A Novel Reaction of HCrO<sub>4</sub><sup>−</sup>with PH<sub>2</sub>O<sub>2</sub><sup>−</sup>, Induced by Molecular Oxygen, Forming Peroxodiphosphate Ions in an Aqueous Solution
作者:Masaru Kimura、Aki Takahashi、Hiroko Kayanoki、Tomomi Sakata、Keiichi Tsukahara
DOI:10.1246/bcsj.70.2699
日期:1997.11
The chromate (VI) ion HCrO4− at pH 2—4 was not appreciablly reduced by the phosphinate ion PH2O2− in the absence of molecular oxygen (O2), but was reduced in the presence of O2, forming peroxodiphosphate ions (denoted by PDP and meaning all forms of P2O84−, HP2O83− etc.) in much higher concentrations than those of the added chromate(VI). Both the rates of the chromate decay and the PDP formation increased with decreasing pH. When the chromate(VI) ion disappeared completely, PDP formation stopped and its concentration remained constant. However, such PDP once formed in the presence of O2 began to decompose after the solution was saturated with N2 gas; its decomposition ceased again when the solution was again saturated with air. Such behaviors are discussed while presenting the reaction mechanisms.
在没有分子氧 (O2) 的情况下,pH 2-4 时的铬酸根 (VI) 离子 HCrO4− 不会被次膦酸根离子 PH2O2− 明显还原,但在 O2 存在的情况下会被还原,形成过氧二磷酸根离子(用 PDP 和 PDP 表示)指所有形式的 P2O84−、HP2O83− 等),其浓度比添加的铬酸盐 (VI) 的浓度高得多。铬酸盐腐烂和 PDP 形成的速率都随着 pH 值的降低而增加。当铬(VI)离子完全消失时,PDP形成停止并且其浓度保持恒定。然而,这种PDP一旦在O2存在下形成,在溶液被N2气体饱和后就开始分解;当溶液再次被空气饱和时,其分解再次停止。在介绍反应机制的同时讨论了此类行为。