Abstract:
A 'quenching buffer' method was developed for the determination of the rate constants of the principal reactions involved in flash photolysis of iodides (RI) in the ultraviolet part of the spectrum in the presence of a buffer gas M which acted as a strong quenching agent on the excited state 52P1/2 (I*) of the iodine atom. The active iodine was in the form of C2F5I molecules, and the buffer consisted of CF3H or H2O molecules. The rate constants of the following reactions were obtained: C2F5+ C2F5 → C4F10, C2F5+I → C2F5I, I* + (RI, M) → I+(RI, M), I + I +(RI, M) → I2 +(RI, M). The coefficients γ, representing broadening of the active transition line of the photodissociation iodine laser by collisions with C2F5I, CF3H, and H2O molecules, were determined. The results demonstrated a correlation between γ and the constant representing quenching of I* by the buffer M.