Lewis acid-base interaction electrostatic attraction/covalent

By far the dominant adhesion mechanism, particularly in the absence of covalent linkages, is the electrostatic attraction of the polar groups of the adhesive to polar groups of the adherends. These are mainly forces arising from the interaction of permanent dipoles, including the special cases of hydrogen bonding (10-25 kJ/mol) and Lewis acid-base interactions (<80 kJ/mole).25 26 These forces provide much of the attraction between the... 

The interaction of several types of species in solution can be considered as special cases of Lewis acid-base behavior. Depending on the nature of the species, the interaction may be primarily the result of electrostatic attraction or the result of covalent bonding. In many cases, both factors come into... 

The FMO definition also helps explain why Pearson s hard-hard and soft-soft interactions form stable complexes. Hard compounds have a large HOMO-LUMO gap, as shown in Figure 14.9 for F. Therefore, hard Lewis acid-base complexes tend to form strongly ionic compounds, such as LiF, where the interaction is dominated by electrostatic attractions. Soft compounds, on the other hand, have a small HOMO-LUMO gap, as shown in Figure 14.9 for I, so that these types of interactions form covalently bonded acid-base adducts, where the strength of the interaction is controlled primarily by the energies of the FMOs that participate in the bonding. 

Intermolecular interaction A collective term for the attractive (and repulsive) forces that control the association of two or more molecular entities. Intermolecular interactions include electrostatic (Coulombic) forces, van der Waals forces including dispersion (London) forces, hydrogen bonding interactions, Lewis acid—Lewis base interactions, electron-donor—electron-acceptor interactions, and the hydrophobic (solvophobic) effect. The same types of interactions can also occur between parts of the same molecular entity (intramolecular interactions). Although some interactions are weak relative to a covalent bond, others are not. The term includes a range of bonding characters from predominantly covalent, polar covalent, or ionic. 

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