Vibrational relaxation of [formula omitted] CF 2(ν 2 = 1–6 in non-reactive collisions

Abstract

Rate constants have been measured for collisional energy transfer as a function of vibrational quantum number in the first excited singlet state of the CF 2 radical. Total vibrational deactivation rates at T = 295 K are reported for the bending mode, A CF 2 (2 n ), for 1 ⩽ n ⩽ 6 in collisions with He, Ne, N 2 and SF 6 which do not electronically quench the A CF 2. The predominant pathway of vibrational deactivation is the single-quantum change A CF 2 (2 n ) + M - A CF 2 (2 n−1 ) + M + Δ E = 494 cm −1. However, as n increases, rates for two- and three-quantum changes become increasingly important. These results are generally consistent with the principles of vibrational energy transfer found previously for ground electronic state molecules.