266 nm Photolysis of HOCl and DOCl: laser-excitation fluorescence detection of OH and OD

Fragment rotational population distributions for OH and OD were observed by laser-excitation fluorescence following the 266 nm photolysis in a free jet molecular beam of HOCl and DOCl, respectively. The photodissociation dynamics show a strong preference for the 2PI(A') OH or OD lambda doublet component in both spin-orbit states. The 2PI3/2 state is more populated than the 2PI1/2 State of OH. The distributions are consistent with photolysis via a repulsive excited state and the measured rotational alignment (-0.28) is compatible with an excited- state symmetry of A' for the dominant dissociation pathway. The high-J limiting value for the degree of electron alignment reaches the extreme value of - 1 for the 2PI1/2 state for both OH and OD, but falls short of this for the 2PI3/2 state, reaching only -0.7