【摘要】 对 17种酚类化合物用半经验量子化学方法AM1计算了表征OH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的生成热之差。经过与实验测定的 17种酚类化合物的OH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OH解离能有很好的相关性 (r =0 .94 95 ) ,优于经验方法 ,比如加和规则对OH解离能的预测。虽然AM1方法在计算间位取代基对OH解离能的贡献方面是无效的 ,但将它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。更多还原

【Abstract】 The OH bond dissociation energy (BDE) experimentally 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 generated after Habstraction reaction (△HOF). It was found that the AM1 calculated △HOF correlated well with the OH BDE ( r =0.9495), and AM1 was better than empirical method such as additive rule derived from experiments to estimate the OH BDE. Although AM1 was invalid to characterize the contribution of meta groups to the OH BDE, it is fairly applicable in calculating BDE like parameters to predict free radical scavenging activity of phenolic antioxidants.更多还原