Radical substitution Flashcards
What are the conditions required for radical subsitition?
UV light
What is a substitution reaction?
A reaction in which an atom or group of atoms is replaced with another atom or group of atoms
What is a radical?
A species with an unpaired electron
What is the chemical notation for a radical?
X°
What are the 3 stages of radical substitution?
Initiation, propagation and termination
What is the type of bond breaking in radical substitution?
Homolytic fission
Why does homolytic fission produce radicals?
It breaks covalent bonds equally and each atom takes 1 from the pair
Why is UV radiation required for the reaction?
Provide activation energy
What are the two stages in propagation?
The halogen radical reacts with the alkane to form a hydrogen halide and alkane radical. This alkane radical then reacts with the halogen to form the haloalkane and halogen radical
What are the key features of the propagation step>
You start and end with the same radicals
What are the 3 possible termination stages?
The two halide radicals react to form a halogen, the halide radical reacts with the alkane radical to form the haloalkane and the two alkane radicals react to form an alkane
What are limitations of using radical substitution in organic synthesis?
Further substitution can occur, substitution at different positions on the C chain can occur and the C chain may change in length
