Lon-dipole forces

When placed in an electric held, a dipole will attempt to orient and become aligned with the field. If the field results from an ion. the dipole will orient itself so that the attractive end (the end with charge opposite to that of the ion) will be directed toward the ion and the other, repulsive end directed away. In this sense, lon-dipole forces may be thought of as "directional," In that they result in preferred orientations of molecules even though elcctrostalic forces are nondirectional. 

FigUfG 13.2 Hydration shells around an Na ion. lon-dipole forces orient water molecules around an ion. In the innermost shell here, six water molecules surround the cation octahedrally. 

These are the electrostatic forces of attractions which exist between an ion and the oppositely charged region of a water molecule, lon-dipole forces are formed between simple metal ions from groups 1 and 2 and anions. 

Critical micelle concentration (Section 19 5) Concentration above which substances such as salts of fatty acids aggre gate to form micelles in aqueous solution Crown ether (Section 16 4) A cyclic polyether that via lon-dipole attractive forces forms stable complexes with metal 10ns Such complexes along with their accompany mg anion are soluble in nonpolar solvents C terminus (Section 27 7) The amino acid at the end of a pep tide or protein chain that has its carboxyl group intact—that IS in which the carboxyl group is not part of a peptide bond Cumulated diene (Section 10 5) Diene of the type C=C=C in which a single carbon atom participates in double bonds with two others... 

The insolubility of ionic compounds in nonpolar solvents is a similar phenomenon. The solvation energies are limited to those from ion-induced dipole forces, which are considerably weaker than ion-dipole forces and not large enough to overcome the very strong lon-ion forces of the lattice. 

Covalent bond Ionic bond lon-dipgle Dipoie dipole Ion-induced dipole Dipole-induced dipole London dispersion forces... 

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