Rotamer-dependent chemiluminescence in the intramolecular charge-transfer-induced decomposition of bicyclic dioxetanes bearing a hydroxyaryl group

Base-induced chemiluminescent decomposition of acylamino-substituted dioxetane 1b bearing a 3-hydroxyphenyl group proceeded according to dual phase kinetics due to syn–anti isomerism of the aryl group. For dioxetane 7 bearing a 6-hydroxynaphthalen-2-yl group, syn- and anti-rotamers were each isolated and their structures were determined by X-ray single crystallographic analysis. Both rotamers underwent base-induced decomposition accompanied by the emission of red light to exclusively give the same keto imide 8. However, a marked difference in chemiluminescence efficiency was observed between anti-7 and syn-7.