Like ammonia, all the three types of amines have one unshared
electron pair on nitrogen atom due to which they behave as Lewis bases Amines are usually formed from nitro compounds, halides, amides, imides, etc They exhibit hydrogen bonding which influence their physical properties In
alkylamines, a combination of electron releasing, steric and H-bonding factors
influence the stability of the substituted ammonium cations in protic polar solvents
and thus affect the basic nature of amines