Rotational and vibrational energy distributions of 16OH(X 2Π) and 18OH(X 2Π) produced in the reaction of O(1D) with H2O and H2 18O

Abstract

Laser induced fluorescence measurements of the rotational population distributions for the ¹⁶OH(X ²Π_i, v = 0, 1) products of the reaction of O(¹D) with H₂O and the ¹⁶OH(X ²Π_i, v = 0, 1) and ¹⁸OH(X ²Π_i, v = 0, 1) products of the reaction of O(¹D) with H₂ ¹⁸O are presented here. The rotational and vibrational distributions of the ¹⁶OH formed in the normal isotopic abundance reactions were found to be close to those expected if the energy of the reaction is statistically distributed amongst all available product states. Isotopic labeling of the oxygen atom in the reactant water molecule demonstrated that the vibrational distribution of the new ¹⁶OH bond formed is significantly more energetic than the remaining ¹⁸OH bond, while the rotational distributions were similar. These results are interpreted as H atom abstraction (or stripping) dynamics predominating over O atom insertion into the water OH bonds.