Among the following amines, the strongest Brönsted base is __________.

• The main reason behind the basic properties of cyclopentyl amine is the availability of unshared electrons on the nitrogen atoms which allows the ease of protonation on the N atom and forming of cation by interacting with acids.

• And also the cyclopentyl ring makes the N more nucleophilic (electron-donating tendency, through the effect of hyperconjugation) it has more basic strength even more than ammonia.

• (i) might be weakest base among them due to conjugation of the –NH₂ group with the benzene ring which eventually makes the lone pair on N atoms less available, which is also partially the case for (iii) also.

• Amines are generally stronger bases than (ii) NH₃ because the n atoms in amines have more ability to form dative bonds with H s, as they have more nucleophilic N atom (more nucleophilic the N atom, more will be the basicity).