Dipole–dipole interaction

An electrostatic interaction between molecules with permanent electric dipoles. Its strength and sign depend on how the molecules are oriented relative to one another.

Electric dipole: A separation of positive and negative charge that gives a system a nonzero electric dipole moment. Permanent molecular dipoles provide the charge distributions whose orientations set this interaction.
Molecular polarity: The unequal distribution of electric charge across a molecule, producing partial positive and negative regions. A molecule must have a permanent dipole to participate in this interaction.
Relative permittivity: A measure of how strongly a material reduces an electric field relative to vacuum. Polar molecules reorient in an applied field, contributing to a substance’s dielectric response.
Dipole-induced dipole interaction: An attraction in which a permanent dipole distorts the electron distribution of a neighboring nonpolar particle. Only one partner has a permanent dipole, unlike the two permanent dipoles here.
Dipole moment: A vector quantity measuring the separation of positive and negative charge in a system. Its magnitude and direction determine each molecule’s contribution to the interaction.
Electronegativity: A measure of an atom’s tendency to attract shared electrons in a chemical bond. Electronegativity differences help create the bond dipoles that combine into molecular polarity.
Boiling point: The temperature at which a liquid’s vapor pressure equals the surrounding pressure. Intermolecular attractions affect the energy needed for polar molecules to enter the vapor phase.
Ion–dipole interaction: An electrostatic interaction between an ion and a molecule with a permanent dipole. A full ionic charge replaces one molecular dipole as the interacting charge distribution.
Coulomb's law: The law describing the electrostatic force between charged particles as a function of their charges and separation. The interaction follows from Coulomb forces between the partial charges in neighboring molecules.
Molecular geometry: The three-dimensional arrangement of atoms in a molecule. Geometry determines whether individual bond dipoles produce a net permanent dipole.

Linked from 18 pages