Pyridine has a delocalized π-molecular orbital containing -

Concept:

Pyridine is a heterocyclic aromatic compound with the molecular formula C₅H₅N. Aromatic compounds commonly feature delocalized π-electrons, which contribute to the molecule's stability and aromatic character.

• Delocalized π-electrons: π-electrons that are not confined to a single bond or atom but rather spread across multiple atoms, contributing to resonance and stability.

• Aromaticity: A property of cyclic, planar structures with a π-electron count that satisfies Hückel's rule (4n + 2 π-electrons, where n is a non-negative integer) ensuring aromatic stability.

• Hückel's Rule: For a molecule to be aromatic, it must have (4n + 2) π-electrons, where n is an integer (0, 1, 2, ...).

Explanation:

Pyridine is a six-membered ring structure, similar to benzene but with one nitrogen atom replacing a carbon. The nitrogen atom and each of the five carbon atoms contribute one p-orbital electron to the π-system. Therefore, pyridine has six π-electrons in its delocalized π-molecular orbital system.

Conclusion:

Therefore, pyridine's delocalized π-molecular orbital contains 6-electrons.