Phosphorus Oxyacids Research Articles

The dealkylation of phosphate and phosphonate esters by lodotrimethylsilane : a mild and selective procedure

Iodotrimethylsilane transforms alkyl esters of phosphorus oxyacids into their corresponding trimethylsilyl esters and alkyl iodide. The reaction is rapid and quantitative at room temperature. The reagent has no effect on aryl phosphate ester functions or upon alkyl carboxylate, ether, bromoalkane, vinyl, and ethynyl functions under the conditions employed for transesterification. The trimethylsilyl esters can be isolated by distillation or solvolysed without purification using methanol or water to afford dealkylated phosphate and phosphonate species. Selective monodealkylation of dialkyl phosphonates cannot be achieved using only one equivalent of the reagent, which leads to the formation of mixed products.

Dissociation constants for certain cyclic oxyacids of phosphorus and values of ?? for cyclic fragments

1. Potentiometric titration in cells with transference has been used to determine dissociation constants for cyclic oxyacids of phosphorus in water, 50, 80, and 95% alcohol solutions, and nitromethane. 2. Dissociation constants have been determined for various acylic oxyacids of phosphorus in 95% ethanol solution and nitromethane. Parameters have been evaluated for the Hammett pK vs ∑σφ equation. 3. Values of σφ have been determined for cyclic fragments. The values obtained for the pentamethylene and tetramethylene fragments are the same for all solvents. The values obtained for the dioxypropylene fragments do not characterize the electronic effects from such substituents, varying markedly in passing from one solvent to the other.

ChemInform Abstract: ISOMERIZATION OF 5‐UNSATURATED CHOLESTENONE CATALYZED BY SOME PHOSPHORUS OXYACIDS

Chemischer InformationsdienstVolume 7, Issue 50 Preparative Organic Chemistry ChemInform Abstract: ISOMERIZATION OF 5-UNSATURATED CHOLESTENONE CATALYZED BY SOME PHOSPHORUS OXYACIDS A. KERGOMARD, A. KERGOMARDSearch for more papers by this authorLE QUANG XANG LE QUANG XANG, LE QUANG XANG LE QUANG XANGSearch for more papers by this authorM. F. RENARD, M. F. RENARDSearch for more papers by this author A. KERGOMARD, A. KERGOMARDSearch for more papers by this authorLE QUANG XANG LE QUANG XANG, LE QUANG XANG LE QUANG XANGSearch for more papers by this authorM. F. RENARD, M. F. RENARDSearch for more papers by this author First published: December 14, 1976 https://doi.org/10.1002/chin.197650123Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume7, Issue50December 14, 1976 RelatedInformation

The synthesis, Mössbauer and vibrational spectra of some triorganotin derivatives of phosphorus oxyacids

Trimethyltin hypophosphite, Me3SnPO2H2, bis(trimethyltin) phosphite dihydrate, (Me3Sn)2PO3H.2H2O, and bis(triphenyltin) phosphite, (Ph3Sn)2PO3H, have been obtained from the organotin chloride and aqueous solutions of the sodium salt of the corresponding phosphorus oxy-acid. (Me3Sn)2PO3H.2H2O can be dehydrated under vacuum at 25 °C, but disproportionation occurs on heating. Tris(trimethyltin) orthophosphate, (Me3Sn)3PO4, was prepared from trimethyltin chloride and silver phosphate in methanol and gave an adduct formulated as [Formula: see text] after recrystallization from 1,4-dioxane. Vibrational spectra and Mössbauer data for Me3SnPO2H2 are consistent with a trigonal bipyramidal structure in which planar Me3Sn groups are bridged symmetrically by PO2H2 groups. The Mössbauer spectra of (Me3Sn)2PO3H, (Ph3Sn)2PO3H, and (Me3Sn)2PO3H.2H2O suggest that the two tin atoms are in similar (probably pentacoordinate) environments, implying at least one three coordinate oxygen per formula unit. For (Me3Sn)3PO4, the vibrational spectra, Mössbauer data, and physical properties are consistent with a weakly associated structure in which all three tin atoms are in similar environments. It is suggested that association is achieved via the phosphoryl (P=O) oxygen atom, which is weakly coordinated to three tin atoms leading to a distortion of the tetrahedral arrangement around tin towards trigonal bipyramidal.

Esters of Phosphorus Oxy Acids as Alkylating Agents. IV. N-Alkylation of Imidazole and Its Analogs with Alkyl Esters of Phosphonic and Phosphinic Acids

Abstract Methyl, ethyl esters of phosphonic and phosphinic acids were found to be efficient alkylating agents for imidazole, benzimidazole, 1,2,4-triazole, 1,2,3-benzotriazole and pyrazole, giving the corresponding N-methyl or N-ethyl derivatives.

N-alkylation of purines with alkyl esters of phosphorus oxy acids.

N-alkylation of purines with alkyl esters of phosphorus oxy acids.

SEPARATION OF THE RECOIL PRODUCTS OF INORGANIC PHOSPHORUS OXYACIDS BY CROSS ELECTROPHORESIS

Abstract An attempt was made to separate the recoil products of phosphorus oxyacids (salts of hypophosphite, phosphite, orthophosphate and pyrophosphate) by a cross electrophoresis using zinc ions. This electrophoresis was found to have a general applicability to the isolation of a trace amount of a proper compound from a given matrix which forms insoluble complexes.

Anwendung der Röntgen-Photoelektronenspektroskopie in der Phosphorchemie, II

P2p binding energies and binding energies of other electrons in phosphorus(III) compounds, phosphonium salts and oxyacids of phosphorus and their salts are tabulated and discussed.

The Synthesis, Mössbauer and Infrared Spectra of some Dialkyltin Salts of Phosphorus Oxy-acids

A number of dialkyltin(IV) salts of phosphorus oxy-acids R2Sn(PO2H2)2 (R = CH3, C2H5, n-C4H9), R2SnPO3X (R = CH3, C2H5, n-C4H9, X = H; R = CH3, X = F, OH), and [(CH3)2Sn]3(PO4)2 have been prepared in aqueous solution from the appropriate dialkyltin(IV) dichloride and the sodium salts of phosphorus oxy-acids.Infrared and 119Sn Mössbauer spectra of the dialkyltin dihypophosphites, R2Sn(PO2H2)2, are consistent with hexacoordination for tin with the alkyl groups in trans-octahedral positions and bidentate bridging hypophosphite groups coordinated through oxygens. For the dialkyltin phosphites, R2SnPO3X, polymeric structures with a non-linear R2Sn arrangement are involved, and the magnetic hyperfine Mössbauer spectrum (X = F) is consistent with either distorted trans-octahedral or distorted trigonal bipyramidal structures (with both apical or both equatorial methyl groups). In [(CH3)2Sn]3(PO4)2 the three tin environments are indistinguishable by Mössbauer spectroscopy, but the high value of the asymmetry parameter [Formula: see text] suggests penta- rather than hexacoordination about tin, for which at least one three-coordinate oxygen per formula unit must be invoked.

Esters of phosphorus oxy-acids as alkylating agents. Part II. N-Alkylation of imidazole and related heterocyclic compounds with trialkyl phosphates

A new method for N-alkylation of imidazole, benzimidazole, pyrazole, 1,2,4-triazole, and benzotriazole using trimethyl, triethyl, and tri-n-butyl phosphates as alkylating agents is described. All these heterocycles are easily converted into the corresponding N-alkyl derivatives in 45–90% yields. Predominant alkylation at N-1 was observed in both triazoles.

Organophosphorus compounds. XII. Proton and phosphorus-31 NMR spectroscopic studies of the protonation and cleavage of trialkyl(aryl)phosphates and phosphites, dialkyl phosphonates, and phosphorus oxy acids in fluorosulfuric acid, and fluorosulfuric acid-antimony pentafluoride

Organophosphorus compounds. XII. Proton and phosphorus-31 NMR spectroscopic studies of the protonation and cleavage of trialkyl(aryl)phosphates and phosphites, dialkyl phosphonates, and phosphorus oxy acids in fluorosulfuric acid, and fluorosulfuric acid-antimony pentafluoride

Phosphorus-31 nuclear magnetic resonance studies of cyclic derivatives of phosphorus oxy-acids

Phosphorus-31 chemical shift data (δ ppm from 85% phosphoric acid) are reported for a series of 5- and 6-membered cyclic phosphites, phosphorochloridates, phosphates, phosphonates and phosphinates. Chemical shift differences between the cyclic and acyclic analogues in each of the series of phosphoryl compounds are Δδ 5−a ⋍ −16 ppm and Δδ 6−a ⋍ +8 ppm, while the phosphites have values of +3 and +9 respectively. The similar values of Δδ 6−a for all of the series, varying from two endocyclic PO to two PC bonds, indicates that a σ-bonding effect, steric in origin, is responsible for the shielding at phosphorus. The negative value of Δδ 5−a for the phosphoryl compounds indicates a significant deshielding at phosphorus on formation of the 5-membered ring. It is suggested that this results from “stereo-electronic” effects whose origins depend on the electronegativities of the ring-atoms bonded to phosphorus and which may well be related to the observed enchanced hydrolysis rates for PO bond cleavage in 5-membered phosphoryl compounds containing an endocyclic PO bond.

The toxic action of phosphine: Studies with 32PH 3; Terminal residues in biological materials

Phosphine- 32P was used to demonstrate the presence of phosphorus residues after PH 3-treatment of wheat, flour, insects and cystine. The radioactive residue on wheat and flour is not removed by thorough aeration or by heating at baking temperature, but is largely water-soluble and consists mainly of hypophosphite and phosphite. At practical PH 3 concentrations, residues of the order of 0·04-1·2 ppm calculated as phosphine on flour and wheat are indicated. Phosphine reduces cystine slowly, either in solution or in the dry state, forming cysteine and oxy-acids of phosphorus. Extracts from insects poisoned with 32PH 3 similarly show a predominance of PH 3-borne phosphorus to be in the lower oxy-acid state although other forms are present. Mice fed one meal of well-aerated 32PH 3-treated flour excreted radioactive phosphorus for several weeks.

Hot Atom Chemistry of Phosphorus Compounds. II. Chemical Effects of Neutron Irradiation on Phosphoric Esters of Hexoses

Abstract Phosphoric esters of hexoses were subjected to neutrons and the resulting 32P-labeled recoil products were separated by paper chromatography and paper electrophoresis. The main recoil products were phosphorous and phosphoric acids, independent of the chemical form of the target material and the kind of its salt. A small amount of inorganic acids containing a P–P or P–O–P bond was also found. The yield of the retention product was less than a few percents. The presence of organic diphosphorus compound was supposed by paper electrophoretic analysis. An addition of a small amount of water to the target material before irradiation favored formation of 32P-labeled phosphorus oxyacids in lower oxidation state. The results from irradiation of aqueous solution gave an unexpected chromatographic behavior owing to some unstable complex of recoil 32P atom with water molecule.

A theoretical study on the zone mobility-pH curve in paper electrophoresis of low molecular weight compounds with a dissociable proton and its application to phosphorus compounds

It was found that the zone mobility of a compound with dissociable proton plotted against the pH value of the background solution is approximately expressed by a hyperbolic tangent function. By the use of this relation, we can easily draw the zone mobility-pH value of the background solution is approximately expressed by a hyperbolic tangent function. By the use of this relation, we can easily draw the zone mobility-pH curve of migrating species and estimate the consecutive dissociation constants. The relationships between the mobility and the molecular weight or the hydrated ionic radius were also discussed. Jokl's equation is only applicable to the first dissociation of a migrating substance and the deviation increases with increasing charge number because of the hydration increment. After considering the hydration ratio, we proposed a modification of the equation. The observed relative zone mobility-pH curves of phosphorus compounds such as phosphorus oxyacids, phenylphosphorus compounds and phosphoric esters of hexoses or inosines were in fair agreement with the calculated ones. The equation proposed is useful in practice for the estimation of the dissociation constant and/or molecular weight of an unknown sample.

PH dependence of phosphorus-31 chemical shifts and coupling constants of some oxyacids of phosphorus

pH dependence of phosphorus-31 chemical shifts and coupling constants of some oxyacids of phosphorus

The attenuated total reflection spectra of polyatomic inorganic anions—I Salts of the oxyacids of phosphorus

The A.T.R. spectra of the sodium and/or potassium salts of ortho-, hydrogen and dihydrogen phosphates, phosphites, hypophosphites, pyrophosphates and triphosphates have been recorded in aqueous solution in the “rock-salt” region. The PO stretching frequencies of the PO3, PO2, and POP groups have been correlated, and these frequencies used to interpret the vibrational spectrum of penta—sodium triphosphate.

Separation of some lower oxy-acids of phosphorus by anion-exchange chromatography

Anion-exchange chromatography employing a gradient elution technique has been used to obtain separations of some lower oxy-anions of phosphorus.

Extraction of Ca(II), Sr(II) and Ba(II) by acidic esters of phosphorus oxy acids

The extraction of Ca(II), Sr(II) and Ba(II) from aqueous mineral acid, in the presence and absence of the corresponding sodium salt, into xylene solutions of (GO) 2PO(OH), G = 2-ethyl hexyl and para (1,1,3,3 tetramethyl butyl) phenyl, and of (GO)G′PO(OH), G = n-octyl and G′ = phenyl and chloro methyl, has been investigated radiometrically. The distribution ratio, K, has been found to be inversely second-power dependent upon the hydrogen ion concentration in the equilibrated aqueous phase. The dependency of K upon the concentration of extractant in the equilibrated xylene phase was found to be 2·5-power for Ca and Sr and 3·0-power for Ba in systems involving bis [para (1,1,3,3 tetramethyl butyl) phenyl] phosphoric acid or n-octyl hydrogen chloromethyl phosphonate; 3·0-power for Ca, Sr and Ba in systems involving n-octyl hydrogen phenyl phosphonate; and 3·0-power for Ca (Sr and Ba not proved) in systems involving bis(2-ethyl hexyl) phosphoric acid. The effect of structural differences in the extractants is discussed, and the extraction of alkaline earths (II) is compared with that of Pm(III) and Cm(III).

Examination of Oxyacids of Phosphorus by Electrochromatography

Examination of Oxyacids of Phosphorus by Electrochromatography