Construction And Application Of Aqueous-phase Tunable Multi-color Luminescent Materials Based On Host-guest Interaction Of Cucurbit[10]uril

Tunable multi-color luminescent materials have attracted broad attention owing to theirpotential applications in fields such as encryption materials,fluorescence sensors,bioimaging,light-emitting diodes,and electronic devices.However,due to the deficiencies of most luminescent materials such as poor dynamic reversible regulation and poor water-solubility,their applications in aqueous solution or thin film state are greatly limited.In recent years,the supramolecular non-covalent strategy has become one of the most popular construction approaches in constructing tunable luminescent materials,due to its reversible modulation and applicability in aqueous solution.In this thesis,by using cucurbit[10]uril（CB[10]）as a host molecule and anthracene derivatives with photoresponsiveness as guest molecules,a series of tunable multi-color supramolecular luminescent systems and a novel water-soluble covalent fluorescent supramolecular organic framework material have been successfully constructed.The potential application of these materials in the fields of anti-counterfeiting,encryption and cell imaging were also explored.The main research contents are as follows:1.Nine cationic anthracene derivatives guest molecules（G1～G9）were designed andsynthesized,and characterized by NMR and Mass spectrometry.The results indicated that a variety of water-soluble anthracene derivatives guest molecules have been successfully prepared.2.We chose CB[10]as a host,three anthracene derivatives（G1,G2,G3）as electron donors and azaanthracene（G4）as an electron acceptor.We successfully constructed a series of tunable multi-color luminescent supramolecular assemblies based on CB[10]enhanced charge-transfer interaction between the guest molecules（homodimer or heterodimer）.Firstly,we investigated the complexation behavior of G1～G3 with CB[10]and the photophysical properties of resulted homodimers assemblies.Subsequently,we introduced CB[10]into the solution of G1～G3 and G4.With increasing equiv.of CB[10],the heterodimers exhibited broader wavelength tunability（from blue to green,yellow and red）relative to the homodimers due to the host enhanced heterodimers intermolecular charge-transfer interactions.Among the three heterodimeric assembly systems,the CB[10]_2n?G2_n?G4_n assembly exhibited higher quantum yield and longer fluorescence lifetimes relative to CB[10]_n?G2_n.The white-light emission was observed when 0.8 equiv.of CB[10]was present in an aqueous solution of equal amounts of G2 and G4,and the host-guest assembly with white emission exhibited light-and humidity-responsive properties when coated on a thin film,providing a handy and feasible strategy for the construction of multi stimulus responsive tunable luminescent materials in the future.3.We covalently modified triphenylamine（TPA）with anthracene units as G5 guest,and successfully prepared a water-soluble two-dimensional（2D）supramolecular organic framework（SOF）with regular morphology by the complexation of G5 with CB[10].The morphology of the SOF was characterized by dynamic light scattering（DLS）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HR-TEM）,and X-ray diffraction（XRD）.Meanwhile,based on CB[10]-promoted[4+4]cycloaddition reaction of anthracene units,we achieved the transformation from SOF to covalent organic framework（COF）in aqueous solution.The results showed that the COF material not only exhibited better stability than the SOF material,but also retained the periodicity and crystallinity features of the SOF.COF material was further used as luminescent platforms,and multi-color tunable luminescence in solution and solid state was achieved by loading different fluorescent donors（compounds:1,2,3）and acceptors（compound:4）,and the application of COF in encryption materials and NIR cell imaging was explored.The results provide a convenient and feasible approach for constructing functional COF material and further expands the application of COF material in the field of anti-counterfeiting luminescent materials and NIR cell imaging.