Carbonyl group

In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom : C=O. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the

The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, e. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. In Chemistry, a ligand is either an Atom, Ion, or Molecule (see also Functional group) that bonds to a central metal generally Traditionally inorganic compounds are considered to be of mineral not biological origin Organometallic chemistry is the study of Chemical compounds containing bonds between Carbon and a Metal. Metal carbonyls are Coordination complexes of Transition metals with Carbon monoxide. g. nickel carbonyl); in this situation, carbon is triple-bonded to oxygen : C≡O. Nickel carbonyl ( IUPAC name tetracarbonylnickel) is a colorless Organometallic complex that is a versatile reagent first described in

The remainder of this article concerns itself with the organic chemistry definition of carbonyl. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation

Carbonyl compounds

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

Compound	Aldehyde	Ketone	Carboxylic acid	Ester	Amide	Enone	Acyl chloride	Acid anhydride
Structure
General formula	RCHO	RCOR'	RCOOH	RCOOR'	RCONR'R''	RC(O)C(R')CR''R'''	RCOCl	(RCO)2O

Other organic carbonyls are urea and carbamates. An aldehyde is an organic compound containing a terminal Carbonyl group. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or Carboxylic acids are Organic acids characterized by the presence of a Carboxyl group, which has the formula -C(=OOH usually written -COOH or -CO2H Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least In Chemistry, an amide is one of three kinds of Compounds (sometimes called acid amide the organic Functional group characterized An enone is an unsaturated Chemical compound or Functional group consisting of a Conjugated system of an Alkene and a Ketone In Organic chemistry, an acyl chloride (or acid chloride) is an Organic compound which is a reactive derivative of a Carboxylic acid. An acid anhydride is an Organic compound that has two Acyl groups bound to the same Oxygen atom Urea is an Organic compound with the Chemical formula ( N[[hydrogen H]]22 C[[oxygen O]] Carbamates, or Urethanes are a group of Organic compounds sharing a common Functional group with the general structure -NH(COO- Examples of inorganic carbonyl compounds are carbon dioxide, carbonyl sulfide and phosgene

Reactivity

Oxygen is more electronegative than carbon, and thus pulls electron density away from carbon to increase the bond's polarity. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Carbonyl sulfide is the Chemical compound with the formula OCS Phosgene is the Chemical compound with the formula COCl2 This colorless gas gained infamy as a Chemical weapon during World War I " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons In Physics, polarity is a description of an attribute typically a binary attribute (one with two values or a Vector (a direction Therefore, the carbonyl carbon becomes electrophilic, and thus more reactive with nucleophiles. In Chemistry, an electrophile (literally electron-lover) is a Reagent attracted to Electrons that participates in a chemical reaction by accepting In Chemistry, a nucleophile (literally nucleus lover as in nucleus and phile) is a Reagent that forms a Chemical bond to Also, the electronegative oxygen can react with an electrophile; for example a proton in an acidic solution or other Lewis Acid.

The alpha hydrogen in a carbonyl compound is much more acidic (~10³⁰ times more acidic) than a typical CH bond. The alpha carbon in Organic chemistry refers to the first carbon that attaches to a Functional group (the carbon is attached at the first or alpha position For example the pK_a values of acetaldehyde and acetone are 16. Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula C[[Hydrogen H]]3CH O or MeCHO Acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is a colorless mobile flammable 7 and 19, respectively. ^[1]

Amides are the most stable of the carbonyl couplings due to their high resonance stabilization between the Nitrogen-Carbon and Carbon-Oxygen bonds.

Carbonyl groups can be reduced by reaction with hydride reagents such as NaBH₄ and LiAlH₄, and by organometallic reagents such as organolithium reagents and Grignard reagents. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Hydride is the name given to the negative Ion of Hydrogen, H− Organometallic chemistry is the study of Chemical compounds containing bonds between Carbon and a Metal. An organolithium reagent is an Organometallic compound with a direct bond between a Carbon and a Lithium atom The Grignard reaction, named for the French chemist François Auguste Victor Grignard, is an organometallic Chemical reaction in which Alkyl -

Other important reactions include:

• Wolff-Kishner reduction
• Clemmensen reduction
• Conversion into thioacetals
• Hydration to hemiacetals and hemiketals, and then to acetals and ketals
• Reaction with ammonia and primary amines to form imines
• Reaction with hydroxylamines to form oximes
• Reaction with cyanide anion to form cyanohydrins
• Oxidation with oxaziridines to acyloins
• Reaction with Tebbe's reagent and phosphonium ylides to alkenes. The Clemmensen reduction is a Chemical reaction described as a reduction of Ketones (or Aldehydes to Alkanes using Zinc Thioacetals are the Sulfur analogue of Acetals They are prepared in a similar way to acetals by reacting a Thiol with an Aldehyde Hemiacetals and hemiketals are compounds of the general formula R1R2C(OHOR3 where R3 is not a hydrogen Hemiacetals and hemiketals are compounds of the general formula R1R2C(OHOR3 where R3 is not a hydrogen An acetal is a Molecule with two single bonded oxygens attached to the same carbon atom A ketal is a Functional group or Molecule containing the functional group of a Carbon bonded to two -OR groups where O is Oxygen Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. An imine is a Functional group or Chemical compound containing a Carbon – Nitrogen Double bond. Hydroxylamine is a reactive chemical with formula NH2OH It can be considered a hybrid of Ammonia and Water due to parallels it shares oxime is one in a class of Chemical compounds with the general formula R1R2 C[[nitrogen N]] O[[hydrogen H]] where R1 is an A cyanide is any Chemical compound that contains the cyano group (C≡N which consists of a Carbon Atom triple-bonded to a A cyanohydrin is a Functional group in Organic compounds Cyanohydrins have the formula R2C(OHCN where R is H Alkyl, or Aryl. Acyloins are a class of Organic compounds in Organic chemistry sharing a common Functional group consisting of a Hydroxyl group placed on the The Tebbe reagent is (C5H52TiCH2ClAl(CH32 an Organometallic compound used in the methylenation of Carbonyl The Wittig reaction is a Chemical reaction of an Aldehyde or Ketone with a triphenyl phosphonium ylide (often called a Wittig reagent In Organic chemistry, an alkene, olefin, or olefine is an unsaturated Chemical compound containing at least one Carbon
• Perkin reaction
• Tishchenko reaction
• Aldol condensation
• Cannizzaro's reaction

α,β-Unsaturated carbonyl compounds

α,β-Unsaturated carbonyl compounds are an important class of carbonyl compounds with the general structure C_β=C_α−C=O. The Perkin reaction is an Organic reaction developed by William Henry Perkin that can be used to make Cinnamic acids by the Aldol condensation The Tishchenko reaction is a Chemical reaction that involves Disproportionation of an Aldehyde lacking a hydrogen atom in the alpha position in the presence An Aldol condensation is an Organic reaction in which an Enolate ion reacts with a Carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone followed In these compounds the carbonyl group is conjugated with an alkene (hence the adjective unsaturated), from which they derive special properties. A chemically conjugated system is a system of atoms Covalently bonded with alternating single and multiple (e In Organic chemistry, an alkene, olefin, or olefine is an unsaturated Chemical compound containing at least one Carbon In Grammar, an adjective is a word whose main syntactic role is to modify a Noun or Pronoun, giving more information about the In Chemistry, saturation has five different meanings In Physical chemistry, saturation is the point at which a Solution of a substance Examples of unsaturated carbonyls are acrolein, mesityl oxide, acrylic acid and maleic acid. Acrolein (systematic name 2-propenal) is the simplest unsaturated Aldehyde. Mesityl oxide is a αβ-Unsaturated ketone with the formula CH3C(OCH=C(CH32 Acrylic acid or prop-2-enoic acid is a Chemical compound ( formula C 3 H 4 O 2 and it Maleic acid or ( Z)-butenedioic acid or cis -butenedioic acid or malenic acid or maleinic acid or toxilic Unsaturated carbonyls can be prepared in the laboratory in an aldol reaction and in the Perkin reaction. The aldol reaction is an important Carbon-carbon bond formation reaction in Organic chemistry. The Perkin reaction is an Organic reaction developed by William Henry Perkin that can be used to make Cinnamic acids by the Aldol condensation The carbonyl group, be it an aldehyde or acid or a ketone, 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. An aldehyde is an organic compound containing a terminal Carbonyl group. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or In Chemistry, an electrophile (literally electron-lover) is a Reagent attracted to Electrons that participates in a chemical reaction by accepting Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water As a general rule with unsymmetric electrophiles hydrogen attaches itself at the α position in an electrophilic addition. In Organic chemistry, an electrophilic addition reaction is an Addition reaction where in a Chemical compound, a Pi bond is removed by the creation On the other hand, these compounds are activated towards nucleophiles in nucleophilic addition. In Chemistry, a nucleophile (literally nucleus lover as in nucleus and phile) is a Reagent that forms a Chemical bond to In Organic chemistry, a nucleophilic addition reaction is an Addition reaction where in a Chemical compound a π bond is removed by the creation

Spectroscopy

• Infrared spectroscopy: the C=O double bond absorbs infrared light at wavenumbers between approximately 1600–1900 cm⁻¹. Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of Wavenumber in most physical sciences is a Wave property inversely related to Wavelength, having SI units of reciprocal meters The exact location of the absorption is well understood with respect to the geometry of the molecule. This absorption is known as the "carbonyl stretch" when displayed on an infrared absorption spectrum. ^[2]
• Nuclear magnetic resonance: the C=O double-bond exhibits different resonances depending on surrounding atoms, generally a downfield shift. The ¹³C NMR of a carbonyl carbon is in the range of 160-220 ppm.

See also

• Organic chemistry

References

Further reading

• L. G. Wade, Jr. Organic Chemistry, 5th ed. Prentice Hall, 2002. Prentice Hall is a leading educational publisher It is an Imprint of Pearson Education Inc ISBN 0-13-033832-X
• The Frostburg State University Chemistry Department. Organic Chemistry Help (2000).
• Advanced Chemistry Development, Inc. IUPAC Nomenclature of Organic Chemistry (1997).
• William Reusch. VirtualText of Organic Chemistry (2004).
• Purdue Chemistry Department [1] (retrieved Sep 2006). Includes water solubility data.
• William Reusch. (2004) Aldehydes and Ketones Retrieved 23 May 2005.
• ILPI. (2005) The MSDS Hyperglossary- Anhydride.