Example of a dipolar compound, represented by a resonance structure (isocyanide)
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.
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.
^IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "dipolar compounds". doi:10.1351/goldbook.D01753
^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
^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
^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): 14446–8. doi:10.1021/ja030191g. PMID 14624592.
^Preferred IUPAC Names: "CHAPTER 7: RADICALS, IONS, AND RELATED SPECIES", September 2004, pp. 56-70
^Rolf Huisgen (IUPAC): Cycloaddition mechanism and the solvent dependence of rate; Pure Appl. Chem.; 1980, Vol.52, pp.2283—2302.
{\ominus }{C}}{:}<->R-{\ddot {N}}=C{:}]}}} In organic chemistry, a dipolarcompound or simply dipole is an electrically neutral molecule carrying a positive...
German Zwitter [ˈtsvɪtɐ] 'hermaphrodite'), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively and negatively...
covalent and an ionic bond; normally written X+–Y−. Ylides are thus 1,2-dipolarcompounds, and a subclass of zwitterions. They appear in organic chemistry as...
In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized...
organometallic compounds and most coordination compounds are described similarly. The term dipolar bond is used in organic chemistry for compounds such as amine...
condensation with benzaldehyde to form diphenylnitrone, a well-known 1,3-dipolarcompound: C6H5NHOH + C6H5CHO → C6H5N(O)=CHC6H5 + H2O Phenylhydroxylamine is...
Group velocity dispersion Birefringence Self-focusing Harmonic generation Dipolar polarisation is a polarisation that is either inherent to polar molecules...
above-mentioned dipolar interaction can be measured directly, e.g. between pairs of heteronuclear spins like 13C/15N in many organic compounds. Furthermore...
atom—such gases serve as the basis for quantum simulation with strongly dipolar atoms. Like many powders, dysprosium powder may present an explosion hazard...
to a cyclopentadienyl anion (both stable and aromatic). In this compound the dipolar structure is calculated to contribute 23% to the total structure...
Diazo compounds react as 1,3-dipoles in diazoalkane 1,3-dipolar cycloadditions. Diazo compounds are used as precursors to carbenes, which are generated...
much more polarised. It has been argued that a more accurate depiction is dipolar (i.e. (RO)3P+-O-), which is similar to the depiction phosphorus ylides...
These nitrile ylides are dipolarcompounds and can be trapped by a variety of dipolarophiles to yield heterocyclic compounds, e.g. pyrrolines. The strained...
coordination sphere. Coordination refers to the "coordinate covalent bonds" (dipolar bonds) between the ligands and the central atom. Originally, a complex...
due to repulsion between the lone pairs of the adjacent oxygen atoms and dipolar effects between the two O–H bonds. For comparison, the rotational barrier...
organic chemistry, a nitrile is any organic compound that has a −C≡N functional group. The name of the compound is composed of a base, which includes the...
consisting of an iminium ion next to a carbanion. They are used in 1,3-dipolar cycloaddition reactions to form five-membered heterocycles, including pyrrolidines...
also frequently used as a carbene source. It readily takes part in 1,3-dipolar cycloadditions. Diazomethane is prepared by hydrolysis of an ethereal solution...
conductivity. The magnetic fields of both Uranus and Neptune are special—non-dipolar and non-axisymmetric. This fact can be explained if the magnetic fields...
aldehyde or ketone (3) in a retro-1,3-dipolar cycloaddition. The oxide and aldehyde or ketone react again in a 1,3-dipolar cycloaddition, producing a relatively...
cycloalkanone which is a waste derived and fully biodegradable aprotic dipolar solvent. It is an environmentally friendly alternative to dimethylformamide...
betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes...
E. V.; Rao, Y. R. (1988). "Phase transfer catalytic preparation of the dipolar aprotic solvents DMI and DMPU". Synthetic Communications. 18 (5): 487–494...
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