialkyl or diarylphos-phosphinic acids utilizing melt or solution systems. The metal polyphosphinates are utilized as additives e.g., Cr(III) polyphosphinates thicken silicones to greases and improve their high-pressure physical properties. Chromium and titanium polyphosphinates impart antistatic properties to a wide range of plastics. 

Contents v. 1. Primary, secondary, and tertiary phosphines, polyphosphines, and heterocyclic organophosphorus(III) compounds— v. 2. Phosphine oxides, sulphides, selenides, and tellurides—[etc.]—v. 4. Ter- and quinque-valent phosphorus acids and their derivatives. 

Primary phosphine oxides are more stable in polar solvents than in the solid slate and considerably more stable in strongly acid media. Strong heating gives polyphosphines. 

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