Reversible formation of excited states in intramolecular donor assisted chemiluminescence reactions of dioxetanesElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b3/b304245f/

Data are presented requiring that the currently accepted CIEEL mechanism for the chemiluminescence of electron donor substituted dioxetanes be modified to include reversible thermal population of a dioxetane excited charge transfer state that undergoes ring scission with excited product formation which is accelerated by energy acceptors.