2528-38-3Relevant articles and documents
Acceleration of the Pseudorotation Rates in Pentacoordinated Phosphorus Compounds. Conformational Transmission versus Hexacoordinated Zwitterionic Intermediates
Keijzer, A. E. H. de,Buck, H.M.
, p. 4827 - 4831 (1988)
A variable-temperature 13C NMR study, accompanied by a high-resolution 1H NMR conformational analysis study, on a series of monocyclic oxyphosphoranes is reported.The selected compounds enabled us to study the acceleration of the rates of intramolecular ligand reorganization on pentacoordinated phosphorus.It allowed us to determine whether the enhancement of the reorganization rates was brought about by accelerated pseudorotation due to the conformational transmission effect or by the involvement of hexacoordinated zwitterionic phosphorus intermediates.The results of the study further substantiate the findings that the involvement of such hexacoordinated intermediates is of no importance in the type of oxyphosphoranes studied.
Experimental determination and model correlation for the solubilities of trialkyl phosphates in supercritical carbon dioxide
Pitchaiah,Sivaraman,Lamba, Neha,Madras, Giridhar
, p. 51286 - 51295 (2016)
The solubilities of a series of trialkyl phosphates in supercritical carbon dioxide have been investigated. The solubility measurement was carried out using a dynamic flow method. The measurements were performed at 313, 323 and 333 K and in the pressure range of 10 to 25 MPa. The trialkyl phosphates were found to be highly soluble in supercritical carbon dioxide and the solubilities were in the range of 0.01 to 0.1 mol fraction. The solubility of trialkyl phosphates increases with an increase in pressure at constant temperature. A reverse behavior was observed, wherein the solubilities decreased with increase in temperature in the investigated pressure region. At constant temperature and pressure, the solubilities of the trialkyl phosphates decrease with the alkyl chain length. The solubility data was found to be consistent with the Mendez-Teja model. The solubilities were correlated by the Chrastil model and an association model based on the van Laar activity coefficient model with absolute deviations of less than 10%. A key result is that the model parameters based on the association model varied linearly with the carbon number.
Electrocatalytic eco-efficient functionalization of white phosphorus
Budnikova, Yulia H.,Yakhvarov, Dmitry G.,Sinyashin, Oleg G.
, p. 2416 - 2425 (2007/10/03)
The novel eco-efficient methods to transform white phosphorus into the esters of phosphoric, phosphorous and phosphonic acids, tertiary phosphines and other organophosphorus compounds under conditions of electrochemical catalysis were elaborated. The mechanism of these processes was investigated using the method of cyclic voltammetry and preparative electrolysis.
Oxidizing alkoxylation of phosphine in alcoholic solutions of iodine
Polimbetova,Borangazieva
, p. 2079 - 2082 (2007/10/03)
Oxidizing alkoxylation of PH3 to trialkyl phosphates was performed in pyridine-alcoholic solutions of iodine. The optimal conditions of the reaction were found.
Oxidative P-O and P-C Coupling of Butanol with Phosphine in the Presence of Oxidizers and Platinum(IV) and Platinum(II)
Dorfman,Polimbetova,Aibasov
, p. 231 - 247 (2007/10/03)
A butanol solution of Na2PtCl6 at 60-80°C in the presence of p-benzoquinone or NaBrO3 is found to rapidly consume even traces of PH3 until complete reduction of benzoquinone to hydroquinone or NaBrO3 to NaBr, respectively. The nature of products depends on the valence state of platinum and the nature of the oxidizer. Without an oxidizer, platinum(IV) is reduced to platinum(II) with formation of tributyl phosphate, the product of P-O coupling of PH3 with BuOH, while platinum(II) is reduced to platinum(0) with formation of butylbis(α-hydroxybutyl)phosphine oxide Bu(α-PrCHOH)2PO, the product of P-C coupling of PH3 with BuOH. In the presence of benzoquinone, which oxidizes Pt(0) to Pt(II), a P-C bond is formed, while in the presence of sodium bromate, which regenerates Pt(II) to Pt(IV), P-O coupling of PH3 with BuOH occurs. The products and principal steps of this new reaction were studied by the methods kinetics, red-ox potentiometry, chemical modeling, inhibition of free-radical reactions, 31P NMR, IR and X-ray photoelectron spectroscopy, X-ray spectral microanalysis, and gas-liquid chromatography. We showed that the P-C coupling of PH3 with BuOH is promoted by platinum(II) complex, while P-O coupling is promoted by platinum(IV) complex. In the key steps the Pt(II) butoxyphosphide complex PtCl3(OBu)(PH2)- arises from reaction of the Pt(II) phosphide complex with platinum(IV). The red-ox decomposition of intermediate complexes leads to formation of phosphinite (BuO)2PH2 and Pt(II), or (α-hydroxybutyl)phosphine and Pt(0). The catalytic cycles are completed by fast steps of oxidative butoxylation of (BuO)PH2 to (BuO)3PO or by α-hydroxybutylation of (PrCHOH)PH2 to Bu(PrCHOH)2PO, and oxidation of Pt(II) to Pt(IV) with bromate or Pt(0) to Pt(II) with benzoquinone, respectively.
Synthesis of dialkyl phosphites and trialkyl phosphates by oxidation of sodium hypophosphite by copper(II) chloride
Dorfman, Ya. A.,Aleshkova. M. M.
, p. 515 - 520 (2007/10/03)
Sodium hypophosphite oxidazies in alcoholic solution of CuCl2 at 50-80 deg C to give dialkyl phosphite and trialkyl phosphate.The yield of trialkyl phosphate increases with decreasing molecular weight of the alcohol and reaches ca. 100percent for MeOH and EtOH.The optimal conditions were found, and the mechanism of oxidation of NaPH2O2 to (RO)2PHO and (RO)3PO by copper(II) chloride was studied.The reaction proceeds via the formation of alkyl hypophosphite and copper(II) complexes with alkyl hypophosphite and dialkyl phosphite, which undergo inner-sphere two-electron redox decomposition with the liberation of dialkyl phosphite and trialkyl phosphate, respectively.
PREPARATION OF ALKYLDIHYDROXYALKYLPHOSPHINE OXIDES AND TRIALKYL PHOSPHATES FROM PHOSPHINE AND ALCOHOLS IN THE PRESENCE OF PLATINUM(IV) HALIDES
Dorfman, Ya. A.,Levina, L. V.,Aibasov, E. Zh.
, p. 1085 - 1092 (2007/10/02)
31P NMR spectroscopy, gas chromatography, and potentiometric methods indicate that an alcoholic solution of Na2PtCl6 rapidly absorbs even traces of PH3 at 373-423 K to give trialkyl phosphates and alkyldihydroxyalkylphosphine oxides, platinum(IV) being reduced to platinum(0). At high temperatures oxidative C-phosphorylation prevails, while at low temperatures O-phosphorylation of alcohols by phosphine dominates. The rate of oxidative C- and O-phosphorylation of alcohol increases with increase in the concentrations of alcohol, phosphine, NaBr, NaI, Pt(IV) and Pt(II) and falls when H2O, HCl, or NaCl are added. Methods of chemical modeling and isolation of intermediate products show that phosphates are formed via stages of oxidation of dialkyl hydrogen phosphites resulting from dealkylation of trialkyl phosphites, while phosphine oxides are formed by isomerization of trihydroxyalkylphosphines.
CHLORINATION OF PHOSPHINE IN ALCOHOLS
Dorfman, Ya. A.,Polimbetova, G. S.,Aibasov, E. Zh.,Borangazieva, A. K.,Kokpanbaeva, A. O.,Faizova, F. Kh.
, p. 1860 - 1864 (2007/10/02)
Trialkyl phosphates are rapidly and selectively formed when dilute gaseous PH-Ar and Cl2-Ar mixtures are passed into alcohols (ROH, R=Bu, i-Bu, Am, i-Am, Oct) at 50-70 deg C.Analogous results are obtained in the presence of pyridine at 8-25 deg C.The reaction was studied by gas chromatography, 31P NMR spectroscopy, and potentiometry.The reaction was shown to pass successively through the stages of the chlorination of phosphine to PCl5, the alcoholysis of phosphorus pentachloride to phosphoryl chloride, and finally by the esterification of phsophoryl chloride to trialkyl and dialkyl phosphates.Pyridine, excess af alcohol, and high temperature accelerate the stage of the esterification of phosphoryl chloride to the trialkyl phosphate.
