Free Radical Stability Homework: Find the Optimal Temp

[Priyadarshini]

Homework Statement

Homework Equations

The Attempt at a Solution

option 1: 1 degree C
option 2: 1 degree C
option 3: 3 degree C
option 4: 1 degree C

SO the answer should be option 3?

 

[Suraj M]

Is that the only stabilizing factor involved here?
Any polar effect involved?
PS- always thought saying tertiary or secondary carbon was a more universal naming system

 

[Priyadarshini]

Is that the only stabilizing factor involved here?
Any polar effect involved?
PS- always thought saying tertiary or secondary carbon was a more universal naming system

Why would there be a polar effect? Carbon and hydrogen have very similar electronegativities.
Yeah tertiary and primary are the universal terms, somehow this book doesn't refer to them as tertiary and primary carbons but as 1 degree, 2 degree and 3 degree carbons.

 

[Suraj M]

By polar effect, I am referring to mesmeric effect in this case

 

[Priyadarshini]

By polar effect, I am referring to mesmeric effect in this case

If the mesomeric effect is considered, then option 3 and 4 are ruled out. But I don't understand why I can't just see which carbon is tertiary and say that's the most stable.

 

[Suraj M]

Mesmeric effect ALWAYS dominates here

 

[Suraj M]

Decide between 1 and 2 then

 

[Wisc17]

I suggest thinking about what types of resonance give the greatest stability. Also consider drawing out resonance structures. Radical stability trends closely resemble carbocation trends (tertiary > secondary > primary). Think about where aromaticity fits into this trend.