Homogeneous chemical reactions disp 2 mechanism

In the former case (second electron transfer at the electrode), the overall sequence is termed ECE it is designated a DISP (rather than an ECDisp) mechanism in the second case because the homogeneous electron transfer step is close to being a disproportionation reaction. Indeed, the latter involves an electron transfer between two chemically related molecules with the same oxidation numbers. In practice the distinction between the two mechanisms is nearly impossible on experimental grounds [96] because their rate-determining step, the B—reaction is identical. 

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