Noncovalent dipole interactions

Charges are heavily delocalized in organic ions, which complicate the theoretical analysis of ion pairing. Between neutral polar molecules the electrostatic contributions comes mostly from dipole-dipole interactions. Perhaps van der Waals interactions are the most important class of dipole-dipole interactions where one or both molecules do not have a permanent dipole. These interactions are valid for any two atoms that come into close contact with each other, and are called van der Waals interactions. Another very important noncovalent interaction is the hydro-phobic interaction. As the term hydrophobic suggests, this interaction is an effective interaction between two nonpolar molecules that tend to avoid water and, as a result, prefer to cluster around each other. 

DIPHTHERIA TOXIN DIPOLAR BOND DIPOLE-DIPOLE INTERACTION NONCOVALENT INTERACTLONS Dipole-dipole resonance energy transfer, FLUORESCENCE... 

Dipole-induced dipole interactions, NONCOVALENT INTERACTIONS DIPOLE MOMENT Diradical,... 

Having introduced the major principles of complexation, association, and organization, it is important to review the physicochemical forces that lead to supramolecular ensemble formation. As mentioned above, supramolecular interactions are by definition noncovalent. In the order of the polarity of the partners involved, they comprise ionic or electrostatic interactions,17 18 ion-dipole interactions,19 dipole-dipole interactions, (ionic) hydrogen bonding, cation-tt and anion-tt interactions,... 

Dipole-dipole force (Section 2.13) A noncovalent electrostatic interaction behveen dipolar molecules. 

Noncovalent interactions of different types may be responsible for complex formation. Particularly important classes are (1) hydrogen bonds (2) ion-ion ( salt ) interactions (3) ion-dipole interactions and, probably, not identical to them (4) cation-tr interactions (5) coordination bonds with metals (6) aromatic stacking interactions and (7) so-called hydrophobic interactions. 

In general, a nonpolar molecule is one that has no polarized bonds or a dipole moment and only noncovalent van der Waal s interactions. Alkanes are a typical example. A polar molecule will have dipole-dipole interactions or... 

The namre of the noncovalent interactions between molecular components, which give rise to supramolecular assembly, can include hydrogen bonding (which is common in natural systems), tt-tt stacking, ion/dipole interactions, and dispersion forces. Somewhat controversially, coordination bond (metal-ligand) associations may also be... 

---