Protonation kinetics of anionic intermediates in the electrochemical reduction of triphenylethylene: a disproportionation mechanism
作者:Giuseppe Farnia、Flavio Maran、Giancarlo Sandonà、Maria Gabriella Severin
DOI:10.1039/p29820001153
日期:——
homogeneous and voltammetric kinetics. In fact, in homogeneous conditions, the rate of decay is second-order in [T–˙], enhanced by water, and inhibited by T. Voltammetric kinetics further support the proposed mechanism showing that, under particular conditions, the reaction is rate-limited by the disproportionation step. Alternative mechanisms can be disregarded on the basis of both kinetic and thermodynamic
三苯乙烯的在质子供体的迹线的存在二甲基甲酰胺的伏安特性(T),表示该基团的阴离子(T - ˙)是稳定的,二价阴离子(T 2-)正迅速质子化,所得负碳离子(TH - )是一个相对强大的基础。在添加水的情况下,T – via通过歧化然后T 2–质子化而衰减。均相动力学和伏安动力学都表明了这一点。实际上,在均匀条件下,衰减率是[T –˙],被水增强,并被T抑制。伏安动力学进一步支持了所提出的机理,该机理表明,在特定条件下,反应受歧化步骤的速率限制。在动力学和热力学数据的基础上,可以忽略其他机制。