Study On The Luminescence Properties Of β-diketonate Rare Earth Supramolecules With AIE Function

Lanthanides-organic supramolecular materials have been attracted increasing attention in recent years for their wide applications in host and guest recognition,biological probes,daily lighting and 3D displays.However,the construction of lanthanide supramolecules with optical functions had disadvantages such as difficulty in synthesis and limited functional modification.In order to solve the above problems,two series of lanthanide supramolecules were designed in this paper by using supramolecular self-assembly.The detailed works were as follows:We designed and synthesized a bis-β-diketone ligand L¹modified by tetraphenylethylene（TPE）with biphenyl as the spacer,and constructed a quadruple-stranded dinuclear helicate（HNEt3）2[Eu2L¹4]through the self-assembly of the bis-β-diketone ligand and Eu³⁺ion.Spectral characterization combined with a semi-empirical optimization model confirmed that quadruple-stranded dinuclear helicate was successfully constructed.Upon excitation at 390 nm,the helicate realized the tunable emission with the colors changing from light white to green in solid state.After hybridization with a polymer,a white-light hybrid material was prepared with the CIE coordinate locating at（0.322,0.332）.The absolute luminescence quantum yields measured to be 16.9%.C₃-symmetric tris-β-diketone ligands（L²and L³）decorated with pendent tetraphenylethylene（TPE）or methyl have been designed and synthesized.six lanthanide tetrahedral cages Ln4（L²）4（Ln=La,Eu,Gd）and Eu4（L³）4（Ln=La,Eu,Gd）have been constructed by self-assembly of ligands with Ln（III）ions in a 1:1stoichiometric ratio.Through a series of spectral characterizations combined with semi-empirical theoretical calculations confirmed that lanthanide tetrahedral cages have been successfully constructed.In addition,after excitation by ultraviolet light,the solid powder of Eu4（L²）4 exhibited characteristic aggregation-induced luminescence properties.