ABSTRACT
Electromagnetic interactions provide the fundamental basis for all the different bonded and nonbonded interactions between atoms and molecules. We will discuss here the interactions between charged atoms, functional groups, and molecules. According to Coulomb’s law, the force between two interacting charges A and B can be described by the equation
F
q q
D d = ⋅
2 (2.1)
where q1 and q2 are charges, d is the distance between the charges, and D is the relative dielectric constant of the medium in which the charges are situated. The values of the dielectric constants of some common solvents are listed in Table 2.1. In crystals the value of D is considered to approach 1⎯the value in vacuum⎯and
2.1 The Electrostatic Interaction ........................................................................... 21 2.2 The van der Waals Interaction .........................................................................23 2.3 The Hydrogen Bond ........................................................................................27 2.4 The Hydrophobic Interaction ..........................................................................28 2.5 Multiple Interactions and Cooperativity ......................................................... 31 Further Reading .......................................................................................................34
