ABSTRACT
Intermolecular forces are attraction or repulsion forces acting between neighboring particles. Compared to the intramolecular forces, which are keeping together the components of a molecule, they are much weaker forces. The intermolecular forces are controlling the state of a substance but also other characteristics, like its boiling point, melting point, vapor pressure, viscosity, absorption data, and superficial tension. They are virtually responsible for all the physical properties of a material. The state of matter is determined by an equilibrium between the kinetic energy of the particles that are composing that substance and the intermolecular forces of attraction. The intermolecular forces are particularly important to assess in order to design and discover new drugs. Parameters used in quantitative structure-activity relationship have a critical importance in determining the types of forces that are implied in drug-receptor interactions. These parameters can be divided in four major classes: electronic parameters, steric parameters, hydrophobic parameters, and biological parameters.
