Journal of Physical Chemistry A, Vol.112, No.39, 9290-9295, 2008
Kinetic study of vibrational energy transfer from a wide range of vibrational levels of O-2(X-3 Sigma(-)(g), v=6-12) to CF4
A wide range of vibrational levels of O-2(X-3 Sigma(-)(g), v = 6-13) generated in the ultraviolet photolysis of O-3 was selectively detected by the laser-induced fluorescence (LIF) technique. The time-resolved LIF-excited B-3 Sigma(-)(u)-X-3 Sigma(-)(g) system in the presence of CF4 has been recorded and analyzed by the integrated profiles method (IPM). The IPM permitted us to determine the rate coefficients k(v)(CF4) for vibrational relaxation of O-2(X-3 Sigma(-)(g), v = 6-12) by collisions with CF4. Energy transfer from O-2 (v = 6-12) to CF4 is surprisingly efficient compared to that of other polyatornic relaxation partners studied so far. The k(v)(CF4) increases with vibrational quantum number v from [1.5 +/- 0.2(2 sigma)] x 10(-12) for v = 6 to [7.3 +/- 1.5(2 sigma)] x 10(-11) for v = 12, indicating that the infrared-active v(3) vibrational mode of CF4 mainly governs the energy transfer with O-2(X-3 Sigma(-)(g), v = 6-12). The correlation between the rate coefficients and fundamental infrared intensities has been discussed based on a comparison of the efficiency of energy transfer by several collision partners.