Dimethylglyoxime

Diacetyl dioxime. C ₄ H ₈ N ₂ O ₂ (116.12). It is synthesized from hydroxylamine and biacetyl monoxime, which is obtained from ethyl nitrite and ethyl methyl ketone. It appears as a colorless needle-like or powdery crystal. Melting point: 238-240 °C. It is easily soluble in ethanol and ether, but insoluble in water. It is a historically famous reagent for precipitating nickel. It forms a red nickel complex salt, Ni(C ₄ H ₇ N ₂ O ₂ ) ₂ , with nickel, and this red color is also used for the colorimetric determination of nickel. It also forms complex salts with palladium, iron, and copper, which produce colored precipitates, so it is used as a quantitative and qualitative reagent. These properties are shared by other α-dioximes, such as benzyl dioxime (colorless leaf-like crystals, melting point: 237 °C (decomposition)). Cyclohexane-1,2-dione dioxime is also used as a quantitative reagent for nickel. [CAS 95-45-4]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

diacetyl dioxime．C₄H₈N₂O₂(116.12)．亜硝酸エチルとエチルメチルケトンから得られるビアセチルモノオキシムと，ヒドロキシルアミンから合成される．無色の針状あるいは粉末状結晶．融点238～240 ℃．エタノール，エーテルに易溶，水に不溶．ニッケルの沈殿試薬として歴史的に有名な試薬である．ニッケルと赤色のニッケル錯塩Ni(C₄H₇N₂O₂)₂をつくり，この赤色はニッケルの比色定量にも利用される．ほかにパラジウム，鉄，銅とも錯塩をつくり，有色の沈殿を生成するので定量および定性試薬に用いられる．このような性質は，ベンジルジオキシム(無色の葉状結晶．融点237 ℃(分解))など，ほかのα-ジオキシム類にも共通している．シクロヘキサン-1,2-ジオン=ジオキシムもニッケルの定量試薬に用いられる．[CAS 95-45-4]

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