Syntheses And Luminescent Properties Of Lanthanide-Titanium Oxo Clusters And Their Polymer Materials

In recent years,studies have shown that lanthanide-titanium oxo clusters(LTOCs)not only have rich and diverse structures,but also have potential luminescence properties.Because of short research time,system of LTOCs is not perfect.Thus study on the structures and properties of LTOCs are of great significance.Based on the above background,we have obtained a series of LTOCs with variors structures and excellent luminescence properties by using benzoic acid derivatives.At the same time,we have synthesized a lanthanide-polymer complex by click reaction.The synthesis condition,characterization method and luminescence property of lanthanide-polymer complex are also researched.The specific research contents are as follows:?:Five lanthanide-titanium oxo clusters formulated as Ln4Ti9(Ln=Eu(1),Tb(2),Gd(3))and Ln4Ti9-N3(Ln=Eu(4),Tb(5))were synthesized by solvothermal methods using p-fluorobenzoic acid and 4-azidobenzoic acid as ligands.The luminescent properties of 1 and 4 were studied,and the effects of different ligands on luminescent properties with the same structure were also investigated.The results showed that quantum yield of Eu4Ti9(1)with p-fluorobenzoic acid ligand was 27.2%,and that of Eu4Ti9(4)with p-fluorobenzoic acid and 4-azidobenzoic acid ligands was 1.8%.Luminescent efficiency of cluster was significantly reduced by introducing azide groups with strong electron-absorbing capacity.?:Seven lanthanide-titanium oxo clusters formulated as Ln3Ti3(Ln=Eu(6),Tb(7),Sm(8),Gd(9),Dy(10))and Ln6Ti8(Ln=Eu(11),Sm(12))were synthesized through solvothermal methods using 4-tert-butylbenzoic acid as ligand.Luminescence properties of clusters 6 and 11 were investigated in the solid state and in solution.In the solid state,luminescence lifetimes were 1212 ?s and 857 ?s while quantum yields were 69.6%and 56.2%.In solution,luminescence lifetimes were 1205 ?s and 997 ?s while quantum yields were 16.9%and 13.6%.Moreover,we tried to introduce fluoride ions into clusters,results reveal that luminescence intensity of cluster 6 was obviously enhanced in solid and in solution.?:We chose the reported cluster Eu8Ti10 as research object and replaced part of the ligands of Eu8Ti10 with 4-azidobenzoic acid ligand by solvothermal methods.Thus,Eu8Ti10-N3(13)was successfully obtained,and characterized by single-crystal X-ray diffraction analyses.Moreover,cluster 13 was allowed to react with the methoxy polyethylene glycol polymer bearing terminal alkyne(1-arm-PEG-ALK,P)via Cu(I)-catalyzed click chemistry(CuAAC)to form a lanthanide-polymer composite(14).Luminescence properties of compounds 13 and 14 were measured,and the changes of luminescence properties before and after the click reaction were compared and analyzed.