Mechanism and kinetics of the 2,2'-bipyridyl catalysis of the chromium(VI) oxidation of malic acid

作者：Shan J H^*; Fan L; Huo S Y; Zhu J J; Liu H M; Shen S G

来源：Journal of the Iranian Chemical Society, 2007, 4(4): 476-480.

• chromium(VI)
• malic acid
• 2,2'-bipyridyl
• catalytic kinetics and mechanism

A spectrophotometric study of the kinetics and mechanism of the oxidation of malic acid (Mal) by chromium(VI) catalyzed by 2,2'-bipyridyl (bpy) in aqueous acidic medium was conducted in a temperature range of similar to 298 to 313 K. This reaction was found to be pseudo-first order with respect to Cr(VI) and first order with respect to malic acid. Under the conditions of the pseudo-first order ([Mal](o) >> [Cr(VI)](o) ), the observed rate constant (k(obs)) increased with the increase in [H+] and [bpy]. There was a weak negative salt effect. Based on the experimental results, a possible reaction mechanism for this oxidation catalyzed by bpy is proposed. The rate equation derived from this mechanism can explain all the experimental phenomena.

• 出版日期2007-12
• 单位河北大学