Spin-orbit Coupling and Intermolecular Energy Transfer

Abstract

RECENTLY^1,2 we reported on the intermolecular energy transfer in chemiluminescent solutions, an excited product of the reaction being a donor and anthracene derivatives being acceptors (activators). The activated chemiluminescence spectra were identical with the fluorescence spectra of the activators, indicating that the singlet state of the activator is the excited one². A dependence of the chemiluminescence intensity on the activator concentration was used for estimating the ratio k_PA/f_P (k_PA, transfer constant, f_P, emission probability of the excited product, P′ (Fig. 1)). The relative values of the k_PA's were found to be greater the more halogens were introduced in the activator molecule and the greater was the atomic weight of the substituent: in this communication these features of the phenomenon are regarded as evidence for the spin-orbit coupling in the activator molecule.