塩化コバルト(Ⅱ) 化学特性,用途語,生産方法
外観
紫赤色〜暗赤色, 結晶〜結晶性粉末
溶解性
水に易溶 (116.5g/100g水, 0℃)。水に極めて溶けやすく、エタノールに溶けやすい。
用途
触媒、医薬原料、乾湿指示薬、陶磁器の着色剤、メッキ材料。
用途
無水物から水和物へと吸湿して変化してゆくにつれて青から赤へと色調が変わり、水を失う場合は可逆的で色調が変化するので、シリカゲルなどに水分の指示薬として添加される。他にも示温顔料、ガラス、陶器の着色、ビールの泡の安定剤、植物が取り込む物質を調べる時、ビタミンB12の原料などにも利用される。
用途
分析におけるCoイオンの供給源、触媒、医薬原料、乾湿指示薬。
使用上の注意
潮解性あり
化学的特性
Cobalt(II) chloride hexahydrate takes the form of purple crystals. Upon heating, it loses its water of crystallisation and decomposes into blue crystals of anhydrous cobalt(II) chloride. Soluble in water, soluble in ethanol, acetone and ether.
Cobalt chloride hexahydrate is utilized in commercial applications such as electroplating, catalyst preparation, painting on glass and porcelain, and in the manufacture of vitamin B12.
使用
Cobalt(II) chloride hexahydrate (CoCl2·6H2O) has been found to be an efficient catalyst for the one-pot synthesis of biscoumarin derivatives through a combination of aromatic aldehydes and 4-hydroxycoumarin in aqueous media at 70°C. Cobalt chloride hexahydrate can be used as an inducer of HIF-1 production used to study apoptotic effects in HepG2 cells. It is also used as APHA color standard.
主な応用
Cobalt chloride hexahydrate can be used as Invisible ink; humidity and water indicator; in hygrometers; tempereture indicator in grinding; in electroplating; for painting on glass and porcelain; preparation of catalysts; fertilizer and feed additive; foam stabilizer in beer; as absorbent for military poison gas and ammonia; in manufacture of vitamin B12.
定義
ChEBI: Cobalt chloride hexahydrate is a hydrate of cobalt chloride containing cobalt (in +2 oxidation state), chloride and water moieties in the ratio 1:2:6. It has a role as an allergen. It contains a cobalt dichloride.
一般的な説明
Cobalt(II) chloride hexahydrate has a cobalt ion surrounded by a tetragonal arrangement of chloride ligands. Four water molecules occupy a square plane about cobalt while chloride ions occupy axial positions. Its crystals belong to the monoclinic lattice system.
純化方法
A saturated aqueous solution at room temperature is fractionally crystallised by standing overnight. The first half of the material that crystallises in this way is used in the next crystallisation. The process is repeated several times, water being removed in a dry-box using air filtered through glass wool and dried over CaCl2 [Hutchinson J Am Chem Soc 76 1022 1954]. It has also been crystallised from dilute aqueous HCl. The hexahydrate m 86o forms pink to red deliquescent crystals. It loses 4H2O on heating at 52-56o and forms the violet dihydrate which loses a further H2O at 100o to form the violet monohydrate which loses the last H2O at 120-140o to give the pale blue anhydrous deliquescent salt m 735o and b 1049o. A pink solution of CoCl2 in H2O becomes blue on heating to 50o or adding conc HCl which may precipitate the mono or dihydrate. The solid dihydrate gives a blue-purple solution with EtOH. Note: CoCl2 in H2O is a “sympathetic ink”, i.e. writing using an aqueous solution is almost invisible on paper, but becomes blue on warming the paper. On cooling or standing, the writing becomes invisible again. The anhydrous salt is soluble in H2O, EtOH, Et2O, Me2CO and pyridine. [Glemser in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1515 1965.]
Structure and conformation
The hexahydrate COCl2.6H2O forms monoclinic crystals in which each cobalt atom is surrounded by four water molecules at the corners of a distorted square (Co-H20 = .12) and by two chlorine atoms (Co-Cl = 2.43) to form a distorted octahedron.
The other two water molecules are not bonded directly to cobalt. In the monoclinic dihydrate CoCl2.2H2O, the octahedral symmetry around the cobalt atom is maintained by the sharing of chlorine atoms between two cobalt atoms. In the flattened octahedral structuress there are two Co-Cl distances of 2-450, two of 2.478 and two Co-H2O distances of 2.040.
塩化コバルト(Ⅱ) 上流と下流の製品情報
原材料
準備製品