ROTATIONAL AND VIBRATIONAL-ENERGY TRANSFER IN CH(A2-DELTA)

Rate constants have been obtained for rotational and vibrational energ y transfer within the A 2DELTA state of CH by collisions with Ar and N 2. By using laser photolysis of CHBr3 as the source of CH(A), it was p ossible to produce a wide range of rotational and vibrational levels ( N less-than-or-equal-to 25, v less-than-or-equal-to 2). The rate const ants for rotational relaxation are comparable to gas kinetic rates (k < 2.5 x 10(-10) cm3 molecule-1 s-1) and decrease with increasing rotat ional quantum number. The efficiency of vibrational relaxation is ca. 10 times less than that of rotational relaxation (k < 6.5 x 10(-12) cm 3 molecule-1 s-1).