Photochemistry of macrocyclic ketones within zeolites: Competition between norrish type I and type II reactivity

Article abstract of DOI:10.1016/0040-4039(91)80562-K

Photolysis of macrocyclic mono- and diketones (1 and 2) included in X and Y zeolites gives Norrish type I products in addition to the products obtained via the Norrish type II process, the only observed process in isotropic media. Enhancement of the type I over the type II process is cationdependent and especially large enhancements are obtained with Li and Na as cations. The zeolite effect is attributed to a reduction in the rate of the Norrish type II α-hydrogen abstraction process.