ニオブ(V)ペンタクロリド 化学特性,用途語,生産方法
外観
黄色～赤黄色、結晶～結晶性粉末又は塊
溶解性
水及びエタノールで分解する。
解説
塩化ニオブ(Ⅴ)NbCl5(270.17)．加熱した金属ニオブに塩素を通じると得られる．黄色の針状晶．密度2.75 g cm－3．融点204.7 ℃，沸点254 ℃．潮解性で，水に溶けて加水分解する．四塩化炭素，エタノールに可溶．半導体材料のイオン注入イオン源，複合触媒(光触媒，太陽電池)の製造原料，高純度ニオブの製造，ニオブ化合物の合成原料などに用いられる．
化学的特性
yellow fine crystalline powder
物理的性質
Yellow monoclinic crystals; deliquesces; density 2.75 g/cm
3; decomposes in moist air with the evolution of HCl; melts at 204.7°C; vaporizes at 254°C; decomposes in water; soluble in alcohol, hydrochloric acid, chloroform and carbon tetrachloride.
使用
Niobium(V) chloride is the precursor in the preparation of pure niobium, and ferroniobium. It is used as a Lewis acid catalyst in organic synthesis in activating alkenes in the carbonyl-ene reaction and the Diels-Alder reaction.
製造方法
Niobium pentachloride is obtained as an intermediate during extraction of niobium from its ores (see Niobium). Also, the pentachloride is obtained readily by direct chlorination of niobium metal at 300 to 350°C: 2Nb + 5Cl
2 → 2NbCl
5The pentachloride also may be made by chlorination of niobium pentoxide in the presence of carbon at 300°C. The products, however, contain small amounts of niobium oxide trichloride, NbOCl
3.
危険性
May evolve fumes of hydrogen chloride.
Keep dry
安全性プロファイル
Poison by
intraperitoneal route. Moderately toxic by
ingestion. May cause kidney injury. When
heated to decomposition it emits very toxic
fumes of Cl-. See also NIOBIUM and
CHLORIDES.
純化方法
It forms yellow, very deliquescent crystals which decompose in moist air to liberate HCl. It should be kept in a dry box flushed with N2 in the presence of P2O5. Wash it with CCl4 and dry it over P2O5. The yellow crystals usually contain a few small, dirty white pellets among the yellow needles. These should be easily picked out. Upon grinding in a dry box, however, they turn yellow. NbCl5 has been sublimed and fractionated in an electric furnace. [Epperson Inorg Synth VII 163 1963, Alexander & Fairbrother J Chem Soc suppl 233 1949.] d2 5 20 pK25
ニオブ(V)ペンタクロリド 上流と下流の製品情報
原材料
準備製品