Li Yaya, Yang Huixu, Wang Yanan, Lv Chunyan, Li Chengjian, Wang Kai, Zhang Yujian
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, Yingbin Road No. 688, Jinhua, 321004, P. R. China.
Department of Materials Chemistry, Huzhou University, East 2nd Ring Rd. No. 759, Huzhou, 313000, P. R. China.
Chemistry. 2025 May 14;31(27):e202500888. doi: 10.1002/chem.202500888. Epub 2025 Apr 16.
The integration of mechanical flexibility with stimuli-responsive optical properties in organic single crystals (OSCs) remains a formidable challenge due to the intrinsic rigidity of π-conjugated systems. Herein, we report a rationally designed OSC, FBCF, that synergistically combines elastic deformability, broad piezochromism, and optical waveguides via a planar benzothiadiazole (BTA) core and fluoroarene termini. The molecular architecture enforces face-to-face slip-stacking via multiple noncovalent interactions (N•••H, π-π, and C-F•••π), yielding centimeter-scale crystals with exceptional elastic bending and full recovery. These crystals exhibit high photoluminescence (PL) efficiency (PLQY = 75.8%) and serve as optical waveguides, maintaining performance even when bent (optical loss coefficients (OLCs): 0.286-0.529 dB mm). Crucially, FBCF exhibits broad pressure-responsive spectral shifts (Δλ = 171 nm), achieving a piezochromic sensitivity of 16.7 nm GPa, exceeding that of most organic systems. Single-crystal X-ray diffraction analyses reveal hierarchical packing: rigid lamellar layers (stabilized by strong π-π/dipole interactions, -118.56 to ‑58.45 kcal/mol) interconnected via weaker interlayer C-F•••π bonds (-18.8 kcal/mol). This architecture enables elastic deformation through interlayer slippage while preserving intralayer order.
由于π共轭体系的固有刚性，在有机单晶（OSCs）中将机械柔韧性与刺激响应光学特性相结合仍然是一项艰巨的挑战。在此，我们报告了一种经过合理设计的有机单晶FBCF，它通过平面苯并噻二唑（BTA）核心和氟芳烃末端，协同结合了弹性变形能力、广泛的压致变色特性和光波导特性。分子结构通过多种非共价相互作用（N•••H、π-π和C-F•••π）强制实现面对面滑移堆积，从而产生具有出色弹性弯曲和完全恢复能力的厘米级晶体。这些晶体表现出高光致发光（PL）效率（PLQY = 75.8%），并用作光波导，即使在弯曲时也能保持性能（光学损耗系数（OLCs）：0.286 - 0.529 dB/mm）。至关重要的是，FBCF表现出广泛的压力响应光谱位移（Δλ = 171 nm），实现了16.7 nm/GPa的压致变色灵敏度，超过了大多数有机体系。单晶X射线衍射分析揭示了分级堆积结构：刚性层状层（通过强π-π/偶极相互作用稳定，-118.56至-58.45 kcal/mol）通过较弱的层间C-F•••π键（-18.8 kcal/mol）相互连接。这种结构能够通过层间滑移实现弹性变形，同时保持层内有序性。
