16637-16-4Relevant articles and documents
INTERACTION BETWEEN URANIUM TETRAFLUORIDE OXIDE AND THE PENTAFLUORIDES OF ARSENIC, NIOBIUM, TANTALUM, AND BISMUTH
Holloway, John H.,Laycock, David,Bougon, Roland
, p. 2303 - 2306 (1983)
No reaction occurs between UF4O and AsF5 but UF4O*3MF5 (M=Nb and Ta) and UF4O*2BiF5 have been obtained as yellow or orange solids by warming mixtures of UF4O with excess of the appropriate pentafluoride in anhydrous HF or by combination of the oxide tetrafluoride with excess of the pentafluoride as a melt.The solid adducts have been charcterized by their reaction stoicheiometries, chemical analyses, and vibrational spectra.Like UF4O*2SbF5, the adducts are fluorine bridged with some ionic character.The thermal decomposition of the adducts results in the production of uranyl species.
A study on pyrrolidone derivatives as selective precipitant for uranyl ion in HNO3
Ikeda, Yasuhisa,Wada, Emiko,Harada, Masayuki,Chikazawa, Takahiro,Kikuchi, Toshiaki,Mineo, Hideaki,Morita, Yasuji,Nogami, Masanobu,Suzuki, Kazunori
, p. 420 - 425 (2004)
We have found out that N-cyclohexyl-2-pyrrolidone (NCP) can selectively precipitate UO22+ ions in HNO3 solutions. In order to investigate factors of such a specific property of NCP, we have examined reactions of NCP with UO22+ ions in HCl, HClO4, or H2SO4, and the precipitation abilities of pyrrolidone derivatives other than NCP for UO2 2+ in HNO3 solutions. As a result, it was found that UO22+ ions in HCl, HClO4, or H 2SO4 are not precipitated by NCP, that N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP) with lower hydrophobicity than NCP do not precipitate UO22+, and that hydrophobic N-dodecyl-2-pyrrolidone can precipitate UO2 2+. Furthermore, we have investigated the crystal structures of UO2(NO3)2(L)2 (L = NMP, NEP) complexes to compare with that of UO2(NO3) 2(NCP)2. The bond distance between uranium and carbonyl oxygen of NCP in UO2(NO3)2(NCP)2 was found to be shorter than those in UO2(NO3) 2(L)2 (L = NMP, NEP). From these results, it is proposed that the specific property of NCP is ascribed to its relatively high hydrophobicity owing to cyclohexyl group, to its strong coordination ability to UO22+ for forming the symmetrical complex accompanied by two bidentate NO3-, and to the surface of UO 2(NO3)2(NCP)2 which is surrounded by the hydrophobic cyclohexyl groups of coordinated NCP.
Formation of Excited Uranyl in Oxidation of U(IV) with Oxygen in HClO4 Aqueous Solutions: II. Catalytic Effect of UO2(2+)
Lotnik, S. V.,Khamidullina, L. A.,Kazakov, V. P.
, p. 56 - 60 (2008/10/08)
Strong effect of uranyl ion on the kinetic and chemiluminescence characteristics of U(IV) oxidation with oxygen in weakly acidic HClO4 solutionsis found. For instance, in the presence of 8E-4 M UO2(2+) the reaction rate constant, maximal intensity of the chemiluminescence, and chemilumi nescence efficiency increase by factors of 50, 100, and 8, respectively.The catalytic effect of uranyl ion is probably caused by both formation of the complex UO2(2+)*UO2(1+) (which decreases the rate of disproporti onation of UO2(1+) participating in the chain propagation) and generation of UO2(1+) in the reaction of UO2(2+) with U(IV).