Synchrotron Photoionization Study of Mesitylene Oxidation Initiated by Reaction with Cl(²P) or O(³P) Radicals

This work studies the oxidation of mesitylene (1,3,5-trimethylbenzene) initiated by O(³P) or Cl(²P) atoms. The O(³P) initiated mesitylene oxidation was investigated at room temperature and 823 K, whereas the Cl-initiated reaction was carried out at room temperature only. Products were probed by a multiplexed chemical kinetics photoionization mass spectrometer using the synchrotron radiation produced at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Reaction products and intermediates are identified on the basis of their time behavior, mass-to-charge ratio, ionization energies, and photoionization spectra. Branching yields are derived for the O-initiated reaction at 823 K and the Cl-initiated reaction at room temperature. Reaction schematics are proposed and presented.