Luminescent Properties Of Organic Small Molecule/Cyclodextrin Metal-Organic Framework Composites

Fluorescent materials（such as organic dyes,carbon dots,quantum dots,metal ions and their complexes）,which are contain fluorescent groups and usually bonded by covalent bonds or non-covalent bonds have shown great application potential in many fields,such as imaging,detection,display,sensing and anti-counterfeiting.However,most of the fluorescent materials are organic fluorescent molecules,and the insolubility in water limits their applications.Therefore,improving the solubility of organic fluorescent molecules in aqueous solution could greatly improve their practical applications,which is of great significance.This work uses cyclodextrin metal-organic frameworks（CD-MOF）as a carrier to load five typical organic fluorescent molecules into its nanostructures to improve their solubility of organic fluorescent molecules in aqueous solution and expand their practical application.According to the background,the content of this work is mainly divided into the following parts:（1）Explored the influence of CD-MOFs with different structure（α-CD-MOF,β-CD-MOF,γ-CD-MOF）were synthesized by methanol vapor diffusion method.Through a series of characterization and testing of the sample structure,three kinds of CD-MOFs with different structures were analyzed from multiple perspectives.Finally,γ-CD-MOF with the largest pore size and the best stability was selected as the metal-organic framework loaded with organic luminescence molecules for subsequent research.And the selection of DPA as the initial load ofγ-CD-MOFs organic luminescent molecules,through a series of characterization and testing on DPA@CD-MOF,CD-MOFs load could improve the water solubility without affecting the luminous performance of DPA,indicating the feasibility of CD-MOFs as a carrier.（2）Four typical organic luminescent molecules were selected:Alq₃,BPEA,Ir（ppy）₃,Ru（bpy）₃,the corresponding CD-MOFs samples were prepared by methanol vapor diffusion and reprecipitation method,and the structure and properties of the four samples were characterized and tested.From the structural morphology,luminescence performance and water solubility of three aspects respectively to explore the changes of CD-MOF loaded organic luminescence molecules,it was found that the load of organic luminescence molecules did not affect the stability of the crystal structure of CD-MOF,colorless transparentγ-CD-MOF load did not affect the luminescence characteristics of organic luminescence molecules,and greatly improve the water solubility of luminous molecules.Finally,a method to improve the water solubility and universality of guest molecules is summarized on the premise of preserving the original properties as much as possible.