Carbonyl Article Index for
Carbonyl
Articles about
Carbonyl
 

Information About

Carbonyl




In Organic Chemistry , a carbonyl group is a Functional Group composed of a Carbon Atom Double-bonded to an Oxygen atom.
The term carbonyl can also refer to Carbon Monoxide as a Ligand in an Inorganic or Organometallic complex (e.g. Nickel Carbonyl ); in this situation, carbon is Triple-bonded to oxygen.

A carbonyl group characterizes the following types of compounds (where -CO denotes a C=O carbonyl group):















































Compound Structure Formula
Aldehyde RCHO
Ketone RCOR'
Carboxylic Acid RCOOH
Ester RCOOR'
Amide RCONR'R"
Enone RCOC(R')=CR"R"'
Acyl Chloride RCOCl
Anhydride (RCO)2O



REACTIVITY

Oxygen is more Electronegative than carbon, and thus pulls electron density away from carbon to increase the bond's Polarity . Therefore, the carbonyl carbon becomes Electrophilic , and thus more reactive with Nucleophile s.

Carbonyl groups can be Reduce d by reaction with Hydride reagents such as NaBH4 and LiAlH4, and by Organometallic reagents such as Organolithium reagents and Grignard Reagent s.

Other important reactions include:


α,β-UNSATURATED CARBONYL COMPOUNDS

α,β-Unsaturated carbonyl compounds are an important class of carbonyl compounds with the general structure Cβ=Cα−C=O. In these compounds the carbonyl group is Conjugated with an Alkene (hence the Adjective Unsaturated ), from which they derive special properties. Examples of unsaturated carbonyls are Acrolein , Mesityl Oxide , Acrylic Acid and Maleic Acid . Unsaturated carbonyls can be prepared in the laboratory in an Aldol Reaction and in the Perkin Reaction .
The carbonyl group, be it an Aldehyde or Acid , draws electrons away from the alkene and the alkene group in unsaturated carbonyls are therefore deactived towards an Electrophile such as Bromine or Hydrochloric Acid . As a general rule with unsymmetric electrophiles hydrogen attaches itself at the α position in an Electrophilic Addition .
On the other hand, these compounds are activated towards Nucleophile s in Nucleophilic Addition .


SPECTROSCOPY

  • light at Wavenumber s between approximately 1680–1750 cm−1. This absorption is known as the "carbonyl stretch" when displayed on an infrared absorption spectrum.

  • Nuclear Magnetic Resonance : the C=O double-bond exhibits different resonances depending on surrounding atoms.

  • Mass Spectrometry





OTHER ORGANIC CARBONYL COMPOUNDS



INORGANIC CARBONYL COMPOUNDS



SEE ALSO



REFERENCES



FURTHER READING