硝基多环芳烃光降解的抽氢反应研究

Investigation of the Hydrogen Abstraction Reaction in Photolysis of Nitro-polycyclic Aromatic Hydrocarbon

硝基多环芳烃的致突变和致癌性远高于多环芳烃,是不可忽视的大气污染物,光降解是其主要降解途径。硝基多环芳烃光照主要产生氮氧自由基、芳氧自由基和最低激发三重态。其最低激发三重态寿命可达微秒量级,极易与气溶胶中的酚类污染物进行氢转移反应,最终被还原成胺。本文选取1-溴-5-硝基萘为研究对象,利用瞬态吸收光谱,获得了其与醇和酚光化学反应的动力学信息和中间体特征吸收。利用量子化学计算指认中间体结构,进而推导氢转移反应的机理。

Nitro-polycyclic aromatic hydrocarbons(NPAHs) in polluted air are more mutagenic and carcinogenic to humans than their comparable unmodified PAHs counterparts. At ambient circumstances, photolysis is the dominant degradation pathway for NPAHs. The main photolysis pr oducts are excited triplet states and aryloxy radicals. The lowest excited triplet state of NPAHs is capable of reacting with phenol compounds emitted from diesel exhaust via hydrogen transfer reaction in the nanosecond to microsecond range. In this paper, nanosecond transient absorption spectroscopy and theoretical calculation were employed to investigate the detailed mechanism of hydrogen transfer reactions from alcohols and phenols to 1-bromo-5-nitronaphthalene.