Jordan University of Science and Technology
Theoretical derivation for reaction rate constants of H abstraction from thiophenol by the H/O radical pool
Marwan Batiha, Mohammednoor Altarawneh, Mohammad Al-Harahsheh, Ibrahem Altarawneh, Saleh Rawadieh
Reaction and activation energy barriers are calculated for the H abstraction reactions
(C6H5SH + X?C6H5S + XH, X = H, OH and HO2) at the BB1K/GTLarge level of theory. The corresponding
reactions with H2S and CH3SH are also investigated using the G3B3 and CBS-QB3 methods in order to
demonstrate the accuracy of BB1K functional in finding activation barriers for hydrogen atom transfer
reactions. Arrhenius parameters for the title reactions are fitted in the temperature range of 300 K?
2000 K. The calculated reaction enthalpies are in good agreement with their corresponding experimental
reaction enthalpies. It is found that H abstraction by OH radicals from the thiophenol molecule proceed in
a much slower rate in reference to the analogous phenol molecule. DfHo
298 of thiophenoxy radical is calculated
to be 63.3 kcal/mol. Kinetic parameters presented herein should be useful in describing the
decomposition rate of thiophenol; i.e., one of the major aromatic sulfur carriers, at high temperatures.