Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole

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

The Huisgen 1,3-dipolar cycloaddition reaction of organic azides and alkynes has gained considerable attention in recent years due to the introduction in 2001 of Cu(1) catalysis by Tornoe and Meldal, leading to a major improvement in both rate and regioselectivity of the reaction, as realized independently by the Meldal and the Sharpless laboratories. The great success of the Cu(1) catalyzed reaction is rooted in the fact that it is a virtually quantitative, very robust, insensitive, general, and orthogonal ligation reaction, suitable for even biomolecular ligation and in vivo tagging or as a polymerization reaction for synthesis of long linear polymers. The triazole formed is essentially chemically inert to reactive conditions, e.g. oxidation, reduction, and hydrolysis, and has an intermediate polarity with a dipolar moment of ∼5 D. The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier. In order to understand the reaction in detail, it therefore seems important to spend a moment to consider the structural and mechanistic aspects of the catalysis. The reaction is quite insensitive to reaction conditions as long as Cu(1) is present and may be performed in an aqueous or organic environment both in solution and on solid support.

Cu-catalyzed azide-alkyne cycloaddition.

Aggregation-induced emission: phenomenon, mechanism and applications.

A series of new disubstituted liquid crystalline polyacetylenes (LCPAs) with general molecular structures of -{(R)C=C[(CH 2 ) m -Mes]} n - and -[(C 6 H 13 )C=C(C 6 H 4 -Mes)] n - (R = CH 3 , C 6 H 5 , m = 3, 4, 9, Mes = mesogen) have been designed and synthesized. All the LCPAs are thermally stable and do not loss their weights when heated to a temperature as high as ~400°C. While a few polymers exhibit nematicity, most of them form enantiotropic S A phase of monolayer structure. Upon photoexcitation, the polymers emit intense UV and blue lights with quantum yield up to 81%. Multilayer light-emitting diodes with a device configuration of ITO/PVK/PA/LiF/Al are constructed, which emits blue light with maximum luminance and external quantum efficiency of 119 cd/m 2 and 0.12%, respectively.

Polyacetylene liquid crystals: new mesomorphic materials with high thermal stability and novel light-emitting properties

Strong Luminescence from Carbazole-containing Poly(1-phenyl-1-alkynes)

Strong Electroluminescence in a Disubstituted Polyacetylene

Functional materials with multi-responsive properties and good controllability are highly desired for developing bioinspired and intelligent multifunctional systems. Although some chromic molecules have been developed, it is still challenging to realize in-situ multicolor fluorescence changes based on a single luminogen. Herein, we reported an aggregation-induced emission (AIE) luminogen called CPVCM, which can undergo a specific amination with primary amines to trigger luminescence change and photoarrangement under UV irradiation at the same active site. Detailed mechanistic insights were carried out to illustrate the reactivity and reaction pathways. Accordingly, multiple-colored images, a quick response code with dynamic colors, and an all-round information encryption system were demonstrated to show the properties of multiple controls and responses. It is believed that this work not only provides a strategy to develop multiresponsive luminogens but also develops an information encryption system based on luminescent materials.

Jacky Wing Yip Lam

Papers

Polyacetylene liquid crystals: new mesomorphic materials with high thermal stability and novel light-emitting properties

Strong Luminescence from Carbazole-containing Poly(1-phenyl-1-alkynes)

Strong Electroluminescence in a Disubstituted Polyacetylene

A Multiresponsive Functional AIEgen for Spatiotemporal Pattern Control and All-round Information Encryption.

Aggregation-Induced Emission, Vapochromism and Electroluminescence of Tetraphenylethylene and Its Blends with Poly(methyl methacrylate)