ABSTRACT
Interest in free radicals began with the work of Gomberg (1900), who demonstrated the existence of the triphenylmethyl radical (Ph
C
∑). The triphenylmethyl radical is stable enough to exist in solution at room temperature, often in equilibrium with a dimeric form. At room temperature, this concentration of Ph
C
in benzene is 2%. Although triphenylmethyl-type radicals are stabilized by resonance, it is steric hindrance to dimerization and not resonance that is the cause of their stability.
