- Absolute viscosity and density of trisubstituted phosphoric esters
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This paper presents measurements on the absolute viscosity (η) and density (ρ) of trisubstituted phosphoric esters which are useful in understanding their flow mechanism necessary for accessing their role as plasticizers. The effect of chain length and branching has been examined on the η and ρ trends. From η data, by using the Vogel-Tammann-Fulchur (VTF) equation, the VTF temperature (To) has been obtained which also represents the ideal glass transition temperature. To is related to the flexibility of the molecules. It is observed that To initially decreases with molecular weight, reaches a minimum, and increases thereafter. The initial decrease in To has been attributed to the enhanced flexibility of the phosphate esters. Reversal of flexibility with relative molar mass beyond 400 is due to the gentle collision of the arms of the trisubstituted phosphoric esters. This has been further corroborated from the molar mass exponent as exhibited in the η-molar mass plot. The isomeric effect on η has also been investigated in tricresyl phosphates, hitherto for the first time. The ortho isomer has highest η among the isomers. The para isomer was found to have lowest To and hence highest flexibility compared to the ortho and meta isomers.
- Kannan,Kishore
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- Trends in small angle neutron scattering of actinide-trialkyl phosphate complexes: A molecular insight into third phase formation
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The "third phase" formation phenomenon in solvent extraction is due to the aggregation of extracted species and formation of reverse micelles. As Small Angle Neutron Scattering (SANS) is a powerful tool to probe colloidal particles, it is considered as an important technique to study the aggregation behaviour of actinide complexes in solvent extraction systems. The actinide specific trialkyl phosphate (TalP) based extractants, namely, tri-n-butyl phosphate (TBP), tri-iso-butyl phosphate (TiBP), tri-sec-butyl phosphate (TsBP) and tri-sec-amyl phosphate (TsAP) have been examined for the first time using the SANS technique to investigate third phase formation phenomena with some of the actinides. SANS was employed to get insight into third phase formation in the extraction of Th(iv) and U(vi) from 1 M HNO3 by 1.1 M solutions of TalP in deuterated dodecane (n-C12D26, 98 atom% D). Deuterated diluent was used in order to provide contrast during the neutron scattering measurements. Potential energy and the stickiness parameter of reverse micelles formed in the above solvent systems have been quantified as a function of organic metal loading. The data are fitted using Baxter's sticky-sphere model. The stickiness parameter, (τ-1) a measure of the attractive interaction between the micelles, as well as the attractive potential energy (U0) was quantified. A clear correlation has been established between the stickiness parameter and the tendency for third phase formation with TalP systems. As U(vi) does not form a third phase with these extractants at 1 M HNO3, comparative studies were carried out with U(vi)-TalP complexes. These studies established lower stickiness and attraction between the micelles with the U(vi) system. The correlation between SANS parameters and third phase formation tendency was extended to a temperature dependence study and these studies established higher third phase limits when the temperature was enhanced, corroborating well with our experimental results. Our studies also revealed the "prediction of third phase formation" before its occurrence for a range of actinide-extractant systems.
- Chandrasekar, Aditi,Suresh,Sivaraman,Aswal
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- Obtaining of trialkylphosphates in anodic dissolution of copper phosphide
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Due to obtain trialkylphosphate is suggested to use anodic solution of copper phosphide in alcohol solutions. At this, it can use copper phosphide, obtained at the processing of wastes of phosphorus production. Moreover, it is presented ways of obtaining of tri-n-butylphosphate and tri-izo-butylphosphate.
- Aueshov,Satayev,Tukibayeva
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- Electrocatalytic eco-efficient functionalization of white phosphorus
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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.
- Budnikova, Yulia H.,Yakhvarov, Dmitry G.,Sinyashin, Oleg G.
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- Oxidative alkoxylation of zinc phosphide in alcoholic solutions of copper(II) chloride
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Oxidative alkoxylation of Zn3P2 with the formation of valuable phosphoric and phosphorous acid esters occurred at a high rate and with a high selectivity in alcoholic solutions of CuCl2 under the action of oxygen at 30-60°C. Depending on the nature of the alcohol, two products were formed, namely, trialkyl phosphates (RO)3PO and dialkyl phosphites (RO)2HPO. Water favored the formation of dialkyl phosphates (RO)2(HO)PO. The kinetics and mechanism of the new catalytic reaction were studied, and the optimal conditions for conducting this reaction were found. The reaction proceeded in a topochemical mode by a separate redox mechanism.
- Dorfman,Ibraimova,Polimbetova
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- Transesterification process
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PCT No. PCT/GB95/01883 Sec. 371 Date Jul. 21, 1997 Sec. 102(e) Date Jul. 21, 1997 PCT Filed Aug. 9, 1995 PCT Pub. No. WO96/05208 PCT Pub. Date Feb. 22, 1996A process for the preparation of a phosphate ester is disclosed. A triaryl phosphate is reacted with an alcohol in the presence of a catalytic quantity of a base to produce the phosphate ester product. The base has a base strength of less than 11, and is preferably potassium fluoride or potassium carbonate. Trialkyl phosphates, dialkyl monoaryl phosphates, monoalkyl diaryl phosphates, and mixtures of these compounds can be produced by this process.
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- Electrochemical Oxidation of Metal Dialkyl Phosphites and Their Reaction with Halogens
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Electrochemical oxidation of sodium dialkyl phosphites with alkyl radicals of normal structure leads to formation of tetraalkyl pyrophosphites as the main products, while electrochemical oxidation of litium dialkyl phosphites and sodium salts with branched alkyl radicals yields tetraalkyl hypophosphates. The reaction of metal dialkyl phosphites with halogens leads to analogous results.
- Romakhin,Zagumennov,Nikitin
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p. 1022 - 1026
(2007/10/03)
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- Synthesis of dialkyl phosphites and trialkyl phosphates by oxidation of sodium hypophosphite by copper(II) chloride
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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.
- Dorfman, Ya. A.,Aleshkova. M. M.
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p. 515 - 520
(2007/10/03)
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- THE INTERACTION OF PHOSPHITE ESTERS WITH α-IODOKETONES IN THE PRESENCE OF SILVER ION
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The reactions of trialkyl phosphites with α-iodoketones in the presence of silver perchlorate or silver tetrafluoroborate yield the corresponding trialkyl phosphates and tetra-alkyl pyrophosphates. Under certain conditions, CIDNP effects indicate the involvement of radical-pairs in the formation of unstable betaine intermediates.
- Hudson, Harry R.,Matthews, Ray W.,Shode, Oluyemisi O.,Yusuf, Ramon O.,Jaszay, Zsuzsa M.,et al.
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- CHLORINATION OF PHOSPHINE IN ALCOHOLS
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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.
- Dorfman, Ya. A.,Polimbetova, G. S.,Aibasov, E. Zh.,Borangazieva, A. K.,Kokpanbaeva, A. O.,Faizova, F. Kh.
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p. 1860 - 1864
(2007/10/02)
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