Rate constants for the quenching of N2 (A 3Σu+, vA = 0 – 8) by CO, CO2, NH3, NO, and O2

Abstract

The techniques of pulse radiolysis and absorption spectroscopy have been used to produce and detect metastable nitrogen (A 3Σu+) in the vibrational levels vA =0–8. Second order quenching rate constants have been determined for a number of additive gases. The rate constants, in units of cm3/sec and for increasing values of vA, are as follows: O2 (1.9±0.3)×10−12; (7.4±0.7) (−12); (5.0±0.3) (−12); (3.4±0.4) (−12); (6.2±0.9) (−12); (5.8±0.5) (−12); (6.5±0.6) (−12); (7.5±3.0) (−12); (5.1±2.0) (−12). CO (1.8±0.5) (−12); (1.8±0.1) (−11); (4.6±0.4) (−11); (2.1±0.3) (−11); (1.9±0.2) (−11); (1.6±0.1) (−11); (1.7±0.2) (−11); (9.0±4.0) (−12); (7.2±0.4) (−12). CO2 (9.9±1.1) (−15); (2.0±0.1) (−14); (1.5±0.2) (−13); (2.9±0.2) (−13); (4.9±0.9) (−13); (1.6±0.2) (−12); (3.1±0.4) (−12); (4.8±0.4) (−12); (4.7±0.2) (−12). NO (2.8±0.5) (−11); (4.0±0.3) (−11); (6.8±0.8) (−11); (1.2±0.1) (−10); (1.1±0.1) (−10); (1.0±0.1) (−10); (9.6±0.7) (−11); (8.9±3.5) (−11); (6.7±0.5) (−11). NH3 (8.2±1.6) (−11); (8.6±2.4) (−11); (1.5±0.2) (−10); (1.2±0.1) (−10); (1.6±0.2) (−10); (1.5±0.1) (−10); (2.3±0.2) (−10); (4.5±1.5) (−11); (1.1±0.1) (−10). An attempt has been made to explain the results in terms of energy transfer processes and to fit the data to a simple model.