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 which make up the compound. Dipolar compounds exhibit a dipole moment.

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.

Contents

Types of dipolar compounds

Examples

See also

References

  1. ^ a b IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (2006–) "dipolar compounds".
  2. ^ Braida et al.: A clear correlation between the diradical character of 1,3-dipoles and their reactivity toward ethylene or acetylene.; J. Am. Chem. Soc.; 2010 Jun 9;132(22):7631-7
  3. ^ Hartmann and Heuschmann: Isolation of a Zwitterion in a Diels–Alder Reaction with Inverse Electron Demand; Angewandte Chemie; september 1989; Volume 28, Issue 9, pages 1267–1268
  4. ^ a b MacHiguchi, Takahisa; Okamoto, Junko; Takachi, Junpei; Hasegawa, Toshio; Yamabe, Shinichi; Minato, Tsutomu (2003). "Exclusive Formation of α-Methyleneoxetanes in Ketene−Alkene Cycloadditions. Evidence for Intervention of Both an α-Methyleneoxetane and the Subsequent 1,4-Zwitterion". Journal of the American Chemical Society 125 (47): 14446. doi:10.1021/ja030191g. PMID 14624592. 
  5. ^ IUPAC: Preferred IUPAC Names; Chapter 7, September 2004, pp. 56-70
  6. ^ Rolf Huisgen (IUPAC): Cycloaddition mechanism and the solvent dependence of rate; Pure & Appl. Chem.; 1980, Vol.52, pp.2283—2302.