title: Formation and Stabilization of Environmentally Persistent Free Radicals Induced by the Interaction of Anthracene with Fe(III)-Modified Clays.
abstract: Environmentally persistent free radicals (EPFRs) are occasionally detected in Superfund sites but the formation of EPFRs induced by polycyclic aromatic hydrocarbons (PAHs) is not well understood. In the present work, the formation of EPFRs on anthracene-contaminated clay minerals was quantitatively monitored via electron paramagnetic resonance (EPR) spectroscopy, and surface/interface-related environmental influential factors were systematically explored. The obtained results suggest that EPFRs are more readily formed on anthracene-contaminated Fe(III)-montmorillonite than in other tested systems. Depending on the reaction condition, more than one type of organic radicals including anthracene-based radical cations with g-factors of 2.0028-2.0030 and oxygenic carbon-centered radicals featured by g-factors of 2.0032-2.0038 were identified. The formed EPFRs are stabilized by their interaction with interlayer surfaces, and such surface-bound EPFRs exhibit slow decay with 1/e-lifetime of 38.46 days. Transformation pathway and possible mechanism are proposed on the basis of experimental results and quantum mechanical simulations. Overall, the formation of EPFRs involves single-electron-transfer from anthracene to Fe(III) initially, followed by H2O addition on formed aromatic radical cation. Because of their potential exposure in soil and atmosphere, such clay surface-associated EPFRs might induce more serious toxicity than PAHs and exerts significant impacts on human health.
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.
authors.forename: Hanzhong
authors.initials: H
authors.lastname: Jia
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.|School of Geology and Mining Engineering, Xinjiang University , Urumqi 830046, China.
authors.forename: Gulimire
authors.initials: G
authors.lastname: Nulaji
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Gao
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.
authors.forename: Fu
authors.initials: F
authors.lastname: Wang
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences , 40-1 South Beijing Road, Urumqi 830011, China.
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Wang
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D006801:Humans; D012987:Soil / Q000737:chemistry
chemical_list: D000873:Anthracenes; D005290:Ferric Compounds; D005609:Free Radicals; D012987:Soil