State-to-state N2(<i>A</i> 3∑+<i>u</i>) energy pooling reactions. II. The formation and quenching of N2(<i>B</i> 3Π<i>g</i>, <i>v</i>′=1–12)

Abstract

We have studied the state-to-state excitation of N2(B 3Πg, v′=1–11) in energy pooling reactions between N2(A 3∑+u, v′=0,1) molecules and subsequent quenching in collisions with molecular nitrogen. Excitation of vibrational levels 10, 2, and 3 appears to be much stronger than excitation of the other vibrational levels. In addition, we failed to observe any emission from v′=12 even though it is energetically accessible. The excitation rate coefficients are quite large, 7.7×10−11 cm3 molecule−1 s−1 for the pooling of two N2(A, v′=0) molecules, and roughly a factor of three larger for energy pooling events involving N2(A, v′=1). The effective rate coefficients for electronic quenching of N2(B) by N2 are also quite large, ≈3×10−11 cm3 molecule−1 s−1. Comparison of our quenching results with the laser-excited, real-time quenching studies of Rotem and Rosenwaks indicates agreement only within factors of 2–3.