QSPRs on photodegradation half-lives of atmospheric chlorinated polycyclic aromatic hydrocarbons associated with particulates

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• 作者：Junfeng Niu ; Lili Wang ; Zhifeng Yang
• 关键词：Photodegradation ; QSPR ; CIPAHs ; PLS ; Quantum chemical descriptors
• 刊名：Ecotoxicology and Environmental Safety
• 出版年：2007
• 期刊代码：77_01476513
• 类别：env
• 出版时间：February 2007
• 卷：66
• 期：2
• 页码：272-277
• 文件大小：182 K

摘要

A quantitative structure–property relationship (QSPR) model which could predict photodegradation half-lives (t_1/2) of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) associated with particulates in the atmosphere was developed by applying quantum chemical parameters computed with quantum chemical PM3 algorithm and using a partial least squares (PLS) algorithm. The cross-validated Q²_cum value for the optimal QSPR model is 0.960, indicating a good predictive capability for log t_1/2 values of ClPAHs. The QSPR results show that the main factors affecting log t_1/2 values of ClPAHs are the energy of the second highest occupied molecular orbital (E_LUMO−1), the energy of the second highest occupied molecular orbital (E_HOMO+1), average molecular polarizability (α), the most positive net atomic charges on a hydrogen atom (), E_LUMO+E_HOMO, E_LUMO−E_HOMO, and (E_LUMO−E_HOMO)². ClPAHs with high E_LUMO−1, E_HOMO+1, E_LUMO−E_HOMO, and (E_LUMO−E_HOMO)² values tend to photolyze slowly in the atmosphere. In contrast, increasing E_LUMO+E_HOMO, α, and values leads to the increase of photodegradation rates.