| Tang’s team firstly reported the aggregation-induced emission(AIE)phenomenon in 2001,which is opposite to the aggregation-caused quenching(ACQ).The main source of AIE effect is the inhibition of the appearance of π-π stacking between molecules.A common feature of these materials is that they basically do not emit fluorescence in pure solution,but the opposite is true in the aggregate state or solid state.Therefore AIE provides a new avenue for applications in optoelectronic devices,bio/chemical sensors,and bioimaging.However,typical compounds with AIE require cumbersome multi-step synthesis,and often result in bulky and structurally complex AIE materials.Therefore,exploring luminescent materials with AIE-active but simple structures is still interesting and valuable.Recently,considerable efforts have been focused on the study of donor(D)-π-acceptor(A)dye system.D-π-A dyes have attracted great attentions in opto-electronic applications.The power conversion efficiency,photo-stability and absorption/emission properties are greatly influenced by D-π-A dye structural system.If the π-conjugated chromophores contain strong terminal donor and acceptor groups,it is more effective for elucidating the enhancement of absorption and emission intensity.Since the barbituric acid group is considered to be a strong acceptor part,barbituric acid derivatives have been very popular as useful fragments in the structural system of donor acceptor dyes.Based on the superior performance of D-π-A dyes in optoelectronic applications,barbituric acid derivatives are used as raw materials to synthesize a series of fluorescent molecules with aggregation-inducing properties through Knoevenagel reaction.Such as PB-1,PB-2,PB-3,CB-1,CB-Ph,etc.The synthesis of the compound was verified by a variety of characterization test methods such as nuclear magnetic and HRMS.The compounds synthesized in this paper all exhibit AIE properties and have been used in many applications using their AIE properties.In the actual application of compounds,based on the characteristics of AIE active molecules "they have strong emission in high water content",compounds with strong fluorescence stability were selected to detect the presence of nitroaromatic hydrocarbon explosives(NACs)in the aqueous medium.The test results show that these compounds have good selectivity and sensitivity to NACs,and have the potential to be an excellent fluorescent sensing material for detecting NACs in water.Based on the properties of crystallization-induced emission enhancement(CIEE)and mechanochromic fluorescence(MFC)of barbituric acid derivative compounds,the possibility of application in encryption and decryption was discussed.We found that the introduction of hydrophobic groups can improve the fluorescence stability of barbituric acid derivatives in mixed solvents with high water content.In summary,this article discusses the optical properties and practical applications of various D-π-A barbituric acid derivatives with AIE effect,and systematically studies the mechanism.It provides a scientific basis for the future design and development of new and efficient AIE active materials. |
