title: Product-state-resolved dynamics of the elementary reaction of atomic oxygen with molecular hydrogen, O(³P) + D₂ → OD(X²Π) + D.
abstract: Elementary three-atom systems provide stringent tests of the accuracy of ab initio theory. One such important reaction, O((3)P) + H2 → OH(X(2)Π) + H, has eluded detailed experimental study because of its high activation barrier. In this reaction, both the ground-state reactant atom and product diatomic molecule have open-shell character, which introduces the intriguing complication of non-Born-Oppenheimer effects in both the entrance and the exit channels. These effects may be probed experimentally in both the fine-structure and the Λ-doublet splittings of the OH product. We have used laser-induced fluorescence to measure OD internal product-state distributions from the analogous reaction of O((3)P) with D2, enabled by a unique high-energy O((3)P) source. We find that the OD (ν' = 0) product is rotationally highly excited, in excellent agreement with earlier theoretical predictions. However, the distributions over the OD(X(2)Π) fine-structure and Λ-doublet states, diagnostic of electronic non-adiabaticity in the reaction, challenge the prevailing theoretical understanding.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Sridhar A
authors.initials: SA
authors.lastname: Lahankar
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhang
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: McKendrick
authors.forename: Timothy K
authors.initials: TK
authors.lastname: Minton
mesh_terms: D003903:Deuterium / Q000737:chemistry*; D004867:Equipment Design; D006859:Hydrogen / Q000737:chemistry*; D007834:Lasers; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry*; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D006859:Hydrogen; D003903:Deuterium; D010100:Oxygen