The reaction of [RuIII(edta)(H2O)]â (1) (edta = ethylenediaminetetraacetate) with hydrogen peroxide was studied kinetically as a function of [H2O2], temperature (5â35 °C) and pressure (1â1300 atm) at a fixed pH of 5.1 using stopped-flow techniques. The reaction was found to consist of two steps involving the rapid formation of a [RuIII(edta)(OOH)]2â intermediate which subsequently undergoes parallel heterolytic and homolytic cleavage to produce [(edta)RuVO]â (45%) and [(edta)RuIV(OH)]â (55%), respectively. The water soluble trap, 2,2â²-azobis(3-ethylbenzithiazoline-6-sulfonate) (ABTS), was employed to substantiate the mechanistic proposal. Reactions were carried out under pseudo-first conditions for [ABTS] â« [HOBr] â« [1], and were monitored as a function of time for the formation of the one-electron oxidation product ABTSË+. A detailed mechanism in agreement with the rate and activation parameters is presented, and the results are discussed with reference to data reported for the corresponding [FeIII(edta)(H2O)]â/H2O2 system.
针对[RuIII(edta)(
H2O)]⁻(1)(edta =
乙二胺四乙酸)与
过氧化氢的反应,在固定pH值为5.1的条件下,利用停流技术研究了反应动力学随[H₂O₂]、温度(5至35°C)和压力(1至1300大气压)的变化情况。研究发现该反应包含两个步骤:首先迅速形成[RuIII(edta)(OOH)]²⁻中间体,随后该中间体分别经过平行异裂和均裂两种途径,生成[(edta)RuVO]⁻(45%)和[(edta)RuIV(OH)]⁻(55%)。为了证实机理假设,采用了
水溶性捕捉剂2,2'-偶氮双(3-乙基
苯并噻唑啉-6-
磺酸酯)(
ABTS)。在[
ABTS]远小于[HOBr]远小于[1]的条件下进行了伪一级反应,并实时监测了单电子氧化产物
ABTS˙⁺的生成情况。本文提出了与速率和活化参数相符的详细反应机理,并参考了[FeIII(edta)( )]⁻/H₂O₂体系的相关数据进行讨论。