The Study On The Regulation Of Photophysical Properties Of Terpyridine Zn(?) Complexes And Their Applications

Smart luminescent materials are a class of materials whose photophysical properties can be responded to external stimuli,including chemical stimuli(metal ions,biomolecules,p H,etc.)and physical stimuli(ultrasound,light,heat,electricity,etc.).In recent years,it has played an important role in information storage,displays,optical imaging,and anti-counterfeiting,etc.Therefore,the research interest in smart luminescent materials is remarkably increasing recently.Conseridering that various smart luminescent materials can exhibit different response ways under diverse external stimuli,a great number of combinations between stimuli and responses can be possibly occurred.The utilization of optical signal changes of smart luminescent materials under different external stimuli can realize the application of information storage and optical anti-counterfeiting.Based on the dynamic metal-ligand coordination,this thesis designs and synthesizes a typical donor-acceptor ligand containing carbazole group and the terpyridine group through an amide bond.When the ligand was coordinated with different zinc salts,the emission colors can be regulated by various external stimuli,and the multicolor encoding and decoding,and security printing have been achieved.1.In Situ Control of Multicolor Luminescence in a Single Chromophore by Sol-Gel Transformation and Dynamic Metal-Ligand CoordinationA molecule with a donor-acceptor structure that connects carbazole and terpyridine through an amide bond is designed and synthesized,and its optical properties can be significantly changed by sol-gel transition.The molecule can be coordinated with different zinc salts,which can change the degree of charge transfer within the molecule,thereby regulating its emission color.In addition,after the molecule is coordinated with the europium salt,characteristic luminescence can be generated,which can further expand the adjustment range of the emission color.Through ultrasonic/thermal control of the sol-gel transition and the reversible metal-ligand coordination between the ligand and various metal salts,a variety of different emission states of blue,green,yellow,red and white are realized.Based on this fantastic function,we successfully realized the switch between five different emission states.Finally,it has demonstrated the potential application in reversible multicolor coding and decoding.This subject realizes the regulation of single-molecule multicolor luminescence behavior through the interaction between the metal and the ligand.2.Design,Synthesis and Application of Excitation Wavelength Dependent Luminescent Zn(II)ComplexWe designed and synthesized a molecule containing carbazole and terpyridine,which can be coordinated with different zinc salts(Zn Br2,Zn(Ac O)2,Zn(Cl O4)2)to obtain luminescent materials with different photophysical properties.The study demonstrate that they can realize the regulation of the luminescence color by changing excitation wavelengths.The theoretical calculations suggest that the large energy level difference between S1 and high excited state may be responsible for this phenomenon.Finally,using the zinc salt aqueous solution as the security ink,the delicate pattern can be printed on the security paper which composed of the ligand and polyethanol-polypropylene glycolpolyethanol(PEG-PPG-PEG).Interestingly,different emission color image can be observed upon excitation at different wavelengths,which is suiable for optical anti-counterfeiting applications.