Handbook of Aggregation-Induced Emission, Volume 2. Группа авторов

Handbook of Aggregation-Induced Emission, Volume 2 - Группа авторов


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were reported in 2011 by Tong's group [70] (Figure 3.26a). With different substituents of salicylaldehyde, the fluorescence of these derivatives in their crystalline states shows green to orange emission (λem = 518 nm/556 nm). X‐ray crystal structure analysis reveals one‐dimensional microrods obtained with carboxyl substitution on the para‐position of aniline due to the promoted formation of intermolecular hydrogen bonds compared with chlorine substitution (Figure 3.26b–e). The microrods also show good optical waveguide property owing to the orderly arrangement and transparency. No matter where the location site of excitation is, the transmission of the excited fluorescence to both ends in a one‐dimensional direction was observed (Figure 3.26f).

      Yang's group reported a class of molecules 54 with AIE and ESIPT properties in 2012 [71]. The fluorescence intensity of 54 in water or powder is significantly enhanced compared to THF solution (Figure 3.26g). X‐ray crystal structure analysis showed that 54 exhibited a J‐type aggregate, and the N⋯π interaction of the N atom in the thiophene ring with the adjacent thiophene ring of another molecule stabilizes this aggregation form (Figure 3.26h). In addition, the cistrans tautomerism of the keto structure is hindered when the molecules are closely packed. Based on these properties, 54 was used as a light‐emitting layer to form a simple three‐layer nondoped OLED device with higher color purity and lower efficiency roll‐off.

Image described by caption.

      Source: Reprinted from Ref. [70] (Copyright 2011 Elsevier B.V.).

      (g) Photographs of 54 under UV illumination at 365 nm in THF solution, water, and powder from left to right, respectively. Insertion was the molecular structure of 54. (h) N⋯π interaction of 54.

      Source: Reprinted from Ref. [71] (Copyright 2012 Royal Society of Chemistry).

Image described by caption.

      Source: Reprinted from Ref. [72] (Copyright 2015 John Wiley and Sons).

      (d) Proposed mechanism for the color change of 67 upon UV irradiation. (e) Generating different patterns on the same film of 67. (f) The thermal fading kinetics of 67 at different temperatures. (g) The dotted lines are the fluorescence intensity of 67 at 545 nm before and after excess UV light irradiation. The scatterplot is the fluorescence intensity of UV‐irradiated 67 at 545 nm exposed in light with different wavelengths for one minute.

      Source: Reprinted with permission from Ref. [73] (Copyright 2017 Royal Society of Chemistry).


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