Design,Synthesis And Sensing Application Of Aggregation Induced Phosphorescence Molecular Probes Based On Polyphenylmercaptobenzene

Luminescent materials have always been a research hotspot in the scientific community because of its huge application prospects.In recent years,organic optoelectronic materials have become an active research field by the attention of more and more domestic and foreign experts.Among them,the aggregation-induced luminescence（AIE）material has become the focus of scientists with its unique advantages.To date,the application of the AIE principle has led to significant advances in a range of related fields from bioimaging,chemical sensing,optoelectronics to stimulus systems.By gaining a deeper understanding of the AIE process,light emission can be effectively controlled,and materials can be better constructed to meet different applications while avoiding damaging effects.For example,the construction of LED materials can be structurally adapted to specific high-tech applications,improving performance while reducing deficiencies.Through the study of the AIE process,it is found that active motion within the molecule can effectively dissipate exciton energy,while limiting intramolecular motion（RIM）can activate radiation transitions,which gives us more opportunities to explore in this field,many Areas that have been difficult to enter so far will also be possible.Although scientists have done a lot of research on the AIE phenomenon,so far we still have a lot of unknown areas for the AIE process that we need to research and explore.More AIE-based applications are waiting for us to develop.In this paper,we designed and synthesized a novel double-emitting molecule hexa（3-hydroxy-1-phenylthio）benzene（HHPB）with hexabromobenzene as raw material.It was found that the unique molecules prepared not only have significant aggregation-induced phosphorescence（AIP）characteristics,but also can achieve reversible conversion of phosphorescence and fluorescence in a single molecule system in a controlled manner.It was found that the unique molecules prepared not only have significant aggregation-induced phosphorescence（AIP）characteristics,but also can achieve reversible conversion of phosphorescence and fluorescence in a single molecule system in a controlled manner.On this basis,we modified the carboxyl functional group to construct a functionalized molecular probe on the HHPB molecule,and realized the detection of ions and imaging in living organisms by using the unique aggregation-induced luminescence properties of molecular probes.The following are the main contents of this paper:（1）The bi-luminescent molecule hexa（3-hydroxy-1-phenylthio）benzene（HHPB）with aggregation-induced phosphorescence was prepared by organic synthesis in an organic solvent.The molecule can be stimulated by external stimuli such as aggregation and The change in pH achieves a reversible transition between phosphorescence and fluorescence.The results show that the twisted structure of hexa（3-hydroxy-1-phenylthio）benzene（Compound 1,HHPB）helps to produce effective room temperature phosphorescence in the aggregate state,and when changing different conditions,the molecule also Significant blue or green fluorescence can be displayed.The conversion between phosphorescence and blue or green fluorescence can be achieved by controlling the aggregation state of HHPB by changes in solvent or pH,and the conversion between blue fluorescence and green fluorescence can be achieved by adjusting the protonation state of the molecule.Theoretical calculations in combination with experiments show that the unique phosphorescent properties of the molecule depend on the twisted structure of HHPB,and also depend on the large-scale triplet state of the appropriate size of S₁ and T₁ or S₁adjacent T-state energy gaps in the molecular structure.Excitons,in turn,promote the production of strong phosphorescence.（2）By introducing a carboxyl group into the hexa（4-hydroxy-1-phenylthio）benzene（HHPB）molecule,a novel phosphorescent molecular probe for the specific detection of aluminum ions was designed and synthesized.A new method based on long-lived time-gated luminescence detection and successfully used for imaging of Arabidopsis organisms.The introduction of a carboxyl group in a hexa（4-hydroxy-1-phenylthio）benzene（HHPB）molecule not only significantly improves water solubility,but also makes it possible to synthesize a specific complex with Al3+.Aggregation-inducedemission（AIE）ofthesynthesized{4-[f-（4-ethoxycarbonylmethoxy-phenylthio）-phenylthio]-phenoxy}-aceticacid（HHPB-6OCH₂COONa）molecule The process realizes the specific recognition of Al³⁺by the probe,and can efficiently stimulate the bright phosphorescence of the molecule.Mechanistic studies show that the unique molecular structure of HHPB-6OCH₂COONa makes it highly selective for Al³⁺.The Al³⁺time-gated luminescence sensor constructed according to this can not only quantitatively detect aluminum ions,but also monitor the aggregation-induced phosphorescence（AIP）process triggered by aluminum ions.In summary,we designed and synthesized a novel bi-luminescence molecule with significant aggregation-induced phosphorescence characteristics by using the properties of aggregation-induced luminescence molecules,and realized phosphorescence and fluorescence by external stimuli such as aggregation state and pH value.Reversible conversion between.On this basis,the specific detection of aluminum ions was successfully achieved by modification of the carboxyl group on the hexathiobenzene molecule,and a new method for time-gated luminescence detection for long-lived emission of aluminum ions was developed,simultaneously with Arabidopsis thaliana.（Arabidopsis thaliana）is a model plant,and its imaging performance for Al³⁺in living cells is further evaluated.