Abstract
The constant of electron exchange rate (kex.) in the system of sym. octamethylferrocene/sym. octamethylferricinium hexafluorophosphate [(СН3)4С5Н]2Fe/(СН3)4С5Н]2Fe+PF6 ] (hereinafter are denoted as Ме8Fс+/0) was determined by method of 1H NMR line broadening. The appearance of eight methyl groups in each reagent of the redox-system of Ме8Fс+/0 increases the constant of exchange rate approximately 4.8 times, in comparison with the unsubstituted ferrocene-ferricinium system [(С5Н5)2Fe/(С5Н5)2Fe+PF6 ] (Fс+/0). The increase of exchange rate in series of Fс+/0Ме6Fc+/0Ме8Fс+/0Ме10Fс+/0, though it corresponds to the electron donor property of the methyl group, is interpreted by us as the result of reduction of reorganization energy of solvent molecule (acetone) by increasing the reagent volumes of the redox couples of МеnFс+/0 (n = 6, 8, 10).