Excitation of iodine by singlet molecular oxygen. Part 1.—Mechanism of the I2 chemiluminescence
Abstract
The strong I2 chemiluminescence produced when iodine is added to oxygen gas containing singlet molecular oxygen is shown to arise by efficient stepwise excitation I2(X1Σ+g)+O2(1Σ+g)→I2(A3π1u)+O2(3Σ–g)(2), I2(A3π1u)+O2(1Δg)→I2(B3π0+u)+ O2(3Σ–g)(3)
Process (2) also yields atomic iodine which recombines to I2 on the flow tube walls. Approximate rate coefficients are derived for these processes.