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carbonyl group(kär`bənĭl), in chemistry, functional groupfunctional group,
in organic chemistry, group of atoms within a molecule that is responsible for certain properties of the molecule and reactions in which it takes part. Organic compounds are frequently classified according to the functional group or groups they contain.
..... Click the link for more information. that consists of an oxygen atom joined by a double bond to a carbon atom. The carbon atom is joined to the remainder of the molecule by two single bonds or one double bond. If the carbonyl group is joined only to alkyl groupsalkyl group
, in chemistry, group of carbon and hydrogen atoms derived from an alkane molecule by removing one hydrogen atom (see radical). The name of the alkyl group is derived from the name of its alkane by replacing the -ane suffix with -yl, e.g.
..... Click the link for more information. or aryl groupsaryl group
, in chemistry, group of atoms derived from benzene or from a benzene derivative by removing one hydrogen that is bonded to the benzene ring (see radical). The simplest aryl group is phenyl, C6H5 ; it is derived from benzene.
..... Click the link for more information. , the compound is a ketoneketone
, any of a class of organic compounds that contain the carbonyl group, C=O, and in which the carbonyl group is bonded only to carbon atoms. The general formula for a ketone is RCOR′, where R and R′ are alkyl or aryl groups.
..... Click the link for more information. ; if it is joined to at least one hydrogen atom, the compound is an aldehydealdehyde
[alcohol + New Lat. dehydrogenatus=dehydrogenated], any of a class of organic compounds that contain the carbonyl group, , and in which the carbonyl group is bonded to at least one hydrogen; the general formula for an aldehyde is RCHO, where R is hydrogen
..... Click the link for more information. . The chemical reactivity of aldehydes and ketones is primarily due to the difference in electronegativityelectronegativity
, in chemistry, tendency for an atom to attract a pair of electrons that it shares with another atom (see chemical bond). For example, the molecule hydrogen chloride, HCl, consists of a hydrogen atom, H, and a chlorine atom, Cl, sharing a pair of electrons.
..... Click the link for more information. between carbon and oxygen. Because oxygen has the greater affinity for electrons, it acquires a partial negative charge, becoming electron-rich; the carbon atom of the carbonyl group thus becomes electron-deficient, acquiring a partial positive charge. One major type of reaction of aldehydes and ketones involves the addition of an electron-rich chemical species to the electron-deficient carbon atom of the carbonyl group. Another type of reaction is due to the tendency of the electron-deficient carbon atom of the carbonyl group to partially attract electrons from carbon atoms adjacent to it in the molecule, thus increasing the acidity of hydrogen atoms that are bonded to the adjacent carbon.
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carbonyl group[′kär·bə‚nil ‚grüp]
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.