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|Section2= |Section3= |Section4= |Section7= |Section8= }} Nickel(II) fluoride is the chemical compound with the formula NiF2. Unlike many fluorides, NiF2 is stable in air. NiF2 comprises the passivating surface that forms on nickel alloys, e.g. monel, which is why such materials are good to store or transport hydrogen fluoride or elemental fluorine. Nickel is one of the few materials that can be used to store fluorine because it forms this coating. It is also used as a catalyst for the synthesis of chlorine pentafluoride. NiF2 is prepared by treatment of anhydrous nickel(II) chloride with fluorine at 350 °C:〔Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.〕 :NiCl2 + F2 → NiF2 + Cl2 The corresponding reaction of cobalt(II) chloride results in oxidation of the cobalt, whereas nickel remains in the +2 oxidation state after fluorination because its +3 oxidation state is less stable. Chloride is more easily oxidized than nickel(II). This is a typical halogen displacement reaction, where a halogen plus a less active halide makes the less active halogen and the more active halide. Nickel(II) fluoride is also produced when fluorine reacts with nickel metal. A melt of NiF2 and KF reacts to give the green compound K2(). The structure of this material is closely related to some superconducting oxide materials.〔Balz, D. "Über die Struktur des K2NiF4" Naturwissenschaften 1953, page 241.〕 Nickel(II) fluoride reacts with strong bases to make nickel(II) hydroxide, a green colored compound. NiF2 + 2 NaOH → Ni(OH)2 + 2 NaF ==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「Nickel(II) fluoride」の詳細全文を読む スポンサード リンク
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