Theoretical Studies on the Reaction Mechanisms of C3H2 (cyclopropenylidene) and O(3p) Radicals

The complex potential energy surface for the reaction of C3H2 (cyclopropenylidene) with O((3)p) was explored computationally using a density functional and ab initio QCISD(T) methods. The geometries of all the stationary points (transition states. intermediates and products) were fully optimized at the B3LYP/6-311+ + G** computational level, and the single point calculation including full population analysis was performed by employing QCISD(T). Our results show that the product P1 (C2H+HCO) is the major product, while the products P-2(C2H2+ CO) and P3 (HC3O+H) are minor products, as confirmed by experiment. Product P1 could be gained through the path: R -> IM1 -> IM2 -> P1, and the C3H2+O(P-3) reaction was expected to be rapid. So, the C3H2+O(P-3) reaction may be an efficient strategy for producing C2H using cyclopropenylidene in atmosphere. The present results can lead us to understand deeply the mechanism of the title reaction.