Dialkylphosphorous Acids Research Articles

Reaction of N-arylamides of dialkylphosphorous and diarylphosphinous acids with benzil

The N-arylamides of dialkylphosphorous and diarylphosphlnous acids react with benzil to give the corresponding imidophosphites and imidophosphonates.

The reaction of anilides of dialkylphosphorous acids with p-nitrobenzaldehyde

Anilides of dialkylphosphorous acids react with p-nitrobenzaldehyde to form O,O-dialkyl-O-p-nitrobenzyl-N-phenylimidophosphates.

Reaction of acid chlorides with amides of dialkylphosphoric and carboxylic acids

1. A study was made of the reaction of the acid chlorides of acetic, butyric and isobutyric acids with the amide of diethylphosphoric acid, and of the acid chloride of diethylphosphoric acid with the amides of acetic, butyric and benzoic acids and with formanilide. 2. With the amide of diethylphosphoric acid the reaction proceeds with the formation of acylamidophosphates, while with the amides of acetic, butyric and benzoic acids and with formanilide the reaction goes with the formation of the ethyl ester of pyrophosphoric acid and the corresponding cyanides or phenyl isocyanide.

Reaction of a midophosphites with dialkylphosphoric and dialkylthiophosphoric acids

1. A simple and convenient method was found for the synthesis of the ester-amides of sub(thio)-phosphoric acid as the result of reacting dialkyl(thio)phosphoric acids with amidophosphites. It was proved that this reaction is reversible. 2. A simple and convenient method was found for the synthesis of the ester-amides of thio- and dithiopyrophosphoric acids by the reaction of dialkyl(thio)phosphoric acids with amidophosphites and sulfur.

Reaction of trialkyl phosphites with?,?-unsaturated acids

1. The addition of trialkyl phosphites toα,β-unsaturated acids can proceed via the prior protonization of the trialkyl phosphites by the unsaturated acid. The dialkylphosphorous acids and unsaturated acid esters that are formed here react with each other to give the trialkyl esters of the correspondingβ-phosphonocarboxylic acids. 2. Not excluded is the possibility that the above indicated reaction can also proceed simultaneously by the mechanism proposed by Kukhtin and Kamai, but without the formation of the cyclic phosphorane as the intermediate step. 3. Together with the trimethyl ester ofβ-phosphonopropionic acid, the cyclic anhydride of the methyl ester ofβ-phosphonopropionic acid is formed when trimethyl phosphite is reacted with acrylic acid. The cyclic anhydride is obtained in much larger amounts in the presence of acetic acid. The corresponding cyclic anhydride was isolated in the same manner when triethyl phosphite was reacted with methacrylic acid.

Reaction of dialkylphosphorous acids with 9-chloro-10-anthracenealdehyde, 9-anthracenealdehyde, and 9-butylmercapto-10-anthracenealdehyde

1. 9-Chloro-10-anthracenealdehyde, 9-anthracenealdehyde, and 9-butylmercapto-10-anthracenealdehyde react with dialkylphosphorous acids in the presence of either sodium alcoholate or triethylamine to give the corresponding dialkyl esters of anthranyl-α-hydroxyphosphonic acids. 2. Even under drastic conditions, 9-chloro-10-anthracenealdehyde does not react with triethyl phosphite.

Solvent extraction of hafnium(IV) — X Extraction by some chelating agents in the presence of monocarboxylic acids

Extraction of hafnium(IV) by benzene solutions of dialkylphosphoric acids, HBPHA, and TTA from 2 M HClO 4 medium was studied in the presence of formic, acetic, lauric, and benzoic acids. The decrease in the distribution ratio of hafnium caused by these acids in systems with dialkyl phosphoric acids is shown to be of antagonistic nature due to the interaction in the organic phase of the extracting agent with monocarboxylic acids. In extractions with HBPHA and TTA, acetic acid concentrations higher than 1 M were necessary to cause the distribution ratio of hafnium to decrease, probably on account of the formation of hafnium acetato complexes in the aqueous phase. Spectrophotometric proof is given for the interaction of TTA with acetic acid.

The solvent extraction of hafnium(IV)—VIII: Extraction of Hf(IV) by some dialkylphosphoric acids from bromide, iodide and sulphate media

The distribution of 175+181Hf(IV) between aqueous hydrobromic, hydroiodic or sulphuric acid and a solution of dibutyl,-di- n-amyl-, diethylhexyl- and di- n-octylphosphoric acids in various organic solvents has been studied. In moderately acidic solutions of halogenacids, Hf is extracted as HfXA 3(HA) x , where HA is the dialkylphosphoric acid and X is the halogen. In strong acidic solutions, the originally ion-exchange extraction mechanism is replaced by an addition type of reaction with the formation of extractable complexes of the composition HfX 4(HA) y . In sulphate solutions, with the exception of dioctylphosphoric acid, complexes of the HfA 4(HA) y type are extracted in moderately acidic medium and in strong acidic medium the extraction mechanism is again changed and solvated sulphate complexes of Hf are formed.

The solvent extraction of hafnium(IV)—VI: Extraction of Hf(IV) by some dialkylphosphoric acids from chloride and nitrate media

The distribution of 175+181Hf(IV) between aqueous hydrochloric or nitric acid and (i) a solution of dibutylphosphoric acid in benzene and chloroform, (ii) di- n-amylphosphoric acid in toluene and (iii) diethylhexyl-and di- n-octylphosphoric acids in n-octane has been studied. In the range of concentrations of Hf used (up to 2 × 10 −6M), Hf is extracted from a hydrochloric acid medium up to C HCI of 3·5 M predominantly as HfClA 3(HA) 2, where HA is the dialkylphosphoric acid. In a medium of nitric acid at C HNO 3 ⩾ 1·5 M, or in one of hydrochloric acid at C HCI ⩾ 4·5 M, the initial ion-exchange reaction mechanism is replaced by an addition type of reaction with the formation of extractable complexes of Hf X 4(HA) y , where X = NO 3, Cl. At higher concentrations of HNO 3, an extractable HNO 3·HA complex is formed which results in a decrease in the distribution ratio of Hf.

Structure and properties of the products of the reactions of trialkylphosphites and dialkylphosphorous acids with ethylideneacetylacetone and ethylideneacetoacetic ester

1. Trialkylphosphites react with ethylideneacetylacetone and ethylideneacetoacetic ester under mild conditions (20–40°, dry nitrogen atmosphere) to form 2,2,2-trialkoxy-3,5-dimethyl-4-acetyl-1-oxa-2-phosphacyclopent-4-enes and 2,2,2-trialkoxy-3,5-dimethyl-4-carboethoxy-1-oxa-2-phosphacyclopent-4-enes, respectively. 2. The reaction of the phosphoranes with alcohol, acetic anhydride, and water results in cleavage of the phosphorane ring at the P-O bond. 3. Hydrolysis of the phosphoranes yields esters of l-methyl-2,2-diacetyl- and 1-methyl-2-acetyl-2-carboethoxyethylphosphonic acids. The keto-enol tautomerism of these compounds was studied by ultra-violet spsctroscopy. 4. Distillation of the phosphorane hydrolysis products resulted in the splitting out of alcohol and the formation of 2-oxo-2-alkoxy-3,5-dimethyl-4-acetyl-1-oxa-2-phosphacyclopent-4-enes and 2-oxo-2-alkoxy-3, 5-dimethyl-4-carboethoxy-l-oxa-2-phosphacyclopent-4-enes, respectively. These same esters were also obtained from the reaction of ethylideneacetylacetone and ethylideneacetoacetic ester with dialkylphosphorous acids. 5. The structures of all compounds synthesized were confirmed by infrared spectra.

The solvent extraction of hafnium(IV)—II extraction of Hf(IV) by some dialkylphosphoric acids from perchloric medium

The distribution of 175+181Hf(IV) was studied between aqueous solutions of perchloric acid and solutions of dibutyl-, diamyl-, diethylhexyl- and dioctylphosphoric acids (=HA) in benzene, chloroform, CCl 4, cyclohexane and n-octane. In the region of existence of mononuclear complexes (up to 1 × 10 −7 M Hf) Hf is extracted predominantly as Hf(ClO 4)A 3·(HA) 2. At higher initial concentration of Hf, polymeric complexes are formed in the aqueous phase, which cause a decrease in the value of the distribution ratio of the Hf (= D). In strongly acidic media (above 4 M HClO 4), the primary ion-exchange reaction mechanisms is replaced by an addition type of reaction, which results in the formation of very extractable complexes of Hf(ClO 4) 4(HA) 4. Consequently a considerable increase in the value of D occurs. When using diamyl- and dibutylphosphoric acids in this medium, the results are affected by adsorption of Hf on the walls. Addition of TBP caused a decrease in D. This antagonistic effect can be explained by the interaction of TBP with the HA.

Acidic organophosphorus extractants—IV: Extraction of strontium by some dialkyl phosphoric acids

The extraction of strontium by dialkyl phosphoric acids, where alkyl is n-butyl, n-amyl, n-octyl and 2-ethylhexyl, has been studied. The highest distribution ratio ( qSr) that can be reached increases with increasing number of carbon atoms in the straight alkyl chain, but in the region of low q Sr the length of the n-alkyl group does not affect the extraction efficiency. Branching of the alkyl group reduces the ability of the diakyl phosphoric acid to extract strontium. The extraction efficiency decreases in the series of diluents: aliphatic hydrocarbons > cyclohexane > carbon tetrachloride > toluene. The composition of the strontium complexes with di-n-amyl phosphoric acid in cyclohexane and carbon tetrachloride is SrA 2.3HA. If −log[H +] > 3·5 for the aqueous phase, the complex SrA 2. xHA(5 − x)NaA is formed in cyclohexane, and SrA 4 4− int he aqoueous phase.

The synergic and antagonistic effects in the extraction of inorganic compounds with a mixture of amines and organophosphoric acids: The system: UO 22+ + H 2SO 4 + H 2O-tri- n-octylamine dialkylphosphoric acid + diluent

It has been found that synergic and antagonistic effects occur during the extraction of uranium (VI) with mixtures of tri- n-octylamine and dialkylphosphoric acids. The influence of the concentration of uranyl sulphate, sulphuric acid, ammonium sulphate, and extractants on the extraction of the uranium (VI) with a mixture of tri- n-octylamine and dialkylphosphoric acids has been studied. The composition of the extracted compounds has been determined, and constitutional formulae of these compounds are proposed. The reasons for the synergic and antagonistic effects are explained.

Acidic organophosphorus extractants—I Extraction of lanthanides by means of dialkyl phosphoric acids—effect of structure and size of alkyl group

The separation efficiency of dialkyl phosphoric acids for the lanthanides does not depend much on the structure, nor on the size of the alkyl group. The extraction efficiency is considerably lowered by branching of the alkyl group; for the same structure it is only insignificantly affected by an increase in the number of carbon atoms in the alkyl group.

Azeotropes of dialkylphosphorous acids with certain alcohols

1. In the interaction of dialkylphosphorous acids(Alk=CH3-, C2H5-, C3H7 -, C4H9) with acetone cyanohydrin, azeotropic mixtures of the composition (RO)2P(O)H: acetone cyanohydrin are formed. R=CH3, 0.66:1, R=C2H5, 1∶1; R=C3H7, 2∶1 and R=i-C4H9, 3∶1. 2. Diethylphosphorous acid forms azeotropes with the cyanohydrins of cyclohexanone, formaldehyde, and butyraldehyde; with chloretone, trichloroethanol, and hexanol.

Ethylenimides of alkyl- and dialkylphosphorous acids

1. The previously unknown ethylenimides of the n-propyl-, isopropyl-, n-butyl-, allyl-, diisopropyl- and di-n-butylphosphorous acids were obtained, and they were converted to the corresponding thiophosphoric acid derivatives by the addition of sulfur to them. 2. The reaction of the diethylenimide of isopropylphosphorous acid with chloral gave the diethylenimide ofα-isopropoxy-β1β2β3-trichloroethylphosphonic acid.

Analysis of alkyl esters of phosphoric acid by gas chromatography

Mono- and di-alkyl phosphoric acids can be converted to volatile methyl esters by treatment with diazomethane in ether. The separationof the mixed methyl alkyl phosphates can readily be achieved by gas chromatography o a 3 ft. column of silicone DC200 on a firebrick support at 188° or silicon E 3oI on a celite support at 197°. the method is applicable to the quantitative analysis of mixtures of alkyl esters of phosphric acid in TBP.

Synergism with Thenoyl Trifluoracetone in the Solvent Extraction of Metallic Species

Thenoyl trifluoroacetone (HTTA) has been used by workers in England and the U. S. as the acid in combination with neutral organophosphates (S) to demonstrate a strong (synergistic) enhancement of extraction of metallic species. This enhancement using HTTA is exhibited by many metal species and is much larger (up to 108) than that obtained with the dialkyl phosphoric acids (up to 102). This effect is increased as S is changed from the neutral alkyl phosphates, through phosphonates, to the phosphine oxides. Examples of synergism with HTTA and S are also given where S, the neutral additive, contains no phosphorus and is an amide, alcohol, or ketone. Tracer work has established the composition of over 30 extracting species containing di, tri, and tetravalent metals of the general formula M(TTA)xSy, where x is the valency of M, and y varies between 1 and 3. Confirmation of these formulas has, in a number of instances, been obtained by ultraviolet spectrophotometry on tenth molar solutions and by analysis of anhydrous microcrystalline solids isolated from solution. Stability constants have also been ascertained for many of these synergistic species. Infrared work indicates the likelihood of some of the chelate Ugands becoming monodentate in the synergistic species with direct bonding of S to the metal.If an excess of neutral ester S is added to a synergistic system, antisynergism, that is the reverse of synergism, occurs and decreases of 108 in extraction coefficient can occur. The degree of antisynergism depends on the quantity and nature of S. S could be an alcohol, amide, ketone, ether, ester (including organophosphorus esters) or, in fact, a so called “inert” diluent such as benzene or chloroform. The cause of these very large antisynergistic effects is bound up with the water content of the neutral additive S and of the diluent. There is ultraviolet spectral evidence that the anhydrous species is destroyed with formation of a hydrated TTA species.

The Synergistic Effects in Organophosphate Extraction Systems

Combinations of dialkylphosphoric acids (HA) and neutral organophosphorus reagents (B) have for some time been known to produce enhanced (synergistic) extraction of and other actinide ions. This effect may be attributed to the formation of a mixed complex—either a substitution product MO2A3HB or an addition product MO2A4H2B resulting from the reaction of B with the extraction complex MO2A4H2 normally formed with HA alone. Available extraction data, when analyzed in terms of the competing hydrogen-bonding interactions between HA and B, appear more consistent with an addition product MO2A4H2B. The stability of this mixed complex as a function of the neutral organophosphate used and as a function of the diluent used is consistent with hydrogen bonding or solvation of MO2A4H2 by B. The much stronger and more general synergism found in systems wherein HA is replaced by the β-diketone, Thenoyltrifluoroacetone (HY) may be attributed to the relatively weaker competing interaction between HY and B and to the less coordinatively saturated extraction complexes formed by HY alone.

The extraction of metallic species by dialkylphosphoric acids

Of the organophosphates, the mono-acidic dialkylphosphates—(RO) 2P(O)OH—have not only proven valuable solvent extraction reagents for the separation of metallic species, they have also proven a rewarding subject for the investigator interested in solvent extraction mechanisms. Studies of extraction behaviour, osmotic behaviour, and infra-red spectra have shown that these reagents are usually present in organic solvents as hydrogen-bonded dimers H 2X 2 which, at low loadings, extract metal cations M z+ to form complexes of the type M(X 2H) z . The demonstrated wide occurrence of this simple cation exchange mechanism—free of complicating extensive association and electrolyte extraction—offers an excellent opportunity to examine theeffects of ion charge, size, and coordination properties on extraction. In contrast, systems at high loadings have shown more varied and complicated behaviour involving polynuclear complex formation and anion extraction. The pronounced and selective “synergistic” enhancement of extraction found when the dialkylphosphoric acids are used in combination with the neutral organophosphorous compounds has aroused considerable interest and deserves continued study.