Journal article

Product detection study of the gas-phase oxidation of methylphenyl radicals using synchrotron photoionisation mass spectrometry

Matthew B Prendergast, Benjamin B Kirk, John D Savee, David L Osborn, Craig A Taatjes, Patrick Hemberger, Stephen J Blanksby, Gabriel da Silva, Adam J Trevitt

Physical Chemistry Chemical Physics | Royal Society of Chemistry | Published : 2019

Abstract

Product detection studies of the gas-phase oxidation of o-methylphenyl radicals and m-methylphenyl radicals are reported at ambient temperature (ca. 298 K) and 4 Torr (533.3 Pa) using VUV synchrotron photoionisation mass spectrometry. It is shown that cyclopentadienone (c-C5H4O) + CH3CO and o-quinone methide (o-CH2C6H4O) + OH are unique product pathways to the o-methylphenyl + O2 reaction due to mechanisms requiring the CH3 group to be adjacent to the phenyl radical site. Common product pathways include methylphenoxy radical + O(3P) and isomers of methylcyclopentadienone (CH3C5H4O) + HCO. G3X-K quantum chemical calculations are deployed to rationalise experimental results for o-methylphenyl ..

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University of Melbourne Researchers

Grants

Awarded by Australian Research Council


Awarded by U.S. Department of Energy's National Nuclear Security Administration


Awarded by Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy


Awarded by Swiss Federal Office of Energy


Funding Acknowledgements

The authors are grateful for the financial support of the Australian Research Council through the Discovery and Future Fellowship programs (DP170101596, DP140101237, DP130100862 and FT130101304). The authors also acknowledge the generous allocation of computing resources by the NCI National Facility (Canberra, Australia) under Merit Allocation Scheme. The participation of J. D. S., D. L. O., and C. A. T., and the development and operation of the MPIMS kinetics apparatus, are supported by the Office of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, United States Department of Energy. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the USDOE or the United States Government. Pyrolysis experiments were performed at the VUV (X04DB) beamline of the Swiss Light Source located at Paul Scherrer Institute, Switzerland. P. H. acknowledges financial support by the Swiss Federal Office of Energy (SI/501269-01) and Patrick Ascher for technical support.