Alkylphosphonic acid

Gao W, Dickinson L, Grozinger C, Morin F G and Reven L 1996 Self-assembled monolayers of alkylphosphonic acids on metal oxides Langmuir M 6429-35... 

Triethyl phosphite is a colourless mobile liquid, insoluble in water. Trialkyl phosphites are valuable intermediates in the preparation of many organophosphorus compounds they readily form dialkyl esters of alkylphosphonic acids by the Arbusov reaction (p. 311). 

Detergents are metal salts of organic acids used primarily in crankcase lubricants. Alkylbenzenesulfonic acids, alkylphenols, sulfur- and methjiene-coupled alkyl phenols, carboxyUc acids, and alkylphosphonic acids are commonly used as their calcium, sodium, and magnesium salts. Calcium sulfonates, overbased with excess calcium hydroxide or calcium carbonate to neutralize acidic combustion and oxidation products, constitute 65% of the total detergent market. These are followed by calcium phenates at 31% (22). 

The recent development and comparative application of modern separation techniques with regard to determination of alkylphosphonic acids and lewisite derivatives have been demonstrated. This report highlights advantages and shortcomings of GC equipped with mass spectrometry detector and HPLC as well as CE with UV-Vis detector. The comparison was made from the sampling point of view and separation/detection ability. The derivatization procedure for GC of main degradation products of nerve agents to determine in water samples was applied. Direct determination of lewisite derivatives by HPLC-UV was shown. Also optimization of indirect determination of alkylphosphonic acids in CE-UV was developed. Finally, the new instrumental development and future trends will be discussed. 

Far less than the stoichiometric amount of sequestrants precipitation of insoluble salts from water hardness can be prevented by slowing down the formation of crystals and crystal growth. This process is called the threshold effect. It has long been used in the preparation of boiler feeding water, e.g., steam vessels of railroad engines. Originally sodium pyrophosphate was used for this task, but alkylphosphonic acids and derivatives thereof are superior in their effect. 

Olefination Reactions Involving Phosphonate Anions. An important complement to the Wittig reaction involves the reaction of phosphonate carbanions with carbonyl compounds 253 The alkylphosphonic acid esters are made by the reaction of an alkyl halide, preferably primary, with a phosphite ester. Phosphonate carbanions are generated by treating alkylphosphonate esters with a base such as sodium hydride, n-butyllithium, or sodium ethoxide. Alumina coated with KF or KOH has also found use as the base.254... 

Reactions and Properties of Phosphonic and Phosphinic Acids and their Derivatives.-A free radical mechanism has been proposed to account for the cleavage of the phosphorus-carbon bond in the alkylphosphonic acids (155) by E coli to give a mixture of alkane (methane only, from methylphosphonic acid) and terminal alkene. 

The reactions used for synthesis of II-VI (CdSe, CdTe), III-V (InP, InAs), and IV-VI (PbS, PbSe, PbTe) semiconductor nanocrystals are outlined by Schemes 3-5.4,17,30-32 The syntheses are carried out at high temperatures, and in the presence of long-chain alkylphosphines (trioctylphosphine,TOP), alkyl-phosphine oxides (trioctylphosphine oxide, TOPO), alkylamines (hexadecyl-amine, HD A), and alkylphosphonic acids as the stabilizing agents. 

Figure 2.8 Use of red phosphorus for the direct generation of an alkylphosphonic acid.

Hydrolysis of the phosphonodiamides 2 (R1 = CH3) under mild conditions gave a-substi-tuted alkylphosphonic acids 3 (R1 = CH3) with excellent yields, with concomitant recovery of the chiral auxiliary. For further examples see Table 1. 

In this case, the EOF was cathodic and its velocity remained almost constant in the pH range of 4-7. The separation performance of IL-coated capillary in an aqueous buffer (sorbic acid) was proved by the separation of seven alkylphosphonic acids and their esters. The separation was accomplished in <6 min. 

Peptide synthesis. The anhydride effects peptide synthesis as shown in equation (I). Free acid groups arc buffered with a tertiary amine such as N-elhylmorpholine. The reaction is complete after 24 hours at room temperature. No raccmization is detected in the Anderson-Young test. The resulting alkylphosphonic acid derivative is soluble in water and easily removed. 

The addition of 0.01 mol L 1 dialkylphosphinic acids and alkylphosphonic acids in a nonirradiated 30% TRPO-kerosene system had no effect on the extraction of Pu(IV) with TRPO. Thus, these acids were not complexing materials for plutonium. The polymeric species were responsible for plutonium retention and emulsification in contact with NaOH or deionized water. The effective elimination of these compounds was obtained by vacuum distillation of the irradiated TRPO-kerosene (67,167). 

Initial screening of water samples and extracts mainly focuses on the presence of polar nonvolatile alkylphosphonic acids and nonvolatile breakdown products of nerve agents in Schedule 2 (Precursors Schedule 2.B.04, 2.B.11, 2.B.12, and 2.B.14) (10). Water samples and extracts are preferably screened without sample preparation, typically with ... 

ROP for capillary zone electrophoretic analysis of the alkylphosphonic acids and related monoesters using indirect UV detection ... 

C.E. Kientz, E.W.J. Hooijschuur and U.A.Th. Brinkman, Capillary electrophoresis coupled online with flame photometric detection determination of alkylphosphonic acids, J. Microcol. Sep., 9, 253-259 (1997). 

E.W. Hooijschuur, C.E. Kientz and U.A. Brink-man, Determination of alkylphosphonic acids by microcolumn liquid chromatography with gradient elution coupled on-line with flame photometric detection, J. Chromatogr. A, 907, 165-172 (2001). 

M. Sokolowski, Mass Spectra and retention parameters of some o-alkyl alkylphosphonic acids, in Proceedings of the NATO Advanced Research Workshop on Analytical Chemistry Associated with Destruction of Chemical Weapons, Brno, Czech Republic, 12-15 May 1996, Kluwer Academic Press, Dordrecht, 99-104, 1997. 

M. Sliwakowski, Ion-trap mass spectra and retention parameters of alkylphosphonic acids low aliphatic alcohols esters, in Proceedings of the 1995 ERDEC Scientific Conference on Chemical and Biological Defense Research, D.A. Berg... 

Diazomethane this reagent converts acids into methyl esters and is used for the conversion of alkylphosphonic acids into methyl alkylphospho-nates. It is one of the most potent methylation reagents. However, it does not methylate the polar alcohols of the CWC Schedule list, for example, thiodiglycol. 

Methyl esters of alkylphosphonic acids may also be obtained by heating these acids together with trimethylphenylammonium hydroxide in the hot (e.g. 250 °C) injection port of the GC/MS system. 

Until recently, another clear advantage of GC/MS has been the lower limits of detection that are generally achievable for trace analysis. Examples are thiodiglycol, thiodiglycol sulfoxide, and methyl alkylphosphonic acids. GC capillary columns usually provide sharp narrow peaks, and techniques such as NICI in combination with fluorinated derivatives are inherently extremely sensitive. However, the latest generation of LC/MS/MS instruments, including some ion traps, triple sector quadrupole and TOF systems, are at least an order of magnitude more sensitive than their predecessors and may eventually provide equally low limits of detection. In terms of initial cost, they are still likely to be more expensive than GC/MS instruments. 

Figure 3. Major fragmentation pathways for alkyl alkylphosphonic acids in positive and negative ion modes...

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