Photodissociation of alkyl iodides

Abstract

The branching ratios for formation of I (5 ²P_1/2) and I (5 ²P_3/2) following broad‐band photolysis of a number of alkyl iodides and their fluorinated and deuterated analogs have been directly determined using time‐resolved atomic absorption spectroscopy. The yields of ground and electronically excited atoms are strongly dependent on the structure of the alkyl group, those possessing secondary or tertiary α‐carbon atoms displaying the lowest yields. The observed correlation between alkyl group structure and branching ratio is discussed using simple symmetry arguments to assess the role of spin–orbit coupling in the photodissociative excited state.