Does resonance help radical stability?

1 Answer
Mar 1, 2017

Absolutely!

Explanation:

Recall that radical stability follows the trend:
https://www.clutchprep.com/organic-chemistry/radical-stability
From left to right we have a primary (#1^@#) radical, a secondary (#2^@#) radical, a tertiary (#3^@#) radical, an allylic radical, and a benzylic radical.

Radicals have an #sp^2# configuration in which the lone electron occupies the unhybridized p orbital. #sp^2# hybridization allows for pi bonding.

Consider this allylic radical
http://www.chem.ucalgary.ca/courses/351/exams/3513/353w13/353mt13mc.html

Using half arrows to denote electron movement, resonance of an allylic radical can be shown. Recall that resonance shows how charges can be delocalized among multiple atoms.

The same can be seen for a benzylic radical
http://web.pdx.edu/~wamserc/C335W07/E1ans.htm

Remember: The more resonance forms a structure has, the more stable it is