How does the basicity of aromatic amines compare with that of aliphatic amines?

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amine Examples of different types of amines.

Aliphatic amines are generally stronger bases than ammonia, whereas aromatic amines are substantially weaker bases.1

Basicity in amines is measured using the $p K_{b}$ value, where a larger $p K_{b}$ indicates a weaker base. For reference, the $p K_{b}$ of ammonia is 4.75. In contrast, aliphatic amines typically exhibit lower $p K_{b}$ values, reflecting their increased basicity compared to ammonia. Aromatic amines, such as aniline, are significantly less basic, as their lone pair of electrons is less available for protonation due to interaction with the aromatic ring.1