Extent of H-atom abstraction from OH + p-cymene and upper limits to the formation of cresols from OH + m-xylene and OH + p-cymene |
| |
| Authors: | Sara M Aschmann Janet Arey Roger Atkinson |
| |
| Institution: | 1. Air Pollution Research Center, University of California, Riverside, CA 92521, USA;2. Department of Environmental Sciences, University of California, Riverside, CA 92521, USA;3. Department of Chemistry, University of California, Riverside, CA 92521, USA;1. Departamento de Clínica Médica, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270, Brazil;2. Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU), Av. Pará, 1720, Bloco 2T, Campus Umuarama, Bairro Umuarama, Uberlândia, MG 38400-902, Brazil;3. Departamento de Medicina Veterinária, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Av. Duque de Caxias Norte 225, Campus da USP, Pirassununga, SP 13635-900, Brazil;1. IDAEA-CSIC, Jordi Girona, 18, E-08034 Barcelona, Spain;2. IRTA, E-08140 Caldes de Montbui, Spain;1. School of Chemistry, The University of Sydney, NSW 2006, Australia;2. School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, NSW 2052, Australia;3. School of Chemistry, UNSW Sydney, NSW 2052, Australia;4. Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA 94720, United States;1. College of Engineering, Center for Environmental Research and Technology, University of California, Riverside, CA 92521, USA;2. Air Pollution Research Center, University of California, Riverside, CA 92521, USA;1. National Institute for Research and Development in Environmental Protection, 294 Splaiul Independentei, 6th District, 060031 Bucharest, Romania;2. University of Bucharest, Faculty of Physics, P.O.Box MG-11, Bucharest, Romania;3. National Meteorological Administration, 97 Bucuresti-Ploiesti, 1st District, 013686 Bucharest, Romania |
| |
| Abstract: | Aromatic hydrocarbons are important constituents of vehicle exhaust and of non-methane volatile organic compounds in ambient air in urban areas. It has recently been proposed that dealkylation is a significant pathway for the OH radical-initiated reactions, leading to the formation of phenolic compounds and/or oxepins (Noda, J., Volkamer, R., Molina, M.J., 2009. Dealkylation of alkylbenzenes: a significant pathway in the toluene, o-, m-, and p-xylene + OH reaction. Journal of Physical Chemistry A 113, 9658–9666.). We have investigated the formation of cresols from the reactions of OH radicals with m-xylene and p-cymene, and obtain upper limits of <1% for formation of each cresol isomer from OH + m-xylene and <2% for formation of each cresol isomer from OH + p-cymene. In addition, we have measured the formation yield of 4-methylacetophenone (the major product formed subsequent to H-atom abstraction from the CH(CH3)2 group) in the OH + p-cymene reaction to be 14.8 ± 3.2%, and estimate that H-atom abstraction from the CH3 and CH(CH3)2 groups in p-cymene accounts for 20 ± 4% of the overall OH radical reaction. We also used a relative rate technique to measure the rate constant for the reaction of OH radicals with 4-methylacetophenone to be (4.50 ± 0.43) × 10?12 cm3 molecule?1 s?1 at 297 ± 2 K. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
