Design for a Solid‐State Luminescent Sensor Through Photo‐Induced Electron Transfer Based on Pyrene‐Modified <i>o</i>‐Carborane

Abstract Aryl‐tethered o ‐carboranes have attracted attention as a platform for obtaining functional solid‐state luminescent materials with stimuli‐responsiveness. To extend the versatility and applicability for advanced sensing technologies, it is essential to establish new mechanisms for regulating solid‐state luminescent properties. In this study, we demonstrate the regulation of solid‐state luminescent properties of the modified o ‐carborane through photo‐induced electron transfer. We synthesized the triad based on o ‐carborane modified with pyrene as a luminophore from intermolecular charge transfer and diethylaniline as a quencher. In the pristine solid state, significant emission was hardly observed due to emission quenching through photo‐induced electron transfer, while intense emission was recovered by acid vapor fuming for protonation at the diethylaniline moiety. Moreover, we confirmed that reversible changes underwent by amine vapor fuming. These results mean that solid‐state luminescent properties of o ‐carborane can be controlled by the commodity photochemical process according to the molecular design.