Groups, Olefins, and Aromatic Hydrocarbons

Similar synergism is observed for other Br0nsted acids (FL4) in the presence of unsaturated carbon centers  

For aromatic hydrocarbons, the more extensive the conjugation, the less negative the potential for direct electron transfer  

The hydrolysis of carbonyl centers yields acidic hydrogens that can be reduced at platinum electrodes, for instance 

Likewise, the enolized form of ketones is a Br0nsted acid that can be reduced at a platinum electrode  

In both cases, the reduction potential is directly related to the Br0nsted acidity, which depends on the basicity of the solvent [e.g, phenol (PhOH) has a pjfa of 16 in MeCN and 21 in Me2SO see Chapter 8]. 

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