Fluolab
【Adv.Optical Mater.】深圳大学刘一手性AIE大环把g_lum放大到10⁻²：蓝到深红、四维刺激响应与CPL信息加密
【Adv.Optical Mater.】深圳大学刘一手性AIE大环把g_lum放大到10⁻²：蓝到深红、四维刺激响应与CPL信息加密
文章标题：Multi‐Color Chiral Aggregation‐Induced Emission Luminogens Toward Multiple Stimuli‐Responsive Circularly Polarized Luminescence and Information Encryption 文章作者：Qi Wu, Simin Li, Mingyu Luo, Cheng He, Qunchao Qiu, Lei Wang, Yi Liu 文章链接：https://doi.org/10.1002/adom.71927
(a) Modular donor-acceptor engineering routes toward multi-color chiral AIEgens. Condition: (i) 4-formylphenylboronic acid, K2CO3, Pd(PPh3)4, Toluene/EtOH/H2O, 100°C; (ii) benzothiazole-2-acetonitrile, CH3COONH4, THF, 80°C; (iii) malononitrile, TEA, DCM. (b) Information encryption based on R/SBT-CN with four dimensions (4D): chemicals, time, light, and CPL.
为什么要把颜色、手性和刺激响应放进一个分子
圆偏振发光材料在三维显示、手性光子和高安全防伪中有用，但同时做到高固态发光效率、颜色可调、多重刺激响应并不容易。已有手性AIEgen多靠外接手性取代基，固有螺旋手性难做，刺激响应往往只对一种外部条件起反应，加密维度单一。本文想用模块化供体-受体工程，在同一个手性大环骨架上实现蓝到深红的发射调控，并让强受体版本对化学、时间、光和CPL四个维度同时响应。
(a) Structure of SBT-CHO from single crystals and theoretical modeling. (b) The intra-layer packing models of SBT-CHO driven by intermolecular hydrogen bonding and π–π stacking.
颜色怎么调，信号怎么放大
作者以手性大环R/SBT-Br为起点，通过Suzuki偶联和Knoevenagel缩合得到R/SBT-CHO、R/SBT-BT和R/SBT-CN。单晶显示BINOL二面角约100.9°，TPE单元呈P/M螺旋，同手性分子靠氢键和π–π堆积成二维层。发射峰从503 nm逐步红移到533、618和637 nm；SBT-CHO在THF/水（fw=90%）中量子产率从10.3%升到55.7%，寿命从0.3到2.0 ns，是典型AIE。三对手性分子在溶液和纳米聚集体中都给出镜像CD和CPL，g_lum在10⁻⁴到10⁻³。分散到向列相液晶5CB（0.5% w/w）后，g_lum放大到10⁻²；强受体R/SBT-BT和R/SBT-CN的CD和CPL信号发生反转，作者推测与5CB的分子间相互作用有关，但原文明确说这还需要更多实验证据。R/SBT-CN的深红发射可被肼在1分钟内转为绿光，氨基酸则需数小时转为黄光；肼加合物在UV照射30分钟后释放肼、恢复醛基，发射红移到550 nm。CPL在DMSO中因PL弱而难以精确测量，作者也承认这一点。利用正、负和无CPL信号，作者用凯撒密码做了“CPL”到“DQM/BOK”的概念验证加密。
(a) UV–vis absorption and PL spectra of chiral emitters in THF. (b) Molecular levels of chiral AIEgens based DFT calculation. PL spectra of SBT-CHO (c), SBT-BT (d), and SBT-CN (e) in the mixture of THF and water. Dependence of relatizsve PL intensity (I/I0) and emission wavelength (λem) of SBT-CHO (f), SBT-BT (g), and SBT-CN (h) on the water fractions. I is the PL intensity at the maximal emission wavelength of the sample with fw = 90%, and I0 is the PL intensity in pure THF. Concentration = 10 µm.
(a) Dual-mode information encryption system with the illustration and photograph of hydrazine and light-responsive modes and their real images under UV lamp. (b) Illustration and photograph of amine-responsive, time-dependent and light-responsive modes with their real images under UV lamp. (c) Information encryption design based on the synergistic effect of amine, time-, and light-responsive models and CPL detector with their real images under UV lamp.
能做加密，但离实用还有距离
这项工作把多色手性发射、液晶放大和多重刺激响应压进一个模块化骨架，给防伪和信息加密提供了一种可设计的分子平台。但加密演示只是概念验证，CPL检测依赖手性光谱仪，实际场景中的稳定性、可重复读取和规模化制备原文没有提供；液晶中信号反转的机制仍是推测。它更适合作为手性光物理和智能材料的研究起点，而不是已经可部署的加密器件。