Journal article

Formation and stability of gas-phase o-benzoquinone from oxidation of ortho-hydroxyphenyl: a combined neutral and distonic radical study

Matthew B Prendergast, Benjamin B Kirk, John D Savee, David L Osborn, Craig A Taatjes, Kye-Simeon Masters, Stephen J Blanksby, Gabriel da Silva, Adam J Trevitt



Gas-phase product detection studies of o-hydroxyphenyl radical and O2 are reported at 373, 500, and 600 K, at 4 Torr (533.3 Pa), using VUV time-resolved synchrotron photoionisation mass spectrometry. The dominant products are assigned as o-benzoquinone (C6H4O2, m/z 108) and cyclopentadienone (C5H4O, m/z 80). It is concluded that cyclopentadienone forms as a secondary product from prompt decomposition of o-benzoquinone (and dissociative ionization of o-benzoquinone may contribute to the m/z 80 signal at photon energies ≳9.8 eV). Ion-trap reactions of the distonic o-hydroxyphenyl analogue, the 5-ammonium-2-hydroxyphenyl radical cation, with O2 are also reported and concur with the assignment o..

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University of Melbourne Researchers


Awarded by Australian Research Council

Awarded by Centre of Excellence For Free Radical Chemistry and Bio-technology

Awarded by National Aeronautics and Space Administration

Awarded by National Nuclear Security Administration

Funding Acknowledgements

The authors are grateful for the financial support of the Australian Research Council through the Discovery programs (SJB: DP140101237; AJT and GdS: DP 130100862; GdS: FT130101304) and Centre of Excellence For Free Radical Chemistry and Bio-technology (CE0561607). The authors also acknowledge the generous allocation of computing resources by the NCI National Facility (Canberra, Australia) under Merit Allocation Scheme. BBK is supported by the National Aeronautics and Space Administration (NNH13AV43I). JDS, DLO, and CAT are supported by the Division of Chemical Sciences, Geosciences, and Biosciences, the Office of Basic Energy Sciences, the U.S. Department of Energy. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under contract DE-AC04-94-AL85000. This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility at the Lawrence Berkeley National Laboratory. MBP would like to acknowledge Dr. Phillip J. Tracey for discussions on distonic radical cation experiments.