Design And Investigate The Properties Of Bifunctional Aggregation-induced Emission Molecule Based On Tetraphenylethene

Among many molecules of aggregation-induced emission organic compounds,tetraphenylethene derivatives,which are currently star molecule in the field of aggregation-induced emission research,have a wide application in analytical chemistry,life chemistry,coordination chemistry and material chemistry due to their unique advantages such as simple synthesis method,easy derivatization and good luminescence properties.In this paper,a novel tetraphenylethene derivative5-?1,2,2-triphenylethylene?isophthalic acid?TPE-2COOH?was synthesized by introducing a carboxyl group on the tetraphenylethene group.In addition to the characterization of its aggregation-induced emission properties,its application in the detection of metal ions and the construction of functional complexes was investigated.The main contents are as follows:Firstly,the application of TPE-2COOH in the detection of metal ion was studied.In aqueous solution,TPE-2COOH exhibited turn-on fluorescent response to Al???due to the complexation of Al???with the carboxyl group.The mechanistic study confirmed that the formation of chelate polymer TPE-2COO-Al in the responsive process resulted in restricted intramolecular rotation?RIR?and strong fluorescence emission at 466 nm.Due to its good water solubility,TPE-2COOH molecule itself has no fluorescent emission in the aqueous solution.After adding Al???,the fluorescence enhancement was as high as 152-fold and the turn-on fluorescence can be observed even by the naked eye upon irradiation with UV lamp.In an aqueous solution with pH=7.0,a linear range of 0.0-50.0?mol/L and a detection limit of 1.96?mol/L for Al???were obtained,respectively.More importantly,the selectivity and anti-interference capability of TPE-2COOH for the detection of Al???were very good.Secondly,the TPE-2COOH molecule was introduced into the structure of the coordination complex,and the first reversible photochromic complex based on tetraphenylethylene ligand[Cd₂?TPE-2COO?₂?DMF?₄]_n?1?was successfully obtained.Mechanistic study showed that there was a photo-induced free radical production in 1under UV light irradiation.More importantly,this system showed fast photoresponse,photostability and excellent fatigue resistance,and the recovery rate was effectively tunable by using different temperatures.Compared with traditional photochromic molecules,the complex exhibited many advantages such as novel structure,simple synthesis,obvious photochromism,photostability and excellent fatigue resistance,and was successfully used as a photo-printing and anti-counterfeiting material.