ABSTRACT

Very weak dipoles will provide only very weak dipole intermolecular attractive forces; the strength of the dipole attractive forces will increase with the strength of the molecular dipole.

4. Hydrogen bonding is a special form of the strong dipole force. The hydrogen “bond” is not a covalent bond but a force of attraction between very specific positive and negative dipole ends. a. The positive end of the attractive force is specifically hydro-

gen covalently bonded to either oxygen, nitrogen, or fluorine:

b. The negative end of the hydrogen bond can be the lone pairs of oxygen, nitrogen, or fluorine, regardless of whether these atoms are bonded to a hydrogen:

5. Hydrogen bonding is stronger than other dipole forces due to the small sizes and high relative charge concentrations of hydrogen and the row-2 elements (O, N, F). Hydrogen bonding can occur in a variety of ways between molecules of the same compound. The positive end is very specific but the negative end can be more variable. Examples: The dashed line (|||||||||||||) indicates hydrogen bonding.