Dipole-Dipole forces are the forces of attraction between the positive end of one polar molecule and the negative end of the other polar molecule. Dipole forces range in power from 5 KJ to 20 KJ per mole. They are much weaker than ionic or covalent bonds and have a significant effect only when the molecules in question are together (touching or almost touching).
The data show two arrangements of polar iodine monoclover (ICL) molecules that have been linked to dopole attraction.
- Polar molecules have a partial negative end and a partial positive end.
- The partially positive end of a polar molecule is attracted to the partially negative end of another.
- In a ICl molecule the more electronegative chlorine atom bears the partial negative charge; the less electronegative iodine atom bears the partial positive charge.
- The partially positive iodine end of one ICl molecule is attracted to the partially negative chlorine end of another ICl molecule.
A dashed line is used to represent an intermolecular attraction between molecules because these forces are NOT as strong as chemical bonds.