The O-H bond dissociation energy (BDE) experimentally determined for 17 phgenols were employed to evaluate the effectiveness of AM1 method used in calculating a parameter characterizing the O-H BDE, the difference of heat of formation between phenol and its free radical generated after H- abstraction reaction (△ HOF). It was found that the AM1 calculated △ HOF correlated well with the O-H BDE (γ=0. 9495), and AM1 was better than empirical method such as additive rule derived from experiments to estimate the O-H BDE. Although AM1 was invalid to characterize the contribution of meta groups to the O- H BDE, it is fairly applicable in calculating BDE-like parameters to predict free radical scavenging activity of phenolic antioxidants.

Key words: QUANTUM CHEMISTRY, CHEMICAL BONDS, BOND PARAMETER, BOND ENERGY, SEMIEMPIRICAL EQUATIONS, PHENOL