Pyridine is a substantially weaker base than alkylamines. The electron pair of pyridine occupies an sp²-hybridized orbital, and lies closer to the nitrogen nucleus than the electron pair in the sp³-hybridized orbital of alkylamines. As a result, pyridine is a weaker base (larger pK_b) than an alkylamine.

Why is pyridine a strong base?

Pyridine consists of a stable conjugated system of 3 double bonds in the aromatic ring. Hence, the lone pair of electrons present on the nitrogen atom in pyridine has the ability to donate a hydrogen ion easily or a Lewis acid. Thus, pyridine is a stronger base than pyrrole.

Is pyridine a strong Nucleophile?

Pyridine is neither a strong base nor a strong nucleophile.