THE KINETICS AND MECHANISM FOR THE UNIMOLECULAR DECOMPOSITION OF ACETOPHENONE: AB INITIO MO AND VTST/RRKM CALCULATIONS

摘要

The kinetics and mechanism for the unimolecular dissociation of acetophenone have been studied at the G2M (RCC, MP2) level of theory and rate constant prediction with statistical theory (VTST/RRKM) calculations. Seven reaction channels are considered in this study and the growing string method developed by Quapp [J. Chem. Phys. 122, 174106 (2005)] is used to obtain the potential energy surface (PES) for each channel. Four primary decomposition channels of acetophenone have been found to produce C{sub}6H{sub}5CO + CH{sub}3 without a barrier with the formation enthalpy of 80.62 kcal/mol, C{sub}6H{sub}5 + CH{sub}3CO without a barrier with the formation enthalpy of 95.92 kcal/mol, C{sub}6H{sub}6 + CH{sub}2CO with a barrier of 82.01 kcal/mol and C{sub}6H{sub}4CO + CH{sub}4 with a barrier of 84.71 kcal/mol. Based on the PES, we carried out VTST and RRKM calculations to predict the rate constants for these processes.