Synthesis,Characterization And Fluorescence Properties Of Lanthanide Complexes Containing Pyridine,Thiophene Bridged Bis-terpyridine And Ferrocenyl Terpyridyl Derivative Ligands

Three ligands:2,6-di-(4-[2,2’:6",2’-terpyridine])-4’-yl)phenyl)pyridine(L1),2,5-di-(4-[2,2’:6’,2’-terpyridine])-4’-yl)phenyl)thiophene(L2)and 4’-(4-ethynylferrocenephenyl)-2,2’:6’,2,-terpyridine(L3)were synthesized according the literature methods,respectively.20 new rare earth complex were obtained by ligating three ligands(Li,L2,L3)with the rare earth nitrate,respectively.The structure was characterized by elemental analyses,MS,IR spectra,1H NMR,themal gravimetric analysis,the optical properties of them were also investigated by UV-visible and fluorescence.Firstly,14 new dinuclear rare earth complexes[Ln2(L1)(NO3)6·xH2O](Ln=Eu(la),Tb(lb),Sm(lc),Dy(ld),Nd(le),Yb(lf),Er(lg)),and[Ln2(L2)(NO3)6·xH2O](Ln=Eu(2a),Tb(2b),Sm(2c),Dy(2d),Nd(2e),Yb(2f),Er(2g)have been synthesized by reactions of Li,L2 with corresponding rare earth nitrate salts under argon condition with ratio of 1:2.The fluorescence spectra of them reveals that ligands of L1 and L2 can not only effectively sensitizing the emission of Eu3+,Tb3+,Sm3+,Dy3+in the visible light region,but also sensitize the emission of Nd3+ and Yb3+ in near infrared region.In addition,studies on complexes la and 2a fluorescence probes show that show that 1a be used to detect nitrobenzene and Cr2O72-ion,and 2a is only effective for fluorescence detection of Cr2O72-ions.Secondly,6 new 3d-4f type metal complex[Ln(L3)(NO3)3·xH2O](Ln=Eu(3a),Tb(3b),Sm(3c),Dy(3d),Nd(3e),Yb(3f))have been synthesized by reactions of L3 with corresponding rare earth nitrate salts under argon condition with ratio of 1:1.From the fluorescence properties,ligand L3 can make Eu3+,b3+,Sm3+,Dy3+ in the visible region of the characteristic luminescence can be effectively sensitized.Lastly,the fluorescence lifetime and quantum efficiency of three series of rare earth complexes la-3f were investigated.The experimental results show that the fluorescence lifetime of Eu2-L1(la)and Eu2-L2(2a)are 1.1478 milliseconds and 1.3470 milliseconds,respectively,and the quantum yields of fluorescence are up to 40%,which may be due to the high energy transfer efficiency of the ligands Li and L2 with of the purple and blue luminescence.So the complexes la and 2a will have potential application value in the optical material.