- Fluorinated phosphorus compounds: Part 5. The boiling points of fluoroalkyl phosphoryl compounds
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The relationship between structure and boiling point for several classes of phosphoryl compounds having fluorinated or hydrocarbon ester groups is discussed, i.e. phosphoramidates (R2N)2P(O)OCH2RF and (RFCH2O)2P(O)NR2, phosphates (RO)2P(O)ORF, (RFCH2O)2P(O)OR, (RFO)3P=O and (RFCH2O)2P(O)OCH2R′ F, and phosphonates (RFO)2P(O)R, where R= alkyl and RF= fluoroalkyl. Fluorination generally produces compounds of similar or lower boiling point than the unfluorinated parent compounds. A key factor governing the boiling point of a fluorinated phosphoryl compound relative to its hydrocarbon analogue is not its molecular weight, but the position and number of fluorine atoms in the ester linkage(s). Molecules with an umbrella of fluorine atoms repel each other, leading to low intermolecular forces: the boiling points of (C3F7CH2O)3P=O and (C3H7CH2O)3P=O are close despite a molecular weight difference of 378. Molecules with protons capable of intermolecular hydrogen-fluorine bonding (i.e. those containing -NHR or -CF2H groups) have higher boiling points than those without, due to attractive forces in the liquid state. Synthetic procedures for four unfluorinated phosphates - (MeO)2P(O)O-i-Pr, (MeO)2P(O)O-n-Bu, (EtO)2P(O)O-i-Pr and (s-BuO)3P=O are outlined.
- Timperley, Christopher M.,Waters, Matthew J.
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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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p. 92905 - 92916
(2016/10/11)
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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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p. 2416 - 2425
(2007/10/03)
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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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