Photodissociation of CH2ClCH2Iat 308 nm

The technique of photofragmentation translational spectroscopy has been used to studythe photodissociation of CH 2 ClCH 2 I at an excitation wavelength of 308 nm. Theexclusive dissociation pathway is C–I bond breakage with formation of CH 2 ClCH 2 andI( 2 P 3/2 ). The centre-of-mass translational energy distribution of the photofragmentsreveals that an average of about 50% of the excess energy appears in translation. Theangular distribution of dissociation products with respect to the laser polarizationindicates that the photodissociation process proceeds via a parallel transition—i.e., thetransition moment must be nearly parallel to the C–I bond. Exclusive production ofground state I( 2 P 3/2 ) with a parallel polarization dependence is unexpected based on theprevailing picture for alkyl iodide photodissociation.