Tang Baolei, Zhang Houyu, Cheng Xiao, Ye Kaiqi, Zhang Hongyu
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Chempluschem. 2016 Dec;81(12):1320-1325. doi: 10.1002/cplu.201600451. Epub 2016 Sep 28.
In this study, 1-[4-(dimethylamino)phenyl]-3-(1-hydroxynaphthalen-2-yl)propane-1,3-dione (DPHND) was designed and synthesized to construct red-emissive organic solids. Although DPHND was weakly yellow fluorescent in organic solvents, its emission intensity showed a significant enhancement when a relatively large amount of poor solvent was added, and displayed typical aggregation-induced enhanced emission (AIEE). Notably, the crystals formed by a solution-diffusion approach showed bright red fluorescence (λ =621 nm), which was greatly redshifted by about 60 nm compared with that in solution. Molecules in crystals took a planar conformation and formed a herringbone packing structure, which effectively avoided π⋅⋅⋅π interactions, and hence contributed to the enhancement of the fluorescent quantum yield. The fluorescence spectrum of the long striplike crystals of DPHND gradually narrowed accompanied by a dramatic enhancement of the intensity when the pump energy of the laser beam was increased (355 nm), which indicated that these red-emissive crystals displayed typical amplified spontaneous emission (ASE). In addition, DPHND with an extended π-conjugated structure clearly improved its thermostability compared with the previously reported analogues, which may pave the way for its application in future electrically driven organic solid-state lasers.
在本研究中，设计并合成了1-[4-(二甲氨基)苯基]-3-(1-羟基萘-2-基)丙烷-1,3-二酮(DPHND)以构建发红光的有机固体。尽管DPHND在有机溶剂中呈弱黄色荧光，但当加入相对大量的不良溶剂时，其发射强度显著增强，并表现出典型的聚集诱导增强发射(AIEE)。值得注意的是，通过溶液扩散法形成的晶体呈现出亮红色荧光(λ =621 nm)，与溶液中的荧光相比，其红移了约60 nm。晶体中的分子呈平面构象并形成了人字形堆积结构，有效避免了π⋅⋅⋅π相互作用，从而有助于荧光量子产率的提高。当激光束的泵浦能量增加(355 nm)时，DPHND的长条状晶体的荧光光谱逐渐变窄，同时强度急剧增强，这表明这些发红光的晶体表现出典型的放大自发发射(ASE)。此外，与先前报道的类似物相比，具有扩展π共轭结构的DPHND明显提高了其热稳定性，这可能为其在未来电驱动有机固体激光器中的应用铺平道路。
