一种Tb(Ⅲ)配合物的合成、结构及发光性能研究

Synthesis,structure and photoluminescence property of Tb(Ⅲ) coordination complex

采用水热合成方法,以对硝基苯甲酸为配体,合成了1种具有1D链状结构的Tb(Ⅲ)配合物[Tb2(C7H4NO4)6(H2O)4.H2O]n,通过X-射线单晶衍射确定了该配合物的晶体结构.结构分析表明,该配合物属三斜晶系,P-1空间群,配合物的不对称单元中包含2个不等效的Tb(Ⅲ)离子,Tb1为8配位,Tb2为9配位.在晶体中,Tb(Ⅲ)离子被对硝基苯甲酸根连成1D链状结构,其中,对硝基苯甲酸根采取3种配位模式,即螯合双齿,桥联双齿,桥联三齿.而1D链之间又通过3种类型的O—H…O氢键被连成2D氢键网络结构.在室温下,测定了该配合物晶体粉末的IR(红外)、UV-Vis-NIR(紫外-可见-近红外)吸收光谱以及荧光激发和发射光谱.光物理研究表明,该配合物在可见光的激发下(λEx=488nm),表现出较强的Tb(Ⅲ)的特征发射,这主要归功于配体的敏化作用.

One new Tb（Ⅲ） coordination complex with the ligand p-nitrobenzoic acid,[Tb2（C7H4NO4）6（H2O）4·H2O]n,has been synthesized by the hydrothermal method.Its structure was determined by single-crystal X-ray diffraction.The structure analysis indicates that the complex crystallizes in the triclinic is space group P-1.Each asymmetric unit contains two crystallographically independent Tb（Ⅲ） ions,i.e.,Tb1 is eight-coordinated and Tb2 is nine-coordinated.In the crystal,Tb（Ⅲ） ions are connected through p-nitrobenzoates into a 1D chain along a direction.The p-nitrobenzoates adopt three kinds of coordination modes,chelating bidentate,bridging bidentate and bridging tridentate.Moreover,these 1D chains are further connected by three types of hydrogen bonds to form 2D hydrogen bonding network.At room temperature in the solid state,the IR,UV-Vis-NIR,excitation and emission spectra of the complex were measured and analyzed.The study of photophysical properties reveals that the complex exhibits intense characteristic emissions of Tb（Ⅲ） ion with the excitation of visible light at room temperature（λEx = 488 nm）,which should be attributed to the sensitization from the organic ligand.