[AFT]

Hi, I'm slightly confused about the relationship between molecular structure and boiling points.

I know that BP's are determined by the intermolecular forces (dipole-dipole, London dispersion & hydrogen bonds) of a given molecule.  As well, BP's vary with bond types (ie. double bonds = greater BP vs. single bonds).

However, I can't seem to understand why CH₃CH₂CH₂NH₂ has a higher boiling point than CH₃CH₂CH₂OH.

[macman104]

Um....it doesn't?

Propylamine:  48°C
1-Propanol:  97.1°C

[vhpk]

Hi, I'm slightly confused about the relationship between molecular structure and boiling points.

I know that BP's are determined by the intermolecular forces (dipole-dipole, London dispersion & hydrogen bonds) of a given molecule.  As well, BP's vary with bond types (ie. double bonds = greater BP vs. single bonds).

However, I can't seem to understand why CH₃CH₂CH₂NH₂ has a higher boiling point than CH₃CH₂CH₂OH.

Basing on my scope and macman104's data, I think that propan-1-ol should have a higher boiling point than propylamine since the former has more effective hydrogen bond, the greater hydrogen bond extend, the more boiling point particle has

[AFT]

Thanks for the replies!  I'd just like to clarify:

Propylamine has a lower boiling point because the EN difference of N-H is less than that of the O-H present in 1-propanol.  Is this correct?

Thanks!

[Yggdrasil]

Yes.  The lower EN difference leads to weaker dipole-dipole interactions (specifically, hydrogen bonding interactions in this case).