Dear All, I need to know the difference between the electrochemical oxidation mechanism of phenol in acidic and alkaline media. By considering the fact that after dissolving phenol in alkaline media we would have sodium phenoxide in the solution. Can anyone help me with that? I am attaching the proposed mechanism of electrochemical oxidation of phenol in acidic media from papers.
Your mechanism is wrong. pKa of phenol is 10. At pH >10 phenol is present in solution as phenolate, which is oxidized to phenoxyl radical. HO- attacks o- and p-positions. The intermediate is oxidized further by one electron to form o- or p-benzoquinone.
"How it is going to loose electrons and protons?" These reactions are called the electron transfer reactions and acid-base equilibria.
You definitely need to read text books on chemistry
"I attached the mechanism of electrochemical oxidation of phenol in acidic media (from papers,(REFERENCE? THE MECHANISM IS WRONG!) and I knew it is not gonna be for alkaline media. My question was how it is going to be in alkaline media? ( I DESCRIBED IT ALREADY). The other thing is the electrochemical oxidation process is direct electrochemical oxidation at very low potentials at 0.5 V vs SHE (SEE DOI: 10.1021/jp983819w ) that is why I talked about loosing electrons and protons (HAVE YOU EVER HEARD ABOUT PCET MECHANISM?)
The Scheme 2 is wrong. The oxidation of phenol to benzoquinone is 2-electron process, but not 1e, as shown on Scheme 2.
Read
Cang Li and Morton Z. Hoffman*
J. Phys. Chem. B, 1999, 103 (32), pp 6653–6656
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