ROTATIONAL LEVEL DEPENDENCE OF PREDISSOCIATION IN THE V'=3-LEVEL OF OH A2-SIGMA+

Using laser-induced fluorescence in a low-pressure flame, relative predissociation rates have been determined as a function of rotational level in the upsilon' = 3 level of the A (2)SIGMA+ state of the OH molecule. A Boltzmann analysis of an excitation scan in the (3,0) band yields an apparent temperature of 970 K in a 1670 K flame, showing that k(pre) increases rapidly with rotational level. The F1 levels predissociate slightly faster than F2 for the same N', agreeing with previous multichannel scattering predictions. The results can be placed on an absolute basis using recent linewidth measurements in a flow tube.