Research On Fluorescent Smart Molecule Based On TPE Linked With Nitrogen Atom Of 2,3,3-trimethyl-3H-indole

Living in this information explosion generation,our life stile becomes faster and faster,There is no accident that the main path for us to get information changes from texts which are known as abstract to specific vivid images and videos.So visualization becomes more and more important with this strong need,As a result,OLED,fluorescence detection,biological fluorescence label etc,becomes research hotspot.Traditional fluorescent materials are always used in detection because of its high flexible.With the better understanding of fluorescent materials,hot pot of these materials change from ACQ materials to AIE materials.Tetraphenylethene(TPE)and its derivatives are one of most usual AIE materials which are applied in many fields because of its high quantum efficiency and easy synthesis properties.They always serve as signal part of functional materials in biological imaging,security,display and so on.Linking fluorophore with functional materials can make test limit obvious.Swich is one of most important part of functional materials.Spiropyrans(SP)are one of most typical organic chromic switches,which is researched for approximately 60 years.SP share several advantageous such as fast response,large molar extinction coefficient,and these makes us easy to see the reversible chromic process of spiropyran and merocyanine(MC).MC is a kind of hemicyanine whose maximum emission wavelength is about 650 nm,and this red emission can be turned off by SP form.To broaden the application of spiropyran,investigators decorate fluorogen(not red)on it,thus,new luminescent SP form and MC form shows large Stokes shift with chromic path.Hemicyanines are one of important part in cyanine platform,which shares low toxicity,high biocompatibility,and widely used in biological label,chemical sensor,ion detection etc.Detection mechanism of hemicyanine is change of the original D-π-A structure or damage of the π conjunction structure,which change the absorbance or emission or quench the emission of hemcyanine.So test limit is difficult to identify by eyes.With the same reason,new hemicyanine linked with fluorogen.Fluorescence quenching path changes into chromic path which greatly increases the test limit.Linkage of fluorescent lumingen and functional part is always conjugate way,and the lumincent path changes from region to entirety(ICT).However the non conjugate linkage is not fully researched.So in this paper linkage of the function part(spiropyran and hemicyanine)and fluorogen(TPE)is by methane,which is not conjugation.The interaction of this two part can only work through space.So we reckon that this two part is relatively independent and two kind of organic materials based on matrix will inherit properties of function part and fluorogen very well.In this paper,the matrix structure is TPE linked with nitrogen Atom of 2,3,3-trimethyl-3H-indole,noted as TPE-N-pre.Because typical hemicyanine and spiropyran shares the same part—2,3,3-trimethyl-3H-indole,we try to get two kind of organic materials based on this matrix.1.Link the matrix TPE-N-pre with 5-nitrosalicylaldehyde/salicylaldehyde.We get TPE-N-SP1 and TPE-N-SP2.Structure of this two is identified by ~1H-NMR and 13C-NMR.Then text 1)photochromic,acid/base chromic,and AIE properties in solution state;2)photochromic,mechanochromic,acid/base chromic properties in solid state;3)photochromic property in PMMA film.TPE-N-SP1 shows great muti-stimulied response properties which get from spiropyran and TPE,however the emission intensity of close form is too low.TPE-N-SP2 shows great emission intensity but can only stimulied by acid/base.2,Link matrix with benzaldehyde.We get TPE-N-hycn,whose structure is similar to open form of TPE-N-SP2.Structure of TPE-N-hycn is identified by ~1H-NMR.Then we text 1)p H response and AIE properties in solution state;2)acid/base chromic properties in solid state.TPE-N-hycn can only respond by acid and base,which is similar to TPE-N-SP2,and the fluorescence intensity is not change with p H linearly.But it will show its chromic property by acidic and basic vapor in PMMA film.