Tetraphenylethylene Derivatives: Synthesis,Structure,Assembly And Application

Tetraphenylethylene is an interesting molecule that exhibits propeller-like and nonplnar conformation and has a well-known aggregation-induced emission(AIE) effect. With the unique structure, TPE can be used in construction of porous materials, such as metal organic frameworks and conjugated miroporous polymers. Taking advantage of the AIE feature, TPE enables the construction of various TPE-based chemo/biosensors. In this thesis, we used TPE as a building block to construct oxacalixarenes, tricyclooxacalixarene cage and TPE-based nanoparticles.Three novel TPE-based expanded oxacalixarenes were synthesized by SNAr reaction of dihydroxytetraphenylethylene with 2,6-dichloropyrazine(2-1), 2,6-dichloropyridine-3,5-dicarbonitrile(2-2) and 1,5-difluoro-2,4-dinitrobenzene(2-3), respectively. The conformation of oxacalixaren 2-1 can be adjusted by the encapsulated guests(benzene or THF), which results in different supramolecular grid structures in the solid state. With the AIE properties, the oxacalixaren 2-2 shows good recognition abilities towards nitroaromatic explosives, such as TNP. A supramolecular grid-like structure bearing two different kinds of pores is assembled by oxacalixarene 2-3 in the solid state, in which different guests of ethyl ether and dichloromethane are directionally encapsulated, respectively.A quadrangular prismatic tricyclooxacalixarene 3-1 based on tetraphenylethylene(TPE) was efficiently synthesized by one-pot SNAr condensation reaction. 3-1 turned on the fluorescence of TPE in solution and validated the aggregation-induced emission(AIE) effect mechanism of restriction of intramolecular rotations(RIR). With the intrinsic and assembled porous structure in the solid state, 3-1 exhibited good CO2 uptake capacity of 12.5 wt % and high selectivity of CO2/N2 of 80(273K, 1bar) with BET surface area of 432 m2 g-1. Moreover, 3-1 can be used as detector for nitroaromatic explosives such as TNP.Temperature-sensitive organic nanoparticles with AIE effect were assembled in water from tetraphenylethene-based poly(N-isopropylacrylamide)(4-2), which was synthesized by ATRP using TPE derivative as initiator. The size and fluorescence of 4-2 nanoparticles can be tuned by varying temperature. These nanoparticles can be internalized readily by HeLa cells and can be used as long-term tracer in live cells to be retained for as long as 7 passages.