Orthoperiodic acid

化学的特性過ヨウ素酸は化学式でIO4–と表される酸化数7のヨウ素の酸です非常に強力な酸化剤として知られており有機合成化学や分析化学において重要な役割を果たしますこの物質は特に有機分子の酸化や微量の金属イオンの定量分析に利用されます

化学的特性Periodic acid exists as colorless crystals, soluble in water and ethanol but slightly soluble in ether. Upon dehydration, it forms metaperiodic acid (HIO₄). Further dehydration leads to decomposition, ultimately yielding iodine pentoxide (I₂O₅).

化学性质過ヨウ素酸は無色の結晶性固体であり水に非常に良く溶けますまたエタノールやアセトンといった有機溶媒にも溶解しますその酸化能力は極めて高く多くの有機化合物を効率的に酸化させることができますしかしその強力な酸化性のため扱いには十分な注意が必要です

解説オルト過ヨウ素酸，市販品では，この物質を過ヨウ素酸とよぶが，IUPACでは両者を区別している．融点約130 ℃．過ヨウ素酸水溶液中では，次の平衡が成立している． H5IO6⇄ H＋ ＋ H4IO6－(K 1×10－3) H4IO6－⇄ IO4－ ＋ 2H2O(K 29) H4IO6－⇄ H＋ ＋ H3IO62－(K 2×10－7)25 ℃ の水溶液ではIO4－がおもなイオンである．森北出版「化学辞典（第2版）

用途PAS反応の酸化剤。

用途分析用試薬、酸化滴定用、有機化合成用(酸化剤)。

使用PERIODIC ACID is used as an oxidiser and in the determination of manganese.

一般的な説明Periodic acid (H5IO6) is an oxoacid of iodine. It is commonly used as an oxidizing agent in organic synthesis for the preparation of useful chemical intermediates. Periodic acid is also used in oxidative cleavage reactions.

A 100 g quantity of Ba₃H₄(IO₆)₂ is moistened with 75 mL of H₂O and treated with 200 mL of colorless nitric acid (HNO₃). The mixture is agitated, heated to 60–70 °C for 1 h, and then cooled to 30–40 °C. The precipitated Ba(NO₃)₂ is filtered off using a glass frit filter. The residue is washed free of periodate by stirring with concentrated HNO₃. The combined filtrate is evaporated at 60–70 °C under aspirator vacuum (if additional Ba(NO₃)₂ precipitates, it is removed by filtration, and evaporation continues) until H₅IO₆ begins to crystallize. After cooling, colorless, glistening crystals of periodic acid (H₅IO₆) form. Due to the tendency of the solution to become supersaturated, prolonged waiting may be required. The crystals are collected by filtration and dried under vacuum at 50 °C. A second crop of crystals may be obtained by further evaporating the mother liquor.