Free Radical Chain Mechanism
A chain mechanism in which the propagating intermediates are species bearing unpaired electrons.
Formula / equation
X· + RH → HX + R·
Unit
Dimensionless
In depth
Initiation generates radicals by homolysis under heat or light, propagation steps consume one radical and produce another, and termination combines two radicals to end the chain. Because propagation steps have low activation energies, the sequence is fast once started.
Examples in the real world
UV light splitting Cl₂ to start methane chlorination; chlorine radicals from CFCs destroying stratospheric ozone.