Design,Synthesis And Property Of Stimuli Response Fluorescence Material Based On Cyanostilbene

Stimuli-responsive luminescent materials are a class of "intelligent" ones,and their colors and fluorescence emission peaks/intensities can be switched or tuned by the external environmental stimuli?such as heat,pressure,vapor,pH,light,water,ions and small organic molecules,etc.?.Stimuli-responsive luminescent materials are used widely in fluorescent sensors,memory chips,security papers,logic operation,optical coding,optical switches,data storage,security ink,biological imaging,and so on.Therefore,the design,synthesis and applications of stimuli-responsive luminescent materials have been received more and more attention by researchers.Stimuli-responsive luminescent materials should have strong fluorescent properties in solutions or in solid state.It is foll of significant theory guidance and practical application value to design and prepare the stimuli-responsive materials with fluorescence properties in solution or in solid state.In this dissertation,the compound 4,TSA,TC and star-like organoboron complex TB1-TB4 with stimuli-responsive fluorescent properties were constructed by introducing cyanostilbene unit which has excellent luminescent property and is easily synthesized according to the design concept of molecular on the basis of full investigating the relevant literatures.The applications in chemical sensors,data storage,and security ink etc of compound 4,TSA and TC as well as the photophysical properties of TB1-TB4 were investigated completely.The main research contents are listed as fellows.1.A linearly conjugated bis-Schiff base compound?E?-N,N'-bis?4-?Z?-2-?4-butoxyphenyl?-1-cyano vinylphenyl?-1,4-benzenebismethanei mine?4?with novel aggregation-induced emission?AIE?activity was designed and synthesized,and its structure was characterized.In tetrahydrofuran?THF?and H₂O/THF,the compound 4+ Hg²⁺ exhibited obvious color and fluorescence emission change,which can be used to detect Hg²⁺ via naked eyes.Adding Hg²⁺ could stimulate and induce compound 4 to enhance fluorescent performance,which can realize to recognize the Hg²⁺ in THF,H₂O/THF and living cells with high selectivity and sensitivity.The detection limits are 3.4 ×10^-9 and 2.4 × 10^-7 M in THF and in H₂O/THF,respectively.The stimulus-response mechanism of 4 for Hg²⁺ was explained reasonably by the aggregation model of 4.2.A novel ?-shaped a-cyanostilbene derivative?TSA?containing active amino-group with fluorescence emission in both solution and solid state was designed and synthesized,and its structure was characterized.The photophysical and multi-stimuli-responsive properties of TSA were investigated.The results show that TSA can recognize PA in H₂O/EtOH mixture with a detection limit of 0.3 ?M.TSA also can detect the trace water in organic solvents,and the detection limit is 0.4 ?M in THF and 0.8 ?M in EtOH.In addition,TSA also showed fluorescence response properties to the stimulation of acid/base,grinding,heat and so on,which can be used in acid-base indicator and information data storage.3.A difluoroboron complex?TC?containing a-cyanostilbene unit and thiophene group was designed and synthesized,and its structure was characterized.TC exhibited high fluorescence emission property in both solution and solid state.Its absolute fluorescence quantum yield??F?is 33.0%in solid state and 26.0%in THF,respectively.The X-ray diffraction analysis demonstrated that the rigid structure,intermolecular hydrogen bonds as well as the loose and ordered molecular packing structures are the major reasons for TC had strong fluorescence mission property.The fluorescence emission of TC would have intensity weakening,wavelength red-shift and lifetime shortening under the external stimuli?such as acid/base,grinding and heat?.The results of X-ray powder diffraction?PXRD?and scanning electron microscopy?SEM?indicate that the mechanochromic luminescent properties of the samples are caused mainly by the crystalline-amorphous state transformation between the original state and ground one of the samples.The high fluorescence emissive and multi-stimuli fluorescent responsive properties of TC can be used in fluorescence indicator for acid/base,security ink and rewritable information storage.4.Four novel star-like Schiff base compounds TX1-TX4 containing cyanostilbene structure unit and their complex derivatives TB1-TB4 with four coordination difluoroboron were designed and synthesized,and their structure were characterized.Their relativity between the structures and photophysical properties was studied preliminarily.The results indicate the compounds TB1-TB4 have high molar absorption coefficient,TB1-TB3 not only have good luminescence properties in both solution and solid state but large Stokes' shift.