精确计算化学键解离能的ONIOM-G3B3方法及其在抗氧化剂研究中的应用  

Accurate Calculation of Bond Dissociation Enthalpy of ONIOM-G3B3 and the Application to Study of Natural Antioxidant

作　　者：李敏杰[1] 傅尧[1] 王华静[1] 李玉琪[1] 刘磊[1] 郭庆祥[1] 

机构地区：[1]中国科学技术大学化学系,合肥230026

出　　处：《化学学报》2007年第13期1243-1252,共10页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.20472079;20602034)资助项目

摘　　要：通过对179个有机化合物C—H,N—H,O—H键离解能的理论计算,系统评估了高精度组合从头算方法(ONIOM-G3B3)和密度泛函理论方法(B3LYP)在预测键离解能上的可靠性.研究发现ONIOM-G3B3方法可以准确预测各类有机化合物的键解离能,精度达到5.9 kJ/mol.运用ONIOM-G3B3方法成功预测了两类重要的天然抗氧化剂维生素E族和茶多酚族的键解离能,并进一步讨论了抗氧化活性、自由基清除机理及其构效关系.Composite ab initio method （ONIOM-G3B3） and density functional theory （B3LYP） were evaluated against 179 experimental C-H, O-H and N-H bond dissociation enthalpies of diverse organic molecules to verify their performance. It was found that the ONIOM-G3B3 predictions were in good agreement with the experimental values for these three types of bond dissociation enthalpies, and the accuracy was about 5.9 kJ/mol. Finally, armed with this powerful tool two interesting classes of natural antioxidants including vitamin E and catechins in tea were studied. Discussions were made about the antioxidant activity, radical scavenge mechanism and structure-activity relationships.

关 键 词：ONIOM—G383 密度泛函理论 键离解能 维生素E 茶多酚 

分 类 号：O641.1[理学—物理化学]