Ion–Dipole Interaction
The attraction between an ion and the oppositely charged end of a polar molecule.
Formula / equation
E ∝ q μ / r²
Unit
kJ/mol
In depth
Stronger than any interaction between neutral molecules, ion–dipole forces are what make ionic solids dissolve in polar solvents: the energy released as ions become solvated compensates for the lattice energy destroyed. The resulting shell of oriented solvent molecules is the hydration sphere.
Examples in the real world
Six water molecules orienting their oxygen atoms towards Na⁺ to give [Na(H₂O)₆]⁺ in solution.