中文摘要：

利用6种密度泛函理论方法（B3LYP，B3P86，MPW1K，TPSS1KCIS，X3LYP，BMK）对碳氯键离解能进行理论计算．结果发现几种新发展的密度泛函（DFT）方法用于碳氯键离解能的计算比传统的B3LYP有较大的改善，其中对能量估算相对准确的B3P86方法对碳氯键离解能的计算精度最高，对17个分子中碳氯键离解能计算的平均绝对偏差为6．58kJ／mol．最后运用B3P86方法对一系列环境危害较大，但可通过光化学降解和生物降解的氯代有机物的碳氯键离解能值进行预测，并讨论了影响碳氯键离解能的结构性质关系．

英文摘要：

The bond dissociation enthalpies （BDEs） of the C-Cl bonds were calculated by using six density functional theory （DFT） methods （B3LYP, B3P86, MPW1K, TPSS1KCIS, X3LYP, BMK）. The results were compared with the corresponding experimental values to examine the reliability of these methods. It was found that although some new methods developed in recent years were found to be superior to B3LYP method, they were not the best density functional methods for the calculation of the BDEs of C-Cl bonds. However, the B3P86/6-311＋＋G （2df, 2p） level of theory was found to be most accurate, with an mean absolute deviation of 6.58 kJ/mol for 17 C-Cl bonds. Finally, armed with the theoretical tool the C-Cl BDEs of some persistent environmental pollutants were calculated. The substituent effects were discussed.