Student Seminar: Luminescent Radicals

     Venue: Rajarshi Bhattacharya Memorial  Lecture Hall, Chemical Sciences Building

Organic π-radicals have garnered significant attention for their potential applications in fields like imaging, quantum information science, spintronics, and organic light-emitting diodes (OLEDs) due to their unique spin properties. To design materials optimized for specific uses, it is essential to understand the excited-state dynamics of these systems in depth. When a luminescent chromophore is linked to a radical, the intrinsic characteristics of the radical often result in weak or even absent emission at low energy, primarily due to enhanced intersystem crossing (EISC). This phenomenon can, however, be leveraged to generate high-spin photoexcited states, making π-radicals ideal candidates for organic spintronics, molecular quantum technologies, and molecular magnetism.In contrast, the use of similar organic spin systems in OLEDs benefits from the photoluminescence (doublet emission) observed in certain π-radical systems, which naturally addresses the triplet harvesting issue common in closed-shell molecules. During my seminar, I will explore the core question of why radicals are typically weakly emissive and discuss how this emission deficiency can be overcome by strategically modifying the radical core. I will also briefly touch on the mechanism of doublet electroluminescence that drives their emission. The seminar will end with a discussion on possible areas for improvement.