Molecular crystals based on 9,10-distyrylanthracene derivatives with high solid state fluorescence efficiency and uniaxial orientation induced by supramolecular interactions

Abstract

Two 9,10-distyrylanthracene (DSA) derivatives CNDSA and t-BUDSA were designed and synthesized, and their photophysical properties and crystal structures were investigated. Compared to DSA, the maximum emission peaks of the two compounds showed red-shift not only in THF solution, but also in crystals, because the introduction of electron-withdrawing substituents to DSA leads to more dispersion of the electrons in the molecules. The two crystals of CNDSA and t-BUDSA show strong fluorescence with the efficiency  F of 45% and 33%, respectively, which may be resulted from no obvious - interactions between molecules inside the crystal due to the large distance between the two adjacent molecules and nearly no overlap between the central anthracene planes. The analysis of crystal structures of the two compounds indicated that the molecules are arranged in the same conformation and orientation in their crystals, i.e. uniaxially oriented packing crystal, because of the supramolecular interaction of CH/ in the two crystals and additional C-H···N interactions in CNDSA.

Folic acid-functionalized AIE Pdots based on amphiphilic PCL-b-PEG for targeted cell imaging

“…It could be clearly observed that the uorescence emissions of AIE Pdots are enhanced by their copolymers. As reported in our early research, 24,26,[41][42][43] the signicantly twisted conformations of DSA derivatives can easily lead to the intramolecular vibration and rotation. DSA derivatives emit weak uorescence in their good solution.…”

“…Different from the notorious ACQ effect, AIE-active uorophores are non-emissive in molecularly dissolved states while give highly uorescence emission when they are in aggregate states. [7][8][9] Previous studies revealed that AIE luminogens are ideal candidates for the fabrication of FPdots with high uorescence quantum efficiencies due to their efficient emission in the aggregate state, 6,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] and the encapsulation of AIE luminogens by an amphiphilic block copolymer is a convenient way to fabricate AIE Pdots. Many encapsulating AIE Pdots showing good biological imaging capability have been prepared, [10][11][12][13][14][15][16] but unfortunately, there unavoidably present dye leakage, resulting in the cytotoxicity when applied in bioimaging.…”

Progress in 9,10-distyrylanthracene derivatives with aggregation-induced emission

“…(PMMA)薄膜中皮秒量级的光谱变化 [16] . [17] ; 三氟甲基取代的化合物18和氟取代的化合 物19, 晶体的荧光均为黄绿色, 荧光效率可达70%以 上 [18] . 孙柏旺研究组 [19,20] 报道了不同卤素取代的化合 物6~9, 其晶体表现出逐渐红移的发光特性, 与溶液完 全不同.…”

Low-Loss Optical Waveguide and Highly Polarized Emission in a Uniaxially Oriented Molecular Crystal Based on 9,10-Distyrylanthracene Derivatives

“…Similar to other DSA derivatives, the molecular conformation of BDTVA in the crystal is remarkably twisted due to the steric hindrance arising from the hydrogen atoms on vinyl and anthracene. 2,20,32 The torsional angle between the double bond and central anthracene is 112.16°(θ (1,2,3,4) ), and the torsional angles between the double bond and two adjacent phenyl rings are 38.37°(θ (3,4,5,6) ) and 133.13°(θ (3,4,7,8) ), respectively (Figure S6 and Table S3). These torsional angles are all larger than those in the BDPVA crystal, 20 suggesting that the introduction of methyl substituents to the BDPVA molecule results in the more twisted molecular conformation.…”

“…Organic single crystals have attracted intense attention for their distinct properties, such as high thermal stability, highly ordered structure, and preferential molecular orientation within the crystal lattice. − Optical waveguides and solid-state lasers based on organic single crystals are under intensive studies. − The performance of these devices is affected by the waveguide and polarized properties of the organic single crystal. For an organic single crystal, the optoelectronic properties not only depend on the luminophor but also depend significantly on the intermolecular interactions and molecular orientation. , An organic crystal with bidirectional molecular packing usually hinders the uniaxial polarization of the emission light, , while uniaxially oriented molecular crystals, in which the molecules are arranged in the same conformation and orientation, may possess excellent waveguide and highly polarized light emission performance, because the same molecular conformation and orientation within the crystal lattice will result in highly anisotropic refractive indices and direct the propagation of the emitting light in the preferential direction. , Over the past decades, only a few works on uniaxially oriented molecular crystals have been reported, ,− because it is difficult to make the organic molecules pack in the same orientation due to the multiple conformations of organic molecules and the various interactions in the crystals .…”