Tong Jiaqi, Wang Yijia, Mei Ju, Wang Jian, Qin Anjun, Sun Jing Zhi, Tang Ben Zhong
MoE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China), Fax: (+86) 571-87953734.
Chemistry. 2014 Apr 14;20(16):4661-70. doi: 10.1002/chem.201304174. Epub 2014 Mar 11.
A tetraphenylethene (TPE) derivative substituted with the electron-acceptor 1,3-indandione (IND) group was designed and prepared. The targeted IND-TPE reserves the intrinsic aggregation-induced emission (AIE) property of the TPE moiety. Meanwhile, owing to the decorated IND moiety, IND-TPE demonstrates intramolecular charge-transfer process and pronounced solvatochromic behavior. When the solvent is changed from apolar toluene to highly polar acetonitrile, the emission peak redshifts from 543 to 597 nm. IND-TPE solid samples show an evident mechanochromic process. Grinding of the as-prepared powder sample induces a redshift of emission from green (peak at 515 nm) to orange (peak at 570 nm). The mechanochromic process is reversible in multiple grinding-thermal annealing and grinding-solvent-fuming cycles, and the emission of the solid sample switches between orange (ground) and yellow (thermal/solvent-fuming-treated) colors. The mechanochromism is ascribed to the phase transition between amorphous and crystalline states. IND-TPE undergoes a hydrolysis reaction in basic aqueous solution, thus the red-orange emission can be quenched by OH(-) or other species that can induce the generation of sufficient OH(-). Accordingly, IND-TPE has been used to discriminatively detect arginine and lysine from other amino acids, due to their basic nature. The experimental data are satisfactory. Moreover, the hydrolyzation product of IND-TPE is weakly emissive in the resultant mixture but becomes highly blue-emissive after the illumination for a period by UV light. Thus IND-TPE can be used as a dual-responsive fluorescent probe, which may extend the application of TPE-based molecular probes in chemical and biological categories.
设计并制备了一种被电子受体1,3-茚二酮（IND）基团取代的四苯乙烯（TPE）衍生物。目标产物IND-TPE保留了TPE部分固有的聚集诱导发光（AIE）特性。同时，由于修饰了IND部分，IND-TPE表现出分子内电荷转移过程和显著的溶剂化变色行为。当溶剂从非极性的甲苯变为高极性的乙腈时，发射峰从543 nm红移至597 nm。IND-TPE固体样品显示出明显的机械变色过程。研磨制备好的粉末样品会导致发射光从绿色（峰值在515 nm）红移至橙色（峰值在570 nm）。在多次研磨-热退火和研磨-溶剂熏蒸循环中，机械变色过程是可逆的，固体样品的发射光在橙色（研磨后）和黄色（热/溶剂熏蒸处理后）之间切换。这种机械变色现象归因于非晶态和晶态之间的相变。IND-TPE在碱性水溶液中会发生水解反应，因此红色橙色发射光可被OH⁻或其他能诱导产生足够OH⁻的物质淬灭。相应地，由于精氨酸和赖氨酸的碱性性质，IND-TPE已被用于从其他氨基酸中选择性地检测它们。实验数据令人满意。此外，IND-TPE的水解产物在所得混合物中发射较弱，但在紫外光照射一段时间后会变为高蓝色发射。因此，IND-TPE可作为一种双响应荧光探针，这可能会扩展基于TPE的分子探针在化学和生物学领域的应用。
