コバルト(II)ジヨージド 化学特性,用途語,生産方法
解説
CoI2(312.74)．無水物にはα，β形の2変態がある．ヨウ素中でコバルト粉末を加熱するとα形の無水物が得られる．α形は黒色の結晶．吸湿性が強い．密度5.58 g cm－3．融点515 ℃(真空中)，沸点570 ℃(真空中)．水に易溶．α形を真空中で加熱昇華するとβ形となる．β形は黄色の粉末．密度5.45 g cm－3．潮解性で，400 ℃ で分解する．水溶液は無色．水酸化コバルト(Ⅱ)をヨウ化水素酸に溶かすと各種の水和物が得られる．六水和物は赤褐色の柱状晶．密度2.90 g cm－3．吸湿性で，空気にさらすとヨウ素を失い，27 ℃ で水6分子を失う．水に可溶．湿度指示薬，有機反応の触媒などに用いられる．[CAS 15238-00-3:CoI2][CAS 15238-00-3:CoI2･6H2O]
森北出版「化学辞典（第2版）
説明
Cobalt iodide appears as black crystals with a slight ‘iodine’-like odour. When
heated to decomposition, it may emit toxic fumes of iodine and oxides of nitrogen.
Anhydrous cobalt (II) iodide is sometimes used to test for the presence of water in various
solvents. Cobalt (II) iodide is used as a catalyst, for example, in carbonylations. It
catalyses the reaction of diketene with Grignard reagents, useful for the synthesis of
terpenoids.
化学的特性
Brownish red crystalline powder
物理的性質
Exists in two isomorphous forms, α- and ?-forms; both modifications highly hygroscopic. The α-form is black hexagonal crystal; density 5.58 g/cm
3; turns dark green in air; melts at 560°C; disolves in water giving pink coloration. The α-forms sublimes in vacuo, partly forming an isomorous yellow modification-the anhydrous β-form.
The β-modification is a yellow powder; density 5.45 g/cm
3; converts to the α-form when heated to 400°C; absorbs moisture from air, the yellow powder becoming green droplets; dissolves readily in water forming a colorless solution which turns pink on heating.
The hexahydrate is red hexagonal crystals; density 2.90 g/cm
3; loses water at 130°C giving anhydrous iodide; soluble in water, ethanol, acetone, chloroform and ether, forming colored solutions, (while the aqueous solution is red below 20°C and green above this temperature; the salt forms blue solution in ethanol, chloroform and ether).
使用
Cobalt(II) iodide is used as a moisture and humidity indicator. It is also used as a catalyst.
製造方法
Cobalt(II) iodide is prepared by heating cobalt powder in a stream of hydrogen iodide at 400 to 450°C:
Co + 2HI → CoI
2 + H
2
The product obtained is the black crystalline α-form.
Cobalt(II) iodide also may be made by heating cobalt powder with iodine vapor.
コバルト(II)ジヨージド 上流と下流の製品情報
原材料
準備製品