Bimolecular preceding C2E and subsequent EC2 reactions

A reducible species may be formed by decomposition of an electro-inactive dimer to the electroactive monomer [11, 147]. 

The assumption of this scheme could explain the d.c. polarographic behaviour of manganous ions in alkaline tartrate solutions [11]. 

Conversely, the reduction product R (mostly a radical) can be inactivated by a dimerization process 

This scheme was found to be applicable to the reduction of benzaldehyde in aqueous ethanol. The final product is 1,2-diphenylglycol [152]. 

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