Abstract:

The mechanism of the reaction HNCO +OH→H2 O +NCO has been studied by using ab initio MO method(at UMP4/6 31G** level) with energy gradient technique. The reaction path was traced with Fukui’s theory of intrinsic reaction coordinate (IRC). Along the IRC, some dynamics properties were investigated by applying reaction path Hamiltonian theory. On this basis, the rate constants of the reaction at different temperatures were calculated by transition state theory with correction of quantum effect. The theoretically calculated rate constants are in good agreement with experimental results. This shows that the reaction is a direct reaction of hydrogen abstraction with only one step.

Key words: Reaction mechanism, Intrinsic reaction coordinate, Reaction rate constants, Ab initio MO method