text: CH3CH2CH2NH2 has hydrogen bonding at the nitrogen, whereas N(CH3)3 does not. Since nitrogen is more electronegative than carbon, an nitrogen bonded to a hydrogen is a very polar bond with the positive end of the dipole at the hydrogen. So the positive hydrogen of one molecule will be attracted to the negative nitrogen of another. This makes it harder to separate molecules of CH3CH2CH2NH2 into the vapor phase, so the boiling point is higher.