过渡金属离子调控微孔铕络合物的荧光性能研究

Study on transition metal-ion-tunable luminescence poperty of aporous En^(3+) lanthanide complex

金属铕(Ⅲ)与3,5-二羧基吡啶(pdc)形成配合物:[Eu(pdc)1.5(DMF)]·(DMF)0.5(H2O)0.5—(1a)。1a受热失去自由水和DMF后形成配合物(2a)—[Eu(pdc)1.5]。结构分析表明配合物2a拥有一维规整的大小为6.3×8.5的六边形孔道,并且未配位的吡啶N原子都朝向空腔,能够吸附亲N原子的过渡金属离子,从而改变原配合物的发光性能。通过对不同价态以及不同浓度金属离子对配合物2a的荧光调控性能分析,发现低浓度金属离子对配合物2a的发光强度起到敏化作用,高浓度金属离子则出现猝灭效应。另外,在10-5 mol/L相同浓度不同金属离子对配合物荧光性能影响中,Cu2+离子敏化效果最强,Fe3+离子的则最弱。

In DMF solvent,the solvothermal reaction of Europium（Ⅲ）and pyridine-3,5-dicarboxylate afforded successfully complex 1awith general formula[Eu（pdc）1.5（DMF）]·（DMF）0.5（H2O）0.5,（pdc=pyridine-3,5-dicarboxylate）.The 1areleased the free water and DMF molecules in the high temperature to form a complex 2awith general formula[Eu（pdc）1.5].The complex 2apossessed one-dimensional hexagonal channels of about 6.3×8.5.Further,the free Lewis basic pyridyl sites oriented towards pore centers,which can easily bond to transition metal ions,and thus tuning the luminescence performance of 2a.Through the analysis of fluorescence performance of 2atuned by different valence states and concentrations of the transition metal ions,the luminescence enhancing by low concentration of metal ions and luminescence quenching by high concentration of metal ions can be achieved.In addition,using different metal ions in checking luminescence intensity at 10-5 mol/L,it was found that,the Cu2＋ion had the strongest sensitization effect on the luminescence intensity,while Fe3＋ion had the weakest ones.