Reactions of Gas-Phase Phenanthrene under Simulated Atmospheric Conditions

Atmospheric Environment

Yang

Meng

et al. 2010

a b s t r a c tThe reactions of gas-phase phenanthrene and suspended phenanthrene particles with ozone were conducted in a 200l chamber. The secondary organic aerosol formation was observed in the reaction of gas-phase phenanthrene with ozone and simultaneously the size distribution of the secondary organic aerosol was monitored with a scanning mobility particle sizer during the formation process. The particulate ozonation products from both reactions were analyzed with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer. 2,2 0 -Diformylbiphenyl was identified as the dominant product in both homogeneous and heterogeneous reactions of phenanthrene with ozone. GC/MS analysis of ozonation products of phenanthrene in glacial acetic acid was carried out for assigning time-of-flight mass spectra of reaction products formed in the homogeneous and heterogeneous reactions of phenanthrene with ozone.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Homogeneous and heterogeneous reactions of phenanthrene with ozone

Atmospheric Environment

Yang

Meng

et al. 2010

“…Early studies on the PAH ozonation mainly involved in the gas phase PAHs with less than three benzenoid rings. Most of these researches were designed to obtain the reaction rates Atkinson and Carter, 1984;Kwok et al, 1994). In the last decade, the reactions of gas phase ozone with PAHs dissolved in organic solvents and coated on various kinds of nucleus were studied intensively.…”

Section: Introductionmentioning

confidence: 99%

Online investigations on ozonation products of pyrene and benz[a]anthracene particles with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer

Gao

Atmospheric Environment

Meng

et al. 2009

a b s t r a c tThe reaction products of ozone with pyrene and benz [a]anthracene absorbed on azelaic acid particles under the pseudo-first-order reaction conditions have been investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The pyrene and benz [a]anthracene particles with the initial concentrations of w1 mg m À3 are respectively exposed to w22 ppm ozone in a reaction chamber with a volume of w180 L. The time-of-flight mass spectra of the particulate ozonides are obtained. The assignments of the mass spectra reveal that 4-carboxy-5-phenanthrenecarboxyaldehyde (71%) and hydroxypyrene (23%) are the main solid state ozonides of pyrene, while 2-(2-formyl)phenyl-3-naphthoic acid (35%), hydroxybenz[a]anthrone (30%), and benz[a]anthracene-7, 12-dione (18%) are the main solid state ozonides of benz [a]anthracene. The pathways of the ozonations are proposed in the paper.

“…The RRKM method has been successfully used to deal with several reactions. 27,54,55 The calculated values along with the for the addition reaction of anthracene with OH radicals. From the good agreement with experimental values, it might be inferred that the RRKM individual rate constants are reasonable.…”

mentioning

confidence: 99%

Role of Water Molecule in the Gas-Phase Formation Process of Nitrated Polycyclic Aromatic Hydrocarbons in the Atmosphere: A Computational Study

Gao

et al. 2014

Environ. Sci. Technol.

Nitro-PAHs are globally worrisome air pollutants because their high direct-acting mutagenicity and carcinogenicity. A mechanistic understanding of their formation is of crucial importance for successful prevention of their atmospheric pollution. Here, the formation of nitroPAHs arising from the OH-initiated and NO 3 -initiated atmospheric reactions of PAHs was investigated by using quantum chemical calculations. It is widely assumed that OH or NO 3 radicals attack on the C atoms of the aromatic rings in the PAH molecule, followed by the addition of NO 2 to the OH−PAH or NO 3 −PAH adducts at the ortho position and the loss of water or nitric acid to form nitro-PAHs. However, calculations show that the direct loss of water from the OH−NO 2 −PAH adducts via the unimolecular decomposition is energetically unfavorable. This study reveals for the first time that water molecule plays an important catalytic effect on the loss of water from the OH−NO 2 −PAH adducts and promotes the formation of nitro-PAHs. In addition, the introduction of water unwraps new formation pathway through the addition of NO 2 to the OH−PAH or NO 3 −PAH adduct at the para position. The individual and overall rate constants for the addition reactions of PAHs with OH and NO 3 radicals were deduced by using the Rice−Ramsperger−Kassel−Marcus (RRKM) theory.