Alkanephosphonic acid

The Arbusov reaction is one of the best known methods for creating a carbon-phosphorus bond. In its simplest form (Michaelis-Arbusov) an alkyl halide reacts with a trialkyl phosphite to an alkanephosphonic acid diester as shown in Eq. (29) ... 

When long-chain alkanephosphonyl dichlorides react with hydroxypolyoxy-alkylene compounds in the presence of pyridine at about 100°C, esters of alkanephosphonic acids are obtained which possess surface-active properties [102]. 

Surface-active polyglycol esters of alkanephosphonic acids are also formed by reaction of long-chain alkanephosphonic acids with olefin oxides, e.g., ethyl-enene oxide or propylene oxide. The reaction may be carried out in an autoclave or at atmospheric pressure, and the temperature may be varied between... 

Carbonic acid amides are known for their good surface-active properties. In particular, alkanolamides are produced on a large scale. But relatively little is known about the synthesis of alkanephosphonic acid amides. Therefore surface-active properties and different ways of synthesizing alkanephosphonic acid bisdialkylamides were investigated [121]. There are three ways to obtain these derivatives ... 

Direct conversion of the amine with the A1C13 complex of the corresponding alkanephosphonic acid dichlorides. 

Reactions leading to surface-active diamides form emulsions of the hydrated [A1(H20)6]C13 complex. However, by hydrolysis of the RPOCl2-AlCl3 complex with water at a molecular ratio of 1 6-7.5 in methylene chloride at a temperature of -10°C, the A1C13 from the complex reacts selectively forming a precipitation of [A1(H20)6]C13, which can be easily filtered off. From the solvent the alkanephosphonic acid dichloride can be isolated in good quality (Table 4). 

The alkanephosphonic acid dichlorides obtained by these methods are converted with amines, with all reactions carried out in solvents such as acetone, benzene, or diethyl ether at 10°C with triethylamine as HC1 captor. The conversion runs quantitatively followed by a purification with the help of column chromatography with chloroform/methanol in a ratio of 9 1 as mobile phase. The alkanephosphonic acid bisdiethanolamides could be obtained as pure substances with alkane residues of C8, C10, C12, and Ci4. The N-(2-hydroxyethane) alkanephosphonic acid 0,0-diethanolamide esters were also prepared in high purity. The obtained surfactants are generally stable up to 100°C. Only the alkanephosphonic acid bismonomethylamides are decomposed beneath this temperature forming cyclic compounds. 

The OH group in the alkyl chain of alkanephosphonic acids is of wide interest. There are many methods for the preparation of hydroxy alkanephosphonic acids. 

Antiseptic detergent compositions with good bacteriostatic and surface-active properties contain C8 18 alkanephosphonic acid C, 4 dialkyl esters. Long-chain alkyl groups can also have an OH or halogen substituent [147]. 

Ethylene oxide adducts of alkanephosphonic acids exhibit a better solubility in water and partly an interesting depression of the surface tension in aqueous solutions (Table 9). Although foamability and wetting rate lie in a medium range, they possess no emulsifying ability. 

In the case of N-containing phosphonates some interesting data were observed [190]. Alkanephosphonic acid bisdiethanolamides, RPO(NCH2CH2OH)2, show good wetting performance and foamability at an alkyl chain length of C,0 and C12 according to Table 10. 

TABLE 10 Surface-Active Properties of Alkanephosphonic Acid Bisdiethanolamides... 

Similar effects are obtained by using the bisdiisopropanolamides of alkanephosphonic acids. The maximum wetting performance and foamability may be observed at an alkyl chain of C8, according to Table 11. 

Detergency was ascertained as the quotient of the whiteness obtained and the whiteness which is theoretically possible, expressed as a percentage. Samples of artificial soiled fabrics are washed under given conditions. Aqueous solutions of alkanephosphonic acid bisdiisopropanolamides show a notable detergency without addition of a builder, e.g., sodium triphosphate [190] see Table 12. 

TABLE 12 Detergency of Alkanephosphonic Acid Bisdiethanolamides and Bisdiisopropanolamides... 

Koch P, Rumpel H, Sutter P, et al. 1989. The reaction of alkanephosphonic acid esters with metals. Phosphorus, Sulfur, Silicon, and Related Elements 44(l-2) 75-85. 

Analysis of the Murchison meteorite led to a completely different type of phosphorus compound the only phosphorus-containing compounds found were alkanephos-phonic acids. Spurred on by these results, de Graaf et al. (1995) irradiated mixtures of o-phosphorous acid in the presence of formaldehyde, primary alcohols or acetone with UV light (low pressure Hg lamp, 254 nm with a 185-nm component) and obtained phosphonic acids, including hydroxymethyl and hydroxyethyl phosphonic acids, which had been found in the Murchison meteorite. Alkanephosphonic acids can be derived from phosphorous acid, with a P-H bond being replaced by a P-C bond. 

The pJ a values of phosphine oxides have been measured. Their deviation from Hammett base behaviour, their Ho dependencies, and their sites of protonation have been studied. The acidifying effects of phosphoryl, phosphinyl, and thiophosphinyl groups have been studied. Ionization constants have been used to examine substituent effects in alkanephosphonic acids and phosphinyl-carboxylic acids, structural correlations in various phosphorus acids, and solvent effects on the properties of thiophosphorus acids. The linear free-energy relationships, which are based mainly on p a data, have been analysed and reviewed. ... 

Whitesides and coworkers [435] have examined the preparation and properties of SAMs obtained by adsorption of long-chain alkanoic acids and alkanephosphonic acids as well as alkanehydroxamic acids onto metal oxide surfaces such as Ti02 and Zr02. Monolayers of octadecanoic acid and octadecanephosphonic acid were formed from solutions in either isooctane or ethanol with concentrations of 1 mM in... 

The patterned structures resulting from etching are continuous and electrically conductive within each pattern, and separated patterns are electrically isolated. Using pCP, Schottky diodes of aluminum have been prepared on p-type Si(lOO). Octadecanephosphonic acids are air stable compounds that are known to form stable, ordered monolayers on metal oxide surfaces [298,435]. SAMs on the native oxides of aluminum [435, 472, 473] and copper or iron [435, 473] have been formed from alkanephosphonic acids. 

PTC is a method of choice for the Wittig-Horner reaction of carbanions derived from esters of alkanephosphonic acids, activated with additional car-banion stabilizing groups, with aldehydes and ketones.. E-Alkenes are usually formed as the main products in good yields. Solid-liquid system KOH/benzene with 18-crown-6 as the catalyst is recommended for these processes however, K2C03/H20/dioxane or 50% NaOH aq was also used. Although the yields are sometimes low, because of the simplicity of the procedure, it can be favorably compared with other base/solvent systems used for this reaction (eqs. 72 and 73). 

No interfacial water was detected in didodecyldimethylammonium bromide-water systems [191], In alkanephosphonic acid-water systems, interfacial water freezes at -20°C, with an average freezing enthalpy of 47.2 J/g surfactant. However, when heated, only one melting peak is detected. This indicates that this type of water was associated with the acid headgroups when liquid, but this association does not exist when the system is a solid phase [54], FT-IR spectra demonstrate that there are no interactions among phosphonate headgroups and water in frozen samples. 

P-Cyclodextrin is also an enantioselective catalyst for HCN-additions on some aromatic aldehydes, but not in the case of 3-phenoxy benzaldehyde [651]. Recently the enzymatic enantioselective cleavage of S-cyanohydrine acetate by lipases from bacteria or Candida cylindrica [652] has [653] been claimed in a patent. Similarly, the optically active S-3-phenoxy-4-fluorobenzaldehyde cyanohydrine 301 can also be prepared by these esteratic methods, preferentially at a pn between 3.5 and 6.0 [654, 655]. Optically active cyanohydrines must be stabilized e.g. by alkanephosphonic acids [646], to inhibit slow racemization, even in the absence of bases. 

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