Theoretical Study of the Reaction O(P-3)+1,2-Butadiene

The triplet and singlet potential energy surfaces of the O(P-3) + 1,2-butadiene reaction have been investigated by electronic structure calculations at the coupled-cluster (CCSD(T)(aug-cc-pVTZ) level. We focused our attention, in particular, on the different sites of attack of atomic oxygen to 1, 2-butadiene. The results for minima, transition states and reaction channel energetics are compared with the results of previous CCSD(T)(aug-cc-pVTZ)-CBS and CASPT2 calculations to explore the adequacy of simpler computational schemes for discussing the reaction dynamics, in particular the product branching fractions derived from crossed molecular beam experiments.