Investigation On The Synthesis And Properties Of Novel Luminescent Organic Solid Matrials

Luminescent organic materials have attracted much attention because of their potential application in organic lightemitting diodes,organic luminescent displays,and optical devices.The traditional organic luminescent emitters are weakly fluorescent in the solid state and not suitable for practical applications due to the aggregation-caused quenching(ACQ)process caused by the strong intermolecular ?–? stacking interactions.To against these limitations,designing a novel strategy called aggregation-induced emission(AIE)with a mechanism of restriction of the intramolecular motion(RIR),which endow the fuorophores with a highly efficient solid state emission.Here,we designed and synthesized a series of dimethylamine substituted binaphthanol based organic fluorophores.Decorating with substituents at the alkene moiety on the binaphthanol core backbone led to organic solid emitters with color tunability from the blue to red regions.These fluorophores exhibited solvatochromic properties and two compounds(2-15,2-16)showed aggregation-induced emission properties.The binaphthanol core structure induced a twisted molecular conformation and special intermolecular packing mode in a single crystal structure,which was beneficial for the inhibition of the strong intermolecular ?–? stacking interaction and induced the AIE feature as well as the fluorescence emission in the solid state.The absorption and emission changes of these molecules under acidic and basic conditions revealed that they had acidochromic properties and could be used as security ink.This work provided a new strategy for the synthesis of organic solid emitters with tunable emissions based on the simple binaphthanol core backbone.We also synthesized a series of dimethylamino substituted naphthol derivatives with diverse alkyl chain length and investigated their optical properties.These compounds exhibited aggregation induced emission,solvatochromic and mechanochromic properties.Powder wide-angle X-ray diffraction and differential scanning calorimetry curves reveal that the initial packing mode of molecules can be changed under various external stimuli,which caused the red-shift emission.Further investigation revealed that these molecules showed acidochromic properties and could be utilized as a security ink and sensors.This work is helpful for the design of novel versatile stimuli-responsive compounds.