Reactivity of biologically important reduced pyridines V. Relative importance of electron versus proton loss in ferricyanide-mediated oxidation of dihydronicotinamides
作者:Marcus E. Brewster、James J. Kaminski、Zoltan Gabanyi、Klara Czako、Agnes Simay、Nicholas Bodor
DOI:10.1016/s0040-4020(01)89076-1
日期:——
Kinetics of ferricyanide-mediated oxidation of various 1-(4-substituted phenyl)-1,4-dihydronicotinamides were studied assuming either a rate determining initial electron loss or a rate determining proton loss following a rapid pre-equilibrium step. Values obtained using both methods were similar. In addition, vertical ionization potentials generated using the AM1 molecular orbital approximation were
研究了铁氰化物介导的各种1-(4-取代的苯基)-1,4-二氢烟碱酰胺氧化的动力学,假定速率决定了初始电子损失或速率决定了快速预平衡步骤后的质子损失。使用两种方法获得的值相似。此外,发现使用AM1分子轨道近似法产生的垂直电离势与log(氧化率)高度相关,而从二氢吡啶基自由基阳离子得到的质子损失的计算则显示出低得多的依赖性。测得的动力学氘同位素效应很小。这些数据表明,二氢烟酰胺的初始电子损失是决定反应速率的最重要事件。