Synthesis,Fluorescence And Antibacterial Properties Of Polycarboxylic Acid Coordination Rare Earth Luminescent Complexes And Their Graphene Oxide Hybrid Materials

In this paper,three polycarboxylic acid compounds L1^L3 were first synthesized:[1,1':3',1''-terphenyl]-4,4'',5'-tricarboxylicacid?L1?,5'-?3,5-dicarboxyphenyl?[1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid?L2?and3',4',5',6'-tetrakis?4-carboxyphenyl?[1,1':2',1''-terphenyl]-4,4''-dicarboxylic acid?L3?,using solvothermal method.L1^L3 were used as ligands to react with rare earth ions Eu³⁺and Tb³⁺to obtain six new rare earth luminescent complexes L-Ln?L=L1,L2,L3,Ln=Eu,Tb?;the same method was used to obtain six rare earth complexes-graphene oxide?GO?hybrid materials GO-Ln-L?L=L1,L2,L3,Ln=Eu,Tb?.The structure and properties of the obtained compounds were characterized and analyzed by IR,¹H NMR,UV-Vis,XRD,XPS,SEM,fluorescence spectroscopy and bacteriostatic experiments.Fluorescence spectroscopy indicated that the ligands L1-L3 could effectively sensitize the luminescence of Eu³⁺and Tb³⁺.The combination of graphene oxide had little effect on the luminescence properties of rare earth complexes,and did not cause strong quenching of fluorescence,and the fluorescence lifetime and CIE coordinates of complexeshave almost not been effected;complexes L1-Tb,L1-Eu,L3-Tb,L3-Eu and hybrid materials GO-L1-Tb,GO-L1-Eu,GO-L3-Tb,GO-L3-Eu can be used to detect nitrobenzene and can be used for fluorescence imaging of cells.SEM analysis showed that the hybrid materials GO-L3-Tb and GO-L3-Eu were affected by the anchoring effect of GO,and their morphology changed from a multi-layered planar hexagon to a multi-layered six-petal structure.And the hybrid materials have good heat resistance,can be used for micro-scale fluorescence anti-counterfeiting;the BET surface areas of GO-L1-Tb,GO-L1-Eu,GO-L2-Tb,GO-L2-Eu are increased due to the presence of GO.Studies on the bacteriostatic ablities of complexes indicated that the antibacterial ablity of the GO-L1-Eu complex is better than that of the L1-Eu complex;complexes L2-Eu,L3-Eu,GO-L2-Eu and GO-L3-Eu can effectively block ultraviolet rays and can be used as ultraviolet protective agent.