Chemiluminiscent Thermolysis of a Peroxylactones

Article abstract of DOI:10.1021/ja00535a039

A comprehensive study of the chemiluminiscent decomposition of a three α-peroxylactones (dimethyl α-peroxylactone (1), phenyl n-butyl α-peroxylactone (2), and diphenyl α-peroxylactone (3)) has been undertaken.Each compound decomposes to yield CO2 and the corresponding ketone in a high yield.The chemiluminiscent species produced in these reactions have been characterized by a number of different measurements including distribution of direct chemiluminiscence, lifetimes, energy transfer, activation parameters, and photochemical reactions.Excited state chemiexcitation efficiences have also been evaluated.It is shown that a combination of conventional kinetic measurements and "step analysis" of the chemiluminiscence intensivity provides a means of evaluating the activation energies for the deactivation paths of electronically excited states that precede the emission step responsible for chemiluminiscence.The latter activation energies may also be monitored directly in some cases by measurement of excited-state lifetimes as a function of temperature.The agreement between the activation energies generated from chemiluminiscence data and direct photoexcitation measurements is within the experimental error.The results for 1 are compared to those for tetramethyldioxetane (4) (both produce electronically excited acetone) and are found to be in excellent agreement.