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Reaction Mechanisms
Organic reaction mechanisms vocabulary
Term | Definition |
---|---|
Carbocation | An alkyl group carrying a single positive charge on one of its carbon atoms. |
Electrophile | A species that can act as an acceptor of a pair of electrons in an organic mechanism. |
Elimination | A reaction in which a small molecule, such as water or HCl, is removed from an organic molecule. |
Free radical | A very reactive atom or molecule that has a single unpaired electron. |
Free-radical substitution | The reaction in which halogen atoms substitute for hydrogen atoms in alkanes in three steps: initiation, propagation and termination. |
Initiation step | The first step in the mechanism of free-radical substitution of alkanes by halogens. It involves the breaking of the halogen-halogen bond by UV light from the Sun to form radicals. |
Friedel-Crafts reaction | The electrophilic substitution of an alkyl or acyl group group into a benzene ring. |
Nucleophile | A species that can act as a donor of a pair of electrons. |
Nucleophilic Adddition | The mechanism of the reaction in which a nucleophile attacks the electron deficient carbon atom in a carbonyl group and adds across the C=O bond. |
Propagation Step | A step in a free-radical mechanism in which the radicals formed can then attack reactant molecules generating more free-radicals in a chain reaction. |
Second-order nucleophilic substitution | The steps in a nucleophilic substitution reaction in which the rate of the reaction invloves two reacting species- the halogenoalkane and the nucleophile. |
First-order nucleophilic substitution | The steps in a nucleophilic substitution reaction in which the rate of the reaction invloves one reacting species- the halogenoalkane. |
Substitution | A reaction that involves the replacement of one atom, or group of atoms in a molecule, by another. |
Termination step | The final step in a free-radical mechanism in which two free radicals react together to form a molecule. |