Bipyrimidines have been chosen as(N^N)(N^N) bridging ligands for connecting metal centers.IrⅢ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes [Ir(dfppy)2(μ-bpm)Ln(TTA)3]Cl were synthesized by using Ir(dfppy)2(bpm)Cl as the ligand coordinating to lanthanide complexes Ln(TTA)3·2H2O.The stability constants between Ir(dfppy)2(bpm)Cl and lanthanide ions were measured by fluorescence titration.The obvious quenching of visible emission from IrⅢ complex in the IrⅢ-LnⅢ(Ln = Nd,Yb,Er) bimetallic complexes indicates that energy transfer occurred from IrⅢ center to lanthanides.NIR emissions from NdⅢ,YbⅢ,and ErⅢ were obtained under the excitation of visible light by selective excitation of the IrⅢ-based chromophore.It was proven that Ir(dfppy)2(bpm)Cl as the ligand could effectively sensitize NIR emission from NdⅢ,YbⅢ,and ErⅢ.
CHEN FangFang,JIANG WeiLi,LOU Bin,BIAN ZuQiang & HUANG ChunHui Beijing National Laboratory for Molecular Sciences,State Key Laboratory of Rare Earth Materials Chemistry and Applications,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China
