オルト過ヨウ素酸

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.