What are the physical properties of an amino functional group?

Amino functional groups can form hydrogen bonds, which generally results in higher boiling points compared to phosphines, though lower than those of alcohols due to their lesser hydrogen bonding ability. Amines can dissolve in water, but their solubility decreases as the number of carbon atoms increases. This is because the larger hydrophobic chains reduce their water compatibility. Aromatic amines, with their lone pair of electrons delocalized into the benzene ring, are less capable of hydrogen bonding. In contrast, aliphatic amines (which are attached to alkyl chains) dissolve well in organic polar solvents.