Addition Reaction

(redirected from addition reactions)
Also found in: Dictionary, Thesaurus, Medical.

addition reaction

[ə′di·shən rē′ak·shən]
(organic chemistry)
A type of reaction of unsaturated hydrocarbons with hydrogen, halogens, halogen acids, and other reagents, so that no change in valency is observed and the organic compound forms a more complex one.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Addition Reaction


one of the main types of chemical reaction in which a single new substance is formed from two or more individual substances, for example, NH3 + HCl = NH4Cl. Addition reactions include many reactions involving the recombination of atoms and radicals (H + H = H2 and CH3 + C2H5 = C3H8), reactions involving the addition of halogens to unsaturated aromatic compounds (C6H6 + 3C12 = C6H6C16), reduction reactions (C2H4 + H2 = C2H6), and reactions for the formation of complex compounds. Addition reactions are often intermediate steps in complex chemical processes.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
When the reaction was performed using [Br.sub.2] as a catalyst without adding any bromoform, only isomerized product was formed with no addition reaction taking place in all three methods.
Vinyl (1,2) microstructure dominates the poly(butadiene) resin (90% of monomer units), and addition reactions may dominate the cure mechanism.
(5-7) Commercial ASPE-based diamines are derived from the Michael addition reaction between aliphatic diamines and diethyl maleate (DEM).
This was already observed in the results section and it was explained by the decrease in residual unsaturation upon increasing the peroxide level, due to enhanced addition reactions, and the subsequent decreased susceptibility for further crosslinking during aging.
Alkenes in general are known to undergo addition reactions at lower temperatures and allylic substitution at higher temperatures.
Alkenes are known to undergo addition reactions at lower temperatures and/or isomerization at higher temperatures.
Of course, the desired reaction pathway for a polymer radical (Po) is crosslink formation either through coupling with another polymer radical or addition reactions through in-chain or pendant double bonds (unsaturated elastomers).
Kinetic Model for Michael Addition Reactions. The following elementary reactions based on the proposed Michael addition reaction mechanism shown in Scheme 2 are considered:
This issue covers reactions of aldehydes and ketones and their derivatives; reactions of carboxylic, phosphoric and sulfonic acids and their derivatives; oxidation and reduction; carbenes and nitrenes; nucleophilic and electrophilic aromatic substitution; carbocations; nucleophilic aliphatic substitution; carbanions and electrophilic aliphatic substitution; elimination reaction; addition reactions (polar addition and cycloaddition); and molecular rearrangements.
The common reactions which occur with the carbodiimides, - N = C = N--, occur as addition reactions. The R groups attached to the carbodiimide functionality determine selectively what type of addition reactions occur and under what kinetically driven conditions.
The kinetic model simulation has to be able to either describe the complete cross-linking process phenomenologically (4) or mechanistically (5-7) including homolytic cleavage of the peroxide, beta cleavage of the oxy radical, hydrogen abstraction, addition reactions, radical coupling (cross-link formation), polymer scission, and radical transfer for a wide range of compositions and an assortment of elastomers, using a single set of rate constants.