Tetraphenylethylene Pillararenes: Synthesis And Application

Ever since it's introduction in 2008, pillararenes have attracted great attention for their versatility functions such as host molecules and self-assembly building blocks. Although great efforts and progresses have made in the development of applicable methods to functionalize pillararenes, the synthetic methods to modify the methyl bridge of pillararene are yet to be developed. Herein, methyl bridge functionalized pillararenes were introduced by employ tetraphenylethylene which is known as an aggregated-induced emission active molecule as building block for the first time. As mentioned, the tetraphenylethylene pillararenes combine the advantages of aggregate-induced emission and macrocycle hosting molecule. As demonstrated here, those compounds have great potential as fluorescent chemical sensors and self-assembly soft materials. In this paper, the following major parts are presented.1. The design, preparation and full characterization using NMR, HRMS, FTIR and x-ray single crystal of tetraphenylethylene pillararenes are discussed. 2. The interaction and recognition of nitroaromatics with those compounds were investigated with fluorescent spectra. The potential of methoxyltetraphenylethylene pillararene to function as chemical sensor of trinitrotoluene was also tested. 3. The mechanism of the recognition behavior was proposed based on the analysis of single crystal data and NMR titration, etc. 4. Hosting with guest molecule such as pyridine salts was demonstrated with NMR titration technique.