Chemiluminescent Reactions of F_2 and F Atoms with I_2 Molecules

In order to obtain high concentration of IF(B) through chemical ways, we studied the chemiluminescent reactions of F2, F with I2 in the flowing afterglow apparatus. Strong emission spectrum IF(B- X) was firstly observed in the F/I2 system. Simple collision theory was used to estimate the IF(B) vibrational energy relaxation in inert gas. The vibrational population distribution of the excited state IF (B) was measured. Compared the IF (B) vibrational distribution of different systems, we conclude that IF(B) were produced through different reaction mechanisms in the reactions of F2, F with I2. The former proceeds via a secondary, reactive encounter of the F atom with the stable thrialogen intermediate I2F, whearas the latter may be the recombination reaction of spin - orbit excited iodine atoms with ground fluorine atoms.