Investigations on the thermal decomposition of 1,2-dioxetanes via DSC

Reproducible measurements, reliable results and 1^st order kinetics for the whole reaction are obtained during the thermal decomposition of dioxetanes only, if inclusions of impurities in commercial sample pans are blocked by additional thick (magnitude of 100 ?m) and close Al₂O₃ protective layers. As a rule, nearly the same activation parameters are then found both for the decomposition of solvent-free dioxetanes and diluted solutions in several solvents. Mixtures of different dioxetanes in the same solvent contribute independently to the overall heat flow rate.