If the N forms 4 bonds it has a positive charge and the resulting compounds are called quaternary ammonium salts. C. Physical Properties 1. Primary and secondary amines have higher boiling points than alkanes of similar moleular weight, but lower boiling points than alcohols of similar molecular mass. Tertiary amines can not provide a H for H bonding, so they have lower boiling points than 1 o or 2 o amines of similar molecular mass. Most low molecular weight amines are soluble in water.
Solubility decreases with increasing molar mass.
Odor-many low molecular weight amines have odors similar to ammonia. Many amines have fowl odors. D. Chirality of Amines and Quaternary Ammonium Salts 1. These isomers cannot be isolated. The R form is converted to the S form and visa versa.