Theoretical investigations on direct photolysis mechanisms of polychlorinated diphenyl ethers

Wang, Se; Hao, Ce; Gao, Zheng-Ming; Chen, Jingwen; Qiu, Jieshan

doi:10.1016/j.chemosphere.2014.03.040

Cited by 14 publications

(6 citation statements)

References 45 publications

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“…According to the UV absorption spectrum of 3,4-dichlorodiphenyl ether inserted in figures 5, 253.7 nm UV radiation could be easily absorbed by 3,4-dichlorodiphenyl ether. Further, previous researches showed that the direct UV photolysis of PCBs has two potential reaction pathways including photodechlorination (C-Cl bond, 3.41 eV) and C-O bond (3.38 eV) photodissociation [41]. It means that the 253.7 nm UV radiation (4.89 eV) absorbed by 3,4-dichlorodiphenyl ether could break its C-Cl bond and C-O bond to achieve effectively photodissociation.…”

Section: Resultsmentioning

confidence: 99%

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

Zhao

Lian

2019

Plasma Sci. Technol.

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A new combined reactor with Hg/Ar electrodeless ultraviolet (EDUV) activated by DBD for 3,4-dichlorodiphenyl ether abatement is presented. The effect of specific input energy and feeding gas component on 3,4-dichlorodiphenyl ether removal efficiency has been explored. Compared with a single DBD system, this new combined process performed a significant promotion on 3,4-dichlorodiphenyl ether abatement. Experiment results verified that active oxygen clearly contributed to the synergistic activity of DBD-EDUV system. Results of emission spectra showed that UV radiation of 253.7 nm could be detected in the DBD-EDUV system. Further, the products of DBD-EDUV process were analyzed via gas chromatographymass spectrometer (GC-MS) to reveal involved decomposition mechanism.

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Section: Resultsmentioning

confidence: 99%

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

Zhao

Lian

2019

Plasma Sci. Technol.

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“…The ground-state and electronic excited-state geometry optimizations of C4A were performed by the DFT and TDDFT methods, respectively [45][46][47][48][49]. In our DFT and TDDFT calculations, the B3-LYP (Becke's three-parameter hybrid exchange function with Lee-Yang-Parr gradientcorrected correlation) functional and the TZVP (triple-ζ valence quality with one set of polarization functions) basis set were used [50,51].…”

Section: Methodsmentioning

confidence: 99%

Role of intramolecular hydrogen bonding in the excited-state intramolecular double proton transfer (ESIDPT) of calix[4]arene: A TDDFT study

Wang

Hao

2016

Open Physics

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Abstract:The time-dependent density functional theory (TDDFT) method was performed to investigate the excitedstate intramolecular double proton transfer (ESIDPT) reaction of calix [4]arene (C4A) and the role of the intramolecular hydrogen bonds in the ESIDPT process. The geometries of C4A in the ground state and excited states (S 1 , S 2 and T 1 ) were optimized. Four intramolecular hydrogen bonds formed in the C4A are strengthened or weakened in the S 2 and T 1 states compared to those in the ground state. Interestingly, upon excitation to the S 1 state of C4A, two protons H1 and H2 transfer along the two intramolecular hydrogen bonds O1-H1· · · O2 and O2-H2· · · O3, while the other two protons do not transfer. The ESIDPT reaction breaks the primary symmetry of C4A in the ground state. The potential energy curves of proton transfer demonstrate that the ESIDPT process follows the stepwise mechanism but not the concerted mechanism. Findings indicate that intramolecular hydrogen bonding is critical to the ESIDPT reactions in intramolecular hydrogen-bonded systems.

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“…PCDEs have been shown to undergo natural photolysis under environmental conditions and pyrolysis to generate PCDD/Fs, hydroxylated PCDEs (HO-PCDE) and chlorobenzene [87,88]. Among them, PCDD/Fs, especially PCDFs, are the main decomposition products [87,89].…”

Section: Photolysis and Pyrolysis Reactionsmentioning

confidence: 99%

Polychlorinated Diphenyl Ethers in the Environment: A Review and Future Perspectives

Wang

et al. 2023

IJERPH

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Polychlorinated diphenyl ethers (PCDEs) are a class of synthetic halogenated aromatic compounds, which have gradually attracted widespread attention due to potential environmental risks to humans and ecosystems. This paper presents a literature review of research on PCDEs using PubMed, Web of Science and Google Scholar as search engines/databases with no constraints on publishing year or number. A total of 98 publications on the sources, environmental levels, environmental behavior and fate, synthesis and analysis and toxicology of PCDEs were retrieved. Existing studies have shown that PCDEs widely exist in the environment with the ability of long-range transport, bioaccumulation and biomagnification, which are almost comparable to polychlorinated biphenyls. They can elicit adverse effects including hepatic oxidative stress, immunosuppression, endocrine disorders, growth retardation, malformations, reduced fertility and increased mortality in organisms, among which some seem to be related to the activation of the aryl hydrocarbon receptor. PCDEs can be metabolized into other organic pollutants, such as hydroxylated and methoxylated PCDEs and even polychlorinated dibenzo-p-dioxins and furans through biotransformation, photolysis and pyrolysis reactions in the environment. Compared with reviews on PCDEs published previously, some new information and findings are summarized in this review, such as new sources, current environmental exposure levels, main metabolism pathways in aquatic organisms, acute toxicity data for more species and relationships between structural parameters and toxicity and bioaccumulation potentials of PCDE congeners. Finally, current research deficiencies and future research perspectives are proposed to facilitate the assessment of health and ecological risks of PCDEs.

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Theoretical investigations on direct photolysis mechanisms of polychlorinated diphenyl ethers

Cited by 14 publications

References 45 publications

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

Role of intramolecular hydrogen bonding in the excited-state intramolecular double proton transfer (ESIDPT) of calix[4]arene: A TDDFT study

Polychlorinated Diphenyl Ethers in the Environment: A Review and Future Perspectives

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