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|Section2= |Section3= |Section4= }} Plutonium hexafluoride is the highest fluoride of plutonium, and is of interest for laser enrichment of plutonium, in particular for the production of pure plutonium-239 from irradiated uranium. This pure plutonium is needed to avoid premature ignition of low-mass nuclear weapon designs by neutrons produced by spontaneous fission of plutonium-240. It is a red-brown volatile crystalline solid;〔 the heat of sublimation is 12.1 kcal/mol〔Alan E. Florin, Irving R. Tannenbaum, Joe F. Lemons: "Preparation and Properties of Plutonium Hexafluoride and Identification of Plutonium(VI) Oxyfluoride", ''Journal of Inorganic and Nuclear Chemistry'', 1956, ''2'' (5–6), p. 368–379; .〕 and the heat of vaporization 7.4 kcal/mol.〔 It is relatively hard to handle, being very corrosive and prone to auto-radiolysis.〔Ned E. Bibler: "α and β Radiolysis of Plutonium Hexafluoride Vapor", ''J. Phys. Chem.'', 1979, ''83'' (17), p. 2179–2186; .〕〔M. J. Steindler, D. V. Steidl, J. Fischer: "The Decomposition of Plutonium Hexafluoride by Gamma Radiation", ''Journal of Inorganic and Nuclear Chemistry'', 1964, ''26'' (11), p. 1869–1878; .〕 It is prepared by fluorination of plutonium tetrafluoride (PuF4) by powerful fluorinating agents such as elemental fluorine.〔〔C. J. Mandleberg, H. K. Rae, R. Hurst, G. Long, D. Davies, K. E. Francis: "Plutonium Hexafluoride", ''Journal of Inorganic and Nuclear Chemistry'', 1956, ''2'' (5–6), p. 358–367; .〕〔Bernard Weinstock, John G. Malm: "The Properties of Plutonium Hexafluoride", ''Journal of Inorganic and Nuclear Chemistry'', 1956, ''2'' (5–6), p. 380–394; .〕 : + → It can also be obtained by fluorination of plutonium(III) fluoride or plutonium(IV) oxide.〔 :2 + 3 → 2 : + 3 → + In 1984, the synthesis of plutonium hexafluoride was achieved at unprecedented low temperatures through the use of dioxygen difluoride. Previous techniques needed temperatures so high that the plutonium hexafluoride produced would decompose rapidly. Hydrogen fluoride is not sufficient; even though it is a powerful fluorinating agent. Under laser irradiation at a wavelength of less than 520 nm, it decomposes to plutonium pentafluoride and fluorine;〔http://www.freepatentsonline.com: ''(Photochemical Preparation of Plutonium Pentafluoride )''; (PDF ).〕 after more irradiation it decomposes further to plutonium tetrafluoride.〔E. A. Lobikov, V. N. Prusakov, V. F. Serik: "Plutonium Hexafluoride Decomposition under the Action of Laser Radiation", ''Journal of Fluorine Chemistry'', 1992, ''58'' (2–3), C 54, p. 277; .〕 == References == 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Plutonium hexafluoride」の詳細全文を読む スポンサード リンク
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