Two-photon dissociation dynamics of hydroxyl radical

Abstract

Two-photon dissociation dynamics of the OH radical is studied using the high-n Rydberg atom time-of-flight (HRTOF) technique. The H(2S)+O(1D) and H(2S)+O(1S) product channels are observed in the dissociation of the OH radical on the 22Π and B2Σ+ repulsive states, respectively, from sequential two-photon excitation via the A2Σ+ (v′=2, J′=0.5−2.5) state. Both H+O product channels have anisotropic angular distributions, with β=−0.97 for H(2S)+O(1D) and 1.97 for H(2S)+O(1S). The anisotropic angular distributions are consistent with a mechanism of OH direct dissociation on the repulsive potential energy curves (PECs) leading to the H+O products. The OH bond dissociation energy D0(O−H) is determined to be 35580±15 cm−1.