摘要
在碱性介质中于 2 5～ 40℃用分光光度法研究了二过碘酸合镍(Ⅳ)配离子(DPN)氧化氨基乙酸的动力学.结果表明:反应对DPN为准一级,对氨基乙酸为正分数级.准一级速率常数(kobs)随[OH-]增加而增加:随[IO4 -]增加而减小,无盐效应并未检出自由基存在,我们假设了一过碘酸合镍(Ⅳ)配离子(MPN)是氧化剂的活性物种,提出包括DPN和MPN存在前期平衡的氧化反应机理。
The kinetics of oxidation of glycine (Gly) by diperiodatonickelate (Ⅳ) complex (DPN) was studies by spectrophotometry in aqueous medium in a temperature range of 25～40℃.The reaction was found to be first order with respect to Ni(Ⅳ) and to be fractional order with respect to Gly. The rate increased with the increase in and decreased with the increase in , showing that monoperiodatonickelate (Ⅳ)(MPN) was the reactive species of oxidation. Added salts did not affect the rate. No free radical was detected. A mechanism of reaction involving a preequilibrium between DPN and MPN was proposed, and the rate equation derived from the mechanism can explain all experimental observations. Activation parameters of the rate_determining step were calculated.
出处
《化学研究》
CAS
2001年第4期21-25,共5页
Chemical Research
基金
NaturalScienceFoundationofHebeiProvince ( 2 95 0 6 6 )
