Journal of Chemical Physics, Vol.117, No.12, 5654-5659, 2002
Reactions of N-2(a(') (1)Sigma(-)(u)) with H-2, CH4, and their isotopic variants: Rate constants and the production yields of H(D) atoms
The reactions of N-2(a(') (1)Sigma(u)(-), v=0) with H-2, CH4, and their isotopic variants were examined. N-2(a('), v=0) was produced by energy transfer from N-2(a (1)Pi(g), v=0), while N-2(a, v=0) was produced by two-photon excitation of ground state N-2. The rate constant for the deactivation of N-2(a('),v=0) can be determined by measuring the decay profiles of N-2(a, v=0) under the conditions that equilibration between N-2(a, v=0) and N-2(a('), v=0) can be assumed. The detection of N-2(a, v=0) was accomplished by a laser-induced fluorescence technique by utilizing the N-2(b(') (1)Sigma(u)(+), v=7) state as an upper state. The rate constants for the quenching of N-2(a('), v=0) by N-2, H-2, D-2, CH4, CH2D2, and CD4 were determined to be (2.0+/-0.1)x10(-13), (2.8+/-0.1)x10(-11), (1.7+/-0.1)x10(-11), (2.9+/-0.2)x10(-10), (2.4+/-0.3)x10(-10), and (2.6+/-0.2)x10(-10) cm(3) molecule(-1) s(-1), respectively. H(D) atoms were identified as reaction products by a two-photon laser-induced fluorescence technique. The yields for the production of H(D) atoms from CH4 and CD4 were both determined to be 0.7+/-0.2 under the assumption that the only exit for H-2(D-2) is the production of two H(D) atoms. No preferential production of H or D atoms was observed in the reaction with CH2D2, suggesting that the reaction proceeds via bound intermediate complexes.