Excitation of iodine by singlet molecular oxygen. Part 2.—Kinetics of the excitation of the iodine atoms

Excitation of atomic iodine in the gas phase by singlet molecular oxygen is shown to involve the following reactions: I + O2(1Δ)= I*+ O2(3∑)(1), I*+ O2(1Δ)= I + O2(1∑)(2), I*= I +hν(3), O2(1∑)= O2(3∑)+hν(4), I*+ O2(3∑)= I + O2(1Δ). (5) Values of k1=(4.6 ± 1.5)× 1013 cm3 mol–1 s–1, k2=(1.6 ± 0.2)× 1010 cm3 mol–1 s–1 and k5=(1.6 ± 0.5)× 1013 cm3 mol–1 s–1 at 295 K are derived, as are limiting rate constants for certain quenching processes.