RUI: Radical Emitters based on the Allyl Radical: Synthesis and Photophysical Characterization

Professor Graham Sazama from the Lawrence University Department of Chemistry is working to endow organic radicals (molecules with unpaired electrons) with the ability to emit light. This research aims to embed molecular components that emit light in typical, non-radical molecules into the framework of the radical BDPA• (bis(diphenylene)phenylallyl). This research will broaden our understanding of the processes involved in emission from radicals and have implications for quantum computing, magnetic information, and communications (spintronics and optics). This research combines synthesis, photophysical spectroscopy, molecular and electronic structure characterization, and will provide undergraduates top-tier training to build their skills and become the next generation of scientists. As part of this training, Professor Sazama will use this research as a venue to engage his students with advanced scientific concepts and develop their scientific literacy and communication skills. This research aims to synthesize and study the luminescence of a new class of radical emitters, based on the allyl radical BDPA•, to broaden our understanding of radical photophysics beyond the scope of known emitting radicals. Their work will take advantage of the highly modular synthesis of BDPA• to incorporate fluorophores either around the periphery of the framework or directly embedded into the singly-occupied molecular orbital that contains the radical. By varying the type and position of the fluorophore, they will investigate structure-function relationships and establish design parameters for emissive radicals. Specifically, they will probe structure-function relationships between fluorophores and BDPA• by synthesizing and characterizing systematically pyrene-substituted BDPA• analogs; tune the molecular orbital energy levels involved in the absorption and emission processes of BDPA• analogs by incorporation of fluorophores and/or heteroatoms directly into the radical electronic structure; and assess the photophysical mechanisms operative for allyl radical-based absorbers and emitters and determine the key structural features that enable luminescent behavior in organic radicals. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.