If pyridine and pyrimidine are both aromatic compounds, how many elctrons does each nirtogen atom contribute to the electron cloud of each compound?

1 Answer
Sep 13, 2016

In each compound, each #"N"# atom contributes one electron to the π cloud.

Explanation:

Pyridine

The structure of pyridine is

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#"N"# has a lone pair and one electron in each of the σ bonds to the carbon atoms on either side.

That leaves 1 valence electron available to participate in the aromatic π cloud.

Pyrimidine

The structure of pyridine is

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The two #"N"# atoms are equivalent.

Each #"N"# has a lone pair and one electron in each of the σ bonds to the carbon atoms on either side.

That leaves 1 valence electron available in each #"N"# atom to participate in the aromatic π cloud.