Stability of Allyl Radicals

Inhibition of Radicals by Molecular Oxygen
• Occasionally, two radicals react to form a sigma bond.
• An example is the reaction of a radical with oxygen (a diradical in its
ground state electronic configuration).
• Reaction with oxygen causes the reaction to slow down or stop, as X–O–
O• radicals are not as reactive as halogen radicals.
• Compounds that prevent radical reactions from occurring are called
radical inhibitors or radical scavengers.
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