Question

Explain how the following two compounds can have the same conjugate base. Is this conjugate base aromatic?

Answer 1

`"When either compound is deprotonated, the same"` `"aromatic anion is generated...."`

What is the Huckel criterion for aromaticity....?

Explanation:

The Huckel criterion specifies `4n+2*pi` `"electrons"`...you have got 2 dienes in the diagram, the which each have `4*pi` `"electrons"`. However, if an hydrogen as a proton is abstracted from the ring (which may be easily accomplished) then you gots `6*pi` `"electrons"`...which are delocalized around the ring.

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And this is a commonly used ligand in organometallic chemistry....