Kinetics and mechanism of the water-assisted reaction of NCO with CH3OH: A quantum chemical study

The mechanism and kinetics of the hydrogen abstraction reaction between the NCO radical and CH3OH without and with one water molecule have been investigated theoretically. The potential energy surface profiles have been constructed at the CCSD(T)/6-311++G(2df,2pd)//BH&HLYP/6-311++G(2df,2pd) + ZPE × 0.9335 level. The calculations show that the presence of one water molecule can noticeably reduce the energy barrier. However, the computed rate constants temperatures of 220–600 K for the reaction with water is much smaller than that of the naked reaction. We would therefore expect that one water molecule could not play important roles on the NCO + CH3OH reaction in the atmosphere.