表征O－H解离能参数的AM1计算

对17种酚类化合物用半经验量子化学方法AM1计算了表征O－H解离能的参数△HOF值，即酚类化合物与其经抽氢反应产生的自由基生成热之差。经过与实验测定的17种酚类化合物的O－H解离能比较，评价了AM1方法在计算△HOF值方面的有效性。发现AM1计算的△HOF值与O－H解离能有很好的相关性(γ=0.9495)，优于经验方法，比如加和规则对O－H解离能的预测。虽然AM1方法在计算间位取代对O－H解离能的贡献方面是无效的，但将用于计算解离能类的参数以预测抗氧化剂活性还是可行的。

AM1 Calculation of a Parameter Characterizing O

The OH bond dissociation energy (BDE) expe rimentally determined for 17 phenols were employed to evaluate the effectiveness of AM1 method used in calculating a parameter characterizing the OH BDE, the difference of heat of formation between phenol and its free radical generat ed after Habstraction reaction (△HOF). It was found that the AM1 calcula ted △HOF correlated well with the OH BDE (r=0.9495), and AM1 was bet ter than empirical method such as additive rule derived from experiments to esti mate the OH BDE. Although AM1 was invalid to characterize the contributio n of meta groups to the OH BDE, it is fairly applicable in calculating BD E-like parameters to predict free radical scavenging activity of phenolic antio xidants.