Preparation And Luminescent Property Of Tetraphenyl Ethylene Derivatives

Traditional fluorescent materials are mostly composed of rigid planar molecules with conjugated structures.Under normal circumstances,most of these fluorescent substances show obvious fluorescence intensity weakening or even fluorescence quenching.However,in the aggregate state,most fluorescent substances have a weak or even quenched fluorescence intensity.It is called aggregation caused quenching(ACQ).In 2001,the discovery of"aggregated induced emission"(AIE)phenomenon provided a new direction for the study of fluorescent materials.The tetraphenylethylene(TPE)derivatives have attracted attention because of their advantages such as simple synthesis,easy functionalization and obvious AIE effect.In this dissertation,the 4,4'-dimethoxybenzophenone was used as the raw material to synthesize the tetraphenylethylene derivative with methoxy structure by Mc Murry reaction and then the tetraphenylethylene derivative(TPE-COOH)was prepared through a series of demethylation,hydrolysis and other reactions.The target product was used to study the photophysical properties by ultraviolet-visible absorption spectroscopy and fluorescence emission spectroscopy.On this basis,a turn off/on fluorescent probe based on TPE-COOH was prepared,and the detection mechanism of fluorescent probe was deeply explored by field emission scanning electron microscope and nanometer particle size analyzer.The experimental results show that the TPE-COOH suspension can selectively identify the copper ions because the copper ions can promote the collapse of the TPE-COOH aggregates and thus the fluorescence of the aggregates is closed.In addition,due to the competitive binding of adenine nucleoside triphosphate(ATP)to Cu²⁺,the introduction of ATP into TPE-COOH/Cu²⁺solution can lead to the reassembly of TPE-COOH and recovery of fluorescence,thus achieving rapid ATP molecules.On this basis,a test paper-based solid-state fluorescence sensor based on TPE-COOH compound was prepared,which provided an experimental basis for the low-cost and rapid detection of trace amounts of Cu²⁺and ATP.The experimental results show that the fluorescent sensor based on tetraphenylethylene derivative(TPE-COOH)can detect Cu²⁺and ATP in pure aqueous solution by fluorescence turning off/on and the fluorescent probe has high sensitivity and selectivity,lower limit of detection,the prepared test strip sensor does not need large instruments and can be used to detect ion concentration in real time.In addition,siloxane molecules are introduced into a tetraphenylethylene chromophore to prepare a recoverable mechanochromism material.The photophysical properties of target molecules were studied by UV-Vis absorption spectroscopy and fluorescence emission spectroscopy.The thermostability and phase behavior of the prepared force-chromic materials were investigated by thermogravimetric analyzer and differential scanning calorimetry.The experimental results show that the mechanical force can change the aggregate structure of the material to achieve the mechanochromism performance.These experimental results provide an experimental basis for the application of such materials in the fields of stress sensing,displacement or deformation detection,and trademark anti-counterfeiting.