Ju Mei,†,‡,∥ Nelson L. C. Leung,†,‡,∥ Ryan T. K. Kwok,†,‡ Jacky W. Y. Lam,†,‡ and Ben Zhong Tang*,†,‡,§ †HKUST-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China ‡Department of Chemistry, HKUST Jockey Club Institute for Advanced Study, Institute of Molecular Functional Materials, Division of Biomedical Engineering, State Key Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China

Aggregation-Induced Emission: Together We Shine, United We Soar!

Luminogenic materials with aggregation-induced emission (AIE) attributes have attracted much interest since the debut of the AIE concept in 2001. In this critical review, recent progress in the area of AIE research is summarized. Typical examples of AIE systems are discussed, from which their structure–property relationships are derived. Through mechanistic decipherment of the photophysical processes, structural design strategies for generating new AIE luminogens are developed. Technological, especially optoelectronic and biological, applications of the AIE systems are exemplified to illustrate how the novel AIE effect can be utilized for high-tech innovations (183 references).

Aggregation-induced emission

Aggregation-induced emission: phenomenon, mechanism and applications.

The present invention relates to novel organic electroluminescent compounds exhibiting high luminous efficiency, and organic electroluminescent devices comprising the same. The organic electroluminescent compounds according to the invention are represented by Chemical Formula (1):

Novel organic electroluminescent compounds and organic electroluminescent device using the same

Boron dipyrromethene (BODIPY) derivatives 1 and 2 consisting of donor and acceptor units with dual photoresponses to solvent polarity and luminogen aggregation are developed through taking advantage of twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) processes. In nonpolar solvents, the locally excited (LE) states of the BODIPY luminogens emit intense green lights. Increasing solvent polarity brings the luminogens from the LE state to the TICT state, causing a large bathochromic shift in the emission color but a dramatic decrease in the emission efficiency. The red emission is greatly boosted by aggregate formation or AIE effect: addition of large amounts of water into the solutions of 1 and 2 in the polar solvents causes the luminogens to aggregate supramolecularly and to emit efficiently. The emission can be enhanced by increasing solvent viscosity and decreasing solution temperature, indicating that the AIE effect is caused by the restriction of the intramolecular ro...

Twisted Intramolecular Charge Transfer and Aggregation-Induced Emission of BODIPY Derivatives

A novel Λ-shaped pyridinium salt 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(p-ethenyl-N-methyl-pyridinium) ditosylate (abbreviated as DMDPS) based on Troger's base was designed, synthesized and characterized. DMDPS exhibits a typical aggregation-induced emission (AIE) behavior that is virtually nonemissive in solution but highly luminescent in solid state. The difference between the structure and the optical properties of DMDPS and 1,4-phenyl-di(p-ethenyl-N-methyl-pyridinium) ditosylate (abbreviated as DPPS) are analyzed and compared. It is concluded that the loose stacking caused by twisted molecular configuration could reduce the distance-dependent intermolecular quenching effect to produce intense fluorescence in the aggregation state while the enantiomerization and/or the intramolecular vibrational motion which induce the nonradiative deactivation process could cause fluorescence quenching in the solution. As a water-soluble AIE-active material, DMDPS would have potential application in th...

Synthesis, Structure, and Aggregation-Induced Emission of a Novel Lambda (Λ)-Shaped Pyridinium Salt Based on Tröger's Base

The lambda (Λ)-shaped pyridinium salts 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(p-ethenyl-N-methylpyridinium) ditosylate (DMDPS), 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(p-ethenyl-N-methylpyridinium) diiodide (DMDPI), and 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(p-ethenyl-N-methylpyridinium) dinitrate (DMDPN) based on Troger’s base exhibit a typical aggregation-induced emission (AIE) behavior that it is virtually nonemissive in solution but highly luminescent in the aggregate state. The possibility of utilizing the AIE effect for protein detection and quantification is explored by using bovine serum albumin (BSA) as a model protein. These bioprobes undergo a large spectral change upon binding to BSA, which can be determined by fluorometry. Furthermore, the plots of photoluminescence intensity versus BSA concentration (0−70 μg/mL) display a good linear relationship, indicating quantitative fluorimetric protein detection may be achieved.

Fluorescent Turn-On Detection and Assay of Protein Based on Lambda (Λ)-Shaped Pyridinium Salts with Aggregation-Induced Emission Characteristics

Effect of substituents on the properties of indolo[3,2-b]carbazole-based hole-transporting materials

Indolo[3,2-b]carbazole: Promising building block for highly efficient electroluminescent materials

Two Λ-shaped BODIPY dyes based on Troger's base, 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) (DFTMB) and 2,8-(6H,12H-5,11-methanodibenzo[b,f]diazocineylene)-di(4,4-difluoro-2,6-diethyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) (DFDEB), were designed and synthesized. Both compounds exhibit intense fluorescence in dilute solution and polycrystalline powder form. From the crystal structure, the impact of the substitutions at the BODIPY core on the crystal packing mode, intermolecular π–π interactions and optical behavior is compared and discussed. The results indicate that the close π–π stacking in the crystalline state has been effectively inhibited by the twisted Λ-shaped Troger's base.

https://www.rsc.org/suppdata/ce/c2/c2ce06260g/c2ce06260g.pdf

Chun-Xue Yuan

Papers

Synthesis, Structure, and Aggregation-Induced Emission of a Novel Lambda (Λ)-Shaped Pyridinium Salt Based on Tröger's Base

Fluorescent Turn-On Detection and Assay of Protein Based on Lambda (Λ)-Shaped Pyridinium Salts with Aggregation-Induced Emission Characteristics

Effect of substituents on the properties of indolo[3,2-b]carbazole-based hole-transporting materials

Indolo[3,2-b]carbazole: Promising building block for highly efficient electroluminescent materials

Crystal structures and solid-state fluorescence of BODIPY dyes based on Λ-shaped Tröger's base