Stable Luminescent Radicals with Efficient Through‐Space Charge‐Transfer Emission

High‐performance luminescent radicals featuring donor‐radical (D‐R) charge‐transfer (CT) excited states have emerged as promising candidates for optoelectronic applications. However, prior studies have predominantly focused on through‐bond charge‐transfer (TBCT) mechanisms. In this work, we report the first examples of luminescent radicals based on TTM (tris(2,4,6‐trichlorophenyl)methyl radical) with through‐space charge‐transfer (TSCT) excited states, represented by TPA‐FR‐TTM and CZP‐FR‐TTM. Spatial separation and non‐bonding character between the donor and radical units minimizes electron‐vibrational coupling and effectively suppresses non‐radiative decay. As a result, CZP‐FR‐TTM exhibits an outstanding photoluminescence quantum efficiency (PLQE) of 64.3% and an ultralow non‐radiative decay rate of 1.3 × 10 6 s −1 , among the lowest ever reported for luminescent radicals. Furthermore, the reduced electronic coupling leads to non‐Aufbau electronic structures, enhancing radical stability. These findings establish TSCT as a powerful design strategy for high‐performance and stable luminescent radicals, opening new avenues for open‐shell optoelectronic materials.