Wang Fang, Song Daniel, Dickie Diane A, Fraser Cassandra L
Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.
Chem Asian J. 2019 May 15;14(10):1849-1859. doi: 10.1002/asia.201801576. Epub 2019 Feb 5.
Emissive β-diketones (bdks) and difluoroboron complexes (BF bdks) show multi-stimuli responsive luminescence in both solution and the solid state. A series of bdk ligands and boron coordinated dyes were synthesized with different cyclic amine substituents in the 4-position to explore ring size effects on various luminescent properties, including solvatochromism, viscochromism, aggregation-induced emission (AIE), mechanochromic luminescence (ML) and halochromism. Red-shifted absorption and emission were observed in CH Cl for both bdk ligands and boron dyes with increasing substituent ring size. The compounds displayed bathochromic emission in more polar solvents, and higher fluorescence intensity in more viscous media. The AIE compounds exhibited enhanced emission when aggregated. For solid-state properties, a large emission wavelength shift was shown for the piperidine substituted bdk after melt quenching on weighing paper. Large blue-shifted emissions were observed in all the boron dye spin cast films after trifluoroacetic acid vapor annealing, and the original emissions were partially recovered after triethylamine vapor treatment.
发射型β-二酮（bdks）和二氟硼配合物（BF bdks）在溶液和固态中均表现出多刺激响应发光。合成了一系列在4位带有不同环胺取代基的bdk配体和硼配位染料，以探索环大小对各种发光性质的影响，包括溶剂化变色、黏滞变色、聚集诱导发光（AIE）、机械变色发光（ML）和酸碱变色。随着取代基环大小的增加，bdk配体和硼染料在CH Cl中均观察到红移吸收和发射。这些化合物在极性更强的溶剂中显示出红移发射，在黏性更强的介质中具有更高的荧光强度。AIE化合物聚集时发射增强。对于固态性质，哌啶取代的bdk在称量纸上熔融淬火后显示出较大的发射波长位移。在三氟乙酸蒸汽退火后，所有硼染料旋涂膜中均观察到大幅蓝移发射，用三乙胺蒸汽处理后，原始发射部分恢复。
