CHEMILUMINESCENT SYSTEMS

The survey of chemiluminescent autoxidation reactions has been continued. Of the forty odd additional compounds screened, the large majority show enhanced chemiluminescence over background in potassium t-butoxide dissolved in dimethylsulfoxide DMSO. About one-third of the reactants exceeded 1 of the standard source brightness. The latter group includes several substituted benzoins, demonstrating the generality of the chemiluminescence of the oxidation of this class of stable radicals. The chemiluminescence of indole and several 3-substituted indoles has been investigated. In t-Bu OK and DMSO solution, 0.005 M skatole is about fifty times brighter than the standard source. At a base concentration of 0.067 M the brightness is an increasing function of skatole concentration to almost 0.1 moleliter. At this concentration the brightness is 400 times that of the standard, or about half that of 0.005 M luminol. Emission and fluorescence spectra uncorrected have been obtained for the basic skatole solution and for the addition, 0.0001 M fluorescein.