Direct Dynamics Simulations of the CH + O Reaction at High Temperature.

Direct dynamics simulations with the M06/6-311++G(d,p) level of theory were performed to study the CH + O reaction at 1000 K temperature on the ground state singlet surface. The reaction is complex with formation of many different product channels in highly exothermic reactions. CO, CO, HO, OH, H, O, H, and HCO are the products formed from the reaction. The total simulation rate constant for the reaction at 1000 K is (1.2 ± 0.3) × 10 cm molecule s, while the simulation rate constant at 300 K is (0.96 ± 0.28) × 10 cm molecule s. The simulated product yields show that CO is the dominant product and the CO:CO ratio is 5.3:1, in good comparison with the experimental ratio of 4.3:1 at 1000 K. On comparing the product yields for the 300 and 1000 K simulations, we observed that, except for CO and HO, the yields of the other products at 1000 K are lower at 300 K, showing a negative temperature dependence.