トリクロロ金(III) 化学特性,用途語,生産方法
解説
最も安定かつ一般的に取り扱われる塩化金は、塩化金(Ⅲ)であり、外観は、赤～赤褐色の結晶です。塩化金(Ⅲ)の製造方法としては、金属金に高温で塩化ガスを直接反応させる方法や塩化金酸を加熱して得る方法が知られています。
塩化金は、GHS分類において皮膚腐食性/刺激性、眼刺激性、皮膚感作性に分類されています。
塩化金の法規制は、毒物および劇物取締法において劇物に指定されています。労働安全衛生法、労働基準法、PRTR法においては、いずれも非該当です。
化学的特性
orange-red to dark red crystals
物理的性質
Red monoclinic crystals; deliquesces; density 4.7 g/cm
3; sublimes at 180°C (760 torr); highly soluble in water; soluble in alcohol and ether; slightly soluble in liquid ammonia.
使用
Gold(III) chloride is used in colloidal gold solutions, in photography and as a print toning agent(gold toning), starting solution to form other gold compounds and a precursor for preparation of ultra pure gold metal. It is used in electroplating and electroless plating as an anode in an electric cell. Gold(III) chloride acts as a gold catalyst and cell body stains for bright field and dark field microscopy.
定義
A compound prepared by
dissolving gold in aqua regia. The bright
yellow crystals (chloroauric acid) produced
on evaporation are heated to form dark red
crystals of gold(III) chloride. The chloride
decomposes easily (at 175°C) to give
gold(I) chloride and chlorine; at higher
temperatures it decomposes to give gold
and chlorine. Gold(III) chloride is used in
photography. It exists as a dimer, Au
2Cl
6.
製造方法
Gold(III) chloride may be produced by the combination of metallic gold with chlorine gas at elevated temperatures:
2Au + 3Cl2 → 2AuCl3
It may be prepared in the laboratory by the reaction of iodine monochloride with metallic gold:
2Au + 6ICl → 2AuCl3 + 3I2
The compound should be stored tightly closed and protected from light.
反応性
When heated at 254ºC, gold(III) chloride decomposes to gold(I) chloride and chlorine.
Passing hydrogen sulfide into an ether solution of the compound yields gold(III) sulfide, Au2S3.
A similar reaction occurs when alcoholic solutions of gold(III) chloride and hydrogen selenide are mixed, producing gold(III) selenide, Au2Se3, a black amorphous solid.
Gold(III) chloride may be reduced readily to metallic gold by common reducing agents. Thus, reduction with stannous chloride in dilute aqueous medium yields colloidal gold in which the atom carries a negative charge. “Cassius purple” is produced from the oxidation of tin to form H2Sn(OH)6, which protects colloidal gold from coagulation, imparting ruby red color to the solution.
Gold(III) chloride reacts with ammonia forming a gold(III)-nitrogen derivative, an explosive product, known as, “fulminate of gold”. Reaction with Grignard reagent, RMgX in ether yields dialkyl gold(III) chloride, R2AuCl3, which may be converted readily to other dialkyl gold(III) complexes by replacement of the chloride anion by a donor ligand.
一般的な説明
The structure of gold chloride is monoclinic in nature. It sublimes at elevated temperatures.
使用用途
塩化金の使用用途としては、めっき、写真感光材、金粉の製造などが挙げられますが、近年では塩化金酸など、その他の金化合物が主に用いられています。
塩化金に特有な使用用途として、触媒での利用が特に注目されています。
参考文献
安全性プロファイル
Experimental
reproductive effects. Human mutation data
reported. Reaction with ammonia or
ammonium salts yields fulminating gold, a
heat-, friction-, and impact-sensitive
explosive similar to mercury and silver
fulminates. See also GOLD COMPOUNDS
and CHLORIDES. When heated to
decomposition it emits toxic fumes of Cl-.
トリクロロ金(III) 上流と下流の製品情報
原材料
準備製品