On the electronic structure of alternant conjugated organic radicals for light-emitting diode applications

Since the demonstration in 2018 that organic radicals can be used to make highly efficient organic light-emitting diodes there has been an explosion of interest in their capabilities and many experimental and computational studies of their performance. Here we take a theoretical view and describe the electronic structure of radicals from an algebraic perspective. By rediscovering and adapting historic investigations of organic radicals we show how many experimentally useful properties can be determined without synthesis or computation, but simply from knowledge of the molecular structure and in particular whether or not the radical is an alternant hydrocarbon. We explain these results in the context of modern organic light-emitting design in order to inform future investigations.