Design,Preparation And Performance Of Dual-state Emission Luminogens

The organic dual-state emissive luminogens（DSEgens）have showed great potentials in bioimaging and smart materials,due to emitting both in solution and solid states.However,the development of organic DSEgens is still at primary stage,therefore further exploring their luminous mechanism and application is extremely urgent.According to their structural design principle-the compatibility of conjugation and twist within a single molecule,a series of 1,8-naphtholactam derivatives（Nps）are synthesized in this dissertation.And these compounds can form intermolecular dimers to extendπconjugation by hydrogen bond interactions.The extension ofπsystems endow these structures with the compatibility of conjugation and twist for achieving the construction of DSEgens.Additionally,the synthesis route and characterization of Nps are systematically introduced in this dissertation.It also investigates the correlations between the molecular structure and emission property,and is divided into the following two parts:In this first section,we respectively incorporate acenaphthene（Ap）and Np molecule into the tetraphenylethylene/triphenylethylene（TPE/HTPE）with twist constructures.The emission behavior of Ap derivatives（Aps）are consistent with TPE/HTPE,showing the typical AIE characteristics.However,Nps exhibit intense dual-state emission with the quantum yields of photoluminescence(Φ_PL)boosting up to 51.84%and 68.31%in the solution and aggregated state,respectively.This work examines this strategy that extendsπconjugation by hydrogen bond is valid to achieve the construction of organic DSEgens.In this second section,based on this hydrogen bond strategy,we incorporate Np skeleton into a series of triphenylamine derivatives with electron-donating characteristics,obtaining TPA-Np,MTPA-Np and OMTPA-Np compounds.These compounds that combine intramolecular charge transfer（ICT）effects with the extension ofπconjugation could redshift the emission maximum up to 614 nm in dichloromethane（DCM）and 597 nm in aggregated states,respectively.Therefore,this double play by ICT effects and extension ofπconjugation would provide a new way to design organic DSEgens with long-wavelength emission.