Construction And Regulation Of Ionic Luminophor Based On Aggregation-induced Emission

In this thesis,two types of“aggregation-induced emission”（AIE）molecules were designed and synthesized,respectively,including the derivatives of pyridinium based on tetraphenylethylene（TPE）and Zn（II）complexes based on cyanostilbene.The structures of the as-synthesized compounds were fully characterized by nuclear magnetic resonance（NMR）spectroscopy and mass spectrometry（MS）.The photophysical properties were investigated by ultraviolet–visible（UV–Vis）spectroscopy,photoluminescent（PL）spectroscopy,etc.The main contents are concluded as follows:A series of ionic compounds with donor–acceptor（D–A）structure were designed and prepared.The typical TPE structure was modified by the substituents of pyridine to give TPE4py,TPE2py and 3Ph1py,and then to obtain the ionic materials namely as TPE4py-4Cl,TPE2py-2Cl and 3Ph1py-Cl by further quaternary ammonium treatment.After exchanging the anions,the AIE materials exhibited different emission wavelength.In addition,the stereoisomers of TPE2py-2Cl and TPE4py-2Cl showed“aggregation induced luminescence enhance”（AIEE）properties,and TPE2py-2Cl also involved twisted intramolecular charge transfer（TICT）effect and showed the solvatochromism behavior.All of the compounds had very high quantum yield（Φ_F）in solid state except 3Ph1py,especially,the highestΦ_F reached as high as 73.5%in trans-TPE2py-2PF₆.DFT calculation was also done to explain the phenomena that the emission wavelength of quaternary ammonium salts was significantly red-shifted,which was consistent with the theoretical results of the decreasing energy gap（E_g）.Besides,the emission wavelength could be tuned well by changing different anions,which would pave a way in constructing the various luminescence.The compound of trans-TPE2py-2Cl also exhibited reversible mechanochromic behavior,which was useful for the applications in sensor and optical information storage,et al.TPE4py-4Cl showed good processing ability and was successfully used to prepare highly ordered patterns by nanoimprinting lithography.Finally,the stereoisomers of TPE2py were separated successfully and the crystals were characterized by single crystal X-ray diffraction instrument,which further provided a reasonable explanation for the different luminescence properties.A novel terpyridine-based ligand functionalized by cyanostilbene was reported and coordinated with Zn（II）to give the organozinc complexes.Both the ligand and the complexes showed the AIEE properties along with TICT effect,but the solvatochromism behavior of the Zn（II）complex was more obvious than that of the relative ligand owing to stronger charge transfer.Also,the emission wavelength of the complexes was obviously bigger than that of the ligands,which could be ascribed to metal to ligand charge transfer and the increase of molecular conjugation.At the same time,the functional tails were more likely to increase the energy barrier of the complexes and furthermore to improve the luminescent efficiency.The volume of the anions could affect the stacking behavior of the complexes and the emission wavelength was red-shifted with the decreasing volume.Finally,the complex of12-Zn-CH₃COO could be imprinted to obtain the highly ordered patterns on certain substrate and 12-Zn-PF₆ showed an electrochromic luminescence（ECL）response.The complexes demonstrated the tremendous potential for stimulation sensing and luminescent devices.