Developing multifunctional luminophore of deferasirox molecule with excitation-sensitive mechanofluorochromic properties
Yanan Wang, Yayun Wang, Lin Wei, Aisen Li, Yuanyuan Fang, Lei Li, Qian Li, Kai Wang
Abstract
• Deferasirox has been developed as a novel multi-stimuli sensitive luminophore. • A unique excitation-dependent mechanofluorochromic phenomenon is observed. • Mechanical study reveals key structural factor that governs luminescence variation. • Deferasirox demonstrates great potential for application in information technology. Stimuli-responsive organic luminophores are emerging smart materials for diverse applications, ranging from chemical/physical sensors to information storage. However, achieving sensitive organic luminescence with timely response to straightforward and multiple stimuli remains a great challenge. Herein, deferasirox is developed as an excitation-sensitive mechanofluorochromic material, leveraging non-equilibrated excited states of intermolecular proton-transfer (ESPT) and excimers. Grinding and vertical pressure induce simultaneous blue-shifts in ESPT and excimer emissions, attributed to the localized structural distortion and destruction. Anisotropic external force also varies the excitation-dependent luminescence from orange/white to yellow/green. Further high-pressure studies reveal key structural factors influencing emission shifts. Pressure-induced molecular rigidity and planarization limit molecular motion, strengthen intermolecular interactions, and decrease potential energy barrier height, facilitating the ESPT process with blue-shifted emission while promoting excimer generation with red-shifted emission. This work not only enriches the understanding of excitation-dependent mechanofluorochromic phenomenon, but also offers innovative methods for developing multifunctional optical materials and broadens the scope of smart-responsive materials for information encryption, anti-counterfeiting and destruction.