|
[摘要]:A time-resolved kinetic study of the reactions of ring-substituted cumyloxyl radicals (4-X-CumO(center dot): X = OMe, t-Bu, Me, Cl, CF3) with methylferrocenes (Me(n)Fc: 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 donor and on going from electron-releasing to electron-withdrawing ring substituents. Computations predict the formation of strongly bound pi-stacked 4-X-CumO(center dot)/DcMFc complexes, characterized by intracomplex pi-pi distances around 4 angstrom. These findings point toward a (nonbonded) inner-sphere ET mechanism for the reactions of the 4-X-CumO(center dot)/Me(n)Fc couples. |
|