Dipole-Dipole Forces

Dipole-Dipole:  Dipole-dipole interaction is the attraction between a partially
negative portion of one molecule and a partially positive portion of a nearby
molecule.  Dipole-dipole interaction occurs in any polar molecule as determined
by molecular geometry.

• are stronger intermolecular forces than Dispersion forces

• occur between molecules that have permanent net dipoles (polar molecules), for example, dipole-dipole interactions occur between SCl₂ molecules, PCl₃ molecules and CH₃Cl molecules. If the permanent net dipole within the polar molecules results from a covalent bond between a hydrogen atom and either fluorine, oxygen or nitrogen, the resulting intermolecular force is referred to as a hydrogen bond (see below).

• The partial positive charge on one molecule is electrostatically attracted to the partial negative charge on a neighbouring molecule.