Laser induced fluorescence study of the F+I2→IF+I reactive collision

We have performed a crossed beam study of the F+I2→IF+I reaction. The IF product was detected by the LIF technique, using a cw single frequency dye laser. About 10 000 lines belonging to the B–X system of IF have been thus recorded. These lines have been assigned and the populations of about 1300 rovibrational levels of the X state were deduced from their intensities. This analysis takes into account the coherent saturation regime of the excitation process. In the present work, only the high vibrational levels of the X state (v‘=8–20) have been studied. A striking result is the observation of bimodal rotational distributions for several vibrational levels: the rotational distribution presents a plateau and a peak for high rotational quantum numbers. The vibrational distribution presents a peak centered at v‘=13, and as we have shown that the v‘=0 peak observed by other authors is in fact an experimental artifact, the general features of the energy disposal in this reaction are now well known.