Abstract: The reactions of F atoms with C_2H_I, C_2F_5I, and C_3H_5I has been studied by the crossed beam laser-induced fluorescence technique within the 570-620 nm wa- velength region. The vibrational and rotational excitation spectra of the reaction product IF were measured. The relative vibrational population densities of v=3, 4, and 5 vibrational levels, and some of the relative fine vibrational rate con- stants, the rotational temperatures, and the mean fractions of rotational energy in individual vibrational states of the reaction product IF were obtained.
The experimental results show that the vibrational state distributions for the products of the reactions F+C_2H_5I and F+C_2F_5I among the v=3, 4 and 5 levels are essentially statistical. This indicates that mechanism of indirect reaction exists in the reactions of F atoms with iodides of saturated or fluorinated polyatomic radicals. The vibrational state distributions for the product of the reaction F+C_3H_5I exhibits population inversion among the v=3, 4 and 5 leveles. This indicates that mechanism of direct reaction exists in the reactions of F atoms with iodides of unsaturated polyatomic radicals.