Quenching of N2(a 1Πg, v′=0) by N2, O2, CO, CO2, CH4, H2, and Ar

We have determined quenching rate coefficients for N2(a 1Πg, v′=0) by N2, O2, H2, CO2, Ar, CH4, and CO using two-photon laser excitation. Quenching by N2 appears to proceed via collisional coupling to N2(a′ 1Σ−u, v=0) with a rate coefficient of 2.2±0.2×10−11 cm3 molecule−1 s−1. Quenching by Ar is nearly as efficient. Gas-kinetic rate coefficients are obtained for quenching by CO, O2, H2, CO2, and CH4. Collisional energy transfer from N2(a,0) to CO(A) is observed in these experiments. However, quenching by O2, H2, CO2, and CH4 is thought to be reactive.