The mechanism and dynamical properties for the reaction of NCS and OH radicals have been investigated theoretically. The minimum energy paths (MEP) of the reaction were calculated using the density functional theory (...The mechanism and dynamical properties for the reaction of NCS and OH radicals have been investigated theoretically. The minimum energy paths (MEP) of the reaction were calculated using the density functional theory (DFT) at the B3LYP/6-311+G** level, and the energies along the MEP were further refined at the QCISD(T)/6-311+G** level. As a result, the reaction mechanism of the title reaction involves three channels, producing HCS+NO and HNC+SO products, respectively. Path I and path II are competitive, with some advantages for path I in kinet-ics. As for path III, it looks difficult to react for its high energy barrier. Moreover, the rate constant have been cal-culated over the temperature range of 8002500 K using canonical variational transition-state theory (CVT). It was found that the rate constants for both path I and path II are negatively dependent on temperature, which is similar with the experimental results for reactions of NCS with NO and NO2, and the variational effect for the rate constant calculation plays an important role in whole temperature range.展开更多
基金Project supported by the Natural Science Foundation of Jilin Province (No. 20010344) the Foundation of Education Bureau of Hainan Province (No. hjkj200312) and the Science Foundation for Excellent Youth of Northeast Normal University (No. 111382).
文摘The mechanism and dynamical properties for the reaction of NCS and OH radicals have been investigated theoretically. The minimum energy paths (MEP) of the reaction were calculated using the density functional theory (DFT) at the B3LYP/6-311+G** level, and the energies along the MEP were further refined at the QCISD(T)/6-311+G** level. As a result, the reaction mechanism of the title reaction involves three channels, producing HCS+NO and HNC+SO products, respectively. Path I and path II are competitive, with some advantages for path I in kinet-ics. As for path III, it looks difficult to react for its high energy barrier. Moreover, the rate constant have been cal-culated over the temperature range of 8002500 K using canonical variational transition-state theory (CVT). It was found that the rate constants for both path I and path II are negatively dependent on temperature, which is similar with the experimental results for reactions of NCS with NO and NO2, and the variational effect for the rate constant calculation plays an important role in whole temperature range.
