free radical substitution Flashcards
1
Q
what are the 3 steps of free radical substitution ?
A
initiation
propagation 1st and 2nd
termination
2
Q
what happens in initiation?
A
halogen akways breaks down into 2 free radicals
3
Q
what happens in propagation 1st step?
A
the starting molecule of equation reacts with a free radical
after arrow HX is formed (x is halogen)
the end product is the starting molecule with one less hydrogen as a free radical
symbol needs to be on left
haloalkane isnt produced yet
4
Q
what happens in 2nd propagation?
A
free radical from end of step 1 reacts with halogen in normal state (X2) diatomic
halogen free radical at the end
5
Q
what happens in termination?
A
2 free radicals form a non free radical
e.g Cl* + Cl*——> Cl2
6
Q
what is an essential condition for this mechanism?
A
uv light or high temp
