High-Temperature Dynamic Organic Phosphorescence Based On Cyclodextrins Supramolecular Assemblies
Yi Chen, Zhenzhen Xu, Miao Yu, Hongbing Fu
Abstract
Dynamic organic phosphorescent materials present great potential for practical applications. But the temperature-sensitive nature of organic phosphors makes the development of high-temperature dynamic organic phosphorescence (HTDOP) a significant challenge. Herein, we report a HTDOP system assembled from β-cyclodextrins (β-CDs) and 4-diphenylamino-benzoic acid (TPAC). The TPAC@β-CDs complex system exhibits only short-lived fluorescence at room temperature but transitions to phosphorescence emission with an ultralong emission lifetime of up to 567 ± 13 ms upon heating. A mechanistic study combining spectroscopic analysis, 1 H NMR, and Fourier Transform Infrared Spectroscopy revealed that the intermolecular hydrogen bonding interactions effectively suppressed nonradiative relaxation of triplets even at temperature as high as 140 °C. Meanwhile, elevated temperatures also drive oxygen out of the system, significantly reducing quenching processes and ensuring the robust survival of HTDOP. Additionally, the introduction of fluorescent dyes permits color regulation of the afterglow from green to red through Förster resonance energy transfer from the triplet to the singlet state. Moreover, this system’s fast and reliable response upon high temperature makes it an excellent candidate for overtemperature trace detection in electronic components and circuit diagnostics. This work discloses an effective strategy for constructing HTDOP systems that can be fully exploited in a range of fields.