User:B Saward/initiation (chemistry)
In chemistry, initiation is a chemical reaction that triggers one or more secondary reactions. Often the initiation reaction generates a reactive intermediate from a stable molecule which is then involved in secondary reactions. In polymerisation, initiation is followed by a chain reaction and termination.[1]
Classes of Initiators
[edit]Different classes of compounds may be broken down under photolytic or thermolytic conditions to produce radical species:
Peroxides
[edit]The peroxides are common initiators due to the weak oxygen-oxygen bond that can be homolytically cleaved by heat or UV-light. An example is benzoyl peroxide which undergoes thermolysis above 160oC, to liberate carbon dioxide and phenyl radicals.
Halogens
[edit]Halogens such as bromine will decompose
References
[edit]- ^ IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). ISBN 0-9678550-9-8. doi:10.1351/goldbook.