Photodissociation of ICl at 235–248 nm

Photodissociation of iodine monochloride has been investigated at 235–248 nm by studying Doppler profiles of (2+1) resonance enhanced multiphoton ionization spectra of fragment chlorine atoms and two-photon laser induced fluorescence spectra of iodine atoms. At 235.3–237.8 nm, a measured branching ratio of [Cl*(2P1/2)]/[Cl(2P3/2)] is 0.68±0.10. At 248 nm, the [I*(2P1/2)]/[I(2P3/2)] ratio is 0.71±0.27. From the measured Doppler profiles and the ab initio calculation, the photoprepared states leading to Cl and Cl* production are assigned to the 3Π0+ (and possibly 3∑−0+) and the 1Π1 states, respectively. Nonadiabatic couplings between the potential curves have been discussed.