Time-Resolved Kinetic Study of the Electron-Transfer Reactions between Ring-Substituted Cumyloxyl Radicals and Alkylferrocenes. Evidence for an Inner-Sphere Mechanism
作者:Massimo Bietti、Gino A. DiLabio、Osvaldo Lanzalunga、Michela Salamone
DOI:10.1021/jo102420p
日期:2011.3.18
A time-resolved kinetic study of the reactions of ring-substituted cumyloxyl radicals (4-X-CumO•: X = OMe, t-Bu, Me, Cl, CF3) with methylferrocenes (MenFc: n = 2, 8, 10) has been carried out in acetonitrile solution. Evidence for an electron transfer (ET) process has been obtained for all radicals and an increase in reactivity has been observed on decreasing the oxidation potential of the ferrocene
环取代的枯基羟自由基(4-X-CumO •:X = OMe,t -Bu,Me,Cl,CF 3)与甲基二茂铁(Me n Fc:n = 2,8)反应的时间分辨动力学研究,10)已在乙腈溶液中进行。已获得所有自由基的电子转移(ET)过程的证据,并且在降低二茂铁供体的氧化电势以及从释放电子到吸电子的环取代基上观察到反应性的提高。计算预测强结合的π堆积4-X-CumO的形成•/ DcMFc络合物,其特征是络合物内的π-π距离约为4Å。这些发现指向4-X-CumO • / Me n Fc对的反应的(非键合)内球ET机制。