Chemiluminescence Energy Transfer Processes and Micellar Effects

Abstract

The first study of intermolecular energy transfer processes in a chemiluminescence system is reported. Energy transfer in the acridinium−hydrogen peroxide chemiluminescence system, observed for the first time, is evaluated for radiative, dipole−dipole, and collisional components in the presence and absence of micelles: cetyltrimethylammonium bromide, Brij-35, and sodium lauryl sulfate. In surfactant solutions, the major components were found to be radiative and collisional. Changing the surfactant had the greatest effect on the dipole−dipole component. Effects can be attributed to ion−ion forces, the mixing process, and the path length of the chemiluminescence measurement. In contrast to photoexcited energy transfer studies, the Rhodamine 110 (acceptor) concentration is varied by almost 4 orders of magnitude and is up to 105 greater than the acridinium (donor) concentration. This can be attributed to the absence of excitation absorption in a chemiluminescence measurement and the increased solubility due to the surfactants. The semiempirical method used for evaluating energy transfer should be adaptable to other systems and requires only the spectra of the donor and acceptor and the measurement of chemiluminescence intensity as a function of acceptor concentration.