Achieving Large Emission Shifts in Organic Lumiphores by Pressure‐Regulated Charge‐Transfer Characteristic

ABSTRACT Piezochromic materials (PCMs) with remarkable color contrast and fatigue resistance, have important potential applications, but few such organic luminophores have been reported. Herein, we propose an acceptor engineering strategy to develop high‐performance PCMs. Three molecules (TTB, TTN, TTNB) were synthesized based on two triphenylethylene‐functionalized triphenylamine donors and a thiadiazole‐derived acceptor. Among them, TTNB with a stronger electron‐withdrawing NBT unit, shows the most pronounced intramolecular charge transfer (ICT). Upon compression, all of them exhibit pressure‐induced red‐shifts. Impressively, TTNB achieves a broad emission shift from 626 nm (yellow) to 771 nm (near‑infrared, NIR) with a high piezochromic coefficient of 27.80 nm/GPa, and excellent linearity. This sensitivity surpasses the other two compounds and most reported luminescent materials. TTNB also demonstrates full reversibility and reproducible color switching upon pressure release. Mechanism studies reveal that the excellent piezochromic behaviors of TTNB originate from strong ICT and synergistic pressure effects, including reduced intermolecular distances and increased planarity. This work elucidates an ICT‐based excited‐state regulation mechanism and offers design principles for high‐performance PCMs.