Atmospheric Oxidation Mechanism of Phenol Initiated by OH Radical

2013 ◽  
Vol 117 (11) ◽  
pp. 2358-2364 ◽  
Author(s):  
Cui Xu ◽  
Liming Wang
Keyword(s):  
Oxidation Mechanism ◽  
Atmospheric Oxidation ◽  
Oh Radical

Atmospheric oxidation mechanism of polyfluorinated sulfonamides — A quantum chemical and kinetic study

2013 ◽  
Vol 91 (6) ◽  
pp. 472-478 ◽  
Author(s):  
Xiaoyan Sun ◽  
Lei Ding ◽  
Qingzhu Zhang ◽  
Wenxing Wang
Keyword(s):  
Rate Constants ◽  
Density Functional ◽  
Single Point ◽  
Oxidation Mechanism ◽  
Basis Set ◽  
Atmospheric Oxidation ◽  
Oh Radicals ◽  
Oh Radical ◽  
Orbital Theory ◽  
Point Energy

Polyfluorinated sulfonamides (FSAs, F(CF2)nSO2NR1R2) are present in the atmosphere and may serve as the source of perfluorocarboxylates (PFCAs, CF3(CF2)nCOO–) in remote locations through long-range atmospheric transport and oxidation. Density functional theory (DFT) molecular orbital theory calculations were carried out to investigate OH radical-initiated atmospheric oxidation of a series of sulfonamides, F(CF2)nSO2NR1R2 (n = 4, 6, 8). Geometry optimizations of the reactants as well as the intermediates, transition states, and products were performed at the MPWB1K level with the 6-31G+(d,p) basis set. Single-point energy calculations were carried out at the MPWB1K/6-311+G(3df,2p) level of theory. The OH radical-initiated reaction mechanism is given and confirms that the OH addition to the sulfone double bond producing perfluoroalkanesulfonic acid directly cannot occur in the general atmosphere. Canonical variational transition-state (CVT) theory with small curvature tunneling (SCT) contribution was used to predict the rate constants. The overall rate constants were determined, k(T) (N-EtFBSA + OH) = (3.21 × 10−12) exp(–584.19/T), k(T) (N-EtFHxSA + OH) = (3.21 × 10−12) exp(–543.24/T), and k(T) (N-EtFOSA + OH) = (2.17 × 10−12) exp(–504.96/T) cm3 molecule−1 s−1, over the possible atmospheric temperature range of 180–370 K, indicating that the length of the F(CF2)n group has no large effect on the reactivity of FSAs. Results show that the atmospheric lifetime of FSAs determined by OH radicals will be 20–40 days, which agrees well with the experimental values (20–50 days), 20 thus they may contribute to the burden of perfluorinated pollution in remote regions.

Products, mechanism, and kinetics of OH radical-initiated oxidation degradation of 2,4,4′-trichlorobiphenyl in the atmosphere

RSC Advances ◽  
2016 ◽  
Vol 6 (66) ◽  
pp. 61794-61802 ◽  
Author(s):  
Yanhui Sun ◽  
Qingzhu Zhang ◽  
Wenxing Wang
Keyword(s):  
Polychlorinated Biphenyls ◽  
Oxidation Mechanism ◽  
Oxidation Products ◽  
Atmospheric Oxidation ◽  
Kinetic Properties ◽  
Oh Radical ◽  
Crucial Importance ◽  
Mechanism And Kinetics ◽  
Oxidation Degradation ◽  
Kinetics Of

To better understand the behavior, fate and oxidation products of polychlorinated biphenyls (PCBs) in the atmosphere, probing the atmospheric oxidation mechanism and kinetic properties of PCBs is of crucial importance.

scholarly journals Atmospheric oxidation of 4-(2-Methoxyethyl) phenol initiated by OH radical in the presence of O2 and NOx: A mechanistic and kinetic study

2020 ◽  
Author(s):  
Junfang Yao ◽  
Yanan Sun ◽  
Yizhen Tang ◽  
yunju zhang ◽  
Wenzhong Wu ◽  
...  
Keyword(s):  
Rate Constant ◽  
Density Functional ◽  
Oxidation Mechanism ◽  
Oxidation Products ◽  
Atmospheric Oxidation ◽  
Oh Radical ◽  
Quantum Chemical Methods ◽  
The Density Functional Theory ◽  
Reaction Channels ◽  
Individual Rate

4-(2-Methoxyethyl) phenol (MEP) is an significant methoxypheolic compound, which has been shown to play an important role in the formation of secondary organic aerosols(SOA). The present work focuses on the gas-phase oxidation mechanism and kinetics of MEP and OH radical by the density functional theory (DFT). Energetically favourable reaction channels and feasible products were identified. The initial reactions of MEP with OH radical have two different channels: OH addition and H abstraction. Subsequent reaction schemes of main intermediates in the presence of O2 and NOx are investigated using quantum chemical methods at M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. Ketene, Phenyldiketones and nitrophenol compounds are demonstrated to be possible oxidation products. The total rate constant(1.69×10-11 cm3 molecule-1 s-1) and individual rate constant are calculated using the traditional transition state (TST) theory at 298K and 1atm. The lifetime of MEP is estimated to be 16.4 hours, which provides a comprehensive explanation for atmospheric oxidation pathway of MEP and shows MEP would be removed by OH radical in the atmosphere.

Atmospheric oxidation of fluoroalcohols initiated by ·OH radical in the presence of water and mineral dusts: Mechanism, kinetics, and risk assessment

2021 ◽  
Author(s):  
Feng-Yang Bai ◽  
Ming-Shuai Deng ◽  
Mei-Yan Chen ◽  
Lian Kong ◽  
Shuang Ni ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Environmental Risks ◽  
Atmospheric Oxidation ◽  
Oh Radical ◽  
Mineral Dusts

The transport and formation of fluorinated compounds are greatly significant due to their possible environmental risks. In this work, the ·OH-mediated degradation of CF3CF2CF2CH2OH and CF3CHFCF2CH2OH in the existence of...

Atmospheric Oxidation Mechanism of 1,2-Dibromoethane†

2009 ◽  
Vol 113 (26) ◽  
pp. 7189-7204 ◽  
Author(s):  
Carrie J. Christiansen ◽  
Joseph S. Francisco
Keyword(s):  
Oxidation Mechanism ◽  
Atmospheric Oxidation
Sign in / Sign up

Export Citation Format

Share Document