Photodissociation Dynamics of 1-Bromo-1-chloro-2,2,2-trifluoroethane at 157 nm

Abstract

Listen

Translate article

The photodissociation dynamics of the title molecule at 157 nm has been studied using photofragment translational spectroscopy. The molecule was found to dissociate competitively via CHBrCF3 + Cl, CHClCF3 + Br, CHCF3 + Br + Cl, and CClCF3 + HBr channels with the branching ratio This result indicates that the stronger C−Cl bond breaks preferentially over the weaker C−Br bond, similar to the case of the photodissociation of CBrF2CHClF studied previously. Compared with the C−Cl:C−Br branching ratio for the photodissociation of CBrF2CHClF at 157 nm, this branching ratio indicates that a larger fraction of molecules dissociate via C−Br bond rupture in this case than in the case of CBrF2CHClF as a result of a higher transition probability from the initially excited nσ*(C−Cl) diabatic surface to the nσ*(C−Br) diabatic surface. This result is qualitatively consistent with the prediction from previous theoretical works that the transition probability from the nσ*(C−Cl) to the nσ*(C−Br) diabatic surface increases w...