title: A theoretical study of the reaction of O(3P) with isobutene.
abstract: The reaction of O((3)P) with isobutene ((CH(3))(2)C=CH(2)) is investigated using the unrestricted second-order Møller-Plesset perturbation (UMP2) and complete basis set CBS-4M level methods. The minimum energy crossing point (MECP) between the singlet and triplet potential energy surfaces is located using the Newton-Lagrange method, and it is shown that the MECP plays a key role. The calculational results indicate that the site selectivity of the addition of O((3)P) to either carbon atom of the double bond of isobutene is weak, and the major product channels are CH(2)C(O)CH(3) + CH(3,) cis-/trans-CH(3)CHCHO + CH(3), (CH(3))(2)CCO + H(2), and CH(3)C(CH(2))(2) + OH, among which (CH(3))(2)CCO + H(2) is predicted to be the energetically most favorable one. The complex multichannel reaction mechanisms are revealed, and the observations in several recent experiments could be rationalized on the basis of the present calculations. The formation mechanisms of butenols are also discussed.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhao
authors.forename: Wensheng
authors.initials: W
authors.lastname: Bian
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D000475:Alkenes; D005609:Free Radicals; C008176:isobutylene; D010100:Oxygen