Synthesis, Characterization And Near Infrared Luminescence Of Schiff Base Rare Earth Complexes

Near infrared fluorescence (NIF) of lanthanide complex has the advantage of high transparency in optical fiber and low spectral interference, and has potential application in optical fiber communication and spectral analysis. However, reports on NIF of lanthanide complex are relatively very fewer. Several lanthanide complex of Shiff base legend was synthesized in the present work. Their structures were characterized by EA, UV-Vis, IR and TG. The NIF spectroscopy was also determined. This work has not been found to be reported. The main conclusion is as following:Nd3+, Gd3+, Er3+ and Yb3+, which all belong to lanthanide ions, form complexes of different structure with same Schiff base ligand. For example, the lanthanide N,N'-bis(salicylidene)ethylenediamine complexes have two formula of Ln(H2L)2Cl3-nH2O(Ln=Nd) and Ln2(H2L)3Cl6-nH2O(Ln=Gd,Er,Yb), while lanthanide salicylidene-2-aminobenzoic acid complexes have formula of Ln(HL)2Cl-H2O (Ln=Nd,Gd,Er) and Ln(HL)Cl2'C2H5OH-H2O (Ln=Yb), which indicated their structures are sensitive to radio of lanthanide ions.Study on NIF of Nd3+ and Yb3+ complexes showed that both N,N'-bis(salicylidene)ethylenediamine and salicylidene-2-aminobenzoic acid could sensitize NIF of lanthanide ions. But N,N'-bis(salicylidene)ethylenediamine is better for Yb3+ while both N,N'-bis(salicylidene)ethylenediamine is better for Nd3+.