Nounsubstituent (plural: substituents)
In organic chemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon. The suffix -yl (meaning "attached to") is used when naming organic compounds that contain a substituent. Additionally, when naming hydrocarbons that contain a substituent, positional numbers are used to indicate which carbon atom the substituent is attached to when such information is needed to distinguish between structural isomers. The polar effect exerted by a substituent is a combination of the inductive effect and the mesomeric effect. Additional Steric effects result from the volume occupied by a substituent.
The phrases most-substituted and least-substituted are frequently used to describe molecules and predict their products. For example:
Number crunchingOne cheminformatics study identified 849,574 unique substituents up to 12 non-hydrogen atoms large and containing only C,H,N,O,S,P,Se and the halogens in a set of 3,043,941 molecules. 50 common substituents are found in only 1% of this set and 438 in 0.1%. 64% of the substituents are unique to just one molecule. The top 5 consists of the phenyl, chlorine, methoxy, hydroxyl and ethyl substituent. The total number of organic substituents in organic chemistry is estimated at 3.1 million creating a total of 6.7×1023 molecules.
- Database of 21,000 substituents and 49,000 linkers extracted from bioactive molecules
substituent in Arabic: مستبدل
substituent in Bulgarian: Заместител
substituent in German: Substituenten
substituent in Spanish: Sustituyente
substituent in Hebrew: מתמיר
substituent in Finnish: Substituentti
substituent in Swedish: Substituent
substituent in Turkish: Ornatık
substituent in Chinese: 取代基