For example, H-Cl has a dipole. The electrons spend more of their time near the Cl atom (the red end in the diagram below). A dipole-dipole interaction is the attraction between two polar molecules. When they approach each other, the negative end one molecule attracts the positive end of the other.
How does dipole dipole work?
Polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule. Unlike covalent bonds between atoms within a molecule ( intramolecular bonding), dipole-dipole interactions create attractions between molecules of a substance ( intermolecular attractions).
What is a dipole dipole interaction?
Dipole-Dipole interactions result when two dipolar molecules interact with each other through space. When this occurs, the partially negative portion of one of the polar molecules is attracted to the partially positive portion of the second polar molecule.