Dipolar compound

In organic chemistry, a dipolar compound or simply dipole is an electrically neutral molecule carrying a positive and a negative charge in at least one canonical description. In most dipolar compounds the charges are delocalized.^[1] Unlike salts, dipolar compounds have charges on separate atoms, not on positive and negative ions that make up the compound. Dipolar compounds exhibit a dipole moment.

${\displaystyle {\ce {[R-{\overset {\oplus }{N}}{\equiv }{\overset {\ominus }{C}}{:}<->R-{\ddot {N}}=C{:}]}}}$

Example of a dipolar compound, represented by a resonance structure (isocyanide)

Dipolar compounds can be represented by a resonance structure. Contributing structures containing charged atoms are denoted as zwitterions. ^{[2] [3] [4] [5] [6]} Some dipolar compounds can have an uncharged canonical form.

Types of dipolar compounds

• 1,2-dipolar compounds have the opposite charges on adjacent atoms.
• 1,3-dipolar compounds have the charges separated over three atoms.^[1] They are reactants in 1,3-dipolar cycloadditions.
• Also 1,4-dipolars,^[4] 1,5-dipolars, and so on exist.

Examples

• 
  Phosphonium ylide
• 
  Diazomethane
• 
  Carbonyl oxide

See also

• Zwitterion
• Ylide
• 1,3-dipole
• 1,3-Dipolar cycloaddition
• Betaine