Hydrogen Bonding Cooperativity Effect Enabling Decoupled Responsiveness to Multiple Mechanical-Stimuli in Tetraphenylethylene-Based Derivatives

Simultaneous monitoring of multiple mechanical stimuli is a widespread requirement in practical applications. However, decoupling the photoluminescence (PL) response to mechanical-stimuli remains elusive for organic emitters. Here, we achieved the decoupled response to grinding and compression in 5-methoxy-1-indanone modified tetraphenylethylene (TPE) derivatives (IT) by employing the hydrogen bonding cooperativity effect (HBCE). The synthesized IT crystals exhibit a significant red-shifted emission from 480 nm to 550 nm under compression and an increased PL quantum yield from 1.87% to 22.2% upon grinding. Detailed experimental analysis shows that the strengthened C–H ··· O interactions between indanone units facilitate denser intermolecular π–π stacking, while the weak C–H ··· π interactions between TPE units regulate intramolecular orbital coupling. The synergy of these two effects enables the decoupling of responses to shear and normal forces during the grinding and compression processes. This HBCE-empowered decoupled responsiveness in the organic emitter opens avenues for the development of multistimuli-response smart materials.