Abstract: Competing ionic and radical photobehavior has been observed for a number of alkyl halides. Irradiation of 1-iodonorbornane (la) in a variety of media afforded predominantly the nucleophilic substitution product 3 or 6, accompanied by lesser amounts of the reduction product norbornane (8). The bromo analogue lb exhibited similar behavior except that a higher proportion of the reduction product norbornane (8) was formed. The 1 ...