Dynamics of the B 3Π(0u+) and A 3Π(1u) States of Chlorine by Laser Induced Fluorescence

Chlorine B 3 Π( 0 u + ) state lifetimes have been measured by laser-induced fluorescence in several predissociated ( υ ′ = 14–19,21) and non-predissociated ( υ ′ = 5–12) levels. Trial and error Franck-Condon calculations have been performed to check the nature and position of the predissociating state. The results have been used to give a value of R e for the A 3 Π( 1 u ) state responsible for predissociation, R e = 2.48 ± 0.01 Å. The obtained data show that interference effects due to crossing between B and A states modify the lifetimes of the B state appreciably. The inadequacy of the low-lying vibrational levels region, i.e. υ ′ < 8, to measure the radiative lifetime of the B state ( τ R (B)) is shown. Previous values for τ R (B) can therefore be affected by considerable errors.