Production Yields of H(D) Atoms in the Reactions of N2(a 1(sigma)u-) with H2O, D2O, and HOD

The deactivation processes of N2(aʹ 1(sigma)u-, v = 0), the lowest metastable singlet-state molecular nitrogen, by H2O, D2O, and HOD were investigated. The overall rate constants as well as the quantum yields for the production of H(D) atoms were determined. N2(aʹ, v = 0) was produced by energy transfer from N2(a 1(product sign)g, v = 0), while N2(a, v = 0) was produced by a two-photon excitation of the ground-state N2. The rate constants for the deactivation by H2O and D2O were determined to be (4.22 (plus-minus) 0.27) × 10^-10 and (4.21 (plus-minus) 0.11) × 10^-10 cm^3 s^-1, respectively, by measuring the decay profiles of N2(a, v = 0) under equilibrated conditions. The quantum yields for the production of H(D) atoms were determined to be 0.9 -0.2^ +0.1 both for H2O and D2O under the assumption that the only exit for H2(D2) is the production of two H(D) atoms. In a reaction with HOD, the yield ratio of [H]/[D] was measured to be 1.0 (plus-minus) 0.1. This lack of the isotope effect suggests that the decomposition proceeds by forming bound intermediate complexes, such as HNNOD and DNNOH.