Study On The Synthesis And Properties Of TPE Tuned Rhodamine Fluorescent Probes

Highly sensitive and selective detection of pollutants and active substances in the environment and in vivo has always been the focus of research in the field of fluorescent probes.Due to its advantages including large molar absorptivity,high fluorescence quantum yield and large stokes shift in solution,Rhodamine fluorescent probe has been widely paid attention.In recent years,thanks to their excellent AIE properties,Tetraphenylethylene(TPE)probes have become a hot area of research.TPE tuned rhodamine fluorescent probe may exhibit the synergistic coupling effect on different luminescence mechanisms to achieve higher selectivity and ultra-high sensitivity and other excellent properties.In this thesis,a series of near-infrared Colorimetric/Fluormetric probes with high selectivity and sensitivity were designed and synthesized by regulating the molecular structure of rhodamine probes with TPE.The research results of this thesis as follows:Four kinds of TPE-rhodamine B Schiff base fluorescent probes are designed and synthesized based on rhodamine B hydrazide and a series of tetraphenylethylene formaldehyde with different coordination atoms.By studying selectivity of these fluorescent probes in Et OH-H₂O system,TPE-OH-Rh has the characteristics of dual cations detection for Cu²⁺and Al³⁺in different proportions of Et OH-H₂O systems,and shows excellent selectivity and sensitivity(Limit of detection for Cu²⁺:17.4 n M,Limit of detection for Al³⁺:0.675?M).Based on FRET and DRET mechanism,a new ratiometric fluorescent probe(TPE-Rh-NS)is designed and synthesized,in which,TPE was selected as the energy donor,rhodanine as the energy receptor,piperazine as the linked group,and thiosemicarbazides as the Hg²⁺recognition group.Thanks to the emissive features of the TPE derivatives in the solid state,fluorescent probe of TPE-Rh-NS shows high selectivity and sensitivity in solution and aggregation.In the dissolved state,the DRET process is conducive to Hg²⁺binding reaction,suitable for the detection of Hg²⁺in the environment;In the aggregated state,FRET processe occurs,showing a ratiometric fluorescence property that is more suitable for cell imaging applications.TPE-RH-NS was successfully applied to Hg²⁺imaging technology in He La cells.Two colorimetric/fluorescent fluorescent probes of Cl O^-are designed and synthesized based on TPE tuned Rhodamine,and using rhodamine amide structure as the recognition group.Both probes exhibite AIE properties,and show high selectivity and sensitivity for Cl O^-recognition in both dissolved and aggregated states.By studying on the average particle size formed by the two probes in the aggregated state,it is found that TPE-acylamide-Rh formed nanoparticles in the aggregated state,which are easier for cell staining and conducive to the application of cell imaging.The experimental results show that TPE-acylamide-Rh successfully detected Cl O^-in He La cells and showed excellent Cl O^-recognition properties.Four salicylicaldehydes schiff base probes(TPE-Rh-Sal,TPE-Rh-o-Me OB,TPE-Rh-p-Me OSal and TPE-Rh-m-Et OSal)of TPE-rhodamine with AIE properties are designed and synthesized by using rhodamine hydrazide as the main body,connecting with TPE via piperazine and reacting with salicylic aldehydes with different functional groups,respectively.The coordination process between probe TPE-Rh-Sal and Cu²⁺is divided into two steps:1)to form a complex;2)Under ultraviolet irradiation,the"ring opening reaction"of rhodamine occurs.Probe TPE-Rh-Sal may be applied to Cu²⁺recognition and UV intensity detection in response to Cu²⁺and UV stimulation,and shows excellent properties(Limit of detection for Cu²⁺was 1.34 n M).Meanwhile,based on ESIPT mechanism,the crystal powders of probe TPE-Rh-Sal and TPE-Rh-p-Me OSal show photochromic properties.The composites of paraffin loaded probe TPE-Rh-Sal and TPE-Rh-p-Me OSal exhibit a fast response time and fine fatigue resistance,and are used to optical information storage,photocontrol duplicative materials and ultraviolet detection.There are 165 figures,9 tables and 181 references in this paper.